EXAM 1 Form B CHEM 101: Sections 565-576 Dr. M. Shatruk FALL 2005

EXAM 1 – Form B CHEM 101: Sections 565-576 Dr. M. Shatruk FALL 2005

1. Stainless steel for marine applications contains chromium and molybdenum – metals which make it highly resistant to corrosion caused by seawater. If the steel is 17% Cr by mass, what is the amount of Cr in grams contained in 955 g of steel? [6 pts]

(A) 475 g (B) 126 g (C) 162 g (D) 793 g

2. Determine the percent composition of sodium in Na2SO3: [7 pts]

(A) 36.5% (B) 38.1% (C) 25.4% (D) 18.8%

3. How much potassium chloride is produced from the reaction of 2.00 g of K and 3.00 g of Cl2? [8 pts]

2K + Cl2  2KCl

(A) 3.15 g (B) 1.90 g (C) 3.81 g (D) 6.31 g

4. 10.2 g of chromium (Cr) reacts with excess Cl2 to produce 23.9 g of chromium(III) chloride, CrCl3. What is the percent yield of CrCl3? (Don’t forget to balance the equation.) [9 pts]

(A) 115% (B) 38.5% (C) 90.3% (D) 76.9%

Page B-1 EXAM 1 – Form B CHEM 101: Sections 565-576 Dr. M. Shatruk FALL 2005

5. An aqueous solution of KBr contains 114 g of KBr and the concentration of potassium bromide is 6.00%. What is the total mass of the solution? [6 pts]

(A) 190 g (B) 1900 g (C) 1784 g (D) 160 g

6. 700 mL of water is added to 100 mL of 1.60 M solution of KOH. What is the molarity of the resulting solution? [6 pts]

(A) 0.200 M (B) 0.458 M (C) 0.229 M (D) 0.400 M

7. What volume of 1.60 M solution of LiOH is needed to react with 300 mL of 0.800 M solution of HNO3 according to the equation: [9 pts]

LiOH + HNO3  LiNO3 + H2O

(A) 300 mL (B) 250 mL (C) 200 mL (D) 150 mL

Page B-2 EXAM 1 – Form B CHEM 101: Sections 565-576 Dr. M. Shatruk FALL 2005 Your Name: ______Section #: ______

8. Express the following numbers in standard exponential form (scientific notation): [5 pts]

(a) 0.007833 (b) 1 234 000 (c) 34 675

9. An atom contains 29 electrons and 36 neutrons. Determine: [6 pts]

(a) the atomic number of the element

(b) the name of the element

(c) the number of protons

(d) the mass of the atom in a.m.u. (calculate the mass without looking at the periodic chart)

10. Write formulas for the following ionic compounds: [7 pts]

(a) calcium sulfate

(b) iron(III) carbonate

(c) ammonium bromide

11. A compound contains 56.3% of phosphorus and 43.7% of oxygen. Its molecular weight is 219.9 a.m.u. Derive its molecular formula. [9 pts]

Page B-3 EXAM 1 – Form B CHEM 101: Sections 565-576 Dr. M. Shatruk FALL 2005

12. Balance the following equations: [7 pts]

(a) ZnS + O2  ZnO + SO2

(b) BiCl3 + H2O  BiOCl + HCl

13. Classify each of the following substances as acid, base, or salt: [6 pts]

(a) KOH

(b) NH4Br

(c) H2SO4

(d) Cu(NO3)2

14. Write the total and net ionic equations for following reactions: [9 pts]

CuCl2 + Na2CO3  CuCO3 + 2NaCl

BaCl2 + H2SO4  BaSO4 + 2HCl

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