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CHM 115 – Exam #2 NAME______________________________ Dr. Kayiran, Fall 2013

There are 25 multiple choice questions in Part A, and each is worth 3 points. Completely fill in the appropriate circle on this sheet for these questions.

For the Short Answer section questions (Part B) place your answers on this exam in the spaces provided. Be sure to show all of your work with correct significant figures and units!!

THE SHORT ANSWER SECTION IS WORTH A TOTAL OF 25 POINTS

You may use the last page of this exam as scrap paper.

A periodic table of the elements as well as useful formulas and constants are included with this exam.

Hand-in all parts of this exam!

Useful Information:

M (M)= n (mol) / V (L)M1 * V1 = M2 * V2

PART A

Multiple Choice Section. Choose the best answer to each question below and completely fill in the appropriate circle on this sheet.

1) A covalent bond is best described as
A) the sharing of electrons between atoms.
B) the transfer of electrons.
C) a bond between a metal and a nonmetal.
D) a bond between a metal and a polyatomic ion.
E) a bond between two polyatomic ions.

2) Which of the following is a molecular (covalent) compound? A) NaCN
B) LiOH
C) SrI2
D) ZnS
E) P4O10

3) Which of the following is an ionic compound?
A) SCl2
B) Mg3(PO4)2
C) Cl2O
D) CH2O
E) PF5

4) Write the name for Ca3(PO4)2.
A) calcium (III) phosphite
B) calcium (II) phosphite
C) calcium phosphate
D) tricalcium phosphorustetraoxide
E) calcium phosphite

5) Give the correct formula for sodium chlorate.
A) NaClO
B) NaClO2
C) NaClO3
D) NaClO4

6) Give the name for H2SO4.
A) sulfuric acid
B) persulfurous acid
C) sulfurous acid
D) hyposulfurous acid
E) persulfuric acid
7) How many C2H4 molecules are contained in 45.8 mg of C2H4? The molar mass of C2H4 is 28.05 g/mol. A) 9.83 × 1020 C2H4 molecules
B) 7.74 × 1026 C2H4 molecules
C) 2.71 × 1020 C2H4 molecules
D) 3.69 × 1023 C2H4 molecules
E) 4.69 × 1023 C2H4 molecules

8) Calculate the mass percent composition of lithium in Li3PO4. A) 26.75 %
B) 17.98 %
C) 30.72 %
D) 55.27 %
E) 20.82 %

9) How many atoms of carbon are contained in 47.6 g of Al2(CO3)3? The molar mass of Al2(CO3)3 is 233.99 g/mol. A) 1.23 × 1023 C atoms
B) 2.96 × 1024 C atoms
C) 2.87 × 1025 C atoms
D) 1.10 × 1024 C atoms
E) 3.68 × 1023 C atoms

10) Determine the molecular formula of a compound that has a molar mass of 183.2 g/mol and an empirical formula of C2H5O2. A) C2H5O2
B) C6H15O6
C) C3H7O3
D) C4H10O4
E) C8H20O8

11. Determine the molecular formula of a compound that is 49.48% carbon, 5.19% hydrogen, 28.85% nitrogen, and 16.48% oxygen. The molecular weight is 194.19 g/mol. A) C8H12N4O2
B) C4H5N2O
C) C8H10N4O2
D) C8H10N2O

12) According to the following balanced reaction, how many moles of HNO3 are formed from 8.44 moles of NO2 if there is plenty of water present?

3 NO2(g) + H2O(l) → 2 HNO3(aq) + NO(g)

A) 2.81 moles HNO3
B) 25.3 moles HNO3
C) 8.44 moles HNO3
D) 5.63 moles HNO3
E) 1.83 moles HNO3

13) Which of the following solutions will have the highest concentration of chloride ions? A) 0.10 M NaCl
B) 0.10 M MgCl2
C) 0.10 M AlCl3
D) 0.05 M CaCl2
E) All of these solutions have the same concentration of chloride ions.

14) How many liters of a 0.0550 M KCl solution contain 0.163 moles of KCl? A) 3.37 L
B) 1.48 L
C) 8.97 L
D) 2.96 L
E) 1.12 L

15) Determine the concentration of a solution prepared by diluting 20.0 mL of a 0.200 M NaCl to 250.0 mL. A) 0.160 M
B) 0.0320 M
C) 2.50 M
D) 0.00800 M
E) 0.0160 M

16) How many molecules of sucrose (C12H22O11, molar mass = 342.30 g/mol) are contained in 14.3 mL of 0.140 M sucrose solution? A) 8.29 × 1022 molecules C12H22O11
B) 1.21 × 1021 molecules C12H22O11
C) 6.15 × 1022 molecules C12H22O11
D) 1.63 × 1023 molecules C12H22O11
E) 5.90 × 1024 molecules C12H22O11

17) Identify sugar.
A) strong electrolyte, weak acid
B) weak...
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