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Student ID : ______

CH 115 Summer 2015 Mock Exam 2

*** Assume that equations are NOT balanced ***

  1. What is the percent composition of oxygen in phosphate?
  2. 60.7%
  3. 80.0%
  4. 56.3%
  5. 16.8%
  6. 67.4%
  1. You are given 15.0 g CH4(g) and 115 g of Cl2(g). How many grams of CH2Cl2(g) could you theoretically make?

CH4(aq) + Cl2(g) → CH2Cl2(g) + HCl(g)

  1. 39.7 g
  2. 68.9 g
  3. 84.9 g
  4. 138 g
  5. 79.4 g
  1. What is the oxidation number for carbon in C2O4-2?
  2. +2
  3. 0
  4. +4
  5. +3
  6. +6
  1. Which of the following are precipitation reactions?

X. Na3PO4(aq) + CrCl3(aq)

Y. Fe(ClO3)2(aq) + NaOH(aq)

Z. NH4NO3(aq) + Mg(CH3COO)2(aq)

  1. X and Y
  2. Y and Z
  3. Z only
  4. Y only
  5. X only
  1. Which of the following lists two weak acids?
  2. CH3COOH and Ca(OH)2
  3. H2CO3 and HClO4
  4. H2SO4 and HNO3
  5. CH3NH2 and NaOH
  6. HCN and C6H5COOH
  7. If 45.5g of NH3 and 90.3g of O2 produce 32.9g of H2O, find the percent yield?

4 NH3 + 3 O2 2 N2 + 6 H2O

  1. 21.6%
  2. 68.4%
  3. 45.6%
  4. 95.1%
  5. 64.7%
  1. Which statements are false?

X. Strong electrolytes are compounds that dissolve completely to form ions.

Y. Strong acids are weak electrolytes.

Z. Most molecular compounds are electrolytes.

  1. X and Y
  2. Z only
  3. X only
  4. X and Z
  5. Y and Z
  1. What is the oxidation number for S in MgS2O3?
  2. +2
  3. -2
  4. -1
  5. +1
  6. 0
  1. Given 2.435 mol of C21H30O2, how many grams do you have?
  2. 0.07 g
  3. 314 g
  4. 766 g
  5. 250 g
  6. 43.0 g
  7. Given 55.0 g of Cu, how many atoms do you have?
  8. 6.02 x 1023 atoms
  9. 3.31 x 1023 atoms
  10. 5.21 x 1023atoms
  11. 4.76 x 1023 atoms
  12. 8.66 x 1023 atoms
  1. Name the compound below
  1. 4-ethyl-3,5,6-trimethylheptane
  2. 4,5-diethyl-2,3-dimethylhexane
  3. 2,3-diethyl-4,5-dimethylhexane
  4. 3-ethyl-1,2-dimethyl-4-(2-methylethyl)pentane
  5. 4-ethyl-2,3,5-trimethylheptane
  1. Given a compound that is 40.0% C, 6.70% H and 53.3% O, with a molar mass of 180.1554 g/mol, findthe molecular formula.
  2. C40H7O53
  3. C6H12O6
  4. C10H20O10
  5. CH2O
  6. C3H6O3
  1. Which element is not in its elemental form?
  2. Li2(s)
  3. H2(g)
  4. P4(s)
  5. N2(g)
  6. S8(s)
  1. Given 5.50 mol of CuSO4(aq) and 5.50 mol of NaOH(aq). How many moles of excess reactantremain?

NaOH(aq) + CuSO4(aq) → Cu(OH)2(s) + Na2SO4(aq)

  1. 2.75 mol excess CuSO4(aq)
  2. 0.0181 mol excess CuSO4(aq)
  3. 2.75 mol excess NaOH(aq)
  4. 0.115 mol excess NaOH(aq)
  5. The reaction is stoichiometric (i.e., no excess reactant)
  1. What is the stoichiometric coefficient for H2S when you balance the following equation?

H2O + Al2S3 → H2S + Al(OH)3

  1. 1
  2. 2
  3. 6
  4. 3
  5. 4
  1. Which of the following involve(s) a weak acid with a strong base?

X. HCN(aq) + NH3(aq)

Y. HCOOH(aq) + NaOH(aq)

Z. H2CO3(aq) + LiOH(aq)

  1. X and Z
  2. Y only
  3. Z only
  4. Y and Z
  5. X and Y
  1. Which of the following reactions requires additional energy to occur?(Hint: Use activity series)
    X. Mg(s) + Li2S(s) MgS(s) + 2 Li(s)

Y. CaCO3(s) + 2 K(s)  K2CO3(s) + Ca(s)
Z. 2 FeI3 (aq) + 3 F2(g)  2 FeF3(s) + 3 I2(s)

a. X and Y

b. Y and Z

c. Z only

d. Y only

e. X only

  1. Which statement best describes the reaction between rubidium hydroxide and hydrochloric acid?
  2. This is an exchange reaction.
  3. One of the products is a soluble ionic compound.
  4. This is an acid-base reaction.
  5. The net ionic equation for the reaction is H+(aq) + OH-(aq)  H2O(l)
  6. All of the above.
  1. How many milliters of 0.400M HCl(aq) do you need to have 5 moles?
  2. 80 mL
  3. 80 mL
  4. 200 mL
  5. 2 mL
  6. 2000 mL
  1. Which statements are true about the following reaction?

Na2CO3(s) + HCl(aq)  NaO + CO2 + H2O

X.This is a gas-forming reaction.

Y.The CO2 comes from the rapid decomposition of H2CO3.

Z.The reaction is already balanced.

  1. Y only
  2. Y and Z
  3. X only
  4. Z only
  5. X and Y
  1. Which reactants would give a product spontaneously?(Hint: Use activity series)

X. CoCl2(aq) + Br2(l)

Y. NiSO4(aq) + Sr(s)

Z. Ca(s) + Ba(NO3)2(aq)

  1. X and Z
  2. Y only
  3. Z only
  4. Y and Z
  5. X and Y
  1. Which statements are false?

X. The equivalence point is reached when stoichiometric amounts of one substance have been added to another.

Y. In titrations, the analyte is the substance of known concentration.

Z. Indicators reveal when you reach the equivalence point in a titration.

  1. Y and Z
  2. Z only
  3. X only
  4. X and Z
  5. X and Y
  1. In the reaction below, which statement is false?

2 KClO3(s)  2 KCl(s) + 3 O2(g)

  1. O is oxidized.
  2. Cl is reduced
  3. K is reducing agent
  4. This is a decomposition reaction.
  5. This is a redox reaction.
  1. Which of the following will not produce a precipitate?
  2. Ca(ClO3)2 + H2SO4
  3. Na2CO3 + AgNO3
  4. NH4Cl + Ba(CH3COO)2
  5. Li2C2O4 + CoSO4
  6. Rb3PO4 + Cu(ClO4)2
  1. Write the neutralization reaction (including phases) of sulfuric acid and strontium hydroxide.
  1. How much energy is necessary to raise the temperature of 47.8g of water by 91.0˚C?
  2. 18200 J
  3. 68.9 J
  4. 84.9 J
  5. 1010 J
  6. 2005 J
  1. How much energy does it take to melt 15g of solid Au that is initially at 800°C?
    The m.p. of gold is 1064°C, specific heat capacity for Au(s) is 0.1290 J/g°C, and ΔHfusion for Au(s) is 63.70 J/g.
  2. -1466 J
  3. -510.8 J
  4. 1466 J
  5. 510.8 J
  6. -955.55 J
  1. Identify the reducing agent and oxidizing agent for the following reaction:

2 CO2 + 5 Cl2  2 CCl4 + 2 ClO2

  1. How many joules are required to heat a frozen can of juice (360 grams) from -5 0 C (the temperature of an overcooled refrigerator) to 110 0C (the highest practical temperature within a microwave oven)?

  1. Name the molecule shown below:
  1. 1,2,5-trimethylheptane
  2. 2-ethyl-5-methylhexane
  3. 2-(2-methylbutyl)butane
  4. 2,5-dimethylheptane
  5. 2,5,6-trimethylheptane
  1. Identify the type of organic compound (2 points per blank, no partial credit)

Structural formula / Type of organic compound

Useful information

  • Heat of fusion (for H2O) = 334.16 J g¯1
  • Heat of vaporization(for H2O) = 2259 J g¯1
  • Specific heat capacity for solid water (ice) = 2.06 J g¯1°C¯1
  • Specific heat capacity for liquid water = 4.184 J g¯1°C¯1
  • Specific heat capacity for gaseous water (steam) = 2.02 J g¯1°C¯1