Relative Mass in Chemistry
A Grade 11 chemistry worksheet covering relative atomic mass, relative molecular mass, and isotopic abundance calculations.
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Relative Mass in Chemistry
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Read each question carefully and provide your answers in the space provided. Show all your work for calculations.
1. Define relative atomic mass (Ar) and explain why it is not usually a whole number.
2. The standard chosen for relative atomic mass is one-twelfth the mass of a single atom of .
3. Relative molecular mass (Mr) is the sum of the of all the atoms in a molecule.
4. Which of the following is the primary reason for the existence of isotopes?
Difference in the number of protons
Difference in the number of electrons
Difference in the number of neutrons
Difference in nuclear charge
5. Chlorine has two main isotopes: chlorine-35 (abundance 75.77%) and chlorine-37 (abundance 24.23%). Calculate the relative atomic mass of chlorine.
6. Calculate the relative molecular mass of sulfuric acid (H2SO4). (Given: Ar(H) = 1.0, Ar(S) = 32.1, Ar(O) = 16.0)