Form Code X
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CHM 2045, Fall 2015, Exam 1 Review Packet (Broward Teaching Center)
Final Packet Instructions: Do your best and don’t be anxious. Read the question, re-read the question,
write down all given or valuable information, and write down what you want to find. As on all graded
events, the loving of moles applies.
1. A solution of sucrose in water is 55.0% sucrose by mass and has a density of 1.59 g/mL. What
mass of sucrose, in grams, is contained in 4.00 L of solution?
1) 3.5x103 g sucrose 2) 1.1x103 g sucrose 3) 3.5 g sucrose 4) 4.4x103 g sucrose 5) 4.5 g sucrose
2. The compound (X) contains 49.48 % carbon, 5.191 % hydrogen, 28.87 % nitrogen, and
16.48% oxygen by mass. Additionally, X’s molecular weight lies between the domain of
Compound Y’s MW and Compound Z’s MW. If MWY = 188 g/mol and
MWZ = 200 g/mol. Determine the molecular formula of the compound.
1) C4H5N2O
2) C8H10N4O2
3) C8H8N3O3
4) C10H7N5O2
5) C8H10N2O
3. The radioactive 50V isotope has which Z, neutron number, and A (respectively)?
1) 23, 23, 27
2) 35, 27, 50
3) 23, 27, 50
4) 20, 81, 35 5) 35, 27, 11
4. If 1.951 g BaCl2·xH2O yields 1.864 g of anhydrous BaSO4 (233.43 g/mol) after treatment with
excess sulfuric acid, what is the value of x in the formula of BaCl2·xH2O? (round to nearest
whole number)
1) one
2) two
3) three
4) four
5) five
5. Calculate the number of oxygen atoms in 29.34 g of sodium sulfate, Na2SO4.
(1) 1.244 x 1023 O atoms (2) 4.976 x 1023 O atoms (3) 2.409 x 1024 O atoms
(4) 2.915 x 1024 O atoms (5) 1.166 x 1025 O atoms
6. If 4.00 g of element G reacts with 7.00 g of element M to produce 13.00 g of a compound with
the formula G3M4, and the atomic mass of M is 160.0 amu, what is the atomic mass of G?
1) 60.5 amu 2) 122.0 amu 3) 72.0 amu 4) 89.5 amu 5) 150 amu
7.
Consider the following reaction: 2A + B 3C + D
If 3.0 mol A and 2.0 mol B react to form 4.0 mol C. What is the percent yield of this reaction?
(1) 100%
(2) 67%
(3) 89%
(4) 50%
(5) 75%
8. If a sheet of aluminum foil (d = 2.70 g/cm3) weighs 6.45 lbs and is 0.0210 mm thick, the surface
area of the foil is closest to…?
1) 9.40 ft2
2) 13.9 ft2
3) 234 ft2
4) 740 ft2
5) 555 ft2
9. Which of the following ionic compounds/names are true?
A) Magnesium Dicholride B) Fe2O3 C) Iron (III) Oxide D) NH3
1) A, B, C, D
2) A only
3) A and B only
4) B and C only
5) D only
10. Which of the covalent compounds are incorrect?
A) P4S5 (tetraphosphorous pentasulfur) B) Si2Br6 (disilicon hexabromide) C) ClO2 (monochorine dioxide)
1) A only 2) B and C only 3) C only 4) B and C only 5) A and C only
11. Which of the following is false?
1) Iron(III) sulfide has three Fe atoms
2) HCl is a strong acid
3) Z is the atomic number symbol
4) N2O3 is dinitrogen trioxide
5) The reaction H2(g) + F2(g)  2HF(g) is a redox reaction
12. Which of the following is closest to the mass of chromium in 1.064 g Cr2O3?
1) 0.342 g 2) 0.727 g 3) 0.682 g 4) 1.064 g 5) 1.042 g
13. Sweetener saccharin (C7H5NO3S) is sometimes dispensed in tablet form. Ten (10) tablets with a
total mass of 0.5894 g were dissolved in water. They were oxidized to convert all the sulfur to
sulfate ion, which was precipitated by adding an excess of barium chloride solution. The mass
of barium sulfate obtained was 0.5032 g. What is the average mass percent of saccharin in the
tablets?
Hint* Think of a pregnant mole….LITERALLY!
1) 69% 2) 40% 3) 65% 4) 39.4% 5) 58.94%
14. Given the reaction: 3 H2S + 2 FeCl3  Fe2S3 + 6 HCl
We have 60.0 g of FeCl3 reacts with 42.0 g of H2S. Which is the limiting reactant. Also, what is
the percent yield given that only 36g of HCl is produced?
1) 88.76% 2) 70% 3) 36% 4) 89.91% 5) 62%
15. Both Mg3N2 (100.9 g/mol) and Mg(OH)2 (58.3 g/mol) can be converted to MgO (40.3 g/mol) by
appropriate means. If a 2.00 g mixture of these two compounds is converted, and 1.50 g of
MgO is obtained, what is the approximate mass percent of Mg3N2 in the mixture?
(1) 11.5% (2) 20% (3) 50% (4) 10% (5) 96%
16. The concentration of LiOH is 0.50 M. If 25 mL of LiOH is needed to titrate 40 mL of HNO3
(nitric acid) what is the concentraiton of HNO3?
1) 0.03125 M HNO3 2) 0.8 M HNO3 3) 0.3125 M HNO3 4) 0.08 M HNO3 5) 1.00 M HNO3
17. Select the false statement below:
(1) Pb2+(aq) + 2I− (aq) → PbI2(s) is a precipitation reaction but is not a redox reaction
(2) CH4(g) + 2O2(g) → CO2(g) + 2H2O(g) is a combustion reaction and a redox reaction
(3) Ca(s) + F2(g) → CaF2(s) is a precipitation reaction and a redox reaction
(4) HNO3(aq) + KOH(aq) → H2O(l) + KNO3(aq) is an acid-base reaction but is not a redox
reaction
(5) H2SO4(aq) + Ba(OH)2(aq) → 2H2O(l) + BaSO4(s) is a precipitation reaction and an acidbase reaction
18. In which of the following equations are the base and conjugate base (proposed bases are
underlined) incorrectly labeled?
(1) HCl + H2O  Cl- + H3O +
(2) H2PO4 - + H2O  H3PO4 + OH(3) CN- + H2O  HCN + OH(4) CH3COOH + H2O  CH3COO- + H3O +
(5) HCO3 - + H2O  H2CO3 + OH-
19. In which of the following equations are the acid and conjugate acid (proposed bases are
underlined) correctly labeled?
1) CH3CO2H(aq) + H2O(l) <-----> H3O+(aq) + CH3CO2-(aq)
2) NH3(g) + H2O(l)→NH4+ (aq) + OH − (aq)
3) HCl + NH3  NH4+ + Cl4) H3O+ + OH-  2H2O
5) H2NO2 + H2O  NO2- + H3O+
20. How many hydrogen ions are present in a 14.6 mL aqueous solution of sulfurous acid given
that density Sulfurous acid = 1.03g/mL.
1) 1.1x1023 H+ ions 2) 0.366 H+ ions 3) 2.207x1023 H+ ions 4) 2.22x1023 5) 2.21x1022 H+ ions
21. Find the percent by mass of hydrogen in ammonium hypochlorite?
1) 5.76%
2) 3.49%
3) 7.66%
4) 4.05%
5) 50%
22. How many mols of Aluminum are in 268.9g Aluminum Oxide?
1) 2.64 mol Al
2) 3.45 mol Al
3) 5.27 mol Al
4) 1 mol Al
5) 142.18 mol Al
23. If 20.00g of Calcium Carbonate reacts with Magnesium Nitrate in a double displacement
reaction, how many mols of nitrate is produced through the reaction? Assume that reaction
goes to completion and that there is no excess of reactants.
Hint* What is the charge of Nitrate?
Hint*This is a double displacement
Hint*Write out the reaction
1) 0.4 mols Nitrate 2) 0.8 mols Nitrate 3) 1.2 mols Nitrate 4) 1.0 mols Nitrate 5) 4.5 mols Nitrate
24. How many grams of sodium are needed to make a 750 mL of a 1.3 M solution of sodium
bromide? Hint* Write out what the units of molarity are. Hint* What does multiplying
molarity by volume leave you with?
1) 22.40 g Sodium 2) 85.43g Sodium 3) 1.73g Sodium 4) 122.40g Sodium 5) 80.00g Sodium
25. How many chromium ions are in 63.54g of potassium chromate?
Hint* What is Chromate?
Hint*What is Potassium’s oxidation number?
Hint*Think of pregnant moles….LITERALLY….AGAIN!!
Hint* Molar mass of Potassium Chromate = 194.2g/mol
1) 0.327x10^23
2) 1.97
3) 2.00
4) 2.00x10^23
5) 1.97x10^23
GOOD LUCK and SMILE ON THE EXAM!!!
-Broward Teaching Center