Bond angle is \(\mathrm{PH}_{4}^{+}\)is more than that of \(\mathrm{PH}_{3}\). This is because

A non-volatile solute, 'A' tetramerises in water to the extent of 80\%. \( 2.5 \mathrm{~g} \) of 'A' in \( 100 \mathrm{~g} \) of
water, lowers the freezing point by \( 0.3^{\circ} \mathrm{C} \). the molar mass of \( \mathrm{A} \) in \( \mathrm{g} \mathrm{mol}^{-1} \) is (Kf for water \( = \)
\( 1.86 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1} \) )

The colour of sky is due to

Match List-I with List-II
\begin{array}{|l|l|l|l|}\hline & \text{List-I (Types of redox reactions)} & & \text{List-II (Examples)} \\\hline \text{a}. & \text{Combination reaction} & \text{(i)} & \mathrm{Cl}_{2(\mathrm{~g})}+2 \mathrm{Br}_{(\mathrm{aq})}^{-} \rightarrow 2 \mathrm{Cl}_{(\mathrm{aq})}^{-}+\mathrm{Br}_{2(\mathrm{l})} \\\hline \text{b.} & \text{Decomposition reaction} & \text{(ii)} & 2 \mathrm{H}_2 \mathrm{O}_{2(\mathrm{aq})} \rightarrow 2 \mathrm{H}_2 \mathrm{O}_{(1)}+\mathrm{O}_{2(\mathrm{~g})} \\\hline \text{c.} & \text{Displacement reaction} & \text{(iii)} & \mathrm{CH}_{4(\mathrm{~g})}+2 \mathrm{O}_{2(\mathrm{~g})} \xrightarrow{\Delta} \mathrm{CO}_{2(\mathrm{~g})}+2 \mathrm{H}_2 \mathrm{O}_{(1)} \\\hline \text{d.} & \text{Disproportionation reaction} & \text{(iv)} & \mathrm{H}_2 \mathrm{O}_{(1)} \xrightarrow{\Delta} 2 \mathrm{H}_{2(\mathrm{~g})}+\mathrm{O}_{2(\mathrm{~g})} \\\hline\end{array}

Choose the correct answer from the options given below.

The compound which is not formed during the dry distillation of a mixture of calcium formate and calcium acetate is

An aqueous solution of alcohol contains \(18 \mathrm{~g}\) of water and \(414 \mathrm{~g}\) of ethyl alcohol. The mole fraction of water is

The number of anti-bonding electrons present in \(\mathrm{O}_{2}^{-}\)molecular ion is

Let \(\mathbf{a}\) and \(\mathbf{b}\) be two unit vectors and \(\theta\) is the angle between them. Then, \(\mathbf{a}+\mathbf{b}\) is a unit vector, if

A stone is thrown vertically at a speed of \( 30 \mathrm{~ms}^{-1} \) making an angle of \( 45^{\circ} \) with the horizontal.
What is the maximum height reached by the stone? Take \( g=10 \mathrm{~ms}^{-2} \).

The statement that is NOT correct is

The locus of the mid points of the chords of the circle \(x^{2}+y^{2}=4\) which subtend a right angle at the origin is

If \(f(x)=\left\{\begin{array}{cl}x^2-1, & 0 < x < 2 \\ 2 x+3, & 2 \leq x < 3\end{array}\right.\),the quadratic equation whose roots are \(\lim _{x \rightarrow 2^{-}} f(x)\) and \(\lim _{x \rightarrow 2^{+}} f(x)\) is

A capacitor of \( 8 \mathrm{~F} \) is connected as shown. Charge on the plates of the capacitor