Question

Calculate the mass of sulphur in 50 g of sodium
thiosulphate (Na S,O3). [Na = 23,0 = 16, S = 32​

Answer 1

Answer :-

MASS OF SULPHUR IN SODIUM THIOSULPHATE

Formula of Sodium thiosulphate = Na2S2O3

Given,

Mass:

• Na = 23
• O = 16
• S = 32

Molar mass of Sodium thiosulphate :

⇒ 23 × 2 + 32 × 2 + 16 × 3

⇒ 46 + 64 + 48

⇒ 158 g

Given,

Mass of Sodium thiosulphate = 50 g

∴ No. of moles = Given mass / molar mass

⇒ no. of moles = 50 / 158

⇒ no. of moles = 0.31 mol

Concentration of Sulphur in 1 mol sodium thiosulphate = 64 g

So,

In 0.31 mol :

⇒ 64 × 0.31

⇒ 19.84 g

Therefore, the mass of sulphur in 50 g of sodium thiosulphate is 19.84 g.

Answer 2

$\huge\tt\pink{Ans:}$$\huge\tt\red{19.84 g}$

$\huge\tt\orange{°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°}$

••••EXPLANATION••••

$\huge\tt\blue{==>}$$\huge\tt\red{23×2+32×2+16×3}$

$\huge\tt\blue{==>}$$\huge\tt\red{46+64+48}$

$\huge\tt\blue{==>}$$\huge\tt\red{15g}$

The mass of sodium thiosulphate [

$\huge\tt\blue{=}$ 50g

$\huge\tt\pink{No of moles }$$\huge\tt\red{=}$$\tt\blue{mass/molar mass}$

$\tt\green{No of mole = 50/158}$

= 0.31 mol

=64 × 0.31

$\tt\pink{Hence,}$the mass of thiosulfate in 50 gram of thiosulphate is $\huge\colorbox{cyan}{= 19.84 g}$