Question

5.The relative molecular mass of Na2S2O3.5H2O is *

Answer 1

Answer:

Sodium thiosulphate Na2S2O3 is available as a Penta hydrate salt. ie., It's Molecular Formula is Na2S2O3. 5H2O. It's Molecular Weight is (46+64+48+90) =248

Explanation:

Answer 2

Given : A compound Na2S2O3.5H2O

To find :relative molecular mass

Solution:

Molecular mass is the molecular weight of the compound which is formed by bonding of same or different elements.

We know atomic mass of:

Na=23

S=32

O=16

H20=18 (2×1+16 =2+16=18)

Now, molecular mass of compound is:

= 2×23+2×32+3×16+ 5×18 ( adding molecular masses of individual elements)

= 46+ 64+ 48+ 90

= 248

Answer: Molecular mass of Na2S2O3.5H2O compound is 248