Question

What mass of oxygen is required to react completely with 3g of hydrogen gas?

Answer 1

We know that,

1 g of hydrogen reacts with oxygen = 8 g

Therefore,

3 g of hydrogen reacts with oxygen = 8 x 3 = 24 g

Thus, 24 g of oxygen gas would be required to react completely with 3 g of hydrogen gas.

Answer 2

1g of hydrogen react with oxygen= 8 g

therefore

3g of hydrogen react with 8g of oxygen

3g×8g= 24g

the answer is 24 g