Question

(b)
Q5. (a) Calculate the mass of 3 moles of C2H5OH. [ Atomic mass of C=12u, H=1u, O=16]
(b) How many moles of molecules are there in:
(i) 18 g of hydrogen H2
(ii) 54 g of H2O​

Answer 1

Explanation:

a) mass of one mole=12×2+1×5+16+1=46

mass of 3 mole=46×3=138

b) moles=mass/molar mass

i) moles=18/2=9

ii) moles=54/18=3