With increase of temperature, which of these changes ?

Important Questions on Some Basic Concepts of Chemistry

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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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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

EASY

Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Reactions in Solutions

Which of the following is dependent on temperature?

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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

EASY

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What is mole fraction of the solute in a $1.00$ m aqueous solution?

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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;

HARD

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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?

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

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The weight percent of sucrose (formula weight $=342 g mo{l}^{-1}$ ) in an aqueous solution is $3.42$. The density of the solution is $1 g m{L}^{-1},$ the concentration of sucrose in the solution in $mol L^{-1}$ is

HARD

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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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In which one of the following reactions, entropy decreases?

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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:

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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 $\dots \dots \dots$

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What would be the molality of 20% (mass/mass) aqueous solution of $\mathrm{K}\mathrm{I}$ ? (molar mass of $\mathrm{K}\mathrm{I}=166\mathrm{ }\mathrm{g}\mathrm{ }\mathrm{m}\mathrm{o}{\mathrm{l}}^{-1}$ )

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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:

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

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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>Reactions in Solutions

$8\mathrm{g}$ 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: