Some Basic Concepts of Chemistry

Two cylinders, both fitted with frictionless pistons, are filled with mixtures of He and Ar gases. In the first cylinder, the masses of He and Ar are $m_1$ and $m_2$, respectively. In the second cylinder, the masses of He and Ar are $m_2$ and $m_1$, respectively. The molar mass of Ar is 10 times the molar mass of He. The external pressure applied by the piston on the first cylinder needs to be 5 times that on the second cylinder so that the volume of the gas mixtures in both the cylinders are equal at the same temperature. Assuming He and Ar behave like ideal gases, the value of $(m_1/m_2)$ is ____.

At 300 K, the ratio of the molar volume of pure B in vapour phase to its molar volume in liquid phase is ____.

The mass of iron converted into $\ce{Fe3O4}$ 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 :

5.33 g of $\ce{CrCl3.6H2O}$, which is a 1 : 3 electrolyte, is dissolved in water and is passed through a cation exchanger. The chloride ions in the eluted solution, on treatment with $\ce{AgNO3}$ results in 8.61 g of AgCl. The ratio of moles of complex reacted and moles of AgCl formed is ________ $\times10^{-2}$. (Nearest integer)
[Molar mass in g mol$^{-1}$ Cr : 52, Ag : 108, Cl : 35.5, H : 1, O : 16]

One mole of an alkane ($x$) requires 8 mole oxygen for complete combustion. Sum of number of carbon and hydrogen atoms in the alkane ($x$) is ________.

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 $\ce{CO2(g)}$ 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)

An organic compound "$x$" where molar ratio of C, O and H are equal, on treatment with 50% KOH under reflux followed by acidification produced "$y$". The most likely structure of "$y$" is :
[Molar mass of '$x$' is 58 g mol$^{-1}$]

Number of moles and number of molecules in 1.4187 L of $\ce{SO2}$ at STP respectively are

2.0 g of a bromo hydrocarbon (X) was subjected to Carius analysis, gave 3.36 g of AgBr. The percentage of carbon in the compound (X) is 26.7%. Total number of carbon atoms in the empirical formula for compound (X) is ________.
(Given molar mass in g mol$^{-1}$ H:1, C:12, Br : 80, Ag : 108)

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:

How many grams of residue is obtained by heating 2.76 g of silver carbonate?
(Given : Molar mass of C, O and Ag are 12, 16 and 108 g mol$^{-1}$ respectively)

What is the mole fraction of water in 10% by weight (w/w) of aqueous urea solution?
[Given: Molar mass of H, O, C and N are 1, 16, 12 and 14 g mol$^{-1}$ respectively.]

One mole of phenol is treated with dilute $\ce{HNO3}$ at 298 K to give a mixture of products. The mixture is separated by steam distillation. The steam volatile compound (X) is separated. The increase in percentage of oxygen in (X) with respect to phenol is ________ $\times 10^{-1}$ %

(Given molar mass in g mol$^{-1}$ H:1, C:12, N:14, O:16)

What volume of hydrogen gas at STP would be liberated by action of 50 mL of $\ce{H2SO4}$ of 50% purity (density = 1.3 g mL$^{-1}$) on 20 g of zinc ?

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

At 298 K, the molar conductivity of $x$% (w/w) MX solution (aqueous) is 123.5 S cm² mol$^{-1}$. The conductance of same solution is $1.9\times10^{-3}$ S. The value of $x$ is ________ $\times10^{-2}$.

(Given : cell constant = 1.3 cm$^{-1}$; molar mass of MX is 75 g mol$^{-1}$, density of aqueous solution of MX at 298 K is 1.0 g mL$^{-1}$)

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

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

First and second ionization enthalpies of lithium are 520 kJ mol$^{-1}$ and 7297 kJ mol$^{-1}$ respectively. Energy required to convert 3.5 mg lithium (g) into $\ce{Li^2+}$(g) [$\ce{Li(g) -> Li^2+(g)}$] is ________ kJ mol$^{-1}$. (nearest integer)

[Molar mass of Li = 7 g mol$^{-1}$]

Consider the following sequence of reactions.

The percentage of nitrogen in the yellow product (X) formed is ________%. (Nearest Integer)

(Given Molar mass in g mol$^{-1}$ H:1, C:12, N:14)

4.7 g of phenol is heated with Zn to give product X. If this reaction goes to 60% completion then the number of moles of compound X formed will be ________ $\times10^{-2}$. (Nearest Integer)

(Given molar mass in g mol$^{-1}$ : H:1, C:12, O:16)

Which of the following contain the same number of atoms ?

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

A. 2 g of $\ce{O2}$ gas

B. 4 g of $\ce{SO2}$ gas

C. 1400 mL of $\ce{O2}$ at STP

D. 0.05 L of He at STP

E. 0.0625 mol of $\ce{H2}$ gas

Choose the correct answer from the options given below :