WorksheetsAP Chem Midterm Review Questions
Total questions: 16
Worksheet time: 8mins
Fun fact: Rice absorbs moisture even faster than salt. You're familiar with the lifesaver of putting your water-damaged phone in a bag of uncooked rice? It's the same concept. By adding just a few grains of rice to your salt shaker, restaurants can guarantee that your salt will pour with ease. How does the percent by mass of Na+ compare in the two shakers?
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The shaker WITHOUT rice has a larger percent by mass Na+. A larger part of the whole 10.0g sample is due to the mass of Na+.
The shaker WITH rice has a larger percent by mass Na+. A larger part of the whole 10.0g sample is due to the mass of Na+.
The shakers have EQUAL percent by mass Na+. They have the same total mass and therefore the same percent by mass Na+.
One salt shaker is pure NaCl. The second salt shaker is a mixture of NaCl and Na2O. How does the percent by mass of Na+ compare in the two shakers?
NOTE: Do not eat Na2O :)
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The shaker WITHOUT Na2O has a larger percent by mass Na+. A larger part of the whole 10.0g sample is due to the mass of Na+.
The shaker WITH Na2O has a larger percent by mass Na+. A larger part of the whole 10.0g sample is due to the mass of Na+.
The shakers have EQUAL percent by mass Na+. They have the same total mass and therefore the same percent by mass Na+.
When a 2.04 g sample of an unknown hydrate of magnesium carbonate, MgCO3 · xH2O(s), is heated, H2O (molar mass 18 g) is driven off. The mass of the anhydrous MgCO3(s) (molar mass 84 g) that remains is 1.68 g. The value of x in the hydrate is
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1
The sample is a monohydrate
MgCO3 · H2O
2
The sample is a dihydrate
MgCO3 · 2H2O
5
The sample is a pentahydrate
MgCO3 · 5H2O
10
The sample is a decahydrate
MgCO3 · 10H2O
A student prepares a solution of potassium permanganate, KMnO4, (molar mass 160g/mol) as the titrant for a REDOX titration. To do so, they dissolve 32.0g in enough water to make 400.mL of solution. What is the molar concentration of the solution?
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0.500M
0.200M
0.100M
0.700M
A mixture of O2(g) and H2(g) is placed in a container, as shown. A reaction occurs, forming H2O(g). Which of the following best represents the contents of the box after the reaction has proceeded as completely as possible?
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Give the net ionic equation for the reaction
Pb(NO3)2 + Li2SO4 → PbSO4 + 2LiNO3
I) Pb2+(aq) + 2(NO3)1-(aq) + 2Li1+(aq) + SO42-(aq) → PbSO4(s) + 2LiNO3(s)
II) 2Li1+(aq) + 2(NO3)1-(aq) → 2LiNO3(s)
III) Pb2+(aq) + SO42-(aq) → PbSO4(s)
IV) Li1+(aq) + (NO3)1-(aq) → LiNO3(s)
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I)
II)
III)
IV)
The diagram shown represents an initial mixture of H2(g), I2(g) and HI(g) in a 1.0L container at 298K. The gases react and reach equilibrium according to the equation below. To reach equilibrium, what will happen to the initial mixture?
H2(g)+ I2(g) ⇄ 2HI(g) K = 9 at 298K
The initial mixture will shift to form more product.
The initial mixture is at equilibrium.
The initial mixture will shift to form more reactant.
This is not an equilibrium reaction.
The diagram shown represents an initial mixture of H2(g), I2(g) and HI(g) in a 1.0L container at 298K. The gases react and reach equilibrium according to the equation below. To reach equilibrium, what will happen to the initial mixture?
H2(g)+ I2(g) ⇄ 2HI(g) K = 9 at 298K
The initial mixture will shift to form more product.
The initial mixture is at equilibrium.
The initial mixture will shift to form more reactant.
This is not an equilibrium reaction.
The diagram shown represents an initial mixture of H2(g), I2(g) and HI(g) in a 1.0L container at 298K. The gases react and reach equilibrium according to the equation below. To reach equilibrium, what will happen to the initial mixture?
H2(g)+ I2(g) ⇄ 2HI(g) K = 9 at 298K
The initial mixture will shift to form more product.
The initial mixture is at equilibrium.
The initial mixture will shift to form more reactant.
This is not an equilibrium reaction.
Cu2+(aq) + Zn(s) → Cu(s) + Zn2+(aq)
E⁰cell= +1.10V
Which of the following correctly describes the equilibrium constant, K, and the standard free energy change, ΔG°, for this reaction?
K is greater than 1
ΔG° is positive
K is greater than 1
ΔG° is negative
K is less than 1
ΔG° is positive
K is less than 1
ΔG° is negtaive
The standard reduction potential of the Cu2+ | Cu electrode is +0.34 V and the standard potential of the cell
Pb(s) + Cu2+(aq) → Pb2+(aq) + Cu(s)
is +0.47 V.
What is the standard reduction potential
of the Pb2+ | Pb electrode?
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+0.13 V
− 0.81V
− 0.13 V
+0.81 V
Based on the information for two different reactions given, which of the following gives the quantities needed to calculate the enthalpy change for the reaction represented by the overall equation below?
2NO(g)+O2(g) → N2O4(g)
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ΔH1 + ΔH2
ΔH1 + (−ΔH2)
(−ΔH1) + ΔH2
ΔH1 + (2×ΔH2)
The oxidation of carbon monoxide can be represented by the chemical equation
2 CO(g) + O2(g) → 2 CO2(g) ΔHrxn = -613kJ/molrxn
Which of the following best represents the energy absorbed or released when 168grams of CO is oxidized?
-1839kJ
1839kJ
-3678kJ
3678kJ
Based on the bond energies shown in the table above, which of the following diagrams best represents the change in energy as the reaction represented below proceeds?
2H2O(l) → 2H2(g) + O2(g)
In which of the following processes is there an increase in entropy?
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NaCl(s) → Na+(aq) + Cl−(aq)
CaCO3(s) → CaO(s) + CO2(g)
H2O(l) → H2O(s)
2H2O(g) → 2H2(g) + O2(g)
When two aqueous solutions are mixed together in a closed container. A precipitate forms and the temperature increases. Which of the following indicates the correct signs for ΔG, ΔH, and ΔS for the process?
-ΔG
-ΔH
-ΔS
+ΔG
-ΔH
-ΔS
-ΔG
+ΔH
+ΔS
+ΔG
+ΔH
+ΔS
