JEE MainsJEE AdvanceBITSAT

JEE Mains | PYQ

A mixture consisting of \( 117 \, \text{g} \) of solid \( \mathrm{NaCl} \) and \( 245 \, \text{g} \) of \( \mathrm{KClO_3} \) is heated strongly until the \( \mathrm{KClO_3} \) fully decomposes into solid \( \mathrm{KCl} \) and \( \mathrm{O_2} \). The resulting solid residue is dissolved in water and treated with an excess of \( \mathrm{AgNO_3} \) solution, the mass of white precipitate of \( \mathrm{AgCl} \) formed is ______ \( \text{g} \).
[Given atomic masses: \( \mathrm{Na} = 23 \, \text{u} \), \( \mathrm{K} = 39 \, \text{u} \), \( \mathrm{Cl} = 35.5 \, \text{u} \), \( \mathrm{O} = 16 \, \text{u} \), \( \mathrm{Ag} = 108 \, \text{u} \)]

The mass of iron converted into \( \mathrm{Fe_3O_4} \) by the action of \( 18 \, \text{g} \) of steam is:
(Given: Molar mass of H, O and Fe are \( 1 \), \( 16 \) and \( 56 \, \text{g mol}^{-1} \) respectively)
Assume iron is present in excess:

Aqueous HCl reacts with \( \mathrm{MnO_2 (s)} \) to form \( \mathrm{MnCl_2 (aq)} \), \( \mathrm{Cl_2 (g)} \) and \( \mathrm{H_2O (l)} \). What is the weight (in \( \mathrm{g} \)) of \( \mathrm{Cl_2} \) liberated when \( 8.7 \,\mathrm{g} \) of \( \mathrm{MnO_2 (s)} \) is reacted with excess aqueous HCl solution?
(Given Molar mass in \( \mathrm{g\,mol^{-1}} \) \( \mathrm{Mn} = 55 \), \( \mathrm{Cl} = 35.5 \), \( \mathrm{O} = 16 \), \( \mathrm{H} = 1 \))

\( 14.0 \, \mathrm{g} \) of calcium metal is allowed to react with excess \( \mathrm{HCl} \) at \( 1.0 \, \mathrm{atm} \) pressure and \( 273 \, \mathrm{K} \). Which of the following statements is incorrect?
\([ \)Given: Molar mass in \( \mathrm{g\,mol^{-1}} \) of \( \mathrm{Ca} – 40 \), \( \mathrm{Cl} – 35.5 \), \( \mathrm{H} – 1 ]\)

In the reaction,

\( 2\mathrm{Al(s)} + 6\mathrm{HCl(aq)} \rightarrow 2\mathrm{Al}^{3+}\mathrm{(aq)} + 6\mathrm{Cl^-}\mathrm{(aq)} + 3\mathrm{H_2(g)} \)

The ratio of mass percentage \( (\text{w/w}) \) of \( \mathrm{C:H} \) in a hydrocarbon is \( 12:1 \). It has two carbon atoms. The weight \( (\text{in g}) \) of \( \mathrm{CO_{2}(g)} \) formed when \( 3.38\ \text{g} \) of this hydrocarbon is completely burnt in oxygen is:

(Given: Molar mass in \( \text{g mol}^{-1} \) \( \mathrm{C:12,H:1,O:16} \) )

\( 4.7 \, \text{g} \) of phenol is heated with \( \text{Zn} \) to give product X. If this reaction goes to \( 60\% \) completion then the number of moles of compound X formed will be ________ \( \times 10^{-2} \). (Nearest Integer)
(Given molar mass in \( \text{g} \, \text{mol}^{-1} \) : H: \( 1 \), C: \( 12 \), O: \( 16 \))

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:

\( 80 \, \text{mL} \) of a hydrocarbon on mixing with \( 264 \, \text{mL} \) of oxygen in a closed U-tube undergoes complete combustion. The residual gases after cooling to \( 273 \, \text{K} \) occupy \( 224 \, \text{mL} \). When the system is treated with KOH solution, the volume decreases to \( 64 \, \text{mL} \). The formula of the hydrocarbon is:

\( \mathrm{A} + 2\mathrm{B} \longrightarrow \mathrm{AB_2} \)
\( 36.0 \, \text{g} \) of ‘\( \mathrm{A} \)’ (Molar mass: \( 60 \, \mathrm{gm \, mol^{-1}} \)) and \( 56.0 \, \text{g} \) of ‘\( \mathrm{B} \)’ (Molar mass: \( 80 \, \mathrm{gm \, mol^{-1}} \)) are allowed to react. Which of the following statements are correct?
\( \mathrm{A}. \) ‘\( \mathrm{A} \)’ is the limiting reagent.
\( \mathrm{B}. \) \( 77.0 \, \text{g} \) of \( \mathrm{AB_2} \) is formed.
\( \mathrm{C}. \) Molar mass of \( \mathrm{AB_2} \) is \( 140 \, \mathrm{gm \, mol^{-1}} \).
\( \mathrm{D}. \) \( 15.0 \, \text{g} \) of \( \mathrm{A} \) is left unreacted after the completion of reaction.
Choose the correct answer from the options given below:

A solution containing \( 200 \, \text{mL} \) of \( 0.5 \, \text{M} \, \mathrm{KCl} \) is mixed with \( 50 \, \text{mL} \) of \( 19\% \, \text{w/v} \, \mathrm{MgCl_2} \) and resulting solution is diluted \( 8 \) times. Molarity of chloride ion in final solution:

The correct order of total number of atoms present in
(A) \( 2 \) moles of cyclohexane
(B) \( 684 \, \text{g} \) of sucrose
(C) \( 90.8 \, \text{L} \) of dihydrogen at STP
is:

Match List-I with List-II.


Choose the correct answer from the options given below:

How many grams of residue is obtained by heating \( 2.76 \, \text{g} \) of silver carbonate?
(Given: Molar mass of C, O and Ag are \( 12 \), \( 16 \) and \( 108 \, \text{g mol}^{-1} \) 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 \( 14 \, \text{g mol}^{-1} \) respectively.]

An oxide of iron contains \( 69.9\% \) iron, it empirical formula, is:
(Given: Molar mass of Fe and O are \( 56 \) and \( 16\,\text{g mol}^{-1} \) respectively)

\( x \) \( \text{mg} \) of pure \( \mathrm{HCl} \) was used to make an aqueous solution. \( 25.0 \, \text{mL} \) of \( 0.1 \, \text{M} \) \( \mathrm{Ba(OH)_2} \) solution is used when the \( \mathrm{HCl} \) solution was titrated against it. The numerical value of \( x \) is _______ \( \times 10^{-1} \). (Nearest integer) [Given: Molar mass of \( \mathrm{HCl} \) and \( \mathrm{Ba(OH)_2} \) are \( 36.5 \) and \( 171.0 \, \text{g mol}^{-1} \) respectively]

Number of moles and number of molecules in \( 1.4187 \, \text{L} \) of \( \text{SO}_2 \) at STP respectively are:

\( 200 \, \text{mL} \) of \( 0.2 \, \mathrm{M} \, \mathrm{H_2SO_4} \) is titrated with \( 0.1 \, \mathrm{M} \, \mathrm{NaOH} \). If the titration is stopped after adding \( 100 \, \text{mL} \) of \( \mathrm{NaOH} \). What volume (in \( \text{mL} \)) of \( 0.2 \, \mathrm{N} \, \mathrm{Ba(OH)_2} \) is required to complete the neutralization?

One mole of \( \mathrm{Cl_2(g)} \) was passed into \( 2 \, \mathrm{L} \) of cold \( 2 \, \mathrm{M} \) \( \mathrm{KOH} \) solution. After the reaction, the concentrations of \( \mathrm{Cl^-} \), \( \mathrm{ClO^-} \) and \( \mathrm{OH^-} \) are respectively (assume volume remains constant)