Chemistry 2202
Unit 1 Test 1
Name: __________________________
Part 1: Multiple Choice Questions. Shade the letter of the correct answer on
the scoreable bubble sheet provided. (1 point each)
1. How many neutrons are in an atom of chlorine-37?
(A) 12
(B) 13
(C) 20
(D) 37
2. A calcium isotope has 20 protons and 20 neutrons per atom. What is the name of this
isotope?
(A) calcium-19
(B) calcium-40
(C) calcium-43
(D) calcium-44
3. How many moles are in a sample that contains 8.67 x 10 24 atoms of aluminum?
(A) 0.222 mol
(B) 4.50 mol
(C) 14.4 mol
(D) 1.63 x 10 48 mol
4. What is the chemical formula for a large carbon molecule that has a molar mass of
600.50 g/mol?
(A) C60
(B) C70
(C) C829
(D) C853
5. What is the molar mass of aluminium hydroxide, Al(OH)3?
(A) 38.00 g/mol
(B) 58.10 g/mol
(C) 74.10 g/mol
(D) 78.01 g/mol
6. How many calcium atoms are there in a 40.08 g sample?
(A) 4.98 × 10−24
(B) 2.01 × 1023
(C) 6.02 × 1023
(D) 1.81 × 1024
7. What is the molar mass of ammonium phosphate, (NH4)3PO4?
(A) 113.02 g/mol
(B) 149.12 g/mol
(C) 303.26 g/mol
(D) 421.04 g/mol
8. How many moles are in 7.500 g of NH4I (Molar mass = 144.95 g/mol)?
(A) 0.05174 mol
(B) 0.07657 mol
(C) 97.95 mol
(D) 734.8 mol
9. The molar mass of a compound with the empirical formula of CH2O is 180.16 g/mol.
What is the molecular formula of the compound?
(A) CH2O
(B) C4H4O8
(C) C4H8O4
(D) C6H12O6
10. Which unit expresses molar volume?
(A) g/mol
(B) L/mol
(C) mol/g
(D) mol/L
11. A sodium chloride solution has a concentration of 0.101 mol/L. How many moles of
NaCl are present in a 2.63 L sample of the solution?
(A) 0.266 mol
(B) 0.700 mol
(C) 1.84 mol
(D) 3.76 mol
12. What is the mass of 2.25 x 10 24 formula units of Al2O3 (Molar mass = 101.96 g/mol)?
(A) 0.0776 g
(B) 381 g
(C) 806 g
(D) 2.92 x 10 50 g
13. Which equation correctly solves for the mass of a compound?
(A) m=n/M
(B) m=v/N
(C) m=nM
(D) m= CM
14. If a hydrated ionic compound is gently heated and the mass decreases, what was
removed?
(A) air
(B) crystal
(C) copper
(D) water
15. What is the concentration of a 0.375 L solution that has 7.90 g of NaCl (Molar mass
= 58.44 g/mol) dissolved?
(A) 0.0507 mol/L
(B) 0.135 mol/L
(C) 0.360 mol/L
(D) 2.77 mol/L
16. What is the average atomic mass of the imaginary element, Newfoundlandium (Nl)?
Isotope
(A)
(B)
(C)
(D)
Average Atomic Mass (amu)
% Abundance
225.89
7.6000
241.06
92.400
119.96 amu
233.48 amu
239.91 amu
394.94 amu
17. What is the volume of 1.25 g of sulfur dioxide, SO2 (Molar mass = 64.07 g/mol), at
STP ?
(A) 8.71 x 10 -4 L
(B) 0.437 L
(C) 1.79 x 10 3 L
(D) 1.15 x 10 3 L
18. A 20.0 g sample of CaCl2 * 2 H2O (Molar mass = 147.02 g/mol) is heated to remove
the water. What mass of anhydrous CaCl2 will be present after all the water is removed?
(A) 0.217 g
(B) 0.783 g
(C) 4.35 g
(D) 15.1 g
19. Which term represents the mass of one mole of an element?
(A) Molar mass
(B) Molar volume
(C) Percent composition
(D) Percent volume
20. A mole is an amount of substance that contains as many particles as exactly 12g of
which substance?
(A) Carbon
(B) Hydrogen
(C) Oxygen
(D) Nitrogen
Part 2: Short Answer Questions. Answer ALL questions in the space provided. All necessary
workings must be shown to receive full marks.
1. What is the percent composition, by mass, of NaHCO3 ? (4)
2. What mass of potassium sulphate, K2SO4, is required to produce 4.75 L of 1.25 mol/L
solution? (3)
3. What is the mass of each element found in 235 g of pure H2SO4? (4)
4. Calculate the mass of 875L of disulfur trioxide gas, S2O3 (g), at STP. (3)
5. Ethanoic acid has a molar mass of 60.06 g/mol and the following percent composition:
C: 40 %, H: 6.7 %, O: 53.3 %. Determine the molecular formula of ethanoic acid. (5)