Question

Hydrogen and oxygen combine in a ratio of 1:8 by mass to form water. What mass of oxygen gas is required to react completely with 3g of hydrogen gas?

• A. 8 g
• B. 16 g
• C. 24 g
• D. 32 g

Answer 1

The correct option is C

24 g

Hydrogen and oxygen combine in a ratio of 1:8 means that 1g of hydrogen gas requires 8g of oxygen gas to form water.

Therefore, 3g of hydrogen gas will require = 8 $\times$ 3 = 24 g of oxygen

Thus, 24g of the oxygen gas is required to react completely with 3 g of hydrogen gas to form water.