Question

A green gold bracelet weighs 56g. The bracelet is made from 75% gold, 20% silver and 5% copper.

(a) What is the mass of the gold in the bracelet?
(b) What is the mass of the copper in the bracelet?

Answer 1

a. 42 g

b. 2.8 g

Explanation:

a. Since the entire thing weighs 56g and gold is 75% of the mass you simply find 75% of the mass. This is done by converting the 75% into decimal form by dividing it by 100 to get 0.75 and then multiply it by the 56 g to get (0.75 * 56 g) = 42 g

b. same thing here as the previous answer. 5%/100 = 0.05. (0.05 * 56 g) = 2.8 g