At STP, a closed vessel contains 1 mole each of He and \(\mathrm{CH}_4\). Through a small hole, 2L of He and 1 L of \(\mathrm{CH}_4\) was escaped from vessel in ' \(t\) ' minutes. What are the mole fractions of He and \(\mathrm{CH}_4\) respectively remaining in the vessel? (Assume He and \(\mathrm{CH}_4\) as ideal gases. At STP one mole of an ideal gas occupies 22.4 L of volume)

Which of the following solution has the highest freezing point?

Which of the follow ing statements are
correct?
(i) Drugs that mimic natural messenger by
switching on the receptor are called
agonists.
(ii) Shape of the receptor does not change
after attachment of chemical messenger.
(iii) A cationic detergent is formed when
stearic acid reacts with polyethylene
glycol.
(iv) Seldane is an antihistamine

Identify \(B\) in the following reaction
\(\mathrm{H}_4 \mathrm{SiO}_4 \underset{-\mathrm{H}_2 \mathrm{O}}{\stackrel{1000{ }^{\circ} \mathrm{C}}{\longrightarrow}} A \underset{\Delta}{\stackrel{\text { Carbon }}{\longrightarrow}} B+\mathrm{CO}\)

The following reaction is a/an
\(\begin{aligned} \mathrm{CH}_3-\mathrm{CH}_2- & \mathrm{CH}_2-\mathrm{Br} \xrightarrow{\mathrm{KOH}} \\ & \mathrm{CH}_3-\mathrm{CH}=\mathrm{CH}_2+\mathrm{KBr}+\mathrm{H}_2 \mathrm{O}\end{aligned}\)

Two alkali halide salts, \(\mathrm{ACl}\) and \(\mathrm{BCl}\) gave crimson red and violet in their flame test respectively. A and B are respectively

\(\mathrm{K}_{\mathrm{c}}\) for the following reaction is 99.0
\(\mathrm{A}_2(\mathrm{~g}) \stackrel{\mathrm{T}(\mathrm{~K})}{\rightleftharpoons} \mathrm{B}_2(\mathrm{~g})\)
In a one litre flask, 2 moles of \(\mathrm{A}_2\) was heated to \(\mathrm{T}(\mathrm{K})\) and the above equilibrium is reached. The concentrations at equilibrium of \(\mathrm{A}_2\) and \(\mathrm{B}_2\) are \(\mathrm{C}_1\left(\mathrm{~A}_2\right)\) and \(\mathrm{C}_2\left(\mathrm{~B}_2\right)\) respectively. Now, one mole of \(\mathrm{A}_2\) was added to flask and heated to \(\mathrm{T}(\mathrm{K})\) to establish the equilibrium again. The concentrations of \(\mathrm{A}_2\) and \(\mathrm{B}_2\) are \(\mathrm{C}_3\left(\mathrm{~A}_2\right)\) and \(\mathrm{C}_4\left(\mathrm{~B}_2\right)\) respectively. What is the value of \(\mathrm{C}_3\left(\mathrm{~A}_2\right)\) in \(\mathrm{mol}^{-1}\) ?

Which of the following metals is used as a catalyst in Haber's process of ammonia synthesis?

If the length of a stretched string is shortened by \(x \%\) and the tension is increased by \(44 \%\). Then the ratio of the final and initial fundamental frequencies is \(1: 2\), then the value of \(x\) is

The directrix of the parabola $2y^2+25x=0$ is _________

A sphere of mass \(2 \mathrm{~kg}\) and diameter \(4.5 \mathrm{~cm}\) is attached to the lower end of a steel wire of \(2 \mathrm{~m}\) length and area of cross-section \(0.24 \times 10^{-6} \mathrm{~m}^2\). The wire is suspended from \(205 \mathrm{~cm}\) high ceiling of a room. When the system is made to oscillate as a simple pendulum, the sphere just grazes the floor at its lowest position. The velocity of the sphere at the lowest position is (Young's modulus of steel \(=2 \times 10^{11} \mathrm{Nm}^{-2}\) and acceleration due to gravity \(=10 \mathrm{~ms}^{-2}\) )

When \(\mathrm{SbF}_5\) reacts with \(\mathrm{XeF}_4\) to form an adduct, the shapes of cation and anion in the adduct respectively are

Which one of the following compounds does not give benzoic acid when treated with alkaline \(\mathrm{KMnO}_4\) ?