Question

10 g hydrogen is reacted with 64 g oxygen. The amount of water formed will be (in moles) _______.
(A) 3
(B) 4
(C) 1
(D) 2

Answer 1

Number of moles of hydrogen = 10/2 = 5 moles

Number of moles of oxygen = 64/32 = 2 moles

2 H2 + O2 -------> 2 H2O

So, each mole of oxygen reacts with 2 moles of hydrogen.

Here, we have 2 moles of O2 in the given sample which will consume 4 moles of H2.

4 H2 + 2 O2 ----------> 4 H2O

Thus, 4 moles of water are formed.