Question 1

A white precipitate of lead chloride, PbCl₂, is formed when a solution of ammonium chloride, NH₄Cl, is added to a solution of lead(II) nitrate, Pb(NO₃)₂. Which of the following ionic equations for this reaction includes the spectator ions as well?

Accepted Answer

The correct answer is B because it includes all the ions present in the reaction, including the spectator ions (NH₄⁺ and NO₃^-).

Question 2

Which of the following is oxidation?

Accepted Answer

All of these options represent oxidation. The loss of electrons (option A) is the most basic definition of oxidation, but oxidation can also involve the loss of hydrogen (option B) or the gain of oxygen (option C). Therefore, option D is the best choice.

Question 3

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

Accepted Answer

The molecular equation should only show the reactants and products in their molecular form. Option A correctly shows CuCl2 and KS as the reactants and CuS and KCl as the products in their molecular forms. Option B includes unnecessary ions and option C shows ions instead of molecules for some of the reactants and products. Option D only shows the formation of CuS and not the reactants involved.

Question 4

Which of the following represents the correct set of spectator ions in the equation Cu²⁺(aq) + 2Cl^-(aq) + 2K⁺(aq) + S^2- (aq) → CuS(s) + 2K⁺(aq) + 2Cl^-(aq)?

Accepted Answer

Spectator ions are ions that appear on both the reactant and product sides of a chemical equation and do not participate in the reaction. In this equation, the spectator ions are K⁺ and Cl^- because they appear on both sides of the equation and do not participate in the reaction. Therefore, option B is the correct set of spectator ions.

Question 5

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

Accepted Answer

All acetate salts and all nitrate salts are soluble in water, making them commonly used as soluble salts in chemical reactions and solutions.

Question 6

A black precipitate of copper sulfide, CuS, is formed when a solution of Cu(II) chloride, CuCl₂, is added to a solution of potassium sulfide, K₂S. Which of the following ionic equations for this reaction includes the spectator ions as well?

Accepted Answer

In option C, all the ions involved in the reaction (including spectator ions) are written in the balanced ionic equation. The spectator ions in this reaction are Cl- and K+. Option A only includes the ions directly involved in the reaction and omits spectator ions. Option B includes all ions, but also includes additional unnecessary species (S2- and Cu2+) that are not involved in the reaction. Option D includes only the reactant and product ions, leaving out the spectator ions. Therefore, option C is the best choice as it includes all relevant ions in the balanced ionic equation.

Question 7

The synthesis of a certain drug requires four steps. The 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 together, then converting to a percentage. So, the overall yield = 0.971 * 0.943 * 0.928 * 0.727 = 0.618 (or 61.8%).

Question 8

The synthesis of a certain drug requires three 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 calculated by multiplying the yields of each step: 0.952 * 0.914 * 0.938 = 0.816, or 81.6%.

Question 9

Which of the following sulfides is soluble in water?

Accepted Answer

Potassium sulfide (K₂S) is soluble in water due to the high solubility of alkali metal compounds in water. The other choices (Ag2S, FeS, and PbS) are insoluble or only slightly soluble in water.

Question 10

Which of the following anions always forms soluble compounds?

Accepted Answer

Acetate (CH3COO-) is known to form soluble compounds with almost all cations, making it an exception to the general solubility rules.

Question 11

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

Accepted Answer

The net ionic equation for the reaction between Cu(II) chloride and potassium sulfide to form copper sulfide involves only the ions that participate directly in the reaction, which are the copper (II) ion (Cu^2+) and the sulfide ion (S^2-), resulting in the formation of copper sulfide (CuS) as a solid precipitate. The potassium (K^+) and chloride (Cl^-) ions are spectator ions and do not appear in the net ionic equation.

Question 12

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 13

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 14

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 15

Which of the following is true of spectator ions?

Accepted Answer

Spectator ions are ions that do not participate in the reaction and remain in solution unchanged. They are simply present to maintain electrical neutrality in the solution. Therefore, option D is the correct answer.

Question 16

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

Accepted Answer

The net ionic equation only includes the ions directly involved in the formation of the precipitate, which are Pb^2+ and Cl^-, combining to form PbCl2(s).

Question 17

Which of the following anions always forms soluble compounds?

Accepted Answer

Nitrate (NO₃⁻) is an anion that always forms soluble compounds in water, regardless of the cation it is paired with.

Question 18

Which of the following ions always forms soluble compounds?

Accepted Answer

All three compounds have ions that are typically soluble in water. Na+ and Cl- are always soluble, NH4+ and NO3- are always soluble, and CH3COO- is also typically soluble. Therefore, all of the compounds listed in the choices are soluble.

Question 19

Which of the following is reduction?

Accepted Answer

Reduction is the gain of electrons, while options B and C refer to specific types of reductions. Option D does not describe reduction at all.

Question 20

Which of the following compounds is insoluble in water?

Accepted Answer

CaCO₃ (calcium carbonate) is insoluble in water. The other compounds listed are soluble in water.

Quiz 4: Chemical Reactions

A white precipitate of lead chloride, PbCl₂, is formed when a solution of ammonium chloride, NH₄Cl, is added to a solution of lead(II) nitrate, Pb(NO₃) ₂. Which of the following ionic equations for this reaction includes the spectator ions as well?

Which of the following is oxidation?

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

Which of the following represents the correct set of spectator ions in the equation Cu²⁺(aq) + 2Cl^-(aq) + 2K⁺(aq) + S^2- (aq) → CuS(s) + 2K⁺(aq) + 2Cl^-(aq) ?

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

A black precipitate of copper sulfide, CuS, is formed when a solution of Cu(II) chloride, CuCl₂, is added to a solution of potassium sulfide, K₂S. Which of the following ionic equations for this reaction includes the spectator ions as well?

The synthesis of a certain drug requires four steps. The 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?

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

Which of the following sulfides is soluble in water?

Which of the following anions always forms soluble compounds?

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

Which of the following compounds is soluble in water?

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

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?

Which of the following is true of spectator ions?

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

Which of the following anions always forms soluble compounds?

Which of the following ions always forms soluble compounds?

Which of the following is reduction?

Which of the following compounds is insoluble in water?

Quiz 4: Chemical Reactions

A white precipitate of lead chloride, PbCl2, is formed when a solution of ammonium chloride, NH4Cl, is added to a solution of lead(II) nitrate, Pb(NO3) 2. Which of the following ionic equations for this reaction includes the spectator ions as well?

Which of the following is oxidation?

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

Which of the following represents the correct set of spectator ions in the equation Cu2+(aq) + 2Cl-(aq) + 2K+(aq) + S2- (aq) → CuS(s) + 2K+(aq) + 2Cl-(aq) ?

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

A black precipitate of copper sulfide, CuS, is formed when a solution of Cu(II) chloride, CuCl2, is added to a solution of potassium sulfide, K2S. Which of the following ionic equations for this reaction includes the spectator ions as well?

The synthesis of a certain drug requires four steps. The 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?

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

Which of the following sulfides is soluble in water?

Which of the following anions always forms soluble compounds?

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

Which of the following compounds is soluble in water?

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

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?

Which of the following is true of spectator ions?

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

Which of the following anions always forms soluble compounds?

Which of the following ions always forms soluble compounds?

Which of the following is reduction?

Which of the following compounds is insoluble in water?

A white precipitate of lead chloride, PbCl₂, is formed when a solution of ammonium chloride, NH₄Cl, is added to a solution of lead(II) nitrate, Pb(NO₃) ₂. Which of the following ionic equations for this reaction includes the spectator ions as well?

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

Which of the following represents the correct set of spectator ions in the equation Cu²⁺(aq) + 2Cl^-(aq) + 2K⁺(aq) + S^2- (aq) → CuS(s) + 2K⁺(aq) + 2Cl^-(aq) ?

A black precipitate of copper sulfide, CuS, is formed when a solution of Cu(II) chloride, CuCl₂, is added to a solution of potassium sulfide, K₂S. Which of the following ionic equations for this reaction includes the spectator ions as well?

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

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