Physical Scie

nce

Take 10 Week #16

SFS-6 Solutions

Day 1 Question 1A pharmacist mixes

together 20 g of crystals of compound A and 10 g of crystals of compound B. The mixture is then dissolved in 120 mL of water to make cough syrup.

The mixture will most likely dissolve fastest under which of the following sets of conditions?

Day 1 Question 2When a sample of potassium chloride

dissolves in water, it separates into potassium ions and chloride ions. Which of the following best accounts for the positive charge of the potassium ions?

A. They have extra mass.B. They have a large volume.C. They have fewer electrons than protons.D. They have a high density of neutrons and

protons.

Day 1 answers1. The mixture will most likely dissolve fastest

under which of the following sets of conditions?

2.When a sample of potassium chloride dissolves in water, it separates into potassium ions and chloride ions. Which of the following best accounts for the positive charge of the potassium ions?

C. They have fewer electrons than protons.

Day 2 Question 1Which of the following solutions has

the highest concentration of solute?A. 1.0 mol solute in 200 mL solventB. 2.0 mol solute in 500 mL solventC. 3.0 mol solute in 1 L solventD. 4.0 mol solute in 1.5 L solvent

Day 2 Question 2A crystal of table salt (NaCl) is dissolved in

water. Which of the following statements explains why the dissolved salt does not recrystallize as long as the temperature and the amount of water stay constant?

A. Na and Cl ions lose their charges in the water.

B. Water molecules surround the Na and Cl ions.

C. Na and Cl ions leave the water through vaporization.

D. Water molecules chemically react with the Na and Cl ions.

Day 2 answers1. Which of the following solutions has the

highest concentration of solute?A. 1.0 mol solute in 200 mL solvent

2. A crystal of table salt (NaCl) is dissolved in water. Which of the following statements explains why the dissolved salt does not recrystallize as long as the temperature and the amount of water stay constant?

B. Water molecules surround the Na and Cl ions.

Day 3 Question 1Calcium hydroxide, Ca(OH)2, is used as a

soil conditioner in home gardens. When mixed with water, it releases hydroxide ions.

Which of the following is the most likely pH for a solution of calcium hydroxide and water?

A. 1B. 3C. 7D. 10

Day 3 Question 2The pH of four different solutions of common

materials is measured. Which of the following lists the solutions in order from most acidic to most basic?

A. battery acid, lemon juice, blood, laundry detergent

B. lemon juice, battery acid, blood, laundry detergent

C. laundry detergent, blood, lemon juice, battery acid

D. battery acid, blood, laundry detergent, lemon juice

Day 3 answers1. Calcium hydroxide, Ca(OH)2, is used as a soil

conditioner in home gardens. When mixed with water, it releases hydroxide ions.

Which of the following is the most likely pH for a solution of calcium hydroxide and water?

D. 102. The pH of four different solutions of common

materials is measured. Which of the following lists the solutions in order from most acidic to most basic?

A. battery acid, lemon juice, blood, laundry detergent

Day 4 Question 1A person left a bottle of distilled water and a bottle

of a sugary drink outside overnight. In the morning, one liquid was frozen but the other was not.

Which liquid was frozen and why did it freeze?A. The sugary drink froze because solutions are

more dense than pure substances.B. The distilled water froze because pure

substances are more dense than solutions.C. The sugary drink froze because solutions have a

higher freezing point than pure substances.D. The distilled water froze because pure

substances have a higher freezing point than solutions.

Day 4 Question 2In the reaction of hydrobromic acid

( HBr) and ammonia ( NH3), ammonia acts as a Brønsted base. Which of the following ions is formed?

Day 4 answersA person left a bottle of distilled water and a bottle

of a sugary drink outside overnight. In the morning, one liquid was frozen but the other was not.

Which liquid was frozen and why did it freeze?D. The distilled water froze because pure substances

have a higher freezing point than solutions.

2. In the reaction of hydrobromic acid ( HBr) and ammonia ( NH3), ammonia acts as a Brønsted base. Which of the following ions is formed?

Day 5 Question 1The formula for carbonic acid is H2CO3 , and the

formula for hydrogen carbonate is HCO3. Together they form a buffer that is found in blood.

Which of the following reactions represents what happens when excess base enters the bloodstream?

Day 5 Question 2A chemical equation representing the reaction of

water (HOH) and ammonia (NH3) is shown below.

Which of the following statements best explains the chemical action of the reactants in this equation?

A. Both water and ammonia are acting as acids.B. Both water and ammonia are acting as bases.C. Water is acting as an acid, and ammonia is acting

as a base.D. Water is acting as a base, and ammonia is acting

as an acid.

Day 5 answers1. The formula for carbonic acid is H2CO3 , and the

formula for hydrogen carbonate is HCO3. Together they form a buffer that is found in blood.

Which of the following reactions represents what happens when excess base enters the bloodstream?

2. Which of the following statements best explains the chemical action of the reactants in this equation?

C. Water is acting as an acid, and ammonia is acting as a base.