Some Basic Concepts of Chemistry

When 800 mL of 0.5 M nitric acid is heated in a beaker, its volume is reduced to half and 11.5 g of nitric acid is evaporated. The molarity of the remaining nitric acid solution is $x\times10^{-2}$ M. (Nearest Integer)

(Molar mass of nitric acid is 63 g mol$^{-1}$)

Hemoglobin contains 0.34% of iron by mass. The number of Fe atoms in 3.3 g of hemoglobin is

(Given: Atomic mass of Fe is 56 u, $N_A=6.022\times10^{23}$ mol$^{-1}$)

A 10 g mixture of hydrogen and helium is contained in a vessel of capacity 0.0125 m$^3$ at 6 bar and 27°C. The mass of helium in the mixture is ______ g. (nearest integer)

Given: R = 8.3 J K$^{-1}$ mol$^{-1}$ (Atomic masses of H and He are 1 u and 4 u, respectively)

A 100 mL solution of $\mathrm{CH_3CH_2MgBr}$ on treatment with methanol produces 2.24 mL of a gas at STP. The weight of gas produced is ______ mg. [nearest integer]

250 g solution of D-glucose in water contains 10.8% of carbon by weight. The molality of the solution is nearest to

(Given: Atomic Weights are, H, 1 u; C, 12 u; O, 16 u)

In the following reaction

The % yield for reaction I is 60% and that of reaction II is 50%. The overall yield of the complete reaction is ______%. [nearest integer]

The normality of $\mathrm{H_2SO_4}$ in the solution obtained on mixing 100 mL of 0.1 M $\mathrm{H_2SO_4}$ with 50 mL of 0.1 M NaOH is ______ $\times10^{-1}$ N. (Nearest Integer)

In the above reaction, 5 g of toluene is converted into benzaldehyde with 92% yield. The amount of benzaldehyde produced is ______ $\times10^{-2}$ g. (Nearest integer)

In the given reaction,

$$\mathrm{X+Y+3Z\rightleftharpoons XYZ_3}$$

if one mole of each of X and Y with 0.05 mol of Z gives compound $\mathrm{XYZ_3}$. (Given : Atomic masses of X, Y and Z are 10, 20 and 30 amu, respectively.) The yield of $\mathrm{XYZ_3}$ is ______ g. (Nearest integer)

An element M crystallises in a body centred cubic unit cell with a cell edge of 300 pm. The density of the element is 6.0 g cm$^{-3}$. The number of atoms present in 180 g of the element is ______ $\times10^{23}$. (Nearest integer)

2L of 0.2M $\mathrm{H_2SO_4}$ is reacted with 2L of 0.1M NaOH solution, the molarity of the resulting product $\mathrm{Na_2SO_4}$ in the solution is ______ millimolar. (Nearest integer)

$$\mathrm{N_{2(g)}+3H_{2(g)}\rightleftharpoons2NH_{3(g)}}$$
20 g 5 g

Consider the above reaction, the limiting reagent of the reaction and number of moles of NH$_3$ formed respectivly are :

Resistance of a conductivity cell (cell constant 129 m$^{-1}$) filled with 74.5 ppm solution of KCl is 100 Ω (labelled as solution 1). When the same cell is filled with KCl solution of 149 ppm, the resistance is 50 Ω (labelled as solution 2). The ratio of molar conductivity of solution 1 and solution 2 is i.e. $\dfrac{\Lambda_1}{\Lambda_2}=x\times10^{-3}$. The value of $x$ is _______. (Nearest integer)

Given, molar mass of KCl is 74.5 g mol$^{-1}$.

In bromination of Propyne, with Bromine 1, 1, 2, 2-tetrabromopropane is obtained in 27% yield. The amount of 1, 1, 2, 2-tetrabromopropane obtained from 1 g of Bromine in this reaction is _______ $\times10^{-1}$ g. (Nearest integer)

(Molar Mass : Bromine = 80 g/mol)

Consider the reaction

$$\mathrm{4HNO_3(l)+3KCl(s)\to Cl_2(g)+NOCl(g)+2H_2O(g)+3KNO_3(s)}$$

The amount of HNO$_3$ required to produce 110.0 g of KNO$_3$ is

(Given: Atomic masses of H, O, N and K are 1, 16, 14 and 39, respectively.)

$\mathrm{C(s)+O_2(g)\to CO_2(g)}$ + 400 kJ
$\mathrm{C(s)+\frac12O_2(g)\to CO(g)}$ + 100 kJ

When coal of purity 60% is allowed to burn in presence of insufficient oxygen, 60% of carbon is converted into 'CO' and the remaining is converted into 'CO$_2$'. The heat generated when 0.6 kg of coal is burnt is _______.

A 1.84 mg sample of polyhydric alcoholic compound 'X' of molar mass 92.0 g/mol gave 1.344 mL of H$_2$ gas at STP. The number of alcoholic hydrogens present in compound 'X' is _______.

The density of 4 molal solution of NaOH is 1.160 g mL$^{-1}$. The molarity of the solution is _______ M. (Given : Molar mass of NaOH = 40 g mol$^{-1}$) (nearest integer)

The value of $\mathbf x$ is ____.

The value of $\mathbf y$ is ____.