Identify the correct statements :

A. Hydrated salts can be used as primary standard.

B. Primary standard should not undergo any reaction with air.

C. Reactions of primary standard with another substance should be instantaneous and stoichiometric.

D. Primary standard should not be soluble in water.

E. Primary standard should have low relative molar mass.

Choose the correct answer from the options given below :

$\mathrm{A}+2 \mathrm{~B} \longrightarrow \mathrm{AB}_2$

36.0 g of 'A' (Molar mass : $60 \mathrm{~g} \mathrm{~mol}^{-1}$ ) and 56.0 g of ' B ' (Molar mass : $80 \mathrm{~g} \mathrm{~mol}^{-1}$ ) are allowed to react. Which of the following statements are correct ?

A. 'A' is the limiting reagent.

B. $77.0 \mathrm{~g}$ of $\mathrm{AB}_2$ is formed.

C. Molar mass of $\mathrm{AB}_2$ is $140 \mathrm{~g} \mathrm{~mol}^{-1}$.

D. $15.0 \mathrm{~g}$ of A is left unreacted after the completion of reaction.

Choose the correct answer from the options given below :

In the reaction,

$ 2 \mathrm{Al}(\mathrm{~s})+6 \mathrm{HCl}(\mathrm{aq}) \rightarrow 2 \mathrm{Al}^{3+}(\mathrm{aq})+6 \mathrm{Cl}^{-}(\mathrm{aq})+3 \mathrm{H}_2(\mathrm{~g}) $

By usual analysis, 1.00 g of compound (X) gave 1.79 g of magnesium pyrophosphate. The percentage of phosphorus in compound (X) is : (nearest integer)

(Given, molar mass in g mol⁻¹: O = 16, Mg = 24, P = 31)

Aqueous HCl reacts with MnO₂(s) to form MnCl₂(aq), Cl₂(g), and H₂O(l). What is the weight (in g) of Cl₂ liberated when 8.7 g of MnO₂(s) is reacted with excess aqueous HCl solution? (Given Molar mass in g mol⁻¹ Mn = 55, Cl = 35.5, O = 16, H = 1)

14.0 g of calcium metal is allowed to react with excess HCl at 1.0 atm pressure and 273 K . Which of the following statements is incorrect?

[Given : Molar mass in $\mathrm{g} \mathrm{mol}^{-1}$ of $\mathrm{Ca}-40, \mathrm{Cl}-35.5, \mathrm{H}-1$ ]

$ \text { Match List - I with List - II. } $

$ \text { Choose the correct answer from the options given below : } $

Which of the following contain the same number of atoms?

(Given : Molar mass in $\mathrm{g} \mathrm{mol}^{-1}$ of $\mathrm{H}, \mathrm{He}, \mathrm{O}$ and S are 1, 4, 16 and 32 respectively)

A. 2 g of $\mathrm{O}_2$ gas

B. 4 g of $\mathrm{SO}_2$ gas

C. 1400 mL of $\mathrm{O}_2$ at STP

D. $0.05 \mathrm{~L}$ of He at STP

E. $ 0.0625 \mathrm{~mol}$ of $\mathrm{H}_2$ gas

Choose the correct answer from the options given below :

An oxide of iron contains $69.9 \%$ iron, its empirical formula, is :

(Given : Molar mass of Fe and O are 56 and $16 \mathrm{~g} \mathrm{~mol}^{-1}$ respectively.)

What volume of hydrogen gas at STP would be liberated by action of 50 mL of $\mathrm{H}_2 \mathrm{SO}_4$ of $50 \%$ purity (density $=1.3 \mathrm{~g} \mathrm{~mL}^{-1}$ ) on 20 g of zinc?

Given : Molar mass of $\mathrm{H}, \mathrm{O}, \mathrm{S}, \mathrm{Zn}$ are 1, 16, 32, $65 \mathrm{~g} \mathrm{~mol}^{-1}$ respectively.

How many grams of residue is obtained by heating 2.76 g of silver carbonate?

(Given : Molar mass of $\mathrm{C}, \mathrm{O}$ and Ag are 12, 16 and $108 \mathrm{~g} \mathrm{~mol}^{-1}$ respectively)

What is the mole fraction of water in $10 \%$ by weight $(\mathrm{w} / \mathrm{w})$ of aqueous urea solution?

[Given: Molar mass of $\mathrm{H}, \mathrm{O}, \mathrm{C}$ and N are $1,16,12$ and $14 \mathrm{~g} \mathrm{~mol}^{-1}$ respectively.]

The correct order of total number of atoms present in

(A) 2 moles of cyclohexane

(B) 684 g of sucrose

(C) 90.8 L of dihydrogen at STP

is :

Number of moles and number of molecules in 1.4187 L of $\mathrm{SO}_2$ at STP respectively are

The ratio of mass percentage (w/w) of C : H in a hydrocarbon is 12 : 1. It has two carbon atoms. The weight (in g) of CO₂(g) formed when 3.38 g of this hydrocarbon is completely burnt in oxygen is :

(Given : Molar mass in g mol^–1 C : 12, H : 1, O : 16)

The mass of iron converted into Fe₃O₄ by the action of 18 g of steam is:

(Given: Molar mass of H, O and Fe are 1, 16 and 56 g mol⁻¹ respectively)

Assume iron is present in excess:

On combustion 0.210 g of an organic compound containing C, H and O gave 0.127 g H₂O and 0.307 g CO₂. The percentages of hydrogen and oxygen in the given organic compound respectively are:

Mass of magnesium required to produce 220 mL of hydrogen gas at STP on reaction with excess of dil. HCl is

Given: Molar mass of Mg is $24 \mathrm{~g} \mathrm{~mol}^{-1}$.

10 mL of 2 M NaOH solution is added to 20 mL of 1 M HCl solution kept in a beaker. Now, 10 mL of this mixture is poured into a volumetric flask of 100 mL containing 2 moles of HCl and made the volume upto the mark with distilled water. The solution in this flask is :

Among $10^{-9} \mathrm{~g}$ (each) of the following elements, which one will have the highest number of atoms?

Element: $\mathrm{Pb}, \mathrm{Po}, \mathrm{Pr}$ and Pt

$\mathrm{CaCO}_3(\mathrm{~s})+2 \mathrm{HCl}(\mathrm{aq}) \rightarrow \mathrm{CaCl}_2(\mathrm{aq})+\mathrm{CO}_2(\mathrm{~g})+\mathrm{H}_2 \mathrm{O}(\mathrm{l})$

Consider the above reaction, what mass of $\mathrm{CaCl}_2$ will be formed if 250 mL of 0.76 M HCl reacts with 1000 g of $\mathrm{CaCO}_3$ ?

(Given : Molar mass of $\mathrm{Ca}, \mathrm{C}, \mathrm{O}, \mathrm{H}$ and Cl are $40,12,16,1$ and $35.5 \mathrm{~g} \mathrm{~mol}^{-1}$, respectively)

On complete combustion 1.0 g of an organic compound $(\mathrm{X})$ gave 1.46 g of $\mathrm{CO}_2$ and 0.567 g of $\mathrm{H}_2 \mathrm{O}$. The empirical formula mass of compound $(\mathrm{X})$ is __________ g. (Given molar mass in $\mathrm{g} \mathrm{mol}^{-1} \mathrm{C}: 12, \mathrm{H}: 1, \mathrm{O}: 16$ )

Choose the correct statements.

(A) Weight of a substance is the amount of matter present in it.

(B) Mass is the force exerted by gravity on an object.

(C) Volume is the amount of space occupied by a substance.

(D) Temperatures below 0°C are possible in Celsius scale, but in Kelvin scale negative temperature is not possible.

(E) Precision refers to the closeness of various measurements for the same quantity.

Choose the correct answer from the options given below :

Concentrated nitric acid is labelled as $75 \%$ by mass. The volume in mL of the solution which contains 30 g of nitric acid is ______________.

Given : Density of nitric acid solution is $1.25 \mathrm{~g} / \mathrm{mL}$.

The elemental composition of a compound is $54.2 \% \mathrm{C}, 9.2 \% \mathrm{H}$ and $36.6 \% \mathrm{O}$. If the molar mass of the compound is $132 \mathrm{~g} \mathrm{~mol}^{-1}$, the molecular formula of the compound is : [Given : The relative atomic mass of $\mathrm{C}: \mathrm{H}: \mathrm{O}=12: 1: 16$ ]

$2.8 \times 10^{-3} \mathrm{~mol}$ of $\mathrm{CO}_2$ is left after removing $10^{21}$ molecules from its ' $x$ ' mg sample. The mass of $\mathrm{CO}_2$ taken initially is Given: $\mathrm{N}_{\mathrm{A}}=6.02 \times 10^{23} \mathrm{~mol}^{-1}$

Density of 3 M NaCl solution is $1.25 \mathrm{~g} / \mathrm{mL}$. The molality of the solution is :

Combustion of glucose $(\mathrm{C}_6 \mathrm{H}_{12} \mathrm{O}_6)$ produces $\mathrm{CO}_2$ and water. The amount of oxygen (in $\mathrm{g}$) required for the complete combustion of $900 \mathrm{~g}$ of glucose is :

[Molar mass of glucose in $\mathrm{g} \mathrm{~mol}^{-1}=180$]

Molality $(\mathrm{m})$ of $3 \mathrm{M}$ aqueous solution of $\mathrm{NaCl}$ is : (Given : Density of solution $=1.25 \mathrm{~g} \mathrm{~mL}^{-1}$, Molar mass in $\mathrm{g} \mathrm{~mol}^{-1}: \mathrm{Na}-23, \mathrm{Cl}-35.5$)

The density of '$x$' $\mathrm{M}$ solution ('$x$' molar) of $\mathrm{NaOH}$ is $1.12 \mathrm{~g} \mathrm{~mL}^{-1}$, while in molality, the concentration of the solution is $3 \mathrm{~m}$ ( 3 molal). Then $x$ is

(Given : Molar mass of $\mathrm{NaOH}$ is $40 \mathrm{~g} / \mathrm{mol}$)

The number of moles of methane required to produce $11 \mathrm{~g} \mathrm{~CO}_2(\mathrm{g})$ after complete combustion is : (Given molar mass of methane in $\mathrm{g} \mathrm{~mol}^{-1}: 16$ )

An organic compound has $42.1 \%$ carbon, $6.4 \%$ hydrogen and remainder is oxygen. If its molecular weight is 342 , then its molecular formula is :

The Molarity (M) of an aqueous solution containing $5.85 \mathrm{~g}$ of $\mathrm{NaCl}$ in $500 \mathrm{~mL}$ water is : (Given : Molar Mass $\mathrm{Na}: 23$ and $\mathrm{Cl}: 35.5 \mathrm{~gmol}^{-1}$)

A sample of $\mathrm{CaCO}_3$ and $\mathrm{MgCO}_3$ weighed $2.21 \mathrm{~g}$ is ignited to constant weight of $1.152 \mathrm{~g}$. The composition of mixture is :

(Given molar mass in $\mathrm{g} \mathrm{~mol}^{-1} \mathrm{CaCO}_3: 100, \mathrm{MgCO}_3: 84$)

If a substance '$A$' dissolves in solution of a mixture of '$B$' and '$C$' with their respective number of moles as $\mathrm{n}_{\mathrm{A}}, \mathrm{n}_{\mathrm{B}}$ and $\mathrm{n}_{\mathrm{C}_3}$. Mole fraction of $\mathrm{C}$ in the solution is

The quantity which changes with temperature is :

A metal chloride contains $55.0 \%$ of chlorine by weight . $100 \mathrm{~mL}$ vapours of the metal chloride at STP weigh $0.57 \mathrm{~g}$. The molecular formula of the metal chloride is

(Given: Atomic mass of chlorine is $35.5 \mathrm{u}$)

A solution is prepared by adding $2 \mathrm{~g}$ of "$\mathrm{X}$" to 1 mole of water. Mass percent of "$\mathrm{X}$" in the solution is :

Given below are two statements: one is labelled as Assertion $\mathbf{A}$ and the other is labelled as Reason $\mathbf{R}$

Assertion A : $3.1500 \mathrm{~g}$ of hydrated oxalic acid dissolved in water to make $250.0 \mathrm{~mL}$ solution will result in $0.1 \mathrm{~M}$ oxalic acid solution.

Reason $\mathbf{R}$ : Molar mass of hydrated oxalic acid is $126 \mathrm{~g} \mathrm{~mol}^{-1}$

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

Match List I with List II

Choose the correct answer from the options given below:

The number of molecules and moles in 2.8375 litres of O$_2$ at STP are respectively

Which of the following have same number of significant figures?

A. 0.00253

B. 1.0003

C. 15.0

D. 163

Choose the correct answer from the options given below

The volume of $0.02 ~\mathrm{M}$ aqueous $\mathrm{HBr}$ required to neutralize $10.0 \mathrm{~mL}$ of $0.01 ~\mathrm{M}$ aqueous $\mathrm{Ba}(\mathrm{OH})_{2}$ is (Assume complete neutralization)

When a hydrocarbon A undergoes combustion in the presence of air, it requires 9.5 equivalents of oxygen and produces 3 equivalents of water. What is the molecular formula of A?

What is the mass ratio of ethylene glycol ($\mathrm{C_2H_6O_2}$, molar mass = 62 g/mol) required for making 500 g of 0.25 molal aqueous solution and 250 mL of 0.25 molar aqueous solution?

'25 volume' hydrogen peroxide means

Consider the reaction

$4 \mathrm{HNO}_{3}(1)+3 \mathrm{KCl}(\mathrm{s}) \rightarrow \mathrm{Cl}_{2}(\mathrm{~g})+\mathrm{NOCl}(\mathrm{g})+2 \mathrm{H}_{2} \mathrm{O}(\mathrm{g})+3 \mathrm{KNO}_{3}(\mathrm{~s})$

The amount of $\mathrm{HNO}_{3}$ required to produce $110.0 \mathrm{~g}$ of $\mathrm{KNO}_{3}$ is

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

$ \begin{aligned} &\mathrm{C}(\mathrm{s})+\mathrm{O}_{2}(\mathrm{~g}) \rightarrow \mathrm{CO}_{2}(\mathrm{~g})+400 \mathrm{~kJ} \\ &\mathrm{C}(\mathrm{s})+\frac{1}{2} \mathrm{O}_{2}(\mathrm{~g}) \rightarrow \mathrm{CO}(\mathrm{g})+100 \mathrm{~kJ} \end{aligned} $

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 '$\mathrm{CO}_{2}$'. The heat generated when $0.6 \mathrm{~kg}$ of coal is burnt is _________.

$ \mathrm{N}_{2(\mathrm{~g})}+3 \mathrm{H}_{2(\mathrm{~g})} \rightleftharpoons 2 \mathrm{NH}_{3(\mathrm{~g})} $

$20 \mathrm{~g} \quad ~~~5 \mathrm{~g}$

Consider the above reaction, the limiting reagent of the reaction and number of moles of $\mathrm{NH}_{3}$ formed respectively are :

$250 \mathrm{~g}$ solution of $\mathrm{D}$-glucose in water contains $10.8 \%$ of carbon by weight. The molality of the solution is nearest to

(Given: Atomic Weights are, $\mathrm{H}, 1 \,\mathrm{u} ; \mathrm{C}, 12 \,\mathrm{u} ; \mathrm{O}, 16 \,\mathrm{u}$)

In Carius method of estimation of halogen, $0.45 \mathrm{~g}$ of an organic compound gave $0.36 \mathrm{~g}$ of $\mathrm{AgBr}$. Find out the percentage of bromine in the compound.

(Molar masses : $\mathrm{AgBr}=188 \mathrm{~g} \mathrm{~mol}^{-1} ; \mathrm{Br}=80 \mathrm{~g} \mathrm{~mol}^{-1}$)

Hemoglobin contains $0.34 \%$ of iron by mass. The number of Fe atoms in $3.3 \mathrm{~g}$ of hemoglobin is

(Given: Atomic mass of Fe is $56 \,\mathrm{u}, \mathrm{N}_{\mathrm{A}}=6.022 \times 10^{23} \mathrm{~mol}^{-1}$.)

$\mathrm{SO}_{2} \mathrm{Cl}_{2}$ on reaction with excess of water results into acidic mixture

$\mathrm{SO}_{2} \mathrm{Cl}_{2}+2 \mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{H}_{2} \mathrm{SO}_{4}+2 \mathrm{HCl}$

16 moles of $\mathrm{NaOH}$ is required for the complete neutralisation of the resultant acidic mixture. The number of moles of $\mathrm{SO}_{2} \mathrm{Cl}_{2}$ used is :

Using the rules for significant figures, the correct answer for the expression ${{0.02858 \times 0.112} \over {0.5702}}$ will be

Production of iron in blast furnace follows the following equation

Fe₃O₄(s) + 4CO(g) $\to$ 3Fe(l) + 4CO₂(g)

when 4.640 kg of Fe₃O₄ 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]

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.

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)

120 g of an organic compound that contains only carbon and hydrogen gives 330 g of CO₂ and 270 g of water on complete combustion. The percentage of carbon and hydrogen, respectively are

If a rocket runs on a fuel (C₁₅H₃₀) and liquid oxygen, the weight of oxygen required and CO₂ released for every litre of fuel respectively are :

(Given : density of the fuel is 0.756 g/mL)