TTU General Chemistry

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Chem 111 - Quiz 3A - Fall, 1996
Chapter III: Chemical Equations and Reaction Stoichiometry

1. How many grams of O2 will be required to completely react with 2.43 grams of Mg metal ribbon to produce MgO? Hint: Start by writing a balanced chemical equations for the reaction.

a) 6.40 g
b) 3.20 g
c) 0.80 g
d) 1.21 g
e) 1.60 g

2. In the bromination of ethane (C2H6) reaction, one wants to produce 10.0 g of C2H5Br product. How many grams of C2H6 would be needed to react with excess Br2?

C2H6 + Br2 ---> C2H5Br + HBr

a) 10.0 g
b) 2.76 g
c) 0.0917 g
d) 5.52 g
e) 20.0 g

3. If equal masses of H2 and O2 (100.0 grams each) are reacted together to produce water, how many grams of water could be produced?

a) 47.0 g
b) 200.0 g
c) 892.8 g
d) 150.0 g
e) 112.5 g

4. In the decomposition of KClO3, 2.0 grams of KClO3 are reacted and 1.0 gram of KCl is actually collected in the experiment after the reaction is over. What is the % yield of this reaction?

2KClO3 ---> 2KCl + 3O2

a) 82.2%
b) 50%
c) 100%
d) 75%
e) 43%

5. Identify the INCORRECT statement below concerning an aqueous solution which is 0.1 M HCl solution:

a) This solution is a homogeneous mixture of ionized HCl and H2O.
b) In this solution water is the solute.
c) The solvent is the dispersing medium, which is the substance present in greatest abundance.
d) In this solution there are essentially no non-ionized HCl molecules present.
e) This solution has a high electrical conductivity.

6. An aqueous glucose solution is 10% glucose by mass. What is the mass of glucose present in 320 grams of solution?

a) 0.0312 g
b) 3200 g
c) 0.320 g
d) 32 g

7. I want to prepare 4 Liters of 0.25 M aqueous sodium chloride solution. How many grams of the salt will I need to weigh out?

a) 1.0 g
b) 58 g
c) 234 g
d) 42 g
e) 9.7 g

8. If 17.0 grams of sodium nitrate are place into a 2.00 L volumetric flask, and the flask is filled to the mark with distilled water, what is the molarity of sodium nitrate in the solution?

a) 0.40 M
b) 0.20 M
c) 8.5 M
d) 0.10 M
e) 11.7 M

9. A 10.00 mL solution which is 6.0 M HCl is pipetted into a 250 mL volumetric flask and the flask is filled to the mark. What is the final molarity of HCl in the flask?

a) 0.24 M
b) 150 M
c) 1.0 M
d) 1 x 10-6 M

10. It takes 41.66 milliliters of an HCl solution to reach the endpoint in a titration against 250.0 mL of 0.100 M NaOH. What is the molarity of the HCl solution?

a) 1.667 M
b) 0.0167 M
c) 0.600 M
d) 6.00 M
e) 11.6 M

11. Identify the INCORRECT statement below:

a) In the most fundamental sense, the properties of the elements are periodic functions of their atomic weight.
b) The periodic law of the elements was first noted by Mendeleev and Meyer in the mid-1800's.
c) The vertical columns of the periodic chart are called groups, sharing similar properties.
d) Elements with atomic numbers of 9, 17, 35, and 53 are members of the halogen family, meaning "salt formers."
e) Elements Li, B, N and F are all in the same period.

12. Arrange the elements silicon, sodium, fluorine, and cesium, in order of decreasing metallic character. (i.e., from most metallic to least)

a) cesium > sodium > silicon > fluorine
b) fluorine > silicon > sodium > cesium
c) sodium > cesium > silicon > fluorine
d) fluorine > sodium > silicon > cesium

13. Which of the following is NOT a typical property of a metal?

a) forms ionic compounds with nonmetals
b) tendency to lose electrons to form cations
c) outer electron shells contain 4 or more electrons
d) high electrical conductivity
e) high thermal conductivity

14. Which of the following substances is a strong electrolyte?

a) sucrose
b) acetic acid
c) methyl alcohol
d) water
e) sodium hydroxide

15. Identify which substance below is NOT a strong acid in aqueous solution:

a) HBr
b) HCl
c) HNO3
d) H2SO4
e) HF

16. Identify the strong base (in aqueous solution) from among the following compounds:

a) Na2S
b) Cu(OH)2
c) NH3
d) NH4Cl
e) KOH

17. Identify the substance below which is INSOLUBLE in water.

a) Na2S
b) Ca3 (PO4)2
c) MgCl2
d) AgNO3
e) CaCl2

KEY

1)e 2)b 3)e 4)a 5)b 6)d 7)b 8)d 9)a 10)c 11)a 12)a 13)c 14)e 15)e 16)e 17)b