NEET UG 2010 — Chemistry Physical Chemistry

2010mcqmedium

$25.3 \mathrm{~g}$ of sodium carbonate, $\mathrm{Na}_2 \mathrm{CO}_3$ is dissolved in enough water to make $250 \mathrm{~mL}$ of solution. If sodium carbonate dissociates completely, molar concentration of sodium ion, $\mathrm{Na}^{+}$ and carbonate ion, $\mathrm{CO}_3^{2-}$ are respectively (Molar mass of $\mathrm{Na}_2 \mathrm{CO}_3=106 \mathrm{~g} \mathrm{~mol}^{-1}$ )

Official previous-year question

Held on 30 Apr 2010 · Verified 9 Jul 2026.

Options

A
$0.955 \mathrm{M}$ and $1.910 \mathrm{M}$
B
$1.910 \mathrm{M}$ and $0.955 \mathrm{M}$
C
$1.90 \mathrm{M}$ and $1.910 \mathrm{M}$
D
$0.477 \mathrm{M}$ and $0.477 \mathrm{M}$

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Solution

$\begin{aligned} \text { Molarity } & =\frac{\text { number of moles of solute }}{\text { volume of solution (in mL) }} \times 1000 \\ & =\frac{25.3 \times 1000}{106 \times 250}=0.9547 \approx 0.955 \mathrm{M} \end{aligned}$ $\mathrm{Na}_2 \mathrm{CO}_3$ in aqueous solution remains dissociated as NEET 2010 Chemistry, Solutions — solution figure

Since, the molarity of $\mathrm{Na}_2 \mathrm{CO}_3$ is $0.955 \mathrm{M}$ , the molarity of $\mathrm{CO}_3^{2-}$ is also $0.955 \mathrm{M}$ and that of $\mathrm{Na}^{+}$ is $2 \times 0.955=1.910 \mathrm{M}$

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NEET UG 2010 — Chemistry Physical Chemistry

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NEET UG 2010 — Chemistry Physical Chemistry

Options

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Solution

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NEET UG Physical Chemistry in other years

More NEET UG Physical Chemistry questions

Other Chemistry topics for NEET UG

Organic Chemistry

Inorganic Chemistry

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