3 points QUESTION 26 Which of the following best describes a solution?

3 points  

QUESTION 26

Which of the following best describes a solution?

Solids settle in the bottom of the beaker after being left to sit.

Solute and solvent cannot be differentiated.

Two samples differ when taken from the same beaker.

Chunks are suspended in a fluid.

3 points  

QUESTION 27

When carbon dioxide gas is dissolved in water, the carbon dioxide gas is called the:

solute

solution

solvent

fluid

3 points  

QUESTION 28

Which of the following is a colligative property of solutions?

Vapor pressure lowering

Boiling point depression

Freezing point elevation

Polarity elevation

3 points  

QUESTION 29

Ethylene glycol, C2H6O2, is a nonvolatile substance unable to form ions in water. If 38.6 grams of ethylene glycol is dissolved in 175 grams of water, what is the freezing point of the solution? Kf = 1.86°C/m; Kb = 0.512°C/m

-6.61°C

1.82°C

6.61°C

-1.82°C

3 points  

QUESTION 30

The smaller the pH scale value, the greater the concentration of H3O+ ions.

TRUE

FALSE

2 points  

QUESTION 31

A solution of NaOH has a concentration of 3.02 x 10-2 M. What is the pOH of this solution?

pOH = 3.02

pOH = 2.00

pOH = 1.52

pOH = 12.48

3 points  

QUESTION 32

Given a solution with a pH of 2.8, what is the [H+] of the solution?

2.8 M

6.31 x 10-12 M

1.58 x 10-3 M

11.2 M

3 points  

QUESTION 33

An HCl solution has a concentration of 3.26 x 10-2 M. What is the pH of this solution?

pH = 12.5

pH = 1.49

pH = 3.3

pH = 2.0

3 points  

QUESTION 34

The equivalence point is:

The point at which the concentrations of base and acid are equal

The point at which the volumes of base and acid are equal

The point at which the concentration and volumes of base and acid are equal

The point at which the number of moles of hydrogen and hydroxide ions are equal

3 points  

QUESTION 35

128 mL of 1.50 x 10-2 M NaOH is used to titrate 225 mL of a monoprotic acid with unknown concentration to reach the equivalence point. What is the concentration of the original acid?

1.50 x 10-2 M

1.17 x 10-1 M

1.92 x 10-3 M

8.53 x 10-3 M

QUESTION 37

Which of the following is not a step in balancing redox reactions in acidic solution, using the half-reaction method?

H2O and OH- are added as needed to the half-reaction equations to make the number of oxygen and hydrogen atoms balance.

Divide the chemical equation into two half-reaction equations, identifying which half-reaction is oxidation and which is reduction.

H2O and H+ are added as needed to the half-reaction equations to make the number of oxygen and hydrogen atoms balance.

Multiply each term in one of the half-reaction equations by a factor that will make the number of electrons lost (in the oxidation) equal to the number of electrons gained (in the reduction)

QUESTION 41

Some type of path is necessary to join both half-cells in order for electron flow to occur.

TRUE

FALSE

2 points  

QUESTION 42

What is the source of the electric current produced by a voltaic cell?

a spontaneous oxidation-reduction reaction

competing salt bridges

non-spontaneous reduction at the cathode

an imbalance of ion charges

3 points  

QUESTION 43

In general, breaking bonds results in a release of energy.

TRUE

FALSE

2 points  

QUESTION 44

A particular chemical reaction releases energy. It is possible to say the reactants had a higher energy than the products.

TRUE

FALSE

2 points  

QUESTION 45

When heat is applied to a solid and a gas begins to form, the change in entropy is positive.

TRUE

FALSE

2 points  

QUESTION 46

Which of the following is an example of +ΔS?

A solid being sublimed

A gas being condensed to form a liquid

A liquid freezing into a solid

A gas being compressed at low temperature to a solid

3 points  

QUESTION 47

A reaction contains two reactants, A and B. If A is doubled, there will be a greater number of effective collisions between reactants.

TRUE

FALSE

2 points  

QUESTION 48

You can study reaction rates to answer which of the following questions?

Will the reaction be reversible?

Will the reaction occur?

How can the reaction be slowed down?

How many grams of product will be formed?

3 points  

QUESTION 49

Which of the following statements regarding chemical equilibrium is true?

Equilibrium is shown with a single arrow and/or an equal sign.

A system at equilibrium maintains the concentrations of all reactants/products over time.

A system at equilibrium stops.

Equilibrium is signified only with an equals sign.

3 points  

QUESTION 50

Which change in the nucleus of an atom is responsible for the emission of an electron?

neutron to proton

proton to neutron

proton to electron

electron to proton

3 points  

QUESTION 51

Which of the following is not true about beta emissions?

Difference of the atomic number by one between the old element and new element formed

Are written as 0-1e

Cannot penetrate concrete

Less penetrating than alpha emissions