# Question #a396f

Jun 20, 2017

6 grams of oxygen yields (if you have enough ${C}_{3} {H}_{6}$) 2.25 grams of water.

#### Explanation:

Let me compute molecular weights first:
${C}_{3} {H}_{6} = 42$ grams, water 18 grams and oxygen (molecule) 32 grams.

If you have 288 grams of oxygen and $2 \times 42 = 84$ grams of ${C}_{3} {H}_{6}$, you will get 108 grams of water (after reaction takes place).

However, you have only 6 grams of oxygen. Therefore, if you have 1.75 grams of ${C}_{3} {H}_{6}$, you get only 2.25 grams of water (after completion of reaction).

Let me explain step by step:
1. Compute amounts of materials that are needed to run this reaction. Express them:

It is: 84 grams of ${C}_{3} {H}_{6}$ reacts with 288 grams of oxygen. When these reactants run this reaction, this reaction yields 264 grams of $C {O}_{2}$ and 108 grams of water.

1. That means if you have 288 grams of oxygen (on the left hand side), you will get 108 grams of water (at the end of reaction).

2. But you have only 6 grams of oxygen, you wonder the amount of water you can produce.

If 288 grams of oxygen yields 108 grams of water
6 grams of oxygen yields (how much) ? water.

Amount of water produced is $108 \times \frac{6}{288}$

$= 2.25$ grams.