Some basic concepts of chemistry practice · Mixed difficulty

The molar solution of $H_2SO_4$ is equal to :

Assertion (A) : $20 \mathrm{g}$ of $50 \%$ pure $\mathrm{CaCO}_3$ on heating gave 2.24 L $\mathrm{CO}_2$ at STP and $15.6 \mathrm{~g}$ non-volatile residue.

$\mathrm{CaCO}_3 \stackrel{\Delta}{\longrightarrow} \mathrm{CaO}+\mathrm{CO}_2$
Reason (R): Pure $\mathrm{CaCO}_3$ is $10 \mathrm{~g}$ which gave $4.4 \mathrm{~g}$ $\mathrm{CO}_2(=0.1 \mathrm{~mol}=2.24 \mathrm{~L}$ at STP $)$ and $15.6 \mathrm{~g}$ residue is left.

Number of ${Zn}$ atoms present in $122 {~g}$ of ${ZnO}$ is (Atomic wt. of ${Zn}=65$ )

$0.2$ g of a sample of ${\mathrm{H}_2}{\mathrm{O}_2}$ required $10$ mL of $N\mathrm{KMn}{\mathrm{O}_4}$ in a titration in the presence of ${\mathrm{H}_2}\mathrm{S}{\mathrm{O}_4}\mathrm{.}$. Purity of ${\mathrm{H}_2}{\mathrm{O}_2}$ is :

The moles of $\mathrm{K}_2 \mathrm{Cr}_2 \mathrm{O}_7$ are required to react completely with $2.4 \mathrm{~mol}$ of $\mathrm{CuS}$ in hot acidic medium

Assertion: Components of a homogeneous mixture cannot be separated by using physical methods.

Reason: Composition of homogeneous mixture is uniform throughout as the components react to form a single compound.

What volume of 0.1 $M\mathrm{KMn}{\mathrm{O}_4}$ is needed to oxidise 100 mg of $\mathrm{Fe}{\mathrm{C}_2}{\mathrm{O}_4}$ in acidic solution?

$0.1$ mole $_3 \mathrm{PO}_x$ is completely neutralised by $5.6 \mathrm{~g} \mathrm{~KOH}$ then the true statement is:

The percentage by volume of $\mathrm{C}_3 \mathrm{H}_8$ in a mixture of $\mathrm{C}_3 \mathrm{H}_8, \mathrm{CH}_4$ and $\mathrm{CO}$ is $36.5.$ The volume of $\mathrm{CO}_2$ produced when $100 \mathrm{~ml}$ of the mixture is burnt in excess of $\mathrm{O}_2$ is

Statement I: Molecular mass of cane sugar $\left( {{C_{12}}{H_{22}}{O_{11}}} \right)$ is $182 \, \text{amu}$

Statement II: Mole of cane sugar contains $6.022 \times 10^{23}$ molecules of cane sugar.

Assertion: $\mathrm{H}_3 \mathrm{BO}_3$ is monobasic Lewis acid but salt $\mathrm{Na}_3 \mathrm{BO}_3$ exist.
Reason: $\mathrm{H}_3 \mathrm{BO}_3$ reacts with $\mathrm{NaOH}$ to give $\mathrm{Na}_3 \mathrm{BO}_3$.

If mass percentage of sulphur in a biomolecule 0.02% then the number of sulphur atoms present in 16 g of biomolecule is

A compound has an empirical formula $\mathrm{C}_2 \mathrm{H}_4 \mathrm{O}$. An independent analysis gave a value of 132.16 for its molecular mass. What is the correct molecular formula?

A sample of hydrogen gas is collected and it is observed that it contains only hydrogen and deuterium atoms in the atomic ratio $6000: 1.$ The number of neutrons in $3.0 \mathrm{~g}$ of such a sample should be nearly

Total no. of electrons present in $48 \mathrm{~g} \mathrm{~Mg}^{2+}$ are:

$10 \mathrm{~g} \mathrm{CaCO}_3$ were dissolved in $250 \mathrm{~mL}$ of $100 \mathrm{M}$ $\mathrm{HCl}$ or the solution was boiled. What volume of $2 \mathrm{M} \mathrm{KOH}$ would be required to equivalence point after boiling? Assume no change in volume during boiling.

Mole fraction of the solute in a $1.00$ molal aqueous solution is

3L mixture of ${O}_2(\mathrm{g})$ and ${N}_2(\mathrm{g})$ is passed through ozonizer. The gas mixture obtained contains ${O}_2, {O}_3$ and ${N}_2$ gases only. This obtained mixture is passed through alkaline pyrogallol and then through turpentine oil, there were $1100 \mathrm{~mL}$ and $600 \mathrm{~mL}$ volume contractions respectively. The volume of ${O}_2(\mathrm{g})$ and ${N}_2(\mathrm{g})$ in the original mixture respectively is

The mole fraction of $\mathrm{CH}_3 \mathrm{OH}$ in its $32 \% \,(\mathrm{w} / \mathrm{w})$ aqueous solution is nearly

$5000 \mathrm{~mL}$ of $0.6 \mathrm{~M} \mathrm{~H}_2 \mathrm{SO}_4$ acid is mixed with $2 \mathrm{~L}$ of 98% (w / V) of $\mathrm{H}_2 \mathrm{SO}_4$ (specific gravity 1.84). If the specific gravity of the resulting mixture is 1.4, what is the molarity of the mixture? (Given that the specific gravity of $0.6 \mathrm{~M} \mathrm{~H}_2 \mathrm{SO}_4$ is 1.02 and also consider there is no loss of mass due to mixing.)

Statement I: When a hydrocarbon is burnt and the products of combustion are cooled to the original temperature and pressure, a contraction in volume occurs.

Statement II: The contraction in volume is solely due to the liquefaction of water vapours.

Which of the following pairs contains equal number of atoms?

Maximum magnitude of work done is obtained during the hydrolysis of $1 \mathrm{~mol}$ of

A compound contains 90 % C and 10 % H. The empirical formula of the compound is

Which of the following has greatest no. of atoms

A gas mixture contains $\mathrm{CH}_4$ and $\mathrm{C}_3 \mathrm{H}_6.$ When this mixture undergo cracking into $\mathrm{C}(\mathrm{s})$ and $\mathrm{H}_2(\mathrm{g}),$ the total number of moles of $\mathrm{H}_2(\mathrm{g})$ obtained is 42. If the total volume of the initial gas mixture at $1.5 \mathrm{~atm}$ and $27^{\circ} \mathrm{C}$ is $246.0 \mathrm{~L},$ then what is the mole per cent of $\mathrm{CH}_4$ gas in the initial mixture?

Statement I : 1 mole of ${H_2}S{O_4}$ is neutralised by 2 mol of NaOH but 1 equivalent of ${H_2}S{O_4}$ is neutralised by 1 equivalent of NaOH
Statement II : Equivalent amount of ${H_2}S{O_4}$ is the quantity that is equal to 1 g H and hence, each mol of ${H_2}S{O_4}$ is equal to 2 equivalents of ${H_2}S{O_4}$
Which statement(s) is/are correct ?

The total number of valence electrons in $33.6 \mathrm{~g} \mathrm{~N}_3^{-}$ ion is

The strengths of 5.6 volume hydrogen peroxide (of density 1 g/mL ) in terms of mass percentage and molarity $(M),$ respectively are (Take molar mass of hydrogen peroxide as 34 g/mol

For the reaction, $2\mathrm{F}{\mathrm{e}^{3 + }} + \mathrm{S}{\mathrm{n}^{2 + }} \to 2\mathrm{F}{\mathrm{e}^{2 + }} + \mathrm{S}{\mathrm{n}^{4 + }}$ The normality of $\mathrm{SnC}{\mathrm{l}_2}$ (mol.wt. = 189.7) solution prepared by dissolving 47.5 g in acid solution and diluting with ${\mathrm{H}_2}\mathrm{O}$ to a total of 2.25 litre is :