These are four questons and four answers:
Answers:
1) 7⁺2) 1⁻3) 3⁺4) 5⁺Explanation:
Question 1) Cl₂O₇:
a) Net charge of the compound: 0
b) Rule: oxygen works with oxidation state +2, except with peroxides.
d) Rule: balance of charges: ∑ of the charges = net charge
Call X the oxidation number of Cl:
2×X + 7 (-2) = 02X - 14 = 02X = +14X = +14 /2 = + 7Conclusion: the oxidation number of Cl in Cl₂O₇ is 7⁺.
Question 2) AlCl₄⁻
a) Net charge of the ion: - 1
b) Rule: common oxidation number of Al in compounds: +3
c) Rule: balance of charges: ∑ charges = net charge = - 1
1 (+3) + 4X = - 1+3 + 4X = - 14X = - 1 - 34X = - 4X = - 1Conclusion: the oxidation number of Cl in AlCl₄⁻ is 1 ⁻.
Question 3) Ba(ClO₂)₂
a) Net charge of the compound: 0
b) Rule: common oxidation number of BA in compounds: +2
c) Rule: common oxidation number of O in compounds (except in peroxides): -2
d) Rule: balance of charges: ∑ charges = net charge = 0
+2 + 2X + 4 (-2) = 02X +2 - 8 = 02X - 6 = 02X = +6X = + 3Conclusion: the oxidation number of Cl in Ba(ClO₂)₂ is 3⁺.
Question 4) CIF₄⁺
a) Net charge of the ion: + 1
b) Rule: common oxidation number of F : - 1 (it is the most electronegative)
c) Rule: balance of charges: ∑ charges = net charge = + 1
X + 4(-1) = +1X - 4 = +1X = +1 + 4X = + 5Conclusion: the oxidation number of Cl in ClF₄⁺ is 5⁺.
If 200 mL of water is evaporated from 400 mL of 0.5 M aqueous salt solution, what is the resulting concentration? 1. 2.5 × 10−1 M 2. 2.5 × 101 M 3. 2.5 × 100 M 4. 2.5 × 10−2 M 5. None of these
Answer:
None of these
Explanation:
Using the dilution formula;
M1V1 = M2V2
where M1 is the initial concentration, V1 is the initial volume, M2 is the concentration attained while V2 is the new volume.
Therefore;
M2 = M1V1/V2
= (400 mL × 0.5) / 200 mL
= 1 M
Therefore, the resulting concentration is 1M
Thus, the correct answer is "none of these"
If 200 mL of water is evaporated from 400 mL of 0.5 M aqueous salt solution, the resulting concentration is 1.0 M.
What is evaporation?Evaporation is a type of vaporization that occurs on the surface of a liquid as it changes into the gas phase.
A 400 mL solution has a concentration of 0.5 M. After 200 mL of water evaporate, 200 mL of solution remain. We can calculate the final concentration using the following expression.
C1 . V1 = C2 . V2
C2 = C1 . V1 / V2
C2 = 0.5 M . 400 mL / 200 mL = 1.0 M
where,
C1 and V1 are the initial concentration and volume.C2 and V2 are the final concentration and volume.If 200 mL of water is evaporated from 400 mL of 0.5 M aqueous salt solution, the resulting concentration is 1.0 M.
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How many moles of NH3 DOES it take to make 8.0 moles of H2O according to the reaction shown, 4NH3 + 5O2 yields 4NO + 6H2O A)8.0 mol B) 3.5 mol C) 12.0 mol D) 5.3 mol
Answer:
The answer is 5.3 because when looking at the moles produced from the coefficient from the balanced equation all you have to do is make the 6 on the left equal 8. IN order to do that you multiply by 1 and 1/3, then do that to the number 4 to get 5.3
Explanation:
Which solution will change red litmus to blue?
A: NaCl
B: CH3COOH
C: KOH
D: HCl
Identify which one is the oxidizing agent in this reaction:
2 KNO3 (s) → 2 KNO2 (s) + O2 (g)
Show ALL work.
Answer:
Nitrogen atom
Explanation:
Oxidation and reduction in a equation can be shown using oxidation numbers.Oxidation number of Oxygen in KNO3 is -2 while in O2 is 0; this indicates reduction.Oxidation number of Nitrogen (N) in KNO3 is + 5, while in KNO2 is +3 , this indicates oxidation.Hence;
Nitrogen has undergone reduction while oxygen has undergone oxidation and therefore, nitrogen is the oxidizing agent and oxygen is the reducing agent.
iodine sublimes by turning from a solid to a vapor when heated. a 100g sample of solid i2 is put in an empty rigid 10 l container and heated to 325k. when al the solid i2 vaporizes what is the pressure(in atm) in the container
Answer:
[tex]\boxed{\text{1.05 atm}}[/tex]
Explanation:
We can use the Ideal Gas Law to calculate the pressure.
pV = nRT Divide both sides by V
p = (nRT)/V
p = (m/M)(RT/V) = (mRT)/(MV)
Data:
m = 100 g
R = 0.082 06 L·atm·K⁻¹mol⁻¹
T = 325 K
M = 253.81 g·mol⁻¹
V = 10 L
Calculations:
p = (100 × 0.082 06× 325)/(253.81 × 10) = 1.05 atm
The pressure in the container is [tex]\boxed{\text{1.05 atm}}[/tex].
When production first began some eighty years ago, ammonia production relied upon the direct reaction between gaseous hydrogen and nitrogen called the Haber process: 3 H2(g) + N2(g) ⇀↽ 2 NH3(g) ∆H = −92.2 kJ Decreasing the temperature of an equilibrated reaction between hydrogen and nitrogen will 1. increase the velocity of the gas molecules. 2. produce more ammonia. 3. increase the kinetic energy of the gas molecules. 4. produce less ammonia. 5. have no effect.
Answer:
Option 2. Produce more ammonia.Explanation:
The influence of temperature in equilibrium reactions can be predicted from the heat (enthalpy) information.
This is the chemical reaction:
3 H₂ (g) + N₂(g) ⇄ 2 NH₃(g) ∆H = −92.2 kJThe information about the enthalpy of the reaction, ∆H = − 92.2 kJ, indicates that energy (heat) has been released to the surroundings (the products of the forward reaction have less energy than the reactants), which is defined as an exothermic reaction.
Then, you can rewrite the equaition in the form:
3 H₂ (g) + N₂(g) ⇄ 2 NH₃(g) + 92.2 kJThis is, the heat can be seen as a product of the direct reaction (or a reactant of the reverse reaction).
Now, it is quite straight to apply Le Chatelier's principle:
a) Decreasing temperature is equivalent to extract heat or having less heat on the left side.
b) Then, the equilibrium must shift in a way that this lack of heat is compensated. Then, the reaction will shift to the right to produce more heat.
As conclusion, you can tell that in exothermic reactions, a decrase in temperature will cause the equilibrium to shift to the right.
This shift, of course, means the production of more ammonia.
The other choices are discarded following this brief reasoning:
1. increase the velocity of the gas molecules: the average velocity of the particles increases when the average kinetic energy increases, and the average kinetic energy will decrease if the temperature decreases. So, this statement is false.
3. increase the kinetic energy of the gas molecules: no, the average kinetic energy is proportional to the temperature, then reducing the temperature decreasese the average kinetic energy.
4. produce less ammonia: it was shown that reducing the temperature will produce more ammonia.
5. have no effect: no, it does have effect, as shown.
In the Haber process of ammonia production, when the reaction temperature is decreased, more ammonia is produced due to the exothermic nature of the reaction following Le Chatelier's Principle. The velocity and kinetic energy of the gas molecules decrease. Real-world ammonia production also accounts for pressure and catalyst factors.
Explanation:The reaction of nitrogen and hydrogen to form ammonia, otherwise known as the Haber process, is an exothermic process, meaning it releases heat. As per Le Chatelier's principle, lowering the temperature of an exothermic reaction at equilibrium favors the production of more products. Therefore, decreasing the temperature of the hydrogen and nitrogen reaction will produce more ammonia (option 2).
Simultaneously, as we decrease the temperature, the average kinetic energy of the gas molecules decreases and, hence, the speed of the gas molecules also decreases. Therefore, the statement that decreasing the temperature will increase the velocity of the gas molecules (option 1) and increase the kinetic energy of the gas molecules (option 3) are incorrect. The option that decreasing the temperature will have no effect (option 5) is also incorrect in this scenario.
In real-world applications, the production of ammonia via the Haber process is influenced by pressure and temperature changes, and also by the usage of a catalyst to overcome the reaction's slow rate at lower temperatures.
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Can someone explain what each of the answer choices will do to the equilibrium? Shiftwise?
Answer:
[tex]\boxed{\text{(B)}}[/tex]
Explanation:
CaF₂(s) ⇌ Ca²⁺(aq) + F⁻(aq); ΔH > 0
According to Le Châtelier's Principle, when a stress is applied to a system at equilibrium, the system will respond in a way that tends to relieve the stress.
Let's consider each of the stresses in turn.
(A) Evaporating some of the water
The concentrations of the ions will increase, so calcium fluoride will precipitate out to remove the stress (the Ca²⁺ and F⁻ ions). The position of equilibrium does not shift, and [Ca²⁺] stays the same.
(B) Adding HNO₃
HF is a weak acid, so F⁻ is a relatively strong base. The added HNO₃ will convert the F⁻ ions to HF, removing them from solution. More CaF₂ will dissolve to replace the F⁻ ions, and this will add more Ca²⁺ ions as well. The position of equilibrium will shift to the right, and [Ca²⁺] will increase.
(C) Adding NaNO₃(aq)
There is no common ion, so NaNO₃ will have no effect. The added water will dilute the solution and decrease the concentrations of the ions. However, more CaF₂ will dissolve to increase the concentrations. The position of equilibrium does not shift, and [Ca²⁺] stays the same.
(D) Adding NaF
This is the common ion effect. F⁻ is the common ion. The added NaF will dissolve, increasing the concentration of F⁻ ions. More CaF₂ will precipitate to remove the added F⁻ ions, but it removes Ca²⁺ ions at the same time. The position of equilibrium shifts to the left, and [Ca²⁺] decreases.
Which description correctly characterizes the acidity or basicity of a solution? The higher the pH is, the more the hydroxide ion concentration decreases and the more acidic the solution becomes. The higher the pH is, the more the hydroxide ion concentration increases and the more basic the solution becomes. The lower the pH is, the more the hydronium ion concentration decreases and the more acidic the solution becomes. The lower the pH is, the more the hydronium ion concentration increases and the more basic the solution becomes.
Answer:
The higher the pH is, the more the hydroxide ion concentration increases and the more basic the solution becomes.
Explanation:
When the pH of a solution is less than 7, then solution is called acidic and as the pH decreases the concentration of Hydronium ion increases.When the pH is about 7, then the solution is said to be neutral. On the other hand, when the pH is greater than 7, the solution is is said to be basic and as the pH increases the concentration of Hydroxide ions increases.Therefore, An acidic solution has a higher concentration of hydrogen ions compared to the concentration of hydroxide ions.Answer:
B
Explanation:
Assign oxidation numbers for the following:
P2O5
(SO4)2-
KClO3
NH4Cl
(NH4)2S
Show all the steps, please.
Answer:
1. P₂O₅ → oxidation number of phosphorous is +5 and Oxygen is -2.
2. (SO₄)²⁻ → oxidation number of sulfur is +6 and Oxygen is -2.
3. KClO₃ → oxidation number of Potassium is +1, Chlorine is +5, and Oxygen is -2.
4. NH₄Cl → oxidation number of Nitrogen is -3, Hydrogen is +1, and Chlorine is -1
5. (NH₄)₂S → oxidation number of Nitrogen is -3, Hydrogen is +1, and Sulfur is -2
Explanation:
General Rules for assigning oxidation numbers
The oxidation number of a free element is always 0.
The oxidation number of a mono-atomic ion equals the charge of the ion.
The alkali metals (group I) always have an oxidation number of +1.
The alkaline earth metals (group II) are always assigned an oxidation number of +2.
Oxygen almost always has an oxidation number of -2, except in peroxides (H₂O₂) where it is -1 and in compounds with fluorine (OF₂) where it is +2.
Hydrogen has an oxidation number of +1 when combined with non-metals, but it has an oxidation number of -1 when combined with metals.
The algebraic sum of the oxidation numbers of elements in a compound is zero.
The algebraic sum of the oxidation states in an ion is equal to the charge on the ion.
Using the above rules:
1. P₂O₅
∵ it is a neutral compound its total charge is 0.
Also, we know that oxygen has an oxidation number of -2.
Let oxidation number of P be x
∴ 2(x)+5(-2)=0 → 2x=+10 → x=+5
∴oxidation number of phosphorous is +5.
2. SO₄²⁻:
∵ it is a charged ion its total charge is -2.
Also, we know that oxygen has an oxidation number of -2.
Let oxidation number of S be x
∴ (x)+4(-2)= -2 → x=+6
∴oxidation number of sulfur is +6.
3. KClO₃:
∵ it is a neutral compound its total charge is 0.
Also, we know that oxygen has an oxidation number of -2 and the oxidation number of K (group I) is +1
Let oxidation number of Cl be x
∴ (+1) + (x) + 3(-2) = 0 → x=+5
∴oxidation number of Chlorine is +5.
4. NH₄Cl:
∵ it is a neutral compound its total charge is 0.
Also, we know that chloride has an oxidation number of -1
Hydrogen has an oxidation number of +1 when combined with non-metals
Let oxidation number of N be x
∴ (x) + 4(+1) + (-1) = 0 → x=-3
∴oxidation number of Nitrogen is -3.
5. (NH₄)₂S:
∵ it is a neutral compound its total charge is 0.
Also, we know that chloride has an oxidation number of -1
Ammonium ion (NH₄⁺) has an oxidation number of +1
Let oxidation number of N be x
∴ 2(+1) + (x) = 0 → x= -2
∴oxidation number of sulfur is -2.
If a solid line represents a covalent bond and a dotted line represents intermolecular attraction, which of these choices shows a hydrogen bond? check all that apply
Answer:
the dotted line showing the intermolecular attraction
Explanation:
Which type of reaction happens when a base is mixed with an acid
nutrition reaction or saline reaction because these reactions generate salts , such as:
HCl + NaOH==>NaCl + H2O
Rutherford created a planetary model for atoms after his experiments. Imagine if Rutherford's idea that electrons radiate energy while orbiting around a nucleus was true. Which other model or scientific idea would have been strengthened by this? Bohr's model of the atom would have been strengthened because Bohr proposed that the energy of electrons is continuous. Bohr's model of the atom would have been strengthened because Bohr proposed that electrons can have only certain energy values. The idea that atoms are unstable would have been strengthened because the orbiting electron would lose energy and fall into the nucleus. The idea that atoms are unstable would be strengthened because the orbiting electron would absorb energy while moving and escape the pull from the nucleus.
The idea that atoms are unstable would have been strengthened because the orbiting electron would lose energy and fall into the nucleus.
Answer:
The idea that atoms are unstable would have been strengthened because the orbiting electron would lose energy and fall into the nucleus.
Explanation:
Based on classical mechanics an electron would spiral and fall on the nucleus thus collapsing the atom. But it was quantum mechanics that proposed that electrons move in definite orbits around the nucleus. Electrons absorb a definite quantum of energy and move from a lower state to an excited state. Also electrons release a definite quantum of energy and move from excited to more stable state.
How many moles of helium are 8.84×1024 atoms of He?
Answer:
14.68 moles of He
Explanation:
To do this, just remember Avogadro's Constant or Avogadro's number. This constant tells us how many units ( in this case atoms) there are in a mole of ANY type of substance.
Avogadro's constant is 6.022140857 × 10²³ units per mole.
Now that we know how many atoms there are in 1 mole, we can use this as our conversion factor.
8.84 x 10²⁴ atoms of He → moles of He
[tex]8.84\times10^{24} atoms of He\times\dfrac{1moleofHe}{6.022140857\times10^{23}atomsofHe}=14.68molesofHe[/tex]
So the answer would be:
14.68 moles of He
What is the molarity of a solution prepared by mixing 12.5 G of FeCl3 in enough water to make 300 mL of solution?
Answer:0.256 M
Explanation: Molarity (M)= (mass/molar mass)(1000/Volume in mL)
M= 12.5x1000/162.2x300=0.256 M
The molarity of the FeCl₃ solution, convert the mass of FeCl₃ to moles, convert the solution volume to liters, and then divide the moles by the volume. The molarity of the FeCl₃ solution is 0.257 M.
The molarity of a solution is calculated by dividing the number of moles of the solute by the volume of the solution in liters. First, we need to convert the mass of FeCl₃ to moles by using its molar mass. Once we have the moles, we can divide by the volume of the solution in liters to find the molarity.
Steps to Calculate Molarity:
Calculate the molar mass of FeCl₃: (55.845 g/mol Fe) + (3 times 35.453 g/mol Cl) = 162.204 g/mol.
Convert the mass of FeCl₃ to moles: 12.5 g \/ 162.204 g/mol = 0.07710 moles.
Convert the volume of the solution to liters: 300 mL = 0.300 L.
Divide the moles of solute by the volume of the solution in liters to find the molarity: 0.07710 moles \/ 0.300 L = 0.257 M.
Therefore, the molarity of the FeCl₃ solution is 0.257 M.
which of the following bases could you write an equilibrium expression for?
A)NaOH
B)KOH
C)NH3
D)Ba(OH)2
D. I hope you have a good morning
- Josie Annette
More gas will dissolve in a liquid if you:
a. increase the size of the container opening
b. use a glass container rather than a metal container
c. decrease the pressure over the liquid
d. raise the temperature of the liquid
e. lower the temperature of the liquid
its c take the pressure away
The study of chemicals and bonds is called chemistry. There are different types of elements and these are metals and nonmetals.
The correct answer is option C which decreases the pressure over the liquid.
What is solubility?The mixing of solute in the solvent is called solubility.
Solubility of solute depends on these factors and these are:-
PressureTemperatureAccording to the question, solubility increases when the pressure in liquid decreases.
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Which is the best description of hydrogen bonding? Which is the best description of hydrogen bonding? the association between a hydrogen atom which is somewhat positive because it is bonded to a small electronegative atom and an atom of O, N or F on another molecule the association between hydrogen of one molecule and a region of another molecule which has become negative due to temporary shifts in electron density the unique chemical bonds between hydrogen and any other atom in the same molecule the temporary attraction between hydrogen atoms on different molecules resulting from shifts in electron density the polarity associated with a bond between hydrogen and a small electronegative atom to which it is bonded
Answer:
The best description of hydrogen bonding is the association between a hydrogen atom which is somewhat positive because it is bonded to a small electronegative atom and an atom of O, N or F on another molecule. (this is the first choice)Explanation:
Hydrogen bonding is a special type of intermolecular force due to dipole - dipole atraction.
In order to the hydrogen bonding can be formed, the hydrogen atom in a molecule must be covalently bonded to an atom of oxygen (O), nitrogen (N), or fluor (F).
The most common example of hydrogen bonding is that of water molecules (H₂0).
Due to the relatively high electronegativity difference between hydrogen (H) and oxygen (O) atoms, each H will bear a high partial positive charge (δ+) and each O will have a high partial negative charge (δ-). Thus, the negative end of each H₂O molecule will be attracted to the negative part of other (neighbor) H₂O molecule. This attraction is the hydrogen bonding and is responsible for many important special properties of water.
Hydrogen bonding is the association between a weakly positive hydrogen atom already bonded to one electronegative atom and an atom of O, N or F on another molecule. It is a weak interaction that occurs due to the attraction between opposite partial charges.
Explanation:The best description of hydrogen bonding is the association between a hydrogen atom which is somewhat positive because it is bonded to a small electronegative atom and an atom of O, N or F on another molecule. This occurs when a weakly positive hydrogen atom already bonded to one electronegative atom is attracted to another electronegative atom from another molecule. Hydrogen bonding is a weak interaction, but it plays a significant role in many chemical and biological processes.
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Drag each tile to the correct location on the image.
Use the periodic table to write the electron configuration of selenium (Se).
s
p
d
1
2
3
4
6
10
Answer:
[Ar] 3d10 4s2 4p4
Explanation:
Answer: The electronic configuration of selenium is [tex][Ar]4s^23d^{10}4p^4[/tex]
Explanation:
Electronic configuration is the representation of electrons that are present in an element.
Selenium is the element which is present in Group 16 and has an atomic number of 34.
Atomic number is defined as the number of protons or number of electrons present in an atom.
The number of electrons present in this element is 34.
So, the electronic configuration of selenium = [tex]Se:[Ar]4s^23d^{10}4p^4[/tex]
The first law of thermodynamics is a restatement of the
the law of thermodyanamic is the restatement of the law of conservation of energy
in which of the following cases will there be precipitation
A)QB)Q=Ksp
C)Q<D)Q>Ksp
Answer:
I think D
Explanation:
Q > Ksp, there are more ions in solution than are necessary for saturation. This is a supersaturated solution (i.e There is a tendency for the extra solute to precipitate).
how does photosynthesis in the biosphere impact the atmosphere
Answer:The biosphere is all life on our planet. ... The impact on climate is mainly due to the connection between the biosphere and the atmosphere. Processes such as photosynthesis and respiration naturally affect the concentrations of gases such as oxygen and carbon dioxide in the atmosphere.
Explanation:
In photosynthesis, plants constantly absorb and release atmospheric gases in a way that creates sugar for food. Carbon dioxide goes in the plant's cells; oxygen comes out. Without sunlight and plants, the Earth would become an inhospitable place unable to support air-breathing animals and people.
What is the wavelength of light that has a frequency of 2.85 x 10^14 Hz [c=3.00 x 10^8]
Answer:
1.05 x 10^-6
Explanation:
Lambda = c / f
f if frequency
c is intensity of light
lambda = 3 x 10^8 / 2.85 x 10^14
= 1.05 x 10 ^-6
Fluorine-18, which has a half-life of 110 min, is used in PET scans.
a. If 100. mg of fluorine-18 is shipped at 8:00 a.m., how many milligrams of the radioisotope are still active after 110 min?
b. If 100. mg of fluorine-18 is shipped at 8:00 a.m., how many milligrams of the radioisotope are still active when the sample arrives at the radiology laboratory at 1:30 p.m.?
Answer:
Part a. 50.0 mgPart b. 12.5 mgExplanation:
For every hal-life time the amount of the radioisotope (fluorine-18) will be cut to half.
Part a.
Since the half-life of fluorine-18 is 110 min, ater this very time, half of the fluorine-18 is still alive, i.e 100. mg / 2 = 50.0 mg. ← answer
Part b.
Compute the time elapsed from 8:00 am, when the fluorine-18 is shipped, to 1:30 pm, when the sample arrives at teh radiology laboratory.
1:30 pm - 8:00 am = 5 hours and 30 minutesConvert to minutes+ 5×60 + 30 = 330 minCompute the number of half-lives in 330 min:
330 min / 110 min per half-life = 3 half-lives.Conclusion:
the radiosotope has been reduced to half 3 times 100.0 mg × (1/2) × (1/2) × (1/2) = 100.0 mg × (1/2)³ = 100.0 mg / 8 = 12.5 mgHence, 12.5 mg of the radioisotope are still alive ← answerAfter one half-life of 110 minutes, 50mg of the 100mg of Fluorine-18 would remain. After the time interval of 5 hours and 30 minutes or 330 minutes, which constitutes three half-lives, the remaining active Fluorine-18 would be 12.5mg.
Explanation:In the case of Fluorine-18, the half-life is 110 minutes. This essentially means that half of the original amount of the radioisotope will decay and become inactive in 110 minutes.
a. If 100mg of Fluorine-18 is shipped at 8:00 a.m., after 110 minutes (or 1 hour and 50 minutes), at 9:50 a.m., half of the original amount, 50mg, will still be active.
b. If 100mg of Fluorine-18 is shipped at 8:00 a.m., and it arrives at the radiology laboratory at 1:30 p.m., this is 5 hours and 30 minutes, or 330 minutes later. As the half-life is 110 minutes, this period encompasses three half-lives (330/110). Starting with 100mg, after one half-life it would be 50mg, after the next it would be halved to 25mg, and after the third it would be 12.5mg remaining active.
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Why are emission spectra referred to as the fingerprints of the elements?
They are referred to as the finger prints of the element because they show the particular properties of the elements which differentiates one element from other elements
The emission spectrum or emission spectra is characteristic for each element as it provides information which is unique to each element.
What is emission spectrum?
Emission spectrum is defined as a spectrum of a chemical compound or substance composed of frequencies of electromagnetic radiation. Radiations which are emitted while electron make transition from higher to lower energy level.
Energy of photon is equal to the difference between the two energy states . There are many possible electronic transitions in an atom and every transition has a specific wavelength.
Collection of different transitions with respect to different wavelengths makes up an emission spectrum.Emission spectrum of each element is unique and therefore spectroscopy is used to identify elements which are present in different substances.
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What is emitted during gamma emission?
Electrons
Light
Alpha particles
Beta particles
Answer:c
Explanation:
Answer
Light
Explanation:
The gamma emission is an electromagnetic radiation, this kind of radiation come from the light.
In gamma ray emission, a gamma ray is photon of light. Given that light does not have mass or charge, the symbol we use to identify it is: 00γ. With two zeroes.
hope i helped
-lvr
How do atoms achieve noble-gas electron configurations in single covalent bonds?
Answer:
Noble gases are the only type of element that are chemically inert, that is, they do not normally undergo chemical reactions with other elements under normal circumstances, this is because they are chemically stable. Their stability is as a result of the eight valence electrons that they have in their outermost shells.
Other elements usually try to attain the stability found in noble gases by undergoing chemical reactions and by forming different types of bonds with other elements. One of the chemical bonds that are usually formed is covalent bond. In simple covalent bond, two elements usually donate one electron each, the two electrons donated are then shared equally by the two of them in order to ensure that each one has eight electrons in its outermost shell.
Atoms achieve noble-gas electron configurations in single covalent bonds through the sharing of electrons between atoms.
Explanation:Atoms achieve noble-gas electron configurations in single covalent bonds through the sharing of electrons between atoms.
In a covalent bond, electrons are shared between atoms, and generally, each atom contributes one or more electrons to the bond. The shared electrons are attracted by the nuclei of both atoms, resulting in a stable electron configuration.
For example, in a double covalent bond between two oxygen atoms (O=O), each oxygen atom contributes two electrons, resulting in a shared configuration that resembles the noble gas, neon.
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Words to equation and balancing
Answer:
Pb(NO₃)₂ ₍aq₎ + 2 KI ₍aq₎ ------------> PbI₂ ₍s₎ + 2 KNO₃ ₍aq₎
Explanation:
Chemical Equation:
lead(II) nitrate: Pb(NO₃)₂
potassium iodide: KI
lead(II) iodide: PbI₂
Potassium nitrate: KNO₃
Pb(NO₃)₂ ₍aq₎ + KI ₍aq₎ ------------> PbI₂ ₍s₎ + KNO₃ ₍aq₎
Balancing the equation:
For balancing the equation all atoms of the elements on both sides of equation i.e reactants and products are equal.
So balancing the above equation we get:
Pb(NO₃)₂ ₍aq₎ + 2 KI ₍aq₎ ------------> PbI₂ ₍s₎ + 2 KNO₃ ₍aq₎
What would be the composition and ph of an ideal buffer prepared from lactic acid (ch3chohco2h), where the hydrogen atom highlighted in boldface is the acidic hydrogen atom? the ka value for lactic acid is 1.38 ?? 10???4.\?
c= 1.4 X [tex]10^-^4[/tex] is the composition and ph of an ideal buffer prepared from lactic acid ([tex]CH_3CHOHCO_2H[/tex]), where the hydrogen atom highlighted in boldface is the acidic hydrogen atom.
What is a buffer solution?A buffer is a solution that can resist pH change upon the addition of an acidic or basic components.
Equilibrium equation
[tex]C_3H_6O_3[/tex] ⇄[tex]C_3H_5O_3^-[/tex] +[tex]H^+[/tex]
Assuming a degree of dissociation [tex]\alpha[/tex] =[tex]\frac{1}{10}[/tex]
And the initial concentration of [tex]C_3H_6O_3[/tex] =c
At equlibrium ;
Concentration of [tex]C_3H_6O_3[/tex] = [tex]c - c\alpha[/tex]
[tex]C_3H_5O_3^-[/tex] = [tex]c\alpha[/tex]
[[tex]H^+[/tex]] = [tex]c\alpha[/tex]
[tex]Ka =\frac{c\alpha X c\alpha }{c-c\alpha }[/tex]
[tex]\alpha[/tex] is very small so 1-[tex]\alpha[/tex] can be neglected and the equation is;
[tex]Ka = c\alpha X \alpha[/tex]
[H^+] = [tex]c\alpha[/tex] =[tex]\frac{k\alpha }{\alpha }[/tex]
pH = -log [[tex]H^+[/tex]]
pH = -log[tex]Ka[/tex] +log [tex]\alpha[/tex]
[tex]Ka[/tex] = 1.38 X [tex]10^{-4}[/tex]
[tex]\alpha[/tex] = [tex]\frac{1}{10}[/tex]
pH = 3.86 -1
pH =2.86
Composition ;
C=[tex]\frac{1}{\alpha }[/tex] X [tex][H^+][/tex]
[tex][H^+][/tex] =0.0014
c= 0.0014 X [tex]\frac{1}{10}[/tex]
c= 1.4 X [tex]10^-^4[/tex]
Hence, c= 1.4 X [tex]10^-^4[/tex] is the composition and ph of an ideal buffer prepared from lactic acid ([tex]CH_3CHOHCO_2H[/tex]), where the hydrogen atom highlighted in boldface is the acidic hydrogen atom.
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An ideal buffer composed of lactic acid involves a mixture of lactic acid and its conjugate base, usually in equal molar amounts. Using the Henderson-Hasselbalch equation, the resulting pH will be close to 3.86, which is the pKa value of lactic acid.
The composition and pH of an ideal buffer prepared from lactic acid (CH3CHOHCO2H), would involve a mixture of lactic acid and its conjugate base, sodium lactate (CH3CHOHCO2Na). By using the Henderson-Hasselbalch equation, pH = pKa + log([A-]/[HA]), where pKa is the negative logarithm of Ka and [A-]/[HA] represents the ratio of the concentration of the conjugate base to the acid, we can determine the pH. For an ideal buffer, the ratio should be close to 1:1 to maintain a pH close to the pKa of lactic acid.
As an example, assume a student has mixed an equal number of moles (not necessary for equal weights as molar masses differ) of lactic acid and sodium lactate. In this case, since the pKa of lactic acid is 3.86, the resulting buffer would ideally have a pH close to 3.86, given that the concentrations of lactic acid and sodium lactate are similar after mixing.
Which of the following is an example of a combustion reaction?
A. Mixing of acid and base
B. Photosynthesis in plants
C. Lighting of a matchstick
D. Reacting sodium and chlorine
Answer:
Option c = Lighting of matchstick
Explanation:
The lightning of match stick is combustion reaction. The chemical potassium chlorate, glue, sulfur and starch is present on the tip of match stick. When the match stick catch the fire combustion process occur and heat is released.
Photosynthesis in plant:
It is the reaction in which plants used the carbon dioxide and water and convert it into sugar and oxygen in the presence of light.
6CO₂ + 6H₂O + light → C₆H₁₂O₆ + 6O₂
Mixing of acid and base:
When an acid react with base it form the salt and water. The reaction is also called neutralization reaction because both neutralize each other.
In neutralization reaction equal amount of acid and base react to neutralize each other and equal amount of water and salt are formed. When pH does not reach to 7 its means there is less amount of one of reactant which is not fully neutralize.
Reacting of sodium and chlorine
The reaction of sodium and chlorine is the formation of ionic compound. It is formed by the complete transfer of electron from sodium to chlorine atom and form ionic bond. In this ionic compound sodium carry positive charge and chlorine carry negative charge there is attraction between these oppositely charged atoms.
Answer:
lighting of a match stick
Explanation:
A type of spectroscopy used to analyze pigments in a painting is:
a. ultraviolet absorption
b. microwave emission
c. X-ray fluorescence
d. Infrared absorption
e. color phosphorescence
I would say the answer is D
Paint samples received by forensic laboratories are usually in the form of small chips or smears. Infrared (IR) spectroscopy is one of the most commonly used tools available for the analysis of these types of samples and serves as a staple comparative technique in the assessment of whether or not a questioned sample could have come from a suspected object
The most direct way to probe the vibrational frequencies of a molecule is through infrared spectroscopy. This is because vibrational transitions typically require an amount of energy that corresponds to the infrared region of the spectrum. Raman spectroscopy, which typically uses visible light, can also be used to directly measure vibration frequencies.
Answer:
d) Infrared absorption
Explanation:
Spectroscopy involves the study of the interaction of electromagnetic radiation with matter. The electromagnetic spectrum is essentially a composite of photons of different wavelengths and frequencies; from the low wavelength gamma rays to the high wavelength radio waves.
The pigments in a painting are organic compounds which can be easily identified via Infrared spectroscopy. When a beam of infrared light (photons in the 700 nm-1000 nm of the electromagnetic spectrum) is passed through the painting, photons of particular wavelengths or energy which are in resonance with the molecular vibrations of the pigment molecules get absorbed whereas the rest of the IR radiation is reflected and directed onto a detector. A plot intensity of the reflected IR light vs wavelength corresponds to the IR spectrum which is unique to a particular chemical substance. Thus, various pigments in a painting that have IR active features can be identified by this method.