Question

Calculate the formula mass of sodium carbonate dehydrate (Na2CO3 –10H2O). pls briefly..​

Answer 1

Answer:

Correct option is

B

286

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