What is the use of formality in chemistry?

Important Questions on Some Basic Concepts of Chemistry

EASY

Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Volumetric Calculations

A solution of sodium sulphate contains $92 g$ of ${\mathrm{Na}}^{+}$ ions per kilogram of water. The molality of ${\mathrm{Na}}^{+}$ ions in that solution in $\mathrm{mol}\mathrm{ }{\mathrm{kg}}^{-1}$ is:

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Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Volumetric Calculations

The volume of 0.1 M strong dibasic acid sufficient to neutralize 1g of a base that furnishes 0.04 mole of $\mathrm{O}{\mathrm{H}}^{-}$ in aqueous solution is :

MEDIUM

Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Volumetric Calculations

A solution is prepared by dissolving $20\mathrm{g} \mathrm{NaOH}$ in $1250\mathrm{mL}$ of a solvent of density $0.8\mathrm{g}/\mathrm{mL}.$ Then the molality of the solution is;

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Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Volumetric Calculations

The mole fraction of glucose $\left({\mathrm{C}}_6{\mathrm{H}}_{12}{\mathrm{O}}_6\right)$ in an aqueous binary solution is $0.1.$ The mass percentage of water in it, to the nearest integer, is $\dots \dots \dots$

HARD

Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Volumetric Calculations

If Avogadro's number is $A_0$ , the number of sulphur atoms present in 200 mL of 1N ${\mathrm{H}}_2{\mathrm{SO}}_4$ is

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Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Volumetric Calculations

In which one of the following reactions, entropy decreases?

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Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Volumetric Calculations

The mole fraction of a solvent in aqueous solution of a solute is $0.8.$ The molality (in mol ${\mathrm{k}\mathrm{g}}^{-1}$ ) of the aqueous solution is:

EASY

Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Volumetric Calculations

A litre of seawater (which weighs $1030 \mathrm{g}$) contains $6\times {10}^{-3} \mathrm{g}$ of dissolved oxygen. The concentration of dissolved oxygen in $\mathrm{ppm}$ is:

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Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Volumetric Calculations

A solution (5 mL) of an acid X is completely neutralized by y mL of 1M NaOH. The same volume (y mL) of 1M NaOH is required to neutralize 10 mL of 0.6 M ${\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_4$ completely. The normality (N) of the acid X is

HARD

Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Volumetric Calculations

What quantity (in $\mathrm{mL}$) of a $45\%$ acid solution of a mono-protic strong acid must be mixed with a $20\%$ solution of the same acid to produce $800 \mathrm{mL}$ of a $29.875\%$ acid solution?

EASY

Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Volumetric Calculations

Dissolving $120 \mathrm{g}$ of urea in $1000 \mathrm{g}$ of water gave a solution of density $1.15\mathrm{g}/\mathrm{mL}.$ The molarity of the solution is:

EASY

Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Volumetric Calculations

$8\mathrm{g}$ of $\mathrm{NaOH}$ is dissolved in $18\mathrm{g}$ of ${\mathrm{H}}_2\mathrm{O}$. Mole fraction of $\mathrm{NaOH}$ in solution and molality (in $\mathrm{ }\mathrm{mol}{\mathrm{kg}}^{-1}$) of the solution respectively are:

EASY

Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Volumetric Calculations

Calculate the concentration of the $2\%(\mathrm{w}/\mathrm{w})\mathrm{NaCl}$ solution in terms of molality.

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Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Volumetric Calculations

The standard enthalpies of formation of ${\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$ and ${\mathrm{CO}}_2\left(\mathrm{g}\right)$ are respectively $-286\mathrm{kJ} {\mathrm{mol}}^{-1}$ and $-394\mathrm{kJ} {\mathrm{mol}}^{-1}$. If the standard heat of combustion of ${\mathrm{CH}}_4\left(\mathrm{g}\right)$ is $-891\mathrm{kJ} {\mathrm{mol}}^{-1},$ then the standard enthalpy of formation of ${\mathrm{CH}}_4\left(\mathrm{g}\right)$ is

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Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Volumetric Calculations

A gas mixture contains $25\%$ $\mathrm{He}$ and $75\% {\mathrm{CH}}_4$ by volume at a given temperature and pressure. The percentage by mass of methane in the mixture is approximately ___ .

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Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Volumetric Calculations

The mole fraction of ethanol in water is $0.08$. Its molality is

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Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Volumetric Calculations

While combusting in air, $4 \mathrm{g}$ of ${\mathrm{H}}_2$ gas was completely converted into water. If $36\mathrm{\mu mole}$ of ${\mathrm{CO}}_2$ from air is dissolved into that water, what is the concentration of ${\mathrm{CO}}_2$ ?

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Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Volumetric Calculations

Dissolving 120 g of a compound of (mol. wt. 60) in 1000 g of water gave a solution of density 1.12 g/mL. The molarity of the solution is :

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Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Volumetric Calculations

The molality of solution containing 15.20 g of urea, (molar mass = 60) dissolved in 150 g of water is

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Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Volumetric Calculations

The amount of sugar $\left({\mathrm{C}}_{12}{\mathrm{H}}_{22}{\mathrm{O}}_{11}\right)$ required to prepare $2\mathrm{L}$ of its $0.1\mathrm{ }\mathrm{M}$ aqueous solution is: