Question

find the molarity of solution containing 21.2 grams of Na2Co3 in 500ml .​

Answer 1

Answer:

Molecular mass of Na

2

CO

3

=106 gmol

−1

∴ Number of moles =

106

53

=0.05mol

As 0.05 mol are dissolved in 500mL;

Number of moles dissolved in 1000mL (1L) or molarity of th solution

=

500

0.05

×1000=0

Answer 2

Answer:

0.04

Explanation:

Given data

weight of Na2Co3 (W) = 21.2g

volume of solution (V) = 500ml

GRAM MOLECULAR WEIGHT OF Na2Co3 =

= 2(23)+12+3(16)

= 46+12+48

= 106

Molarity = weight. x 1000

__________________________

gram molecular weight x volume

= 21.2 x 1000

____________

106 x 500

= 0.04 M