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Chemistry I
Final Review
Practice Problems
1. Tell the number of significant figures in the following: 0.06700, 8501, 6.260 X 102
2. Round each of the numbers in #1 to three significant figures.
3. Add the following numbers to the correct number of significant figures: 125.02, 78.650, 25.1
4. Find the product of the following numbers to the correct number of significant figures: 15.89, 7.251
5. Convert to grams: 1500 mg, 7.99 kg
Convert to liters: 1925 mL, 17000 cm3
Convert to meters: 143 cm, 90 km, 20 mm
6. What is the mass of an object that has a density of 0.83 g/mL and displaces 23 mL of water?
7. How many protons, neutrons, and electrons are in the following isotopes:
53Cr,
boron-7
8. How many protons and electrons are in the following ions: Al+3, F-1
9. Calculate the average atomic mass of an element with the following:
isotope 1 has a mass of 76 and is 35% abundant
isotope 2 has a mass of 79 and is 65% abundant
25. Write the electron configurations for the following atoms: A) Ca B) Cl C) V
26. Draw the electron filling chart for sulfur. How many half-filled orbitals does it have?
27. Which of the following formulas represents a molecular compound?
a) MgO
b) O2
c) CuI2
d)NO3
28. Which of the following compounds contains the tin (II) ion?
a) SnO2
b) SnCl4
c) Sn2O
d) Sn5O3
d)SnO
29.
a)
b)
c)
d)
e)
Which set of chemical name and chemical formula for the same compound is correct?
copper(II) oxide, CuO
magnesium sulfide, MgS2
lead(II) bromide, PbBr4
barium chloride, Ba2Cl2
aluminum chlorate, AlCl3
30. The correct formula for magnesium carbonate is
a) Mg(HCO3)2
b) Mg(HCO4)2
c) MgCO3
d) MgCO4
e) MgS
31. The correct formula for barium bisulfate is
a) BaH2SO4
b) Ba2HSO4
c) Ba(HSO4)2
d) BaHSO4
e)Ba(H2SO4)2
.
.
32. Which of the following shows both the correct formula and correct name of an acid?
a) HFO2, fluoric acid
b) H2CO2, hydrocarbonic acid
c) H3PO2, phosphoric acid
d) HBr, hydrobromic acid
33. Balance the following equations:
a.
Ca + H2O  Ca(OH)2 +
b.
Cu +
O2 
c.
Mg +
AlCl3 
MgCl2 +
d.
Ni +
NaCl 
NiCl3 +
H2
CuO
Al
Na
34. Tell whether the following equations represent exothermic or endothermic reactions:
a.
AgOH + CaCl2 + 63 kJ  AgCl + Ca(OH)2
b.
CH4 + O2  CO2 + H2O + 120 kJ
35. Convert the following to moles: 8.82 X 1026 atoms of He, 589 grams of BaSO4, 99 L of O2 gas (STP)
36. How many molecules of H2 are in 7.9 moles? How many grams? How many liters of gas?
37. Determine the percent composition of FeSO4.
38. Determine the number of grams of sulfur in 180 g of FeSO4 based on what you found in #37.
39. Determine the empirical formula of a compound that is 70% Fe and 30% O.
40. Determine the molecular formula of a compound when the empirical formula is CH2O and the gram
formula mass is 180 g.
41. For the following reaction:
2K(s) + 2H2O(l) → 2KOH(aq) + H2(g)
a) Determine the number of grams of KOH that will be produced when 97 g of potassium are used.
b) Determine the number of liters of H2 gas that will be produced when 6.5 X 1024 molecules of water
are reacted.
42. Suppose you have a sample of NO2 in a container at a volume of 2.5 L and 25°C. What is the final
volume of the gas if the pressure is constant and you raise the temperature to 48°C?
43. A sample of SO2 has a pressure of 950 mm Hg in a volume of 460 mL. The sample is moved to a new
flask in which the pressure of the gas is now 400 mm Hg. What is the volume of the new flask?
44. Suppose that a balloon is launched when the temperature is 26°C and the barometric pressure is 735
mm Hg. If the balloon’s volume is 20.4 L, what will it be at a height of 10 miles, where the pressure is
110.0 mm Hg and the temperature is 0°C?
45. At a constant volume, what will the pressure of a gas be when the temperature is increased from
30°C to 150°C and the original pressure was 770 mm Hg?
46. What mass of NaCl is needed to make 1.3 L of a 0.5 M solution?
47. When a 4.0 M solution is used to make 1.0 L of a 0.6 M solution, what is the final volume?