Answer:
1.02 (or 1.03 if rounded)
Explanation:
Given 16.4 grams of oxygen gas, you would want to write that down to set up your unit conversions.
16.4 g O2/1 * 1 mol of O2/31.998 g O2 * 2 mol H2O/1 mol O2
Multiply the numbers on the top and divide that by the product of the numbers on the bottom.
16.4 * 1 * 2 = 32.8
1 * 31.998 * 1 = 31.998
32.8/31.998 = 1.025...
Don't forget to consider the number of significant figures if it asks!
