Question

Calculate the formula unit mass of Na2CO3.10H2O. ( Na = 23u, C = 12u, O = 16u, H=1u)​

Answer 1

Answer:

Formula Unit mass of NaHCO3=  

mass of Na + mass of H + mass of C + mass of O

= 23 + 1 + 12 + 3(16)

= 23 + 1 + 12 + 48

= 84 u

Answer 2

Answer:

Formula unit mass of Na2CO3

= 2×atomic mass of Na+1×atomic mass of C+3×atomic mass of O

=2×22.98+1×12.01+3×16

=105.97u

Formula unit mass of 10H2O=10×atomic mass of H2O

=10×18.02

=180.02u

Formula unit mass of Na2CO3.10H2O=105.97+180.02 

=285.99u