WorksheetsChem 2023 Spring Semester Review
Total questions: 62
Worksheet time: 1hrs 2mins
Name
Class
Date
1.
Breaking bonds ________ energy.
a)
requires
b)
releases
c)
transfers
d)
destroys
2.
Which of following is NOT true according to the laws of thermodynamics.
a)
Energy can be transferred from one form to another, but can not be created or destroyed
b)
The entropy of the universe is always increasing.
c)
The energy of the universe is always increasing.
d)
Heat will flow from hot to cold until there thermal equilibrium is reached.
3.
Which of the following is true about the reaction pictured below?
a)
I and III
b)
II and IV
c)
II and III
d)
I and IV
4.
What is the estimated energy required to break the bonds at the beginning of the reaction pictured?
a)
80 kJ
b)
160 kJ
c)
240 kJ
d)
280 kJ
5.
How much heat is released when 125 g of sulfur dioxide are produced according to the following reaction: S + O₂ → SO₂ H = -296 kJ
a)
-577 kJ
b)
-296 kJ
c)
-1156 kJ
d)
-32 kJ
6.
A 28.4 g sample of metal is heated to 39.4°C, then is placed in a calorimeter containing 50.0 g of water. Temperature of water increases from 21.00°C to 23.00°C. What is the specific heat of the metal? (q=cmΔT, specific heat of water = 4.18 J/g°C)
a)
4.18 J/g°C
b)
0.897 J/g°C
c)
1.345 J/g°C
d)
0.374 J/g°C
7.
Liquid water turns to ice. Is this process endothermic or exothermic? Choose the best answer.
a)
Endothermic. The water absorbed heat and got colder, thereby forming ice.
b)
Endothermic. Energy in the form of heat was given off by the water, which became colder and formed ice.
c)
Exothermic. The water released thermal energy, slowing down the water molecules so that solid ice formed.
d)
Exothermic. Heat was absorbed by the water, moving its molecules faster so that they condensed on an object and formed ice.
8.
Which has the most entropy?
a)
A
b)
B
c)
C
d)
They all have the same entropy.
9.
Which one of the following processes produces a decrease in the entropy of the system?
a)
dissolving of solid KCl in water
b)
mixing of two gases into one container
c)
freezing water to form ice
d)
boiling water to form steam
10.
The thermodynamic quantity that expresses the degree of disorder in a system is __________.
a)
entropy
b)
internal energy
c)
heat flow
d)
enthalpy
e)
bond energy
11.
A reaction has the following thermodynamic data. Which of the following statements is true?
ΔH° = -75.2 kJ/mol
ΔS° = 53.4 J/mol · K
a)
The reaction is never thermodynamically favorable.
b)
The reaction is thermodynamically favorable at high temperatures.
c)
The reaction is thermodynamically favorable at all temperatures.
d)
The reaction is thermodynamically favorable at low temperatures.
12.
If two objects have different temperatures, heat will flow from the warmer object to the cooler one UNTIL ____________
a)
one reaches a temperature of zero.
b)
they both have an equal temperature.
c)
one runs out of energy.
13.
The solubility curve below most likely represents a solute that is a ____.
a)
gas
b)
liquid
c)
solid
d)
none of these
14.
How do the concentrations of Solution X and Y (in the picture below) compare?
a)
Solution X has a greater concentration.
b)
Solution Y has a greater concentration.
c)
They have the same concentration.
d)
There is no way to determine the answer.
15.
True or False: If you were to hold an endothermic reaction in your hand, your hand would get colder because the reaction is gaining heat energy from your hand.
a)
True
b)
False
16.
An unknown solid substance is heated until it vaporizes and the heating curve below is produced. According to the heating curve, the approximate melting point of this unknown substance is ______°C.
a)
30
b)
48
c)
50
d)
55
17.
Which reaction has a lower activation energy?
a)
with enzyme
b)
without enzyme
18.
What is the change in enthalpy for the reaction described by the energy diagram below?
a)
80 kJ
b)
-80 kJ
c)
160 kJ
d)
-160 kJ
19.
A negative sign for the change in enthalpy for a reaction indicates that the reaction is:
a)
fast
b)
slow
c)
exothermic
d)
endothermic
20.
The phase changes B → C and D → E are not associated with temperature increases because the heat energy is used to __________.
a)
increase distances between molecules
b)
break intramolecular bonds
c)
rearrange atoms within molecules
d)
increase the velocity of molecules
21.
True or False: Melting and freezing occur at the same temperature.
a)
True
b)
False
22.
The particle model below best represents which part of the heating curve below?
a)
1
b)
2
c)
3
d)
4
e)
5
23.
The heating curve for two molecular covalent compounds is shown below. Which substance has stronger intermolecular attractive forces?
a)
Substance 1
b)
Substance 2
c)
Need more information to tell.
24.
Which of the following has the strongest dispersion forces and therefore the highest boiling point?
a)
F₂
b)
Cl₂
c)
Br₂
d)
I₂
25.
In order for a diamond (Cₓ) to melt, you have to weaken which type of attractive force?
a)
hydrogen bond
b)
covalent bond
c)
ionic bond
d)
dipole dipole attractive force
26.
Which of the following is NOT an INTRAmolecular force?
a)
ionic bond
b)
hydrogen bond
c)
covalent bond
d)
metallic bond
27.
Equal sized samples of P and Q are heated over time and the temperature is recorded as shown in the graph below. Which substance has a lower specific heat?
a)
P
b)
Q
c)
Need more information
28.
Identify the type of intermolecular force shown in the picture below.
a)
covalent bond
b)
hydrogen bond
c)
london dispersion
d)
dipole-dipole
29.
If the equilibrium product to react ratio (K) is 4.5 x 10^ ⁻¹¹ for a reaction, which of the following would be true?
a)
Reactants are favored at equilibrium
b)
Products are favored at equilibrium
c)
Reactants and products are equally favored at equilibrium
30.
Imagine you have a saturated solution of magnesium chloride in water with undissolved solid at the bottom. Which of the following would increase the amount of solid sitting at the bottom?
heat + KNO₃(s) ⇌ K⁺(aq) + NO₃¹⁻(aq)
a)
Cooling the solution.
b)
Heating the solution.
31.
When the the reaction quotient (Q) is less than the equilibrium constant (K), the reaction will shift _____ to reach equilibrium.
a)
towards the products
b)
towards the reactants
c)
in neither direction
32.
From the following statements, choose which is(are) ALWAYS true about a system at equilibrium.
a)
I only
b)
III only
c)
I, II, III, and IV
d)
II and III
33.
Consider the reaction below. The equilibrium constant at 400ºC is K=0.50. Suppose we make a mixture with the following concentrations: [NH₃] = 1.0M, [N₂] = 1.0M, [H₂] = 1.0M. Which direction will the reaction shift to reach equilibrium?
a)
Towards the products.
b)
Towards the reactants.
c)
To the middle.
d)
No shift will occur because this reaction is already at equilibrium.
34.
The reaction A + B ⇌ AB is represented below and has reached equilibrium. A is the red particles, blue is the B particles. Which of the following is true about the equilibrium constant, K, for this reaction?
a)
greater than 1
b)
less than 1
c)
equal to 1
35.
The reaction A₂ + B₂ ⇌ 2AB has an equilibrium constant K = 1.5. The following diagrams represent reaction mixtures containing A₂ molecules (red), B₂ molecules (blue), and AB molecules. Which reaction mixture is at equilibrium?
a)
i
b)
ii
c)
iii
36.
A container filled with carbon dioxide and carbon tetrafluoride is allowed to react and reach equilibrium. If more CO₂ is added after the system reaches equilibrium, what will happen?
a)
The system will have a new equilibrium constant, K.
b)
The forward reaction will speed up until equilibrium is achieved again.
c)
The reaction will shift to the left.
d)
The forward reaction will speed up forever!!!
37.
Your teacher decides to make a solution in class one day by dissolving lemonade powder in water. Then your teacher adds ice to make it nice and cold. Which substance is the solvent?
a)
Lemonade Power
b)
Water
c)
Lemonade Mixture
d)
Ice
38.
Ionic compounds like table salt will dissolve best in solvents that are ____.
a)
polar
b)
nonpolar
c)
either polar or nonpolar
d)
neither polar or nonpolar
39.
How does increasing the temperature affect the solubility of solids in liquids?
a)
Increasing temperature decreases the solubility of solids
b)
Increasing temperature increases the solubility of solids
c)
Increasing temperature has no effect on the solubility of solids
40.
What volume, in liters, of a 1.75 M solution would contain 0.65 moles of solute?
a)
2.7 L
b)
1.1 L
c)
0.37 L
d)
37 L
41.
The factor that affects the rate AND amount of a solution that can dissolve is ___.
a)
stirring/agitation
b)
surface area
c)
temperature
42.
A student is adding small amounts of a substance to 10 grams of water at room temperature until the solution becomes saturated. What is the maximum amount of solute that can dissolve according to the graph to the right?
a)
0.2 mol
b)
0.80 mol
c)
0.90 mol
d)
0.7 mol
e)
0.4 mol
43.
How many grams of KClO₃ are required to make a saturated solution at 60℃?
a)
15 g
b)
20 g
c)
24 g
d)
60 g
44.
Approximately how many grams of KCl will dissolve at 60℃ in 215 g of water?
a)
45 g
b)
161 g
c)
97 g
d)
477 g
45.
A saturated solution is made by adding 15 g of KCl to 50 g of water. What is the temperature of the solution?
a)
0℃
b)
10℃
c)
15℃
d)
20℃
46.
Which of the following is the correct equilibrium expression for the reaction below?
a)
A
b)
B
c)
C
d)
D
47.
Which of the following correctly describes a reaction system at equilibrium?
a)
All reactions stop at equilibrium and no detectable changes can be made.
b)
Reactions continue to occur, but there is no detectable changes in concentration of reactants or products.
c)
Reactions continue to occur, and concentrations of reactants and products can increase or decrease.
d)
Reactions continue to occur, decreasing concentrations of reactants and increasing concentrations of the products.
48.
Which way will the reaction shift to reestablish equilibrium when chlorine gas is added?
a)
left
b)
right
c)
no shift
49.
Which way will the reaction shift to reestablish equilibrium when HCl gas is added?
a)
left
b)
right
c)
no shift
50.
What is the name of the following acid?
a)
sulfurous acid
b)
hyposulfuric acid
c)
sulfuric acid
51.
What is the name of the following acid?
a)
hypofluorous acid
b)
hydrofluoric acid
c)
fluoric acid
52.
The following pictures represent aqueous solutions of three acids (HX, HY and HZ). Water molecules have been omitted for clarity. Rank the solutions from highest pH (14) to lowest pH (1).
a)
HX, HY, HZ
b)
HZ, HY, HX
c)
HY, HZ, HX
d)
They all have the same pH.
53.
A concentrated _________ acid could have the same pH as a dilute ______ acid.
a)
strong/weak
b)
dilute/concentrated
c)
dilute/strong
d)
weak/strong
54.
In a neutralization reaction, an acid reacts with a base to form what two compounds?
a)
Water and a conjugate base
b)
Water and a conjugate acid
c)
Water and a metal oxide
d)
Water and a salt
55.
One hundred molecules of hydrochloric acid are dissolved in water. All one hundred molecules dissociate. Hydrochloric acid would be classified as a ________.
a)
buffer
b)
strong acid
c)
weak acid
d)
salt
56.
An unknown sample of strong acid is titrated with NaOH. A graph of the titration is shown below. How many mL of NaOH were required to reach the equivalence point and neutralize the unknown strong acid?
a)
7.0 mL
b)
8.7 mL
c)
10.5 mL
d)
12.8 mL
57.
As a solution becomes more basic, _____.
a)
[H₃O⁺] increases while [OH⁻] decreases.
b)
[H₃O⁺] decreases while [OH⁻] increases.
c)
Both [H₃O⁺] and [OH⁻] increase.
d)
Both [H₃O⁺] and [OH⁻] decrease.
58.
Below are two molecular level representations of acids in solution. Which one is a weak acid?
a)
A
b)
B
c)
Need more information to tell.
59.
What is the pH of a solution with a hydronium ion concentration of 3.5 x 10⁻⁶ M ?
a)
6.0
b)
5.5
c)
8.5
d)
12.0
60.
Solution of A has a pH of 2.00. Solution B has a pH of 4.00. Which of the following statements is true?
a)
Solution B has two times as much hydronium as solution A.
b)
Solution A has one hundred times as much hydronium as solution B.
c)
Solution A has two times as much hydronium as solution B.
d)
Solution B has one hundred times as much hydronium as solution A.
61.
A student performs a titration on an unknown sample of hydrochloric acid. He/she uses 20.0 mL of 0.10 M calcium hydroxide to neutralize 12.0 mL of aqueous hydrochloric acid solution. What is the molarity of the hydrochloric acid solution?
a)
2.0 M
b)
0.33 M
c)
0.083 M
d)
0.17 M
62.
What is the molarity of an HCl solution if 40.0 mL of it is neutralized in a titration by 30.0 mL of 0.400 M NaOH?
a)
12.0 M
b)
0.300 M
c)
16.0 M
d)
0.533 M
100 %
