Question 1

Of the following anions, which almost always forms soluble compounds?

Accepted Answer

Iodide (I^-) generally forms soluble compounds, except with a few exceptions like silver, lead, and mercury.

Question 2

Which of the following sulfides is soluble in water?

Accepted Answer

Potassium sulfide (K₂S) is soluble in water, as it dissociates into potassium ions (K+) and sulfide ions (S2-) which are both highly polar and can interact with the polar water molecules, allowing for dissolution. The other three options are insoluble in water.

Question 3

The synthesis of a certain drug requires 4 steps. First three steps were relatively easy with percent yields of 97.1%, 94.3% and 92.8% respectively. However, the last step was very difficult with a percent yield of 72.7%. What was the overall percent yield?

Accepted Answer

The overall percent yield is calculated by multiplying the yields of each step: 0.971 * 0.943 * 0.928 * 0.727 = 0.618 or 61.8%.

Question 4

When an acid is added to a solution, no gas is formed. Which of the following ions cannot be in the solution?

Accepted Answer

When an acid is added to a solution containing carbonate ions (CO₃²⁻), carbon dioxide gas (CO₂) is typically formed. If no gas is formed, CO₃²⁻ cannot be present.

Question 5

Which of the following compounds is insoluble in water?

Accepted Answer

CaCO3 is insoluble in water, while the other compounds listed are all soluble in water.

Question 6

When an acid is added to a solution, a gas is formed. Which of the following ions might be in the solution?

Accepted Answer

When an acid is added to a solution containing carbonate ions (CO₃²⁻), carbon dioxide gas (CO₂) is formed as a result of the reaction between the acid and the carbonate ions.

Question 7

Which of the following is true of carbonate salts and phosphate salts?

Accepted Answer

Most carbonate salts and most phosphate salts are generally insoluble in water, with some exceptions such as salts of alkali metals. This is a basic principle in chemistry related to the solubility rules.

Question 8

When a solution of ammonium chloride, NH₄Cl, is added to a solution of lead(II) nitrate, Pb(NO₃)₂, a white precipitate of lead chloride, PbCl₂, forms. Which of the following is the total ionic equation for this reaction?

Accepted Answer

The total ionic equation shows all of the ions that are present in the solution, and the precipitate that forms. In this case, the ions are NH₄⁺, Cl^-, Pb²⁺, and NO₃^-. The precipitate is PbCl₂. The total ionic equation is:2 NH₄⁺(aq) + 2 Cl^-(aq) + Pb²⁺(aq) + 2 NO₃^-(aq) → PbCl₂(s) + 2 NH₄⁺(aq) + 2 NO₃^-(aq)

Question 9

Which of the following compounds is soluble in water?

Accepted Answer

Silver acetate (AgC2H3O2) is soluble in water, unlike the other silver halides listed (AgCl, AgBr, AgI), which are generally insoluble in water.

Question 10

When a solution of Cu(II) chloride, CuCl₂ , is added to a solution of potassium sulfide, K₂S, a black precipitate of copper sulfide, CuS, forms. Which of the following is the molecular equation for this reaction?

Accepted Answer

The molecular equation for the reaction between Cu(II) chloride and potassium sulfide can be written as: CuCl2 (aq) + K2S (aq) → CuS (s) + 2 KCl (aq) Note that the formula for copper (II) chloride is CuCl2 and not CuCl₂. The formula for potassium sulfide is K2S and not K₂S. The balanced equation shows that one mole of CuCl2 reacts with one mole of K2S to form one mole of CuS and two moles of KCl. The subscripts in option A are not correct, but the overall equation is the most accurate representation of the reaction.

Question 11

Which of the following is true of acetate salts and nitrate salts?

Accepted Answer

Both acetate salts and nitrate salts are generally soluble in water. This is because acetate (CH3COO-) and nitrate (NO3-) are both small, negatively charged ions that are attracted to the positive ends of water molecules through ion-dipole interactions. As a result, acetate and nitrate salts dissolve easily in water to form homogeneous solutions. Therefore, choice A and B are incorrect, and choice D is completely wrong. Choice C is the best choice because it accurately reflects the solubility behavior of both types of salts.

Question 12

Of the following ions, which always forms soluble compounds?

Accepted Answer

All of these ions form soluble compounds because they are either alkali metal ions (Na+) or ammonium ion (NH4+) which form soluble salts with most anions, or they are common anions (S2-, SO42-, Cl-, NO3-, etc.) which form soluble salts with most cations.

Question 13

Of the following anions, which almost always forms soluble compounds?

Accepted Answer

The answer of Of the following anions, which almost always...

Question 14

When a solution of ammonium chloride, NH₄Cl, is added to a solution of lead(II) nitrate, Pb(NO₃)₂, a white precipitate of lead chloride, PbCl₂, forms. Which of the following is the net ionic equation for this reaction?

Accepted Answer

The ammonium and nitrate ions do not participate in the precipitation reaction and can be written as spectator ions. The net ionic equation for the reaction is:
Pb^2+(aq) + 2Cl-(aq) → PbCl2(s)

Question 15

The synthesis of a certain drug can be carried out with 91.7% yield. In one experiment 14.8 g of the drug was obtained. What was the theoretical yield for this experiment?

Accepted Answer

Yield percentage = (actual yield/theoretical yield) x 100%
Rearranging the formula: theoretical yield = (actual yield/yield percentage) x100%
Substituting the given values, theoretical yield = (14.8 g / 91.7%) x 100% = 16.1 g. Therefore, the answer is choice C.

Question 16

When a solution of Cu(II) chloride, CuCl₂ , is added to a solution of potassium sulfide, K₂S, a black precipitate of copper sulfide, CuS, forms. Which of the following is the net ionic equation for this reaction?

Accepted Answer

The net ionic equation includes only the ions that participate in forming the precipitate, which are Cu²⁺ and S^2-, forming CuS(s).

Question 17

Diethyl ether can be made from ethanol. The reaction is: 2 C₂H₅OH(l) → (C₂H₅)₂O(l) + H₂O(l) The percent yield of diethyl ether in one experiment was 94.0% and actual yield was 68.6 G) How much ethanol did the chemist use in this experiment?

Accepted Answer

The answer of Diethyl ether can be made from ethanol....

Question 18

Ethyl chloride is prepared by the reaction of ethane with chlorine according to the reaction: 2 C₂H₆ (g) + Cl₂(g) → C₂H₅Cl(l) + HCl(g) The percent yield of ethyl chloride in one experiment was 96.3% and the actual yield was 74.4 G) How much ethylene did the chemist use in this experiment?

Accepted Answer

The percent yield is calculated as (actual yield / theoretical yield) x 100%. The theoretical yield is the amount of product that would be produced if the reaction went to completion. In this case, the theoretical yield can be calculated using the stoichiometry of the reaction. For every 2 moles of ethane that react, 1 mole of ethyl chloride is produced. Therefore, the theoretical yield of ethyl chloride is:theoretical yield = (74.4 g / 64.5 g/mol) x (1 mol C2H5Cl / 2 mol C2H6) = 56.8 gThe percent yield is then calculated as:percent yield = (74.4 g / 56.8 g) x 100% = 96.3%This means that the chemist used 96.3% of the theoretical yield of ethyl chloride. Therefore, the amount of ethylene that the chemist used in this experiment is:amount of ethylene used = (56.8 g / 0.963) = 59.0 g

Question 19

When a solution of Cu(II) chloride, CuCl₂ , is added to a solution of potassium sulfide, K₂S, a black precipitate of copper sulfide, CuS, forms. Which of the following is the total ionic equation for this reaction?

Accepted Answer

The ionic equation represents the dissociation of all soluble ionic species into their constituent ions, leaving only the insoluble precipitate(s) in their solid form. In the reaction given, Cu(II) chloride dissociates into Cu(II) and Cl- ions, while potassium sulfide dissociates into K+ and S2- ions. The Cu(II) ions and S2- ions combine to form the insoluble precipitate of copper sulfide, leaving K+ ions and Cl- ions in solution.

The correct ionic equation is:

Cu2+ (aq) + S2- (aq) + 2K+ (aq) + 2Cl- (aq) → CuS (s) + 2K+ (aq) + 2Cl- (aq)

Simplifying the equation by canceling out the spectator ions (K+ and Cl- ions) present on both sides of the equation, we get:

Cu2+ (aq) + S2- (aq) → CuS (s)

Thus, the total ionic equation is:

CuCl2 (aq) + K2S (aq) → CuS (s) + 2KCl (aq)

Option C correctly represents this equation by breaking down all the ionic species into their constituent ions and showing them in their ionic form. Option A is incorrect because it shows only the species that are directly involved in the reaction and does not include the spectator ions. Option B is incorrect because it shows unnecessary additional species and is overly complicated. Option D is incorrect because it does not show any ionic species and only shows the reactant and product as molecular species.

Question 20

The synthesis of a certain drug requires 3 steps. The percent yield for the steps are 95.2%, 91.4% and 93.8% respectively. What is the overall percent yield?

Accepted Answer

The overall percent yield is the product of the percent yields of the individual steps. So, the overall percent yield is 95.2% x 91.4% x 93.8% = 81.6%.

Quiz 4: Chemical Reactions

Of the following anions, which almost always forms soluble compounds?

Which of the following sulfides is soluble in water?

The synthesis of a certain drug requires 4 steps. First three steps were relatively easy with percent yields of 97.1%, 94.3% and 92.8% respectively. However, the last step was very difficult with a percent yield of 72.7%. What was the overall percent yield?

When an acid is added to a solution, no gas is formed. Which of the following ions cannot be in the solution?

Which of the following compounds is insoluble in water?

When an acid is added to a solution, a gas is formed. Which of the following ions might be in the solution?

Which of the following is true of carbonate salts and phosphate salts?

When a solution of ammonium chloride, NH₄Cl, is added to a solution of lead(II) nitrate, Pb(NO₃) ₂, a white precipitate of lead chloride, PbCl₂, forms. Which of the following is the total ionic equation for this reaction?

Which of the following compounds is soluble in water?

When a solution of Cu(II) chloride, CuCl₂ , is added to a solution of potassium sulfide, K₂S, a black precipitate of copper sulfide, CuS, forms. Which of the following is the molecular equation for this reaction?

Which of the following is true of acetate salts and nitrate salts?

Of the following ions, which always forms soluble compounds?

Of the following anions, which almost always forms soluble compounds?

When a solution of ammonium chloride, NH₄Cl, is added to a solution of lead(II) nitrate, Pb(NO₃) ₂, a white precipitate of lead chloride, PbCl₂, forms. Which of the following is the net ionic equation for this reaction?

The synthesis of a certain drug can be carried out with 91.7% yield. In one experiment 14.8 g of the drug was obtained. What was the theoretical yield for this experiment?

When a solution of Cu(II) chloride, CuCl₂ , is added to a solution of potassium sulfide, K₂S, a black precipitate of copper sulfide, CuS, forms. Which of the following is the net ionic equation for this reaction?

Diethyl ether can be made from ethanol. The reaction is: 2 C₂H₅OH(l) → (C₂H₅) ₂O(l) + H₂O(l) The percent yield of diethyl ether in one experiment was 94.0% and actual yield was 68.6 G) How much ethanol did the chemist use in this experiment?

When a solution of Cu(II) chloride, CuCl₂ , is added to a solution of potassium sulfide, K₂S, a black precipitate of copper sulfide, CuS, forms. Which of the following is the total ionic equation for this reaction?

The synthesis of a certain drug requires 3 steps. The percent yield for the steps are 95.2%, 91.4% and 93.8% respectively. What is the overall percent yield?

Quiz 4: Chemical Reactions

Of the following anions, which almost always forms soluble compounds?

Which of the following sulfides is soluble in water?

The synthesis of a certain drug requires 4 steps. First three steps were relatively easy with percent yields of 97.1%, 94.3% and 92.8% respectively. However, the last step was very difficult with a percent yield of 72.7%. What was the overall percent yield?

When an acid is added to a solution, no gas is formed. Which of the following ions cannot be in the solution?

Which of the following compounds is insoluble in water?

When an acid is added to a solution, a gas is formed. Which of the following ions might be in the solution?

Which of the following is true of carbonate salts and phosphate salts?

When a solution of ammonium chloride, NH4Cl, is added to a solution of lead(II) nitrate, Pb(NO3) 2, a white precipitate of lead chloride, PbCl2, forms. Which of the following is the total ionic equation for this reaction?

Which of the following compounds is soluble in water?

When a solution of Cu(II) chloride, CuCl2 , is added to a solution of potassium sulfide, K2S, a black precipitate of copper sulfide, CuS, forms. Which of the following is the molecular equation for this reaction?

Which of the following is true of acetate salts and nitrate salts?

Of the following ions, which always forms soluble compounds?

Of the following anions, which almost always forms soluble compounds?

When a solution of ammonium chloride, NH4Cl, is added to a solution of lead(II) nitrate, Pb(NO3) 2, a white precipitate of lead chloride, PbCl2, forms. Which of the following is the net ionic equation for this reaction?

The synthesis of a certain drug can be carried out with 91.7% yield. In one experiment 14.8 g of the drug was obtained. What was the theoretical yield for this experiment?

When a solution of Cu(II) chloride, CuCl2 , is added to a solution of potassium sulfide, K2S, a black precipitate of copper sulfide, CuS, forms. Which of the following is the net ionic equation for this reaction?

Diethyl ether can be made from ethanol. The reaction is: 2 C2H5OH(l) → (C2H5) 2O(l) + H2O(l) The percent yield of diethyl ether in one experiment was 94.0% and actual yield was 68.6 G) How much ethanol did the chemist use in this experiment?

Ethyl chloride is prepared by the reaction of ethane with chlorine according to the reaction: 2 C2H6 (g) + Cl2(g) → C2H5Cl(l) + HCl(g) The percent yield of ethyl chloride in one experiment was 96.3% and the actual yield was 74.4 G) How much ethylene did the chemist use in this experiment?

When a solution of Cu(II) chloride, CuCl2 , is added to a solution of potassium sulfide, K2S, a black precipitate of copper sulfide, CuS, forms. Which of the following is the total ionic equation for this reaction?

The synthesis of a certain drug requires 3 steps. The percent yield for the steps are 95.2%, 91.4% and 93.8% respectively. What is the overall percent yield?

When a solution of ammonium chloride, NH₄Cl, is added to a solution of lead(II) nitrate, Pb(NO₃) ₂, a white precipitate of lead chloride, PbCl₂, forms. Which of the following is the total ionic equation for this reaction?

When a solution of Cu(II) chloride, CuCl₂ , is added to a solution of potassium sulfide, K₂S, a black precipitate of copper sulfide, CuS, forms. Which of the following is the molecular equation for this reaction?

When a solution of ammonium chloride, NH₄Cl, is added to a solution of lead(II) nitrate, Pb(NO₃) ₂, a white precipitate of lead chloride, PbCl₂, forms. Which of the following is the net ionic equation for this reaction?

When a solution of Cu(II) chloride, CuCl₂ , is added to a solution of potassium sulfide, K₂S, a black precipitate of copper sulfide, CuS, forms. Which of the following is the net ionic equation for this reaction?

Diethyl ether can be made from ethanol. The reaction is: 2 C₂H₅OH(l) → (C₂H₅) ₂O(l) + H₂O(l) The percent yield of diethyl ether in one experiment was 94.0% and actual yield was 68.6 G) How much ethanol did the chemist use in this experiment?

When a solution of Cu(II) chloride, CuCl₂ , is added to a solution of potassium sulfide, K₂S, a black precipitate of copper sulfide, CuS, forms. Which of the following is the total ionic equation for this reaction?