B). if 4 mole of hydrogen gas (h2) reacted with oxygen how many mole of water would be produced
from the reaction?

There would be 4 moles of water (H20) produced.

Explanation:

Step 1: Data given

Number of moles of H2 = 4 moles

Molar mass of H2 = 2.02 g/mol

Suppose oxygen is in excess

Step 2: The balanced equation

2H2 + O2 → 2H2O

Step 3: Calculate moles of H2O

H2 is the limiting reactant.

For 2 moles of H2 consumed, we need 1 mol of O2 to produce 2 moles of H2O

For 4 moles of H2 we'll have 4 moles of H2O

There would be 4 moles of water (H20) produced.

it means there are 3 atoms of oxygen