Question

A sample of chemical x is found to contain 5.0 grams of oxygen, 10.0 grams of carbon, and 20.0 grams of nitrogen. The law of definite proportion would predict that a 61 gram sample of chemical x should contain how many grams of carbon? 17 grams

Answer 1

A simple proportion,
$10 \div 35 = x \div 61$
$61 \times 10 = 610$
$610 \div 35 = 17.42857$
so x= 17.43~