Functional groups create active sites in molecules. The polar part of a molecule that can hydrogen bond to water is said be hydrophilic. Pi (π) bonds create active sites and will react with electron-deficient species. A electronegative heteroatom like nitrogen, oxygen, or a halogen makes a carbon atom ____________ . The nonpolar part of a molecule that is not attracted to water is said to be hydrophobic.

Answer:

0.346 M

Explanation:

Let's consider the following neutralization reaction.

NaOH + HCl → NaCl + H₂O

24.7 mL of 0.140 M NaOH react. The reacting moles are:

24.7 × 10⁻³ L × 0.140 mol/L = 3.46 × 10⁻³ mol

The molar ratio of NaOH to HCl is 1:1. The moles of HCl that reacted are 3.46 × 10⁻³ moles.

3.46 × 10⁻³ moles of HCl are contained in 10.0 mL. The molarity of HCl is:

3.46 × 10⁻³ mol/ 10.0 × 10⁻³ L = 0.346 M

Answer:

See explanation below.

Explanation:

Dipoles are molecules that have partial charges. It happens because of the difference in electronegativity of the elements. This property is the tendency that the atom has to take the electron to it, so, in the covalent bond, the shared pair of electrons is easily found at the more electronegativity atom, and so, it has a partial negative charge, and the other, a partial positive charge. This is a natural dipole.

If the difference of electronegativity is 0, or extremely close to 0, then the molecule is nonpolar, and so the molecule doesn't have partial charges. But, to be joined together and form the substance, the partial charge must be induced, so it's an induced dipole.

Final answer:

An electric dipole consists of two opposite charges separated by a distance, and is seen in natural structures like water molecules. A permanent dipole is due to molecular structure, while an induced dipole occurs due to an external electric field. The dipole moment represents the strength and direction of this separation of charges.

Explanation:

An electric dipole consists of two equal but opposite charges separated by a distance. This model is crucial in understanding atomic and molecular interactions. A common example of a natural dipole is the water molecule. The unequal distribution of electron density throughout a molecule can lead to a positive end and a negative end, resulting in a dipole moment.

Natural vs. Induced Dipole

A permanent dipole is inherent within a molecule and results from an unequal distribution of electron density due to its molecular structure. In contrast, an induced dipole occurs when an external electric field influences a neutral atom or molecule, causing the displacement of charges and creating the dipole moment. The induced dipole moment will be aligned with the external electric field.

The strength and direction of an electric dipole are expressed by the dipole moment, a vector quantity that represents the size of the charge separation and the distance between the charges. The physical significance of the dipole moment lies in its alignment parallel to an external electric field and its role in decreasing the total electric field within the dipole region, which has applications in areas like capacitors.

Answer:

The melting point would be 250. That is the answer I think

Explanation:

The solid substance will turn into vapor when the temperature is increased from room temperature into meeting point temperature.

The given parameters;

A substance boils when the atmospheric pressure is equal to the vapor pressure.

Since the vapor pressure of the solid substance occurs at the meeting temperature of the substance, once the temperature of the solid substance is increased to the meeting point temperature, the solid substance will turn into vapor (gas).

Thus, we can conclude that the solid substance will turn into vapor when the temperature is increased from room temperature into meeting point temperature.

Learn more here:https://brainly.com/question/2694622

Explanation:

The reaction equation will be as follows.

        [tex]C_{6}H)_{12}O_{6}(s) + 6O_{2}(g) \rightarrow 6CO_{2}(g) + 6H_{2}O(l)[/tex]

It is given that the total energy liberated is -2810 kJ/mol. As the sign is negative this means that energy is being released. Also, it is given that the energy required to synthesis is -64.1 kJ/mol.

Therefore, calculate the number of moles of compound as follows.

         No. of moles = [tex]\frac{\text{total energy}}{\text{energy necessary to synthesise 1 mole of compound X}}[/tex]

                               = [tex]\frac{-2810 kJ}{-64.1 kJ/mol}[/tex]

                               = 43.83 mol

                               = 44 mol (approx)

Thus, we can conclude that the number of moles of compound is 44 mol.

The number of moles of the compound that could theoretically be generated resulting in approximately 44 moles when rounded to two significant figures.

To calculate the number of moles of hypothetical compound X that can be generated from the combustion of one mole of fructose, we use the provided Gibbs free energy change (ΔG°') of fructose and compound X. The energy liberated from the combustion of fructose is given as -2810 kJ/mol, and the energy required to synthesize one mole of compound X is -64.1 kJ/mol.

By dividing the total energy released by combustion by the energy required to synthesize one mole of compound X, we can find out the number of moles of compound X that can be theoretically produced.

Here’s the calculation:

Rounded to two significant figures, the number of moles of compound X that can be theoretically generated is 44 moles.

This is an incomplete question, here is a complete question.

The heat of combustion of bituminous coal is 2.50 × 10² J/g. What quantity of the coal is required to produce the energy to convert 106.9 pounds of ice at 0.00 °C to steam at 100 °C?

Specific heat (ice) = 2.10 J/g°C

Specific heat (water) = 4.18 J/g°C

Heat of fusion = 333 J/g

Heat of vaporization = 2258 J/g

A) 5.84 kg

B) 0.646 kg

C) 0.811 kg

D) 4.38 kg

E) 1.46 kg

Answer : The correct option is, (A) 5.84 kg

Explanation :

The process involved in this problem are :

[tex](1):H_2O(s)(0^oC)\rightarrow H_2O(l)(0^oC)\\\\(2):H_2O(l)(0^oC)\rightarrow H_2O(l)(100^oC)\\\\(3):H_2O(l)(100^oC)\rightarrow H_2O(g)(100^oC)[/tex]

The expression used will be:

[tex]Q=[m\times \Delta H_{fusion}]+[m\times c_{p,l}\times (T_{final}-T_{initial})]+[m\times \Delta H_{vap}][/tex]

where,

[tex]Q[/tex] = heat required for the reaction = ?

m = mass of ice = 106.9 lb = 48489.024 g      (1 lb = 453.592 g)

[tex]c_{p,l}[/tex] = specific heat of liquid water = [tex]4.18J/g^oC[/tex]

[tex]\Delta H_{fusion}[/tex] = enthalpy change for fusion = [tex]333J/g[/tex]

[tex]\Delta H_{vap}[/tex] = enthalpy change for vaporization = [tex]2258J/g[/tex]

Now put all the given values in the above expression, we get:

[tex]Q=145903473.2J[/tex]

Now we have to calculate the quantity of the coal required.

[tex]m=\frac{Q}{\Delta H}[/tex]

[tex]m=\frac{145903473.2J}{2.50\times 10^4J/g}[/tex]

[tex]m=5836.138929g=5.84kg[/tex]      (1 g = 0.001 kg)

Thus, the quantity of the coal required is, 5.84 kg

Answer:

The balanced chemical reaction is given as:

[tex]C_4H_9OH(l)+6O_2(g)\rightarrow 4CO_2(g)+5H_2O(g)[/tex]

Explanation:

Combustion is defined as chemical reaction which an organic compounds reacts with oxygen gas to to give water and carbon dioxide as a products along with releases of heat energy.

The combustion of liquid butanol gives water vapor and carbon dioxide as a product and this reaction is given as:

[tex]C_4H_9OH(l)+6O_2(g)\rightarrow 4CO_2(g)+5H_2O(g)[/tex]

According to reaction, 1 mole of butanol reacts with 6 moles of oxygen gas to gives 4 moles of carbon dioxide gas and 5 moles of water vapors.

The combustion of liquid butanol, in the presence of oxygen, forms carbon dioxide and water vapor. The balanced chemical equation is: C4H9OH(l) + 6O2(g) → 4CO2(g) + 5H2O(g).

The combustion of liquid butanol (C4H9OH) in the presence of oxygen (O2) produces carbon dioxide (CO2) and water (H2O). The balanced chemical equation for the combustion of liquid butanol can be written as:  

C4H9OH(l) + 6O2(g) → 4CO2(g) + 5H2O(g)

Here, C4H9OH(l) represents liquid butanol, O2(g) represents oxygen gas, CO2(g) represents carbon dioxide gas and H2O(g) represents water vapor. This equation states that one mole of butanol reacts with six moles of oxygen to form four moles of carbon dioxide and five moles of water vapor.

https://brainly.com/question/34137415

#SPJ3

Answer:

1.3 × 10³ mL

Explanation:

Let's consider the following reaction.

Zn + 2 HCl → ZnCl₂ + H₂

The percent yield is 78.0%. The real yield (R) of zinc chloride is 35.5 g. The theoretical yield (T) of zinc chloride is:

35.5 g (R) × (100 g T/ 78.0 g R) = 45.5 g T

The molar mass of zinc chloride is 136.29 g/mol. The moles corresponding to 45.5 g of zinc chloride is:

45.5 g × (1 mol/ 136.29 g) = 0.334 mol

The molar ratio of HCl to ZnCl₂ is 2:1. The moles of HCl that react with 0.334 moles of ZnCl₂ are 2 × 0.334 mol = 0.668 mol.

We need 0.668 moles of a 0.50 M HCl solution. The volume required is:

0.668 mol × (1000 mL/0.50 mol) = 1.3 × 10³ mL

Answer:

Goiter.

Explanation:

The thyroid gland is responsible for the secretion of the triidotyronine and thyroxine hormone in the body. The thyroid hormone regulates the metabolism and amount of particular ions in the body.

The iodine acts as the precursor for the maintenance of the thyroxine. The deficiency of the thyroid hormone can cause goiter.  The thyroid gland gets swollen and cause problem in the breathing. The production of mucus and cough is common in goiter.

Thus, the answer is goiter.

Answer:

214 milliliters of KOH needs to be added in 1 litre of 0.784 M acetic acid to make a acetate buffer of 5.31

Explanation:

To solve the problem, let us first use the Henderson-Hasselbalch equation to determine the amount of acetate needed to make a buffer of pH 5.31.

Henderson-Hasselbalch equation:

[tex]pH=pKa + log(\frac{[CH_{3}COO^{-}]}{[CH_{3}COOH]})[/tex]

Here, let us consider the moles of both species instead of the molar concentration, as the volume for both is the same. Also, acetate will be formed by the neutralization of acetic acid, hence the final moles of acetic acid will be the difference of initial moles of acetic acid and the moles of acetate formed. Now the equation becomes as follows:

[tex]pH=pKa + log(\frac{n_{ CH_{3}COO^{-}}}{n_{iCH_{3}COOH}-n_{ CH_{3}COO^{-}}}})[/tex]

From given data

pH = 5.31

pKa = 4.76

n(CH₃COO⁻) = ?

ni(CH₃COOH) = 0.784 mol (initial moles of acetic acid)

Placing the data in the equation, we get:

[tex]5.31=4.76 + log(\frac{n_{ CH_{3}COO^{-}}}{0.784-n_{ CH_{3}COO^{-}}}})\\ \\ n_{ CH_{3}COO^{-}}=10^{5.31-4.76}(0.784-(n_{ CH_{3}COO^{-}}))\\ \\ n_{ CH_{3}COO^{-}}= 2.78 mol-3.55(n_{ CH_{3}COO^{-}})\\ \\ n_{ CH_{3}COO^{-}}= 0.61mol[/tex]

The molar ratio of KOH and CH₃COOH is 1:1, i.e 1 mol of KOH will react with CH₃COOH and give 1 mol of acetate (CH₃COO⁻). Hence, 0.61 mol of KOH will give 0.61 mol of KOH. Now to determine the volume of 2.85 M KOH that contains 0.61 moles:

[tex]M_{KOH} =\frac{n_{KOH} }{V_{KOH} (L)}[/tex]

[tex]2.85=\frac{0.61}{V_{KOH} (L)}\\ \\ V_{KOH} (L)=\frac{0.61}{2.85}\\ \\ V_{KOH}=0.214 litre[/tex]

Finally convert liter into milliliter dividing by 1000 (mL/L)

Volume of KOH required = 214 milliliters

Answer:

The answer is 10 electrons

Explanation:

From periodic table its possible to find

Nitrogen atom has 5 VE (Valence)  

Hydrogen atom has 1 VE (Valence)

Carbon atom has 4 VE ( Valence)

5+1+4=10 Electrons

The Lewis structure of a covalent compound containing one nitrogen atom, one hydrogen atom, and one carbon atom would contain 10 electrons. This is calculated by summing up the valence electrons of each atom: nitrogen (5), hydrogen (1), and carbon (4).

The Lewis structure of a covalent compound represents the arrangement of atoms and the bonding electrons. In this case, we have one nitrogen atom, one hydrogen atom, and one carbon atom. Nitrogen has 5 valence electrons, hydrogen has 1, and carbon has 4. Altogether, the Lewis structure of this covalent compound should contain 10 electrons.

https://brainly.com/question/34631490

#SPJ3

Answer:

Ratio of rates of effusion of He to Ne is 2.245

Explanation:

According to Graham's law rate of effusion is inversely proportional to square root of molar mass of a gas

So, [tex]\frac{r_{He}}{r_{Ne}}=\sqrt{\frac{M_{Ne}}{M_{He}}}[/tex]

where, [tex]r_{He}[/tex] and [tex]r_{Ne}[/tex] are rate of effusion of He and Ne respectively. [tex]M_{He}[/tex] and [tex]M_{Ne}[/tex] are molar mass of He and Ne respectively.

Molar mass of He = 4.003 g/mol

Molar mass of Ne = 20.18 g/mol

So, [tex]\frac{r_{He}}{r_{Ne}}=\sqrt{\frac{20.18}{4.003}}=2.245[/tex]

So, ratio of rates of effusion of He to Ne is 2.245

Answer:

a. 3MnO2 + 4Al —> 3Mn+ 2Al2O3

3 moles of MnO2 required 4 moles of Al to produce 3 moles of Mn and 2moles of 2Al2O3

b. B203 + 3CaF2 —> 2BF3 + 3CaO

1mole of B203 requires 3 moles of CaF2 to produce 2moles of BF3 and 3 moles of CaO

c. 3NO2 + H2O —> 2HNO3 + NO

3 moles of NO2 requires 1mole of H2O to produce 2moles of HNO3 and 1mole of NO

d. C6H6 + 3H2 —> C6H12

1mole of C6H6 requires 3 moles of H2 to produce 1mole of C6H12

Final answer:

To balance the equations, ensure there are equal numbers of each atom. The balanced equations and their meanings in terms of molecules and moles are...

Explanation:

In order to balance the equations, you need to ensure that there are equal numbers of each type of atom on both sides of the equation. Here are the balanced equations for each reaction:

a. MnO2(s) + 2Al(s) -> Mn(s) + Al2O3(s)

b. B2O3(s) + 3CaF2(s) -> 2BF3(g) + 3CaO(s)

c. 2NO2(g) + H2O(l) -> HNO2(aq) + NO(g)

d. C6H6(g) + 3H2(g) -> C6H12(g)

In terms of the number of individual molecules, the balanced equation shows the ratio in which the reactants combine to form the products. In terms of moles of molecules, the balanced equation allows you to calculate the amount of each substance involved in the reaction using the mole ratio.

Answer:

See picture below

Explanation:

To do this, we first need to know how are the bonds in this molecule are. To do so, let's calculate the number of insaturations in the molecule:

n°I = C+1 - (H-N+X)/2

These numbers indicate if the molecule has double bond, triple bond, ring, cyclo, among other options:

n°I = 3 - (3+1)/2

n°I = 1

As it's a very small molecule, we can assume this molecule only have a double bond, and it's an alkene.

So the lewis structure, shows the electrons and the bonding, and also shows the unshared electron pairs, depending on how much electron have each molecule.

In the case of carbon:

[C] = [He] 2s2 2p2 ----> 4 electrons

[H] = 1s1 ----> 1 electron

[Cl] = [Ne] 3s2 3p5 ----> 7 electrons.

Therefore, we also know that Carbon has a double bond, so, the main molecule would have something like this:

C = C

so next to the carbons, we can put two hydrogens and in the other carbon, the chlorine and the remaining hydrogen.

See picture below for structure:

The Lewis structure of C₂H₃Cl is attached in the image below.

Lewis structures are also known as Lewis dot structures or electron dot structures. They are diagrams that represent the arrangement of atoms and valence electrons in a molecule or ion.

In a Lewis structure, the symbol of each atom is used to represent the nucleus and inner-shell electrons, while dots or lines are used to represent the valence electrons. Valence electrons are the outermost electrons involved in bonding and determining the chemical properties of an atom. The image is attached below.

Learn more about Lewis structures, here:

https://brainly.com/question/29603042

#SPJ6

Answer:

Reversible Processes:

- solid melting infinitesimally slowly at its melting point

- gas condensing infinitesimally slowly at its condensation point

- a single swing of frictionless pendulum

- liquid vaporizing infinitesimally slowly at its boling point

- liquid freezing infinitesimally slowly at its freezing point

Irreversible Processes:

- a single swing of a real pendulum

- solid melting infinitesimally slowly above its melting point

- liquid freezing below its freezing point

- gas condensing below its condenation point

- liquid vaporizing above its boiling point

Explanation:

Hint to help solve: "spontaneous processes, such as a solid melting above its melting point, are not reversible according to the scientific definition. Certainly one could place the melted substance in a cold environment and it would freeze again, but the surroundings would not be restored to their original state before melting and, in fact, would be further altered in the cooling process" - Mastering Chem.

Answer:

pH = 4.8

Explanation:

We will use the Henderson-Hasselbach equation to calculate the pH of the buffer:

pH = pKₐ + log [A⁻]/[HA]

From the information given:

pKₐ = 3.86

[A⁻] =  0.100 M

[HA] = 0.020 M

Plugging our values:

pH = 3.86 + log ( 0.100/0.020 ) = 4.6

For part b the same equation is utilized.

However we have to realize that the concentrations of the acid and its conjugate base have changed according to the neutralization reaction :

NaOH + lactic acid ⇒ sodium lactate + H₂O

# mol NaOH reacted = (8.0 mL x 1 L / 1000 mL ) x 1.00 M

= 8.0 x 10⁻³ mol

mol  sodium lactate produced = 8.0 x 10⁻³ mol   ( 1:1 )

number of moles mol lactic acid   originally = 1 L x 0.020 mol/L = 0.020 mol

new mol lactic acid after reaction = 0.020 - 8.0 x 10⁻³ =  0.012 mol

new mol sodium lactate after reaction = 0.100 mol/L x 1 L + 8.0 x 10⁻³ = 0.108

Here we do not need to calculate the new concentrations since molarity  is mol/V, and  the volumes cancel each other in the Henderson-Hasselbach equation because  they are in a ratio.

Now we are in position to determine the pH.

pH = 3.86 + log ( 0.108/0.012 ) = 4.8

This the usefulness of buffers, we are adding a 1.00 M  strong base NaOH, and the pH did not change that much (  a long as they are small additions within reason )

Answer:

Side products coincides with a loss in percentage yield of the product

Explanation:

- The product yield is defined as

product yield= actual yield/theoretical yield

- Byproducts are undesired products that come from the same reaction pathway that our products → even if the reaction procedes ideally , we will always have byproducts → byproducts do not alter the Yield by themselves

- Side products , however , come from undesired products from side reactions  and consume reactants due to these alternative pathways without producing our product → side products do alter the yield of the product

The given question is lacking some details, the complete question is following

Question:

An aqueous solution at 25 °C has a OH⁻ concentration of 2.5 x 10⁻⁴ M . Calculate the H₃O⁺ concentration. Be sure your answer has the correct number of significant digits

Answer:

Concentration of H₃O⁺ is:

[tex][H_{3}O^{+}]=4.0X10^{-9} M[/tex]

Explanation:

In aqueous solutions the product of the concentration of hydronium ions H₃O⁺ and hydroxide ions OH⁻ is 1.0 x 10⁻¹⁴. This value is the dissociation or ionization constant of water at 25 °C. Its formula is given as:

[tex]Kw = [H_{3} O^{+}][OH^{-} ][/tex]

[tex]1.0 X 10^{-14}= [H_{3}O^{+}](2.5 X 10^{-4})[/tex]

[tex][H_{3}O^{+}]= \frac{1.0X10^{-14}}{2.5 X 10^{-4}}[/tex]

[tex][H_{3}O^{+}]=4.0X10^{-9} M[/tex]

P.S: As the smallest number of significant figure in the ratio was two, so the answer contains two significant figures.

To calculate the hydronium ion concentration from the hydroxide ion concentration of 0.001 M at 25 °C, use the water ion-product constant, Kw (1.0 × 10^-14), and the inverse relationship between [H3O+] and [OH-] to find [H3O+] = 1.0 × 10^-11 M.

To calculate the hydronium ion concentration in an aqueous solution with a hydroxide ion concentration of 0.001 M at 25 °C, we use the ion-product constant for water (Kw), which is 1.0 × 10-14 at 25 °C. The concentration of hydronium ions [H3O+] and hydroxide ions [OH-] are inversely proportional, which means as the concentration of one goes up, the other goes down. Therefore, the calculation for the hydronium ion concentration can be done using the equation:

Kw = [H3O+] × [OH-]

Substituting in the values we have:

1.0 × 10-14 = [H3O+] × 0.001

Therefore, the concentration of hydronium ions [H3O+] is:

[H3O+] = ⅖{1.0 × 10-14}{0.001}

[H3O+] = 1.0 × 10-11 M

Make sure that your final answer has the correct number of significant figures, which is guided by the number of significant figures in the given hydroxide ion concentration (0.001 M has one significant figure).

Answer:

1.84 × 10³ N

Explanation:

To determine the weight of the system, we will determine its mass which is equal to the sum of the masses of the plastic tank (8 kg) and the water.

We have 0.18 m³ of water with a density of 1000 kg/m³. Its mass is:

0.18 m³ × 1000 kg/m³ = 180 kg

The mass of the system is 180 kg + 8 kg = 188 kg.

We can find the weight (w) of the system using Newton's second law of motion.

w = m × g = 188 kg × 9.81 m/s² = 1.84 × 10³ N

where

g is the gravity

The weight of the combined system, including the plastic tank and the water, is 180 kg.

The weight of an object depends on its mass and the gravitational force acting on it. To find the weight of the combined system, we need to determine the mass of the plastic tank and the water it contains. The 8-kg plastic tank does not contribute to the weight of the system, but the weight of the water can be calculated using its density.

The volume of the water is given as 0.18 m³, and the density of water is 1000 kg/m³. Multiplying these values together will give us the mass of the water:

Weight of the water = density × volume = 1000 kg/m³ × 0.18 m³ = 180 kg

Therefore, the weight of the combined system, including the plastic tank and the water, is 180 kg.

Answer:

Hi

The Fermi Level is a term used to describe the set of electron energy levels at a temperature of absolute zero. Fermi's energy concept is important for the understanding of the electrical and thermal properties of solids. Both electrical and thermal processes involve energy values of a small fraction of an electron-volt. In thermal equilibrium, the net current of both electrons and holes is zero.

Explanation:

Under equilibrium conditions, the probability of an electron state being occupied if it is located at the Fermi level is 50 percent probability.

Fermi Level is the term that is used to define the highest or most optimal energy level that an electron can occupy when the temperature is at absolute zero.

The Fermi level is equidistant between the valence band and conduction band. This is because when the temperature is at absolute zero, the electrons are all in the lowest state of energy.

Learn more about Fermi at:

https://brainly.com/question/1329027

Answer:

True

True

False

False

False

True

True

Explanation:

The recrystallization is a purification process, in which a solid with impurities is dissolved in a hot solvent. The substance must be soluble in the hot solvent, so the impurities can leave the solid crystal. Then, the solution is cold, until the crystals are formed again, thus, the substance can't be soluble in the cold solvent, because if so, the recrystallization will not happen. The crystals are then separated.

Let's check the statements:

The solvent should not dissolve the compound when cold.

As explained above, this is true.

The solvent should either dissolve the impurities at all temperatures or not dissolve the impurities at all.

The impurities must be separated from the crystal, so if the solvent dissolves it has higher, it should dissolve it when it's cold because if it didn't happen, the impurities will recrystallize too. If the solvent doesn't solubilize it when it is hot, so, the impurities crystal will be formed first, and when the solvent is cold it can dissolve it because the impurities can enter the crystal compound again. So, it's true.

The solvent should not dissolve the compound while hot.

As explained above, the solvent must dissolve the compound while hot, so it's false.

The solvent should chemically react with the compound.

If the solvent reacts with the compound, a new substance will be formed, and the purification will not happen. So, it's false.

The solvent should dissolve the compound while cold.

As explained above, the compound must be solid in the cold solvent, so it's false.

The solvent should not chemically react with the compound.

As explained above, this is true.

The solvent should dissolve the compound while hot.

As explained above, this is true.

Answer: 25.37055324733817mol

Approximately 25.371mol

Explanation: Number of moles of a substance is the mass of that substance containing the same amount of fundamental units, for instance atom in 12.0g of 12°C

Therefore:

Number of moles= mass/ molecular mass

Where mass of fluorine given= 482g

Standard Molecular mass of fluorine= 18.9984032g/mol

Substituting value in equation

Mole= 482g/18.9984032g/mol = 25.37055324733817mol

Approximately : 25.371mol

Answer:

5.3 × 10⁻³ kg

Explanation:

There is some info missing. I think this is the original question.

A chemist adds 135.0 mL of a 0.21 M zinc nitrate (Zn(NO₃)₂) solution to a reaction flask. Calculate the mass in kilograms of zinc nitrate the chemist has added to the flask. Be sure your answer has the correct number of significant digits.

We have 135.0 mL of a 0.21 M zinc nitrate (Zn(NO₃)₂) solution. The moles of zinc nitrate are:

0.1350 L × 0.21 mol/L = 2.8 × 10⁻² mol

The molar mass of zinc nitrate is 189.36 g/mol. The mass corresponding to 2.8 × 10⁻² moles is:

2.8 × 10⁻² mol × 189.36 g/mol = 5.3 g

1 kilogram is equal to 1000 grams. Then,

5.3 g × (1 kg/1000 g) = 5.3 × 10⁻³ kg

Explanation:

For a compound to show hydrogen bonding it is necessary that the hydrogen atom of the compound should be attached to more electronegative atom like fluorine, oxygen or nitrogen.

For example, [tex]CH_{3}CH_{2}OH[/tex], [tex]CH_{3}NH_{2}[/tex] and [tex]NH_{3}[/tex] all these compounds contain an electronegative atom attached to hydrogen atom.

Therefore, these pure compounds will exhibit hydrogen bonding.

Thus, we can conclude that out of the given options [tex]CH_{3}CH_{2}OH[/tex], [tex]CH_{3}NH_{2}[/tex] and [tex]NH_{3}[/tex] are the pure compounds which will exhibit hydrogen bonding.

The question is incomplete, complete question is:

371 mg of an unknown protein are dissolved in enough solvent to make  5.00 mL of solution. The osmotic pressure of this solution is measured to be 0.118 atm  at 25°C .

Calculate the molar mass of the protein. Be sure your answer has the correct number of significant digits.

Answer:

The molar mass of unknown protein is 15,384.43 g/mol.

Explanation:

To calculate the molar mass of protein, we use the equation for osmotic pressure, which is:

[tex]\pi=icRT[/tex]

where,

[tex]\pi[/tex] = osmotic pressure of the solution = 0.118 atm

i = Van't hoff factor = 1 (for non-electrolytes)

c = concentration of solute = ?

R = Gas constant = [tex]0.0820\text{ L atm }mol^{-1}K^{-1}[/tex]

T = temperature of the solution = [tex]25^oC=[273+25]=298K[/tex]

Putting values in above equation, we get:

[tex]0.118 atm=1\times c\times 0.0821\text{ L.atm}mol^{-1}K^{-1}\times 298 K\\\\c=0.004823 mol/L[/tex]

[tex]concentration=\frac{Moles}{Volume (L)}[/tex]

[tex]0.004823 mol/L=\frac{n}{0.005 L}[/tex]

[tex]n=2.4115\times 10^{-5} mol[/tex]

To calculate the molecular mass of solute, we use the equation:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]

Moles of solute = [tex]2.4115\times 10^{-5} mol[/tex]

Given mass of solute = 371 mg = 0.371 g ( 1mg = 0.001 g)

Putting values in above equation, we get:

[tex]2.4115\times 10^{-5} mol=\frac{0.371 g}{\text{Molar mass of solute}}\\\\\text{Molar mass of solute}=15,384.43 g/mol[/tex]

Hence, the molar mass of unknown protein is 15,384.43 g/mol.

Answer:

11,547.67 meters of copper can be drawn.

Explanation:

Mass of mineral = 6.95 lb = 6.95 × 453.592 = 3,152.46 g

1 lbs = 453.592 g

An ore of copper is 66.0% copper by mass, So mas of copper in  3,152.46 grams of ore= m

[tex]m = \frac{66.0}{100}\times 3,152.46 g=2080.63 g[/tex]

Volume of copper = V

Density of copper = d = [tex]8.95 /cm^3[/tex]

[tex]V=\frac{m}{d}=\frac{2080.63 g}{8.95 /cm^3}=232.47 cm^3[/tex]

Diameter of the wire drawn from the [tex]232.47 cm^3[/tex] of copper= d

d = [tex]6.304\times 10^{-3} inch=6.304\times 10^{-3}\times 2.54 cm=0.01601 cm[/tex]

(1 inch= 2.54 cm)

Radius of the wire= r = 0.5 ×  d =0.5 × 0.01601 =0.008005 cm

Length of the wire = h

Volume of the cylindrical wire = [tex]\pi r^2 h[/tex]

[tex]V=\pi r^2 h[/tex]

[tex]232.47 cm^3=3.14\times (0.008005 cm)^2\times h[/tex]

Solving for h :

h =1,154,767.015 cm

1 cm = 0.01 m

h = 1,154,767.015 cm = 1,154,767.015× 0.01 m = 11,547.67 m

11,547.67 meters of copper can be drawn.

Answer:

Oxygen       35.6 percent

Carbon        60 percent

Hydrogen    4.4 percent

Explanation:

Molecular mass of aspirin[tex](C_9H_8O_4)=180 gm/mol.[/tex]

Mass of carbon in 180 gm of aspirine[tex]=12\times 9=108\ gm.[/tex]

Therefore, percentage of carbon in aspirin is [tex]=\dfrac{108}{180}\times 100=60\ percent.[/tex]

Similarly, mass of hydrogen in 8 gm of aspirine[tex]=1\times 8=8\ gm[/tex].

Hydrogen's percentage in aspirin[tex]=\dfrac{8}{180}\times 100=4.4\ percent.[/tex]

Also, mass of oxygen in aspirin is [tex]=16\times 4=64\ gm.[/tex]

Oxygen's percentage in aspirin[tex]=\dfrac{64}{180}\times 100=35.6\ percent.[/tex]

Hence, this is the required solution.

Final answer:

The percent composition of aspirin (C9H8O4) is calculated based on its molecular mass of 180.15 amu. It is 60.03% carbon, 4.48% hydrogen, and 35.49% oxygen.

Explanation:

To determine the percent composition of aspirin, which has the molecular formula C9H8O4, we need to calculate the percentage of each element in the compound based on its molecular mass. The molecular mass of aspirin is 180.15 amu. This is calculated by adding the masses of nine carbon (C) atoms, eight hydrogen (H) atoms, and four oxygen (O) atoms together.

To find the percent composition, we first calculate the total mass of each type of atom in one molecule of aspirin and then divide it by the molecular mass of aspirin. To express it as a percentage, we multiply by 100%. The atomic masses are approximately 12.01 amu for carbon, 1.008 amu for hydrogen, and 16.00 amu for oxygen.

The calculations for percent composition are as follows:

Therefore, the percent composition of aspirin (C9H8O4) is 60.03% carbon, 4.48% hydrogen, and 35.49% oxygen.

Answer:

0.08 mL

Explanation:

The solution of the skin test has a concentration of 0.2% (w/v), which means that there are 0.2 g of the antigen per 100 mL of the solution. If a new solution will be done using it, then this solution will be diluted, and the mass of the antigen added must be the same in the volume taken and at the diluted solution.

The mass is the concentration (in g/mL) multiplied by the volume of the solution (in mL), so, if m is the mass, C the concentration, V the volume, 1 the initial solution, and 2 the diluted:

m1 = m2

C1*V1 = C2*V2

Where

C1 = 0.2 g/100 mL = 0.002 g/mL

V1 = ?

C2 = 0.04 mg/mL = 0.00004 g/mL

V2 = 4 mL

0.002*V1 = 0.00004*4

V1 = 0.08 mL

Considering the definition of dilution, 0.08 mL of a 0.2% solution of a skin test antigen must be used to prepare 4 mL of a solution containing 0.04 mg/mL of the antigen.

First of all, you have to know that when it is desired to prepare a less concentrated solution from a more concentrated one, it is called dilution.

Dilution is the process of reducing the concentration of solute in solution, which is accomplished by simply adding more solvent to the solution at the same amount of solute.

In a dilution the amount of solute does not change, but as more solvent is added, the concentration of the solute decreases, as the volume (and weight) of the solution increases.

A dilution is mathematically expressed as:

Ci×Vi = Cf×Vf

where

In this case, you know:

Replacing in the definition of dilution:

0.002 [tex]\frac{g}{mL}[/tex] × Vi= 0.00004 [tex]\frac{g}{mL}[/tex]× 4 mL

Solving:

[tex]Vi=\frac{0.00004 \frac{g}{mL}x4 mL}{0.002\frac{g}{mL} }[/tex]

Vi= 0.08 mL

In summary, 0.08 mL of a 0.2% solution of a skin test antigen must be used to prepare 4 mL of a solution containing 0.04 mg/mL of the antigen.

Learn more about dilution:

Answer:

Brønsted-Lowry acid : H2SO4, HF, HNO2

Brønsted-Lowry Base : NH3, C3H7NH2, CH3)3N

Neither : NaBr, CCl4

Explanation:

H2SO4, HNO2, and HF are Brønsted-Lowry acids. (CH3)3N, C3H7NH2, and NH3 are Brønsted-Lowry bases. NaBr and CCl4 are neither.

In the Brønsted-Lowry definition, an acid is a substance that can donate a proton (H+) and a base is a substance that can accept a proton. Looking at your list:

 NaBr and CCl4 are neither Brønsted-Lowry acids nor bases since they do not participate in proton donation or acceptance.  

https://brainly.com/question/22821256

#SPJ6

The mass of HCl that is contained in the solution is 147 g HCl

Why?

To find the mass of HCl we have to apply what is called a conversion factor. In a conversion factor we put the units we don't want at the bottom, and the ones we want at the top.

For this question, we want to go from liters of solution to mass of HCl, and the conversion factor is laid out as follows:

[tex]0.356Lsolution*\frac{1000mL}{1L}*\frac{1.19 g solution}{1 mL solution}*\frac{34.70 g HCl}{100 g solution}=147 g HCl[/tex]

Have a nice day!

#LearnwithBrainly

Explanation:

It is known that 1 SCF produces approximately 1000 Btu of thermal energy.

As it is not mentioned for how many hours the gas is used in this process. Therefore, we assume that the total number of hours natural gas used in this process are as follows.

        [tex]365 \times 24[/tex] = 8760 hours

Now, we will calculate the annual cost of natural gas used in the process as follows.

               [tex]8760 \times 63400[/tex]

              = 555384000 SCF

Hence, annual cost of natural gas used in this process = loss of thermal energy

This will be equal to,  [tex]555384000 \times 1000[/tex]

                           = 555,384,000,000 BTU

Thus, we can conclude that the annual cost of natural gas used in the process is 555,384,000,000 BTU.

To calculate the annual cost of natural gas used in the process, multiply the hourly usage by the number of hours in a year and the cost per SCF. The total gives you an approximate annual expenditure.

The exact annual cost of natural gas usage of the said process will depend on the current cost per SCF (standard cubic foot) of natural gas, which can fluctuate throughout the year based on economic conditions and demand. If you know the cost per SCF, you can calculate the annual cost by multiplying the hourly usage (63,400 SCF/h) by the number of hours in a year (8,760 hours), then multiply that result by the cost per SCF.

For instance, if natural gas cost $0.01 per SCF, your annual cost would be 63,400 SCF/hr * 8,760 hours * $0.01/SCF. This would give you an approximate annual expense for natural gas used in the process. However, it's prudent to cross-check this number with those in your bills and other related documents whenever practical.

https://brainly.com/question/34895359

#SPJ12