Answer: 1g of formaldehyde
Explanation:
Molar Mass of benzene (C6H6) = (12x6) + (6x1) = 78g/mol
1mole(78g) of benzene contains 6.02x10^23 molecules.
1g of benzene with contain = (6.02x10^23) /78 = 7.72x10^21 molecules
Molar Mass of formaldehyde (CH2O) = 12 +2+16 = 30g/mol
1mole (30g) of formaldehyde contains 6.02x10^23 molecules.
1g of formaldehyde will contain = (6.02x10^23) /30 = 2.01x10^22 molecules
Molar Mass of TNT(C7H5N3O6) = (12x7)+(5x1)+(14x3)+(16x6) = 227g/mol
1mole(227g) of TNT contains 6.02x10^23 molecules.
1g of TNT will contain = (6.02x10^23)/227 = 2.65x10^21 molecules
Molar Mass of naphthalene (C10H8) = (12x10) +8 =128g/mol
1mole(128g) of naphthalene contains 6.02x10^23 molecules.
1g of naphthalene will contain = (6.02x10^23)/128 = 4.7x10^21 molecules
Molar Mass of glucose(C6H12O6) = (12x6) + 12 +(16x6) = 180g/mol
1mole(180g) of glucose contains 6.02x10^23 molecules.
1g of glucose will contain = (6.02x10^23)/180 = 3.34x10^21 molecules
Therefore, 1g of each of the compound contains the following:
Benzene = 7.72x10^21 molecules
Formaldehyde = 2.01x10^22 molecules
TNT = 2.65x10^21 molecules
Naphthalene = 4.7x10^21 molecules
Glucose = 3.34x10^21 molecules
From the above, we see clearly that formaldehyde has the largest number of molecules
Final answer:
The compound with the largest number of molecules is formaldehyde with 2.00 x 10^22 molecules.
Explanation:
The substance with the largest number of molecules can be determined by calculating the number of moles of each substance and then using Avogadro's number to convert moles to molecules. The formula to calculate the number of moles is moles = mass / molar mass. By using this formula:
For benzene: moles = 1g / 78.11g/mol = 0.0128 moles
For formaldehyde: moles = 1g / 30.03g/mol = 0.0333 moles
For TNT: moles = 1g / 227.13g/mol = 0.0044 moles
For naphthalene: moles = 1g / 128.2g/mol = 0.0078 moles
For glucose: moles = 1g / 180.16g/mol = 0.0055 moles
Then, we can use Avogadro's number (6.022 x 10^23 molecules/mol) to convert moles to molecules:
For benzene: molecules = 0.0128 mol x 6.022 x 10^23 molecules/mol = 7.72 x 10^21 molecules
For formaldehyde: molecules = 0.0333 mol x 6.022 x 10^23 molecules/mol = 2.00 x 10^22 molecules
For TNT: molecules = 0.0044 mol x 6.022 x 10^23 molecules/mol = 2.65 x 10^21 molecules
For naphthalene: molecules = 0.0078 mol x 6.022 x 10^23 molecules/mol = 4.68 x 10^21 molecules
For glucose: molecules = 0.0055 mol x 6.022 x 10^23 molecules/mol = 3.31 x 10^21 molecules
Therefore, the compound with the largest number of molecules is formaldehyde with 2.00 x 10^22 molecules.
How many moles are contained in 70. milliliters of a 0.167 M solution of p-toluidine hydrochloride? Enter only the number to two significant figures.
Answer: The amount of p-toluidine hydrochloride contained is 2.4 moles.
Explanation:
To calculate the number of moles for given molarity, we use the equation:
[tex]\text{Molarity of the solution}=\frac{\text{Moles of solute}\times 1000}{\text{Volume of solution (in mL)}}[/tex]
Molarity of p-toluidine hydrochloride solution = 0.167 M
Volume of solution = 70. mL
Putting values in equation 1, we get:
[tex]0.167=\frac{\text{Moles of p-toluidine hydrochloride}\times 1000}{70}\\\\\text{Moles of p-toluidine hydrochloride}=\frac{(0.167\times 70}{1000}=2.38mol=2.4mol[/tex]
Hence, the amount of p-toluidine hydrochloride contained is 2.4 moles.
Which element in each of the following sets would you expect to have the lowest IE₃?
(a) Na, Mg, Al (b) K, Ca, Sc (c) Li, Al, B
Answer:
(a) AL
(b) Sc
(c)Al
Explanation:
Ionization Energy is the energy required to remove electrons from the outer most orbitals of atom.
The higher the electron is on energy level the farther its from nucleus and more loosely bonded thus need lesser energy.
By looking at electron configuration we can figure out which electron will need more energy.
(a)Na, Mg, Al1s², 2s², 2p⁶, 3s², 3p⁶,4s², 3d¹
Na₁₁ ⇒ 1s², 2s², 2p⁶, 3s¹
Mg₁₂ ⇒ 1s², 2s², 2p⁶, 3s²
Al₁₃ ⇒ 1s², 2s², 2p⁶, 3s², 2p¹
Al will have lowest IE₃ as its third electron will be in highest energy level and more loosely bonded to nucleus.
(b) K, Ca, ScK₁₉⇒1s², 2s², 2p⁶, 3s², 3p⁶,4s²
Ca₂₀⇒1s², 2s², 2p⁶, 3s², 3p⁶,4s²
Sc₂₁⇒1s², 2s², 2p⁶, 3s², 3p⁶,4s², 3d¹
Sc will have lowest IE₃ as its third electron will be in highest energy level and more loosely bonded to nucleus.
(c) Li, Al, BLi₃ ⇒ 1s², 2s¹
Al₁₃ ⇒ 1s², 2s², 2p⁶, 3s², 2p¹
B₅ ⇒ 1s², 2s², 2p¹
Al will have lowest IE₃ as its third electron will be in highest energy level and more loosely bonded to nucleus.
Answer:
A. Al
B. Sc
C. Al
Explanation:
The third ionisation energy is the energy required to an extra electron from a +2 ion or the energy required to remove the third electron from an element.
Lithium - 1s2 2s1
Sodium - 1s2 2s2 2p6 3s1
Magnesium - 1s2 2s2 2p6 3s2
Aluminium - 1s2 2s2 2p6 3s2 3p1
Potassium - 1s2 2s2 2p6 3s2 3p6 4s1
Calcium- 1s2 2s2 2p6 3s2 3p6 4s2
Boron - 1s2 2s2 2p1
Scandium - 1s2 2s2 2p6 3s2 3p6 3d1 4s2
Removing 2 electrons,
Li2+- 1s1
Na2+ - 1s2 2s2 2p5
Mg2+ - 1s2 2s2 2p6
Al2+ - 1s2 2s2 2p6 3s1
K2+ - 1s2 2s2 2p6 3s2 3p5
Ca2+ - 1s2 2s2 2p6 3s2 3p4
Boron - 1s2 2s1
Scandium - 1s2 2s2 2p6 3s2 3p6 4s1
So comparing,
A. Na, Mg, Al
The third electron is lost from a p- orbital and the energy level of p- is less than s- orbital but 3s is way less than the 2p so the lowest third ionisation energy is Al
B. K, Ca, Sc
The third electrons are lost from the 3p orbital in K and Ca but in 4s in Sc and if you remember, 4s has a lesser energy level than 3p orbital. So, Sc has the lowest third ionisation energy.
C. Li, Al, B
Al has the lowest third ionisation energy because Li loses its from 1s which is closest to the nucleus and B from 2s which is also close to the nucleus.
A drop of liquid tends to have a spherical shape due to the property of 1. viscosity. 2. capillary action. 3. surface tension. 4. vapor pressure. 5. close packing.
Answer:
surface tension.
Explanation:
Atomic hydrogen produces well-known series of spectral lines in several regions of the electromagnetic spectrum. Each series fits the Rydberg equation with its own particular n₁ value. Calculate the value of n₁ (by trial and error if necessary) that would produce a series of lines in which:
(a) The highest energy line has a wavelength of 3282 nm.
(b) The lowest energy line has a wavelength of 7460 nm.
Answer: a) The value of n₁ that would produce a series of lines in which the highest energy line has a wavelength of 3282 nm is 6.
b) The value of n₁ that would produce a series of lines in which the lowest energy line has a wavelength of 7460 nm is 5.
Explanation:
The formula that relates wavelength of emissions to Rydberg's constant and the n₁ values is
(1/λ) = R ((1/(n₁^2)) - (1/(n2^2))
Where λ = wavelength, R = (10.972 × 10^6)/m, n2 = ∞ (since they're emitted out of the atom already)
a) n₁ = ?
λ = 3282 nm = (3.282 × 10^-6)m
(1/(3.282 × 10^-6)) = (10.972 × 10^6) ((1/(n₁^2) (since 1/∞ = 0)
n₁^2 = (3.282 × 10^-6) × (10.972 × 10^6) = 36
n₁ = 6.
The value of n₁ that would produce a series of lines in which the highest energy line has a wavelength of 3282 nm is 6.
b) n₁ = ?
λ = 7460 nm = (7.46 × 10^-6)m
(1/(7.46 × 10^-6)) = (10.972 × 10^6) ((1/(n₁^2)) - (1/(n2^2)) for lowest energy line, n2 = n₁ + 1
(n₁^2)((n₁+1)^2))/(2n₁+1) = (7.46 × 10^-6) × (10.972 × 10^6) = 81.85
(n₁^2)((n₁+1)^2))/(2n₁+1) = 81.85
Solving the quadratic eqn,
n₁ = 5.
The value of n₁ that would produce a series of lines in which the lowest energy line has a wavelength of 7460 nm is 5.
QED!
(4 points) The following lead compound for a pharmaceutical drug contains a rotatable bond. Using the principles of rigidification, draw two analogs that would enable testing of two different conformations
Answer:
Explanation:
The solution has been attached
Classify each of the following compounds as a strong acid, weak acid, strong base, or weak base, and write the Ka expression for any weak species:
1. LiOH
2. HF
3. HCl
4. NH3
Ka expression: ___________
Answer:
1. LiOH : strong base
2. HF : weak acid
3. HCl : strong acid
4. NH3 : weak base
Ka expression: Ka = [A- ] * [H+] / [HA]
Explanation:
The Acidity Constant:
The acid dissociation constant, Ka, (or acidity constant, or acid ionization constant) is a measure of the strength of a weak acid (which is not completely dissociated):
HA ↔ A- + H +
HA is a generic acid that dissociates into A- (the conjugate base of the acid), and the hydrogen or proton ion, H +.
The dissociation constant Ka is written as the ratio of equilibrium concentrations (in mol / L):
Ka = [A- ] * [H+] / [HA]
When we write in square brackets, we refer to the concentration of that element.
Final answer:
LiOH is a strong base, HF is a weak acid with a Kₐ expression of Kₐ = [H⁺][F⁻]/[HF], HCl is a strong acid, and NH₃ is a weak base with a Kₐ expression for its conjugate acid NH₄⁺ as Kₐ = [NH₄⁺][OH⁻]/[NH₃].
Explanation:
Compounds can be identified as strong acids, weak acids, strong bases, or weak bases depending on their ability to dissociate in solution. The classification is based on the strength of the acids and bases, which is a measure of their tendency to donate or accept protons.
LiOH (Lithium hydroxide) is a strong base. Strong bases like LiOH completely dissociate into ions in an aqueous solution.HF (Hydrofluoric acid) is a weak acid. Weak acids do not fully dissociate in solution. The Kₐ expression for HF is as follows: Kₐ = [H⁺][F⁻]/[HF].HCl (Hydrochloric acid) is a strong acid. Strong acids fully dissociate into their constituent ions in aqueous solution.NH₃ (Ammonia) is a weak base. The Kₐ expression for the hydrolysis of the ammonium ion (NH₄⁺) is relevant here and would be: Kₐ = [NH₄⁺][OH⁻]/[NH₃].Using only the periodic table, rank the elements in each set in order of increasing size: (a) Se, Br, Cl; (b) I, Xe, Ba.
Answer:
A. Cl, Se, Br
B. I, Xe, Ba
Explanation:
The elements arranged in their increasing atomic size using periodic table positions are:
a) Cl < Br < Se
b) Xe < I < Ba.
To rank elements by increasing atomic size, we need to refer to their positions on the periodic table. Atomic size generally increases as we move down a group and decreases as we move across a period from left to right.
(a) Se, Br, Cl
These elements are all in Group 16 (Se), 17 (Br), and 17 (Cl), respectively. Since size increases down a group and decreases across a period:
Cl (smallest)BrSe (largest)(b) I, Xe, Ba
These elements are in Group 17 (I), 18 (Xe), and 2 (Ba), respectively. Comparing their positions:
Xe (smallest)IBa (largest)Suppose you are presented with a clear solution of sodium thiosulfate, Na2S2O3 . How could you determine whether the solution is unsaturated, saturated, or supersaturated?
Explanation:
A solution is said to saturated when it cannot dissolve any extra solute in it. The extra solute put remains undissolved.
A solution is said to unsaturated, when the concentration of solute is less as compared to solubility of the solution it is said to be unsaturated.
A solution is said to be super saturated when it contains more of the solute than the solvent can dissolve under normal conditions is called super saturated.
We can determine whether the solution is unsaturated, saturated, or supersaturated by knowing the amount of solute in the solution.
What is unsaturated, saturated, or supersaturated?A solution is said to be saturated when it cannot dissolve any extra solute in it, a solution is said to be unsaturated solution, when the concentration of solute is less as compared to solubility of the solution and the solution is able to dissolve more solute.
Whereas, a solution is said to be super saturated when it contains more of the solute than the solvent can dissolve under normal conditions.
Learn more about solution here: https://brainly.com/question/24372553
Calculate the boiling point (in degrees C) of a solution made by dissolving 7 g of naphthalene {C10H8} in 14.4 g of benzene. The Kbp of the solvent is 2.53 K/m and the normal boiling point is 80.1 degrees C. Enter your answer using 2 decimal places.
Answer:
The boiling point = 89.69 °C
Explanation:
Step 1: Data given
Mass of naphthalane = 7.0 grams
Mass of benzene = 14.4 grams
The Kbp of the solvent = 2.53 K/m
The normal boiling point is 80.1°C
Naphthalene, C10H8 , is a non-electrolyte, which means that the van't Hoff factor for this solution will be 1
Step 2: Calculate moles naphthalene
Moles naphthalene = mass / molar mass
Moles naphthalene = 7.0 grams / 128.17 g/mol
Moles naphthalene = 0.0546 moles
Step 3: Calculate molality
Molality = moles naphthalene / mass water
Molality = 0.0546 moles / 0.0144 kg
Molality = 3.79 molal
Step 4:
ΔT = i*Kb*m
ΔT = 1*2.53 K/m * 3.79 molal
ΔT = 9.59 °C
The boiling point = 80.1 °C + 9.59 °C = 89.69 °C
The boiling point of a solution made by dissolving 7 g of naphthalene in 14.4 g of benzene, with a Kbp of 2.53 K/m, is 89.68 degrees C.
Explanation:To calculate the boiling point of a solution made by dissolving naphthalene in benzene, we can use the boiling point elevation formula: \(\Delta T = i \cdot K_{bp} \cdot m\), where \(\Delta T\) is the boiling point elevation, \(i\) is the van't Hoff factor (which is 1 for non-electrolytes like naphthalene), \(K_{bp}\) is the ebullioscopic constant of the solvent, and \(m\) is the molality of the solution.
The molality (\(m\)) is calculated using the formula: \(m = \frac{moles\ of\ solute}{kilograms\ of\ solvent}\). Naphthalene's molar mass is 128.17 g/mol. Thus, the moles of naphthalene are \(\frac{7\ g}{128.17\ g/mol} = 0.0546\ moles\). The mass of benzene is 14.4 g, which is 0.0144 kg. So, the molality is \(\frac{0.0546\ moles}{0.0144\ kg} = 3.79\ m\).
Now, we can find the boiling point elevation: \(\Delta T = 1 \cdot 2.53\ K/m \cdot 3.79\ m = 9.58\ K\). Convert K to \(\degree C\) by using the normal boiling point of benzene (80.1 \(\degree C\)) plus the boiling point elevation: \(80.1 \(\degree C\) + 9.58 \(\degree C\) = 89.68 \(\degree C\)\).
The boiling point of this solution is 89.68 degrees C.
A liquid mixture of 0.400 mole fraction ethanol and 0.600 methanol was placed in an evacuated (i.e., no air) bottle and after many days is now in equilibrium with its vapor. Assuming Raoult's Law applies (actually, both activity coefficients are within 0.02 of unity), what is the mole fraction of each compound in the vapor at 25C? at 40C?
Answer:
mole fraction methanol = 0.76
mole fraction ethanol = 0.24
Explanation:
Raoult´s law gives us the partial vapor pressure of a component in solution as the product of the mole fraction of the component and the value of its pure pressure:
PA = X(A) x Pº(A)
where PA is the partial vapor pressure of component A, X(A) is the mole fraction of A, and Pº(A) its pure vapor pressure.
From reference literature the pure pressures of methanol, and ethanol are at 25 ºC :
PºCH₃OH = 16.96 kPa
PºC₂H₅OH = 7.87 kPa
Given that we already have the mole fractions, we can calculate the partial vapor pressures as follows:
PCH₃OH = 0.600 x 16.96 kPa = 10.18 kPa
PC₂H₅OH = 0.400 x 7.87 kPa = 3.15 kPa
Now the total pressure in the gas phase is:
Ptotal = PCH₃OH + PC₂H₅OH = 10.18 kPa + 3.15 kPa = 13.33 kPa
and the mole fractions in the vapor will be given by:
X CH₃OH = PCH₃OH / Ptotal = 10.18 kPa/ 13.33 kPa = 0.76
X C₂H₅OH = 1 - 0.76 = 0.24
Calculate the mass of sucrose necessary to make a 5% by mass sucrose solution if the solution contains 50.0 ml of distilled water.
Answer: 2.5g
Explanation:
5 % sucrose solution means that 5 % of the weight of the solution is sucrose.
If 1 liter of water weighs 1000 grams. To prepare 5% sucrose solution 5/100 x 1000 = 50 grams. Since 1 liter equals 1000ml, thus a 5 % solution has 50 grams of solute dissolved in one liter.
To prepare 5% sucrose solution in 50mls
=5/100 x 50
= 0.05 x 50
= 2.5g
Therefore to prepare 5% sucrose solution in 50mls we dissolve 2.5g of sucrose in 50ml of water
Final answer:
To prepare a 5% by mass sucrose solution with 50.0 ml of distilled water, approximately 2.63 g of sucrose is required, which is calculated using the percent by mass formula and assumes that water's density is 1 g/ml.
Explanation:
The student's question asks to calculate the mass of sucrose necessary to prepare a 5% by mass sucrose solution using 50.0 ml of distilled water. The concept involved here is the percent by mass calculation which is used in preparing solutions in chemistry. To calculate the mass of the sucrose needed, one must use the formula:
Percent by mass = (mass of solute / mass of solution) × 100%
Given that we want a 5% sucrose solution, we can rearrange the formula to solve for the mass of sucrose:
Mass of sucrose = (Percent by mass × mass of solution) / 100%
First we need to convert the volume of water to mass, assuming the density of water is approximately 1 g/ml:
Mass of water (solvent) = 50.0 ml × 1 g/ml = 50.0 g
The total mass of the solution will be the mass of the water plus the mass of the sucrose, which we can call 'x':
Mass of solution = mass of water + x
Now, plugging in the known values and solving for 'x' gives us:
x = (5% × (50.0 g + x)) / 100%
Solving this equation for 'x' yields:
0.05 × 50.0 g + 0.05x = x
2.5 g + 0.05x = x
2.5 g = x - 0.05x
2.5 g = 0.95x
x = 2.5 g / 0.95
x = 2.6316 g
Therefore, the mass of sucrose necessary to make a 5% sucrose solution with 50.0 ml of distilled water is approximately 2.63 g.
There are three sets of sketches below, showing the same pure molecular compound (water, molecular formula H_2 O) at three different temperatures. The sketches are drawn as if a sample of water were under a microscope so powerful that individual atoms could be seen. Only one sketch in each set is correct. Use the slider to choose the correct sketch in each set. You may need the following information: melting point of H_2 O: 0.0 degree C boiling point of H_2 O: 100.0 degree C
Answer:
Only sketch B has the water molecules in the right form/state that the temperature presented predicts!
Explanation:
N.B - With the initial assumption that all the processes or water states exist at normal conditions of atmospheric pressure and temperature!
In the image attached to this solution, sketch A is at -23°C, sketch B is at 237°C and sketch C is at 60°C.
But for water, it's boiling point is 100°C; meaning that the this is the temperature where water molecules change form from fairly free to move around, almost incompressible liquid state to the gaseous state in which the water molecules (now called steam) are totally free to move around.
Its melting point is 0°C; that is, this is the temperature where the water molecules change form from the orderly solid form (called ice) where motion is totally restricted to only vibrations into the more free liquid state.
This explanation indicates that water molecules at temperatures below 0°C exist in the orderly solid form.
Water molecules at temperatures between 0°C and 100°C exist as the fairly free liquid and at temperatures higher than 100°C, the water molecules exist in the free to move about gaseous state.
In the sketches attached to this solution, sketch A evidently shows the water molecules in the fairly free to move about form (that is, liquid form), but matches this state with a temperature of -23°C which corresponds more to the solid, orderly state of water molecules shown in sketch C. Hence, that is a mismatch.
Sketch B shows water molecules in the very freeing state of gaseous form and rightly matches that form with a temperature way above the boiling point of water, 237°C. Thereby indicating a correct match between temperature and the sketch.
Sketch C however shows water molecules in their very organized solid form but mismatches this form to 60°C which corresponds more to the liquid state sketch in sketch A.
Only sketch B has the water molecules in the right form/state that the temperature presented predicts!
Hope this helps!!!
200.0 mL of 0.200 M HCl is titrated with 0.050 M NaOH. What is the pH after the addition of 100. mL of the NaOH solution
Answer : The pH of the solution is, 0.932
Explanation :
First we have to calculate the moles of HCl and NaOH.
[tex]\text{Moles of HCl}=\text{Concentration of HCl}\times \text{Volume of solution}=0.200mole/L\times 0.200L=0.040mole[/tex]
[tex]\text{Moles of NaOH}=\text{Concentration of NaOH}\times \text{Volume of solution}=0.050mole/L\times 0.100L=0.0050mole[/tex]
The balanced chemical reaction will be,
[tex]HCl+NaOH\rightarrow NaCl+H_2O[/tex]
From the balanced reaction we conclude that,
As, 1 mole of NaOH neutralizes by 1 mole of HCl
So, 0.0050 mole of NaOH neutralizes by 0.0050 mole of HCl
Thus, the number of neutralized moles = 0.0050 mole
Remaining moles of HCl = 0.040 - 0.0050 = 0.035 moles
Total volume of solution = 200.0 mL + 100.0 mL = 300.0 mL = 0.300 L
Now we have to calculate the concentration of HCl(acid).
[tex]Concentration=\frac{Moles}{Volume}=\frac{0.035mol}{0.300L}=0.117M[/tex]
As we know that, 1 mole of HCl dissociates to give 1 mole of hydrogen ion and 1 mole of chloride ion.
So, concentration of [tex]H^+[/tex] = 0.117 M
Now we have to calculate the pH of solution.
[tex]pH=-\log [H^+][/tex]
[tex]pH=-\log (0.117)[/tex]
[tex]pH=0.932[/tex]
Thus, the pH of the solution is, 0.932
"The pH after the addition of 100.0 mL of 0.050 M NaOH to 200.0 mL of 0.200 M HCl is approximately 2.68.
To find the pH, we first need to determine the moles of HCl and NaOH involved in the reaction:
Moles of HCl = volume (L) — concentration (mol/L)
Moles of HCl = 0.200 L — 0.200 mol/L = 0.0400 mol
Moles of NaOH = volume (L) — concentration (mol/L)
Moles of NaOH = 0.100 L — 0.050 mol/L = 0.0050 mol
The balanced equation for the reaction between HCl and NaOH is:
[tex]\[ \text{HCl} + \text{NaOH} \rightarrow \text{NaCl} + \text{H}_2\text{O} \][/tex]
From the equation, we see that the reaction between HCl and NaOH is 1:1. Therefore, the moles of NaOH added will neutralize an equal number of moles of HCl.
Moles of HCl remaining after neutralization = moles of HCl initially - moles of NaOH added
Moles of HCl remaining = 0.0400 mol - 0.0050 mol = 0.0350 mol
The new concentration of HCl after the addition of NaOH is:
[tex]\[ \text{Concentration of HCl} = \frac{\text{moles of HCl remaining}}{\text{total volume}} \] \[ \text{Concentration of HCl} = \frac{0.0350 \text{ mol}}{0.200 \text{ L} + 0.100 \text{ L}} = \frac{0.0350 \text{ mol}}{0.300 \text{ L}} \] \[ \text{Concentration of HCl} = 0.1167 \text{ M} \][/tex]
Since HCl is a strong acid, it dissociates completely in water. Therefore, the concentration of HCl is equal to the concentration of H+ ions in the solution.
[tex]\[ \text{pH} = -\log[\text{H}^+] \] \[ \text{pH} = -\log(0.1167) \] \[ \text{pH} \approx 2.68 \][/tex]
Thus, the pH of the solution after the addition of 100.0 mL of 0.050 M NaOH is approximately 2.68."
When a salt is added to a polar solvent like water, the ions interact with the solvent molecules via ____ , which overcome the forces originally holding the ions together.
Answer:
ion - dipole interactions
Explanation:
Ion - dipole interactions -
It refers to the interaction between the ion and a dipole , ( any species which is capable to get produce slight positive and slight negative charge ) , is known as ion - dipole interactions .
Water is a polar compound , and due to more electronegative oxygen atom , it can have slight negative charge and correspondingly , hydrogen atom can attain slight positive charge , and thereby generates a dipole .
Now , from the question,
The salt when dissolved in water , breaks down to ions , cations and anion , and these ions interacts with the polar water molecules , giving rise to the ion - dipole interactions .
In a typical fireworks device, the heat of the reaction between a strong oxidizing agent, such as KClO₄, and an organic compound excites certain salts, which emit specific colors. Strontium salts have an intense emission at 641 nm, and barium salts have one at 493 nm. (a) What colors do these emissions produce? (b) What is the energy (in kJ) of these emissions for 5.00 g each of the chloride salts of Sr and Ba? (Assume that all the heat released is converted to light emitted.)
Answer:
a) The wavelength 641nm of strontium emits a red color in visible spectrum of strontium saltsThe wavelength 493nm of Barium emits a green color in visible spectrum of barium salts.Explanation:
The detailed and step by step calculation is as shown in the attachment.
A 0.10 M solution of Na2HPO4 could be made a buffer solution with all of the following EXCEPT ________. View Available Hint(s) A 0.10 solution of could be made a buffer solution with all of the following EXCEPT ________. K3PO4 Na3PO4 H3PO3 NaH2PO4
Final answer:
The answer to the question is Na3PO4, as it provides the same anion as Na2HPO4 without a conjugate acid or base, making it unable to form a buffer solution with Na2HPO4.
Explanation:
A buffer solution is formed from a weak acid and its conjugate base, or a weak base and its conjugate acid. Therefore, a 0.10 M solution of Na2HPO4 (which is sodium hydrogen phosphate) could be made into a buffer solution with another compound that either provides its conjugate acid or its conjugate base. Na2HPO4 can act as both a weak acid (donating H+) and a weak base (accepting H+).
A buffer solution with Na2HPO4 could be made using the following combinations:
H3PO4 and Na2HPO4 (H3PO4 is the conjugate acid of Na2HPO4)NaH2PO4 (NaH2PO4 can provide the conjugate acid of Na2HPO4)K3PO4 (K3PO4 can provide the conjugate base of Na2HPO4)The one that cannot be used to form a buffer with Na2HPO4 is Na3PO4, because Na3PO4 is the fully deprotonated form and provides the same anion as Na2HPO4 without an accompanying conjugate acid or base. Therefore, the correct answer is Na3PO4.
How does a volcanic eruption affect the Earth's atmosphere? A) Eruptions shoot out ash and poisonous gases into the air. B) The clouds that form around a volcano drys out the surrounding area. C) Volcanoes can disturb the surrounding air and create extremely high winds. D) The lava ejected from the volcano can clean and purify the air around the volcano.
Answer:
A
Explanation:
A volcanic eruption affects the Earth's atmosphere mainly through the release of ash and poisonous gases. These materials can impact global climate, air travel, human health, and regional weather patterns.
Explanation:A volcanic eruption impacts the Earth's atmosphere in a number of ways, largely through the release of volcanic gases and ash. The most significant aspect is option A, eruptions shooting out ash and poisonous gases into the air.
These gases, including sulfur dioxide, can contribute to the formation of aerosols in the higher layers of the atmosphere, potentially affecting global climate patterns. For example, a large volcanic eruption can lead to cooler temperatures worldwide for a few years.
Additionally, the ash particles ejected during a volcanic eruption can have a range of effects, from impacting air travel to affecting human health and altering regional weather patterns.
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The net change in the multistep biochemical process of photosynthesis is that CO₂ and H₂O form glucose (C₆H₁₂O₆) and O₂. Chlorophyll absorbs light in the 600 to 700 nm region. (a) Write a balanced thermochemical equation for formation of 1.00 mol of glucose. (b) What is the minimum number of photons with λ = 680. nm needed to prepare 1.00 mol of glucose?
Answer:(a) 6CO2 (g) + 6H2O (l) → C6H12O6 (s) + 6O2 (g)
(b) 5.55*10^37photons
Explanation:
(a) Here we have to write a balanced thermochemical equation for formation of 1.00 mol of glucose.
In this question it has been given that Chlorophyll absorbs light in the 600 to 700 nm region,
1st we will write a chemical equation for biochemical process of photosynthesis is that CO2 and H2O form glucose (C6H12O6) and O2.
6CO2 (g) + 6H2O (l) → C6H12O6 (s) + 6O2 (g)
The heat change off the reaction can be calculated as,
={(1 mol)(6 mol) }- {(6 mol) [H2O]}
=[1 1273.3 kJ + 6(0)] - [6 (-39.5 kJ) + 6 (-285.840 kJ)]
= 2802.74 or 2802.7 kJ
Thus the balanced equation can be written as,
6CO2 (g) + 6H2O (l) → C6H12O6 (s) + 6O2 (g) = 2802.7 kJ for 1.00 mol of glucose.
A chemist in an imaginary universe where electrons have a different charge than they do in our universe preforms Millikan's oil drop experiment to measure the electron charge. The charges of the drops are recorded below. What is the charge of the electron in this imaginary universe?a. Drop A-6.9 X 10^-19 Cb. Drop B-9.2 X 10^-19 Cc. Drop C-11.5 X 10^-19 Cd. Drop D-4.6 X 10^-19 C
Charge of the electron: [tex]-2.3\cdot 10^{-19}C[/tex]
Explanation:
In Millikan experiment, it was discovered that the electric charge on the oil drops is discrete - and its value is always an integer multiple of a certain charge [tex]e[/tex], called fundamental charge (the charge of the electron). This is because an oil drop always contains an integer number of electrons, so the charge must be a multiple of [tex]e[/tex].
This means that we can write the charge on an oil drop as
[tex]Q=Ne[/tex]
For the drop recorded in this experiment, we have:
[tex]Q_A = N_A e = -6.9\cdot 10^{-19}C[/tex]
[tex]Q_B = N_B e = -9.2\cdot 10^{-19}C[/tex]
[tex]Q_C = N_C e = -11.5\cdot 10^{-19}C[/tex]
[tex]Q_D = N_D e = -4.6\cdot 10^{-19}C[/tex]
By dividing drop A by drop D, we get
[tex]\frac{Q_A}{Q_D}=\frac{3}{2}[/tex]
Also by dividing deop B by drop D we get
[tex]\frac{Q_B}{Q_D}=\frac{4}{2}[/tex]
And also, by dividing drop C by drop D we get
[tex]\frac{Q_C}{Q_D}=\frac{5}{2}[/tex]
This means that the charges on drop A, B, C and D are in the ratio
3 : 4 : 5 : 2
And therefore, the fundamental charge must be half of the charge on drop D:
[tex]e=\frac{Q_D}{2}=-2.3\cdot 10^{-19}C[/tex]
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Consider the generic acid, HA, and how it interacts with water:HA (aq) + H2O (l) ⇌ H3O+ (aq) + A-Consider the following statements and answer true or false. The stronger A- is as a weak base, the stronger HA will be as a weak acid.a. True b. False Having a greater number of electron withdrawing groups is typically the best way to stabilize a conjugate base.a. True b. False If HA is a strong acid, A- will be a relatively strong weak conjugate base.a. True b. False An acid with a Ka value of 1.2 x 10-4 is a weaker acid than an acid with a Ka value of 1.5 x 10-8.a. True b. False
Answer:
B. False
A. True
B. False in
Explanation:
1.
From Bronsted-Lowrys definition of Acids and bases, a strong acid is a substance that gives up a proton (to form a weak conjugate base), while a strong base is one that willingly accepts a proton.
Therefore in the reaction,
HA(aq) + H2O (l) ⇌ H3O+ (aq) + A-
The stronger HA is, the weaker the A- and vice versa; the weaker HA is, the stronger A-. Example, HCl is a strong acid and its conjugate base, Cl- is a weak base.
B. False
2.
Electron drawing groups are molecules and/or atoms that enable the release of a proton from a specie. They cause inductive as well as mesomeric effects. Examples, -NO2, -COOH, -OH etc.
Fluoride ion is the most stable in this series because it's the most electronegative while carbon is the least stable because it's the least electronegative. Because of this, we were able to say that H-F was the most acidic, because it had the most stable conjugate base.
A. True.
3.
pKa1 = -log[Ka1]
= -log[1.2 x 10-4]
= 3.92
pKa2 = -log[Ka2]
= -log[1.5 x 10-8]
= 7.82
Using Bronsted-Lowry definition, the smaller the pKa value the more ease the acid loses its proton, that is, the smaller the pKa value, the stronger the acid.
Therefore, pKa2 > pKa1, so Ka value of 1.2 x 10-4 is a stronger acid than Ka value of 1.5 x 10-8
B. False.
1. B. False
2. A. True
3. B. False
1.
Bronsted Lowry Concept:
According to Bronsted Lowry, an acid is a proton (H⁺) donor, and a base is a proton acceptor.
The given reaction,
[tex]HA(aq) + H_2O (l)[/tex] ⇌ [tex]H_3O^+ (aq) + A^-[/tex]
The stronger HA is, the weaker the A- and vice versa; the weaker HA is, the stronger A-.
Example, HCl is a strong acid and its conjugate base, Cl- is a weak base.
Thus the given statement is False.2.
Electron drawing groups are molecules and/or atoms that enable the release of a proton from a species. Examples, -NO₂, -COOH, -OH etc.
Fluoride ion is the most stable in this series because it's the most electronegative while carbon is the least stable because it's the least electronegative. Because of this, we were able to say that H-F was the most acidic, because it had the most stable conjugate base.
Thus the given statement is True.3.
[tex]p_{Ka_1} = -log[Ka_1]\\\\p_{Ka_1}= -log[1.2 * 10^{-4}]\\\\p_{Ka_1}= 3.92[/tex]
[tex]p_{Ka_2} = -log[Ka_2]\\\\p_{Ka_2}= -log[1.5 * 10^{-8}]\\\\p_{Ka_2}= 7.82[/tex]
Using Bronsted-Lowry definition, the smaller the pKa value the more ease the acid loses its proton, that is, the smaller the pKa value, the stronger the acid.
Therefore, [tex]p_{Ka_2} > p_{Ka_1}[/tex], so Ka value of[tex]1.2 * 10^{-4}[/tex] is a stronger acid than Ka value of [tex]1.5 * 10^{-8}[/tex]
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A molecule from a new organism contains adenine, cytosine, guanine, and thymine. What molecules is being looked at?
Since, the options are not given the question is incomplete. The complete question is as follows:
A molecule from a new organism contains adenine, cytosine, guanine, and thymine. What is this unknown molecule?
DNA
lipid
carbohydrate
RNA
protein
Answer: DNA
Explanation:
The DNA short for deoxyribonucleic acid is a genetic material that can be found in majority of the living beings on earth. It is composed of two strands that are coiled around each other. Each strand consists of nucleotides. Each nucleotide is composed of four nitrogen exhibiting nucleobases like guanine, cytosine, adenine and thymine along with the deoxyribose sugar and phosphate group. In DNA there are two groups of nitrogenous bases these includes the pyrimidines and purines. The pyrimidines are cytosine and thymine and the purines are guanine and adenine.
According to the given situation, a molecule from a new organism consists of adenine, cytosine thymine and guanine these all are nitrogenous bases which can be found in DNA.
ANSWR ASAP fill in the blanks
Answer:
1. Gender role
2. Sex
Explanation:
What species is undergoing reduction in the following reaction? NO3-(aq) + 4Zn(s) + 7OH-(aq) + 6H2O(l) → 4Zn(OH)42-(aq) + NH3(aq)
In the given chemical equation, zinc is undergoing reduction as it gains electrons.
What is chemical equation?
Chemical equation is a symbolic representation of a chemical reaction which is written in the form of symbols and chemical formulas.The reactants are present on the left hand side while the products are present on the right hand side.
A plus sign is present between reactants and products if they are more than one in any case and an arrow is present pointing towards the product side which indicates the direction of the reaction .There are coefficients present next to the chemical symbols and formulas .
The first chemical equation was put forth by Jean Beguin in 1615.By making use of chemical equations the direction of reaction ,state of reactants and products can be stated. In the chemical equations even the temperature to be maintained and catalyst can be mentioned.
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A Se ion has a mass number of 79 and a charge of − 2 . Determine the number of neutrons, protons, and electrons in this ion.
Answer:
45, 34, 36
Explanation:
The atomic number of Selenium is 34 and the atomic number is 79 also the atom has gained two electron denoted by superscript -2
number of neutrons = mass number - atomic number = 79 - 34 = 45
number of proton = atomic number = 34
number of electron = 34 + 2 = 36. In an atom the number of proton is always equal to number of electron if the atom is neutral but this Se atom has gain two so the number of electron will exceed the number of proton by 2.
The Se ion has 34 protons, 45 neutrons and 36 electrons.
The mass number (A) is given by the sum of the protons and neutrons:
A = protons + neutrons = 79
From the Periodic Table, we can see that the chemical element Selenium (Se) has an atomic number (Z) of 34, which is equal to the number of protons of a chemical element:
Z = protons = 34
Thus, we calculate the number of neutrons as the difference between A and Z:
neutrons = A - Z = 79 - 34 = 45
In a neutral atom (without electric charge), the number of electrons is equal to the number of protons. Since Se ion has 34 protons and a charge of -2, it has 34 electrons to be neutral and then it gained 2 electrons, so the number of electrons is equal to:
electrons = protons + 2 = 34 + 2 = 36
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Draw two constitutional isomers that share the molecular formula C2H7P. Your structures will have the same molecular formula but will have different connectivities.
Answer:
Explanation:
Two constitutional isomers of C₂H₇P
1 ) CH₃-CH₂ - PH₂ ( Ethyl phosphane )
2 ) CH₃ - PH - CH₃ ( Dimethyl phosohane )
The chemical formulae of constitutional isomers are the same, but their connectivities differ. Constitutional isomers include ethanol and dimethyl ether, as well as n-butane and isobutane.
Although structural (constitutional) isomers share the same chemical formula, their atoms are bonded in different ways. Stereoisomers share the same atomic configurations and chemical formulae. Only the spatial arrangement of the groups within the molecule separates them from one another.
Compounds with the same chemical formula but different properties are known as isomers. Constitutional isomers are isomers that have different atom connections.
Two constitutional isomers of C₂H₇P
1 ) CH₃-CH₂ - PH₂ ( Ethyl phosphane )
2 ) CH₃ - PH - CH₃ ( Dimethyl phosphane )
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The vapor pressure of ethanol is 54.68 mm Hg at 25°C. How many grams of estrogen (estradiol), C18H24O2, a nonvolatile, nonelectrolyte (MW = 272.4 g/mol), must be added to 239.0 grams of ethanol to reduce the vapor pressure to 54.11 mm Hg ?
Answer: The mass of estrogen that must be added is 2.83 grams
Explanation:
The equation used to calculate relative lowering of vapor pressure follows:
[tex]\frac{p^o-p_s}{p^o}=i\times \chi_{solute}[/tex]
where,
[tex]\frac{p^o-p_s}{p^o}[/tex] = relative lowering in vapor pressure
i = Van't Hoff factor = 1 (for non electrolytes)
[tex]\chi_{solute}[/tex] = mole fraction of solute = ?
[tex]p^o[/tex] = vapor pressure of pure ethanol = 54.68 mmHg
[tex]p_s[/tex] = vapor pressure of solution = 54.11 mmHg
Putting values in above equation, we get:
[tex]\frac{54.68-54.11}{54.68}=1\times \chi_{\text{estrogen}}\\\\\chi_{\text{estrogen}}=0.0104[/tex]
This means that 0.0104 moles of estrogen are present in the solution
To calculate the number of moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
Moles of estrogen = 0.0104 moles
Molar mass of estrogen = 272.4 g/mol
Putting values in above equation, we get:
[tex]0.0104mol=\frac{\text{Mass of estrogen}}{272.4g/mol}\\\\\text{Mass of estrogen}=(0.0104mol\times 272.4g/mol)=2.83g[/tex]
Hence, the mass of estrogen that must be added is 2.83 grams
Phthalic acid is a diprotic acid having the formula HO2CC6H4CO2H that can be converted to a salt by reaction with base. Which of the following is expected to be most soluble in water? A) HO2CC6H4CO2H B) HO2CC6H4CO2Na C) HO2CC6H4CO2K D) NaO2CC6H4CO2Kand why?
Answer:
D) NaO2CC6H4CO2K
Explanation:
Water is a polar solvent and tends to solvate polar molecules. This allows solute molecules to interact with the solvent and that is why the solubility of a molecule in water increases with the increase in its polarity. So, the salt of phthalic acid is more soluble in water than phthalic acid itself. Although the monosodium and monopotassium salts are also more soluble than phthalic acid, the dialkali phthalate salt (NaO2CC6H4CO2K) is the most soluble due to the highest polarity.
What is the product of the reaction of hydrobromic acid and 2-bromo-1-butene in the presence of acid and ether?
Answer: The major product of the reaction between Hydrobromic Acid and 2-bromo-1-butene in the presence of ether and acid is 2,2-dibromobutane.
Explanation:
The mechanism of the reaction is supported by the Markovnikov's rule which explains that in the addition reaction of alkenes by hydrogen-halogen compounds, the incoming halogen substituent goes to the more substituted Carbon. It can also be stated that incoming hydrogen atom goes to the Carbon with more Hydrogen atoms.
The only case when the reverse of Markovnikov's rule takes place is when Hydrogen peroxide is present and the addition reagent is HBr.
This case is not like that and it simply follows the Markovnikov's rule.
I'll add an attachment of the reaction to this now.
Answer:
On the reaction the product is 2-2-dibromobutane.
Explanation:
2-Bromo-1 butene is given as in the figure. On the breaking of the double bond 2 local electrophilic and nucleophilic radicals will be formed in the 2-Bromo-1-butene and H-Br respectively.
Due to the Markovnikov Rule the nucleophilic radical of the attacking compound bonds with the carbon atom with least number of H atoms so the product formed will be 2-2-dibromobutane as indicated in the figure.
If the molecular weight of a semiconductor is 27.9 grams/mole and the diamond lattice constant is 0.503 nm, what is the density of the semiconductor in grams/cc ? Two significant digits, fixed point notation.
Explanation:
The given data is as follows.
Mass = 27.9 g/mol
As we know that according to Avogadro's number there are [tex]6.023 \times 10^{26}[/tex] atom present in 1 mole. Therefore, weight of 1 atom will be as follows.
1 atoms weight = [tex]\frac{38}{6.023 \times 10^{26}}[/tex]
In a diamond cubic cell, the number of atoms are 8. So, n = 8 for diamond cubic cell.
Therefore, total weight of atoms in a unit cell will be as follows.
= [tex]\frac{8 \times 27.9 g/mol}{6.023 \times 10^{26}}[/tex]
= [tex]37.06 \times 10^{-26}[/tex]
Now, we will calculate the volume of a lattice with lattice constant 'a' (cubic diamond) as follows.
= [tex]a^{3}[/tex]
= [tex](0.503 \times 10^{-9})^{3}[/tex]
= [tex]0.127 \times 10^{-27} m^{3}[/tex]
Formula to calculate density of diamond cell is as follows.
Density = [tex]\frac{mass}{volume}[/tex]
= [tex]\frac{37.06 \times 10^{-26}}{0.127 \times 10^{-27} m^{3}}[/tex]
= 2918.1 [tex]g/m^{3}[/tex]
or, = 0.0029 g/cc (as 1 [tex]m^{3} = 10^{6} cm^{3}[/tex])
Thus, we can conclude that density of given semiconductor in grams/cc is 0.0029 g/cc.
__Zn(s)+__HCl(aq)--->______+_______
Answer:
Zn + 2HCl —> ZnCl2 + H2
Explanation:
This is a displacement reaction, in which Zn displaces H2 from acid. The equation for the reaction is given below:
Zn + 2HCl —> ZnCl2 + H2