Question

calculate the molarity of solution obtained by dissolving 0.100g of na2co3 in 250ccm3 of sol​

Answer 1

Answer :

3.7 × 10⁻³ mol/L

Explanation :

Given mass of Na₂CO₃ = 0.1 g

Molar mass of Na₂CO₃ = [ 2(23) + 12 + 3(16) ] g/mol

= 106 g/mol

Number of moles of Na₂CO₃ = 0.1/106 mol

Volume of solution = 250 cm³

[ 1 L = 1000 cm³ ] = ¼ L

Now,

Molarity = Number of moles of Na₂CO₃ / Volume of solution (in L)

= (0.1/106) / (¼)

= 3.7 × 10⁻³ mol/L

Answer 2

Explanation:

molar mass of sodium carbonate = 23×2+12×1 + 16×3

=106g/mol

$molarity = \frac{given \: mass \: \times 1000}{molar \: mass \: \times volume \: in \: ml \: or \: {cm}^{3} }$

$\frac{0.100 \times 1000}{106 \times 250}$

$\frac{10}{106 \times 25}$

$\frac{1}{53 \times 5}$

$\frac{1}{265}$

$0.0037$

0.0037M