Some basic concepts of chemistry practice · Mixed difficulty

Assertion (A): On changing volume of the solution by $20 \%$, molarity of solution also changes by $20 \%$.

Reason (R): Molar concentration or molarity of solution is not affected on dilution.

Some bottles of colourless liquids were being labelled when the technicians accidentally mixed them up and lost track of their contents. A $15.0 \mathrm{~ml}$ sample withdrawn from one bottle weighed $22.3 \mathrm{~g}.$ The technicians knew that the liquid was either acetone, benzene, chloroform or carbon tetrachloride (which have densities of $0.792 \mathrm{~g} /\mathrm{cm}^3, 0.899 \mathrm{~g} / \mathrm{cm}^3, 1.489 \mathrm{~g} / \mathrm{cm}^3$, and $1.595 \mathrm{~g} / \mathrm{cm}^3$, respectively). What was the identity of the liquid?

The number of atoms in 4.25 g of $N{H_3}$ is

The ratio of the masses of methane and ethane in a gas mixture is $4: 5$. The ratio of number of their molecules in the mixture is

A sample of ammonium phosphate, ${\left( {N{H_4}} \right)_3}P{O_4}$, contain 6 mole of hydrogen atoms. The number of moles of oxygen atoms in the sample is

In a chemical reaction, $A + B \to AB$ if B is acting as a limiting reagent then choose the correct option

Give the correct order of initials T or F for following statements. Use T if statement is true and F if it is false.
(i) Gay-Lussac’s law of gaseous volumes is actually the law of definite proportion by volume.
(ii) Law of conservation of mass is true for physical change, but not for chemical change.
(iii) The percentage of oxygen in $H_2O_2$ is different from that in $H_2O.$ Hence, it violates law of definite proportions.
(iv) Fixed mass of A reacts with two different masses of B (say x and y), then the ratio of x/y can be any positive integer.
(v) At STP, 5 mL of $N_2$ and $H_2$ have different no. of molecules.

1 mole of chlorine combines with a certain weight of a metal giving 111 g of its chloride. The atomic weight of the metal (assuming its valency to be 2) is :

The molarity of $4.9 \%$ (w / w) $\mathrm{H}_2 \mathrm{SO}_4$ solution having density $1.98 \mathrm{~g} / \mathrm{ml}$ will be

How many moles of $\mathrm{P}_4 \mathrm{O}_6$ and $\mathrm{P}_4 \mathrm{O}_{10}$ will be produced by the combustion of $12.4 \mathrm{~g}$ of phosphorous (atomic mass 31) in $12.8 \mathrm{~g}$ of oxygen, leaving no $\mathrm{P}_4$ or $\mathrm{O}_2$ ?

A: Number of ions in 9 gram of ${NH}_4^{+}$is equal to Avogadro's number $\left({N}_{{A}}\right)$.

R: Number of ions is equal to number of atoms.

How much ${AgCl}$ will be formed by adding $200 \mathrm{~mL}$ of $5 {~N}$ ${HCl}$ to a solution containing $1.7 \mathrm{~g} \, {AgNO}_3$ $({Ag}=108)?$

If 65.5 g of a metal chloride contains 35.5 g chlorine, then equivalent mass of metal is

Equivalent weight of $\mathrm{FeS}_2$ in the half reaction, $\mathrm{FeS}_2 \longrightarrow \mathrm{Fe}_2 \mathrm{O}_3+\mathrm{SO}_2$ is :

One gram mole of a gas at NTP occupies 22.4 L. This fact was derived from

Solid ${NaHCO}_3$ will be neutralized by $40.0 \mathrm{~mL}$ of $0.1\, {MH}_2 {SO}_4$ solution. What would be the weight of solid ${NaHCO}_3$ in gram?

How many moles of ${H_2}S{O_4}$ are present in 4.9 g ${H_2}S{O_4}$

Which among the following has maximum number of atoms among the following?

If $6.25$ is to be rounded off to $A$ and if $6.35$ is to be rounded off to $B$. Here, $A$ and $B$ refer to

The no. of Pi bonds in increasing order is present in

How many g of KCl would have to be dissolved in 60 g ${H_2}O$ to give 20% by weight of solution?

What is the number of moles of Fe${\left( {\mathrm{OH}} \right)_3}\left( \mathrm{s} \right)$ that can be produced by allowing 1 mole of $\mathrm{F}{\mathrm{e}_2}{\mathrm{S}_3}$, 2 moles of ${\mathrm{H}_2}\mathrm{O}$ and 3 moles of ${\mathrm{O}_2}$ to react as
$2\mathrm{F}{\mathrm{e}_2}{\mathrm{S}_3} + 6{\mathrm{H}_2}\mathrm{O} + 3\mathrm{O} \to 4\mathrm{Fe}{\left( {\mathrm{OH}} \right)_3} + 6\mathrm{S}?$

Insulin contains 3.4% Sulphur. The minimum mol. weight of insulin is:

$2 \mathrm{KMnO}_4+16 \mathrm{HCl} \rightarrow$ $2 \mathrm{KCl}+2 \mathrm{MnCl}_2+5 \mathrm{Cl}_2+8 \mathrm{H}_2 \mathrm{O}.$ Find $n_{\text {factor }}$ of $\mathrm{HCl}$ in above reaction.

A mixture of salts was treated to determine the barium content. $\mathrm{A}\, 0.230 \mathrm{~g}$ sample was dissolved and treated with excess potassium chromate. The precipitate of $\mathrm{BaCrO}_4$ was dissolved in dil $\mathrm{HCl}$ to 2 convert $\mathrm{BaCrO}_4$ to $\mathrm{Cr}_2 \mathrm{O}_7^{2-}$ anion. The solution treated with excess sodium iodide and tri lodide produced was titrated with $21 \mathrm{~mL}$ of $0.095 \mathrm{~M}$ sodium thiosulphate. Calculate the $\%$ of $\mathrm{BaCl}_2 . 2 \mathrm{H}_2 \mathrm{O}$ in the sample. [given Molar Mass of $\mathrm{BaCl}_2. 2 \mathrm{H}_2 \mathrm{O}=244$]

Density of dry air containing only $\mathrm{N}_2$ and $\mathrm{O}_2$ is $1.15 \mathrm{~g} / \mathrm{L}$ at $740 \mathrm{~mm}$ of $\mathrm{Hg}$ and $300 \mathrm{~K}$. What is $\%$ composition of $\mathrm{N}_2$ by weight in the air?

The equivalent weight of an element can be calculated from:

Which one of the following is not a redox reaction

$\mathrm{BaCl}_2+\mathrm{Na}_2 \mathrm{SO}_4 \rightarrow \mathrm{BaSO}_4+2 \mathrm{NaCl}$
How many moles of $\mathrm{NaCl}$ are produced when initially there are 3 moles of $\mathrm{Na}_2 \mathrm{SO}_4$ and 1 mole $\mathrm{BaCl}_2$ ?

The isotopic abundance of C-12 and C-14 is 98% and 2% respectively. What would be the number of C-14 isotope in 12 g carbon sample?