Take note of the subscript written for each element in the compound. To find the total number of moles, make sure to multiply the subscript with the number of moles of compound. The answer for each is written below:
a. 3*1 = 3 moles Nitrogen; 3*3 = 9 moles Hydrogen
b. 0.25*2 = 0.5 moles Hydrogen; 0.25*1 = 0.25 moles Oxygen
c. 5*2 = 10 moles Hydrogen; 5*1 =5 moles Sulfur; 5*4 = 20 moles Oxygen
d. 0.75*1 = 0.75 moles Calcium; 0.75*1*2 = 1.5 moles Nitrogen; 0.75*3*2 = 4.5 moles Oxygen
