Answer: There are 
atoms present in 0.500 mol of 
.
Explanation:
According to the mole concept, there are 
atoms present in 1 mole of a substance.
In a molecule of there is only one carbon atom present. Therefore, number of carbon atoms present in 0.500 mol of are as follows.
Thus, we can conclude that there are atoms present in 0.500 mol of .
The grams of oxygen that are required to produce 1 mole of H₂O is 16 g ( answer B)
<u><em> calculation</em></u>
2 CH₄ + 2NH₃ +3 O₂ → 2HCN + 6H₂O
step 1: use the mole ratio to find moles of O₂
from equation above the mole ratio of O₂: H₂O is 3:6 therefore the moles of O₂ = 1 mole x3/6 =0.5 moles
step 2: find mass of O₂
mass= moles x molar mass
from periodic table the molar mass of O₂ = 16 x2= 32 g/mol
mass O₂ = 0.5 moles x 32 g/mol = 16 g (answer B)
