Single Choice

$$8$$g of $$NaOH$$ is dissolved in $$18$$g of $$H_2O$$. Mole fraction of $$NaOH$$ in solution and molality (in mol $$kg^{-1}$$) of the solutions respectively are:

A$$0.167, 11.11$$
Correct Answer
B$$0.2, 22.20$$
C$$0.2, 11.11$$
D$$0.167, 22.20$$

Solution

$$8$$g $$NaOH$$, mol of $$NaOH$$ $$=\dfrac{8}{40}=0.2$$mol

$$18$$g of $$H_2O$$, mol of $$H_2O=\dfrac{18}{18}=1$$ mol

$$\therefore X_{NaOH}=\dfrac{0.2}{1.2}=0.167$$

Molality $$=\dfrac{0.2\times 1000}{18}=11.11$$m.

Hence, the correct option is $$A$$

SIMILAR QUESTIONS

Some Basic Concepts of Chemistry

When the volume of the solution is doubled, ______ becomes exactly half.

Some Basic Concepts of Chemistry

1%(w/v) of an aqueous solution of NaOH is isomolar with:

Some Basic Concepts of Chemistry

Formula of Molarity (in ml) is .................. $$\times 100/v$$

Some Basic Concepts of Chemistry

What will be the molarity of a solution which contains $$5.85\; g$$ of $$NaCl(s)$$ per $$500$$ ml?

Some Basic Concepts of Chemistry

Stock phosphoric acid solution is $$85$$% $$H_3PO_4$$ and has a specific gravity of $$1.70$$ . Hence, molarity of $$H_3PO_4$$ solution is:

Some Basic Concepts of Chemistry

The amount of $$NaOH$$ in $$750ml$$ of $$0.2M$$ solution (Molecular weight $$=40$$) is:

Some Basic Concepts of Chemistry

An antifreeze mixture consists of $$40$$% ethylene glycol $$(C_2H_6O_2)$$ by weight in aqueous solution. If the density of this solution is $$ 1.05$$ g/mL, what is the molar concentration?

Some Basic Concepts of Chemistry

A semi molar solution is the one which contains:

Some Basic Concepts of Chemistry

Molarity of $$4\%$$ (w/v) solution of $$NaOH$$ is:

Some Basic Concepts of Chemistry

The amount of sugar $$(C_{12}H_{22}O_{11}$$) required to prepare $$2L$$ of its $$0.1 M$$ aqueous solution is:

Contact Details