Some Basic Concepts of Chemistry

1 L aqueous solution of $\mathrm{H_2SO_4}$ contains 0.02 m mol $\mathrm{H_2SO_4}$. 50% of this solution is diluted with deionized water to give 1 L solution (A). In solution (A), 0.01 m mol of $\mathrm{H_2SO_4}$ are added. Total m mols of $\mathrm{H_2SO_4}$ in the final solution is ______ $\times10^3$ m mols.

Number of grams of bromine that will completely react with 5.0 g of pent-1-ene is ______ $\times10^{-2}$ g. (Atomic mass of Br = 80 g/mol) [Nearest integer]

A protein 'A' contains 0.30% of glycine (molecular weight 75). The minimum molar mass of the protein 'A' is ______ $\times10^3$ g mol$^{-1}$ [nearest integer]

The neutralization occurs when 10 mL of 0.1M acid 'A' is allowed to react with 30 mL of 0.05 M base $\mathrm{M(OH)_2}$. The basicity of the acid 'A' is ______.

[M is a metal]

A commercially sold conc. HCl is 35% HCl by mass. If the density of this commercial acid is 1.46 g/mL, the molarity of this solution is :

(Atomic mass : Cl = 35.5 amu, H = 1 amu)

An evacuated glass vessel weighs 40.0 g when empty, 135.0 g when filled with a liquid of density 0.95 g mL$^{-1}$ and 40.5 g when filled with an ideal gas at 0.82 atm at 250 K. The molar mass of the gas in g mol$^{-1}$ is :

(Given : $R=0.082$ L atm K$^{-1}$ mol$^{-1}$)

CNG is an important transportation fuel. When 100 g CNG is mixed with 208 g oxygen in vehicles, it leads to the formation of $\mathrm{CO_2}$ and $\mathrm{H_2O}$ and produces large quantity of heat during this combustion, then the amount of carbon dioxide, produced in grams is ______. [nearest integer]

[Assume CNG to be methane]

The moles of methane required to produce 81 g of water after complete combustion is ______ $\times10^{-2}$ mol. [nearest integer]

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A) : At 10°C, the density of a 5 M solution of KCl [atomic masses of K & Cl are 39 & 35.5 g mol$^{-1}$ respectively], is '$x$' g ml$^{-1}$. The solution is cooled to $-21$°C. The molality of the solution will remain unchanged.

Reason (R) : The molality of a solution does not change with temperature as mass remains unaffected with temperature.

In the light of the above statements, choose the correct answer from the options given below.

Two elements A and B which form 0.15 moles of $\mathrm{A_2B}$ and $\mathrm{AB_3}$ type compounds. If both $\mathrm{A_2B}$ and $\mathrm{AB_3}$ weigh equally, then the atomic weight of A is ______ times of atomic weight of B.

116 g of a substance upon dissociation reaction, yields 7.5 g of hydrogen, 60 g of oxygen and 48.5 g of carbon. Given that the atomic masses of H, O and C are 1, 16 and 12, respectively. The data agrees with how many formulae of the following ? ______.

A. $\mathrm{CH_3COOH}$ B. HCHO C. $\mathrm{CH_3OOCH_3}$ D. $\mathrm{CH_3CHO}$

A 2.0 g sample containing $\mathrm{MnO_2}$ is treated with HCl liberating $\mathrm{Cl_2}$. The $\mathrm{Cl_2}$ gas is passed into a solution of KI and 60.0 mL of 0.1 M $\mathrm{Na_2S_2O_3}$ is required to titrate the liberated iodine. The percentage of $\mathrm{MnO_2}$ in the sample is ______. (Nearest integer)

[Atomic masses (in u) Mn = 55; Cl = 35.5; O = 16, I = 127, Na = 23, K = 39, S = 32]

Compound A contains 8.7% Hydrogen, 74% Carbon and 17.3% Nitrogen. The molecular formula of the compound is,

Given : Atomic masses of C, H and N are 12, 1 and 14 amu respectively.

The molar mass of the compound A is 162 g mol$^{-1}$.

Production of iron in blast furnace follows the following equation

$$\mathrm{Fe_3O_4(s)+4CO(g)\rightarrow3Fe(l)+4CO_2(g)}$$

when 4.640 kg of $\mathrm{Fe_3O_4}$ and 2.520 kg of CO are allowed to react then the amount of iron (in g) produced is :

[Given : Molar Atomic mass (g mol$^{-1}$) : Fe = 56; Molar Atomic mass (g mol$^{-1}$) : O = 16; Molar Atomic mass (g mol$^{-1}$) : C = 12]

Using the rules for significant figures, the correct answer for the expression $\dfrac{0.02858\times0.112}{0.5702}$ will be

Blister copper is produced by reaction of copper oxide with copper sulphide.

$$\mathrm{2Cu_2O+Cu_2S\rightarrow6Cu+SO_2}$$

When $2.86\times10^3$ g of $\mathrm{Cu_2O}$ and $4.77\times10^3$ g of $\mathrm{Cu_2S}$ are used for reaction, the mass of copper produced is ______ g. (nearest integer)

(Atomic mass of Cu = 63.5 a.m.u, S = 32.0 a.m.u, O = 16.0 a.m.u)

$\mathrm{SO_2Cl_2}$ on reaction with excess of water results into acidic mixture

$$\mathrm{SO_2Cl_2+2H_2O\rightarrow H_2SO_4+2HCl}$$

16 moles of NaOH is required for the complete neutralisation of the resultant acidic mixture. The number of moles of $\mathrm{SO_2Cl_2}$ used is :

56.0 L of nitrogen gas is mixed with excess of hydrogen gas and it is found that 20 L of ammonia gas is produced. The volume of unused nitrogen gas is found to be ______ L.

A sample of 4.5 mg of an unknown monohydric alcohol, R-OH was added to methylmagnesium iodide. A gas is evolved and is collected and its volume measured to be 3.1 mL. The molecular weight of the unknown alcohol is ______ g/mol. [Nearest integer]

Chlorophyll extracted from the crushed green leaves was dissolved in water to make 2 L solution of Mg of concentration 48 ppm. The number of atoms of Mg in this solution is $x\times10^{20}$ atoms. The value of $x$ is ______. (Nearest Integer)

(Given : Atomic mass of Mg is 24 g mol$^{-1}$; $N_A=6.02\times10^{23}$ mol$^{-1}$)