Question

4. SEP Use Math A chemist produces 4.50 grams of a compound made of copper and chlorine. Further experiments show that the sample contains 2.12 grams of copper. Find the percent composition of copper and chlorine in the compound and then identify the compound as either copper(I) chloride (CuCl) or copper(II) chloride (CuCl2).

Answer 1

The whole compound has a mass of 4.50 grams and we have in this compound 2.12 grams of Copper, how many percent of the compound would this represent? Let's do the math:

4.50g = 100%

2.12g = x %

x = 47.1% of the compound is Copper

Therefore we will have 52.9% of Chlorine

Now what is the correct formula? Since Copper has a molar mass of 63.54 g/mol and Chlorine has a molar mass of 35.45g/mol, It is correct to assume that the best formula for this compound would be CuCl2, or the Copper (II) chloride