Chemistry
Name __________________
Chapter 2 Quantitative Problems
1. For simple table salt (sodium chloride) having the chemical formula NaCl,
a) Determine the mass of this compound in amu:
b) Determine the percent by mass sodium in the compound:
c) Determine the percent by mass of chlorine in the compound:
d) If 42.5 g of this compound was decomposed by electrolysis, determine mass of
sodium that would be obtained:
2. Epsom salts consist mostly of the compound magnesium sulfate, having the chemical
formula MgSO4.
a)
Determine the mass of this compound in amu:
1
b)
Determine the percent by mass magnesium in the compound:
c)
Determine the percent by mass of sulfur in the compound:
d)
Determine the percent by mass of oxygen in the compound:
e)
If 125 g of this compound was decomposed to its elements, determine mass of
sulfur that would be obtained:
3. For the decomposition of sodium chloride to its elements by electrolysis,
a) Write a chemical equation representing this reaction and balance it using coefficients:
b) Using atomic masses of elements, show how mass is conserved in your balanced
equation:
c) Is this reaction an example of a physical or chemical change? Explain.
2
4. An object has a mass of 20.0 kg. Determine its
a) Weight on earth:
b) Mass on Jupiter:
c) Weight on Jupiter:
Note: Jupiter has a mass roughly 320 times that of Earth
5. You are given a mixture of sand, salt, and iron filings. Outline a flowchart that will allow
you to separate all three substances. Include the basis of separation.
3