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 ox
idation 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