Question 11 Mark
Write relationship between $K_a, K_w$ and $K_n$ for KCN .
Answer$K _{ h }=\frac{ K _{ w }}{ K _{ a }}$ (Salt of weak acid and strong base).
View full question & answer→Question 21 Mark
What will be the effect on ionisation of $H _2 S$ in presence of HCl ?
Answer $H _2 S$ is a weak acid. Hence in presence of HCl (weak acid), due to common ion effect, ionization of $H _2 S$ get suppressed.
View full question & answer→Question 31 Mark
State the nature of aqueous solution of $Na _2 CO _3$.
Answer $Na _2 CO _3$ is a salt of weak acid $\left( H _2 CO _3\right)$ and strong base $( NaOH )$. Hence its aqueous solution will be be bic.
View full question & answer→Question 41 Mark
Write the solubility product expression for silver chromate $\left( Ag _2 CrO _4\right)$
AnswerSolubility product $\left( K _{ sp }\right)=\left[ Ag ^{+}\right]^2\left[ CrO _4^{-2}\right]$
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State the pH and pOH of 1 M NaOH solution.
AnswerThe pOH of 1 M NaOH is 0 and pH is 14 .
View full question & answer→Question 61 Mark
What will the effect of rise in temperature on value of $K _{ w }$ ?
AnswerOn increasing temperature, ionization of water increases. Hence, $K _{ w }$ increases.
View full question & answer→Question 71 Mark
Find out Lewis acid and base from following :$
H_2 O, BCl_3, FeCl_3, C_2 H_5 OH, PCl_5 .
$
AnswerLewis acid $- BCl _3, FeCl _3, PCl _5$Lewis bases $- H _2 O , C _2 H _5 OH$.
View full question & answer→Question 81 Mark
Which of the following is strongest Lewis acid? $Li ^{+}, K ^{+}, Na ^{+}, Rb ^{+}$
Answer$Li ^{+}$because due to its small size it have high tendency to attract electron.
View full question & answer→Question 91 Mark
Give two examples of aprotic solvents.
AnswerBenzene $\left( C _6 H _6\right)$ and chloroform $\left( CHCl _3\right)$.
View full question & answer→Question 101 Mark
Which will have maximum proton donor capacity? $NH _3, OH ^{-}, SHO _4^{-}$and $H _3 O ^{+}$.
View full question & answer→Question 111 Mark
Which of the following species will be strong proton acceptor? $HPO _4^{-2}, H _2 PO _4^{-}$and $PO _4^{-3}$.
View full question & answer→Question 121 Mark
For two acids HA and HB the value of $K _{ a }$ is $10^{-4}$ and $10^{-6}$ respectively then which conjugate base of these acids will be strong?
Answer HB because $K _{ a }$ of HBr have less value. Hence it is a weak acid. So its conjugate base will be strong.
View full question & answer→Question 131 Mark
Write conjugate bases for $H _2 PO _4^{-}$and HCN .
Answer$HPO _4^{-2}$ and $CN ^{-}$
View full question & answer→Question 141 Mark
Give one example each of real and imaginary electrolytes.
Answer KCl is a real electrolyte while HCl is an imaginary electrolyte.
View full question & answer→Question 151 Mark
In exothermic reaction if temperature is increased what will be the effect on equilibrium constant?
Answer On increasing temperature in exothermic reaction, rate of backward reaction increases. Hence $K _{ c }$ decreases.
View full question & answer→Question 161 Mark
What will be the effect on pH of pure water when temperature increases?
AnswerOn increasing the temperature the ionisation of water increases. Hence $\left[ H ^{+}\right]$will increase and value of pH decreases.
View full question & answer→Question 171 Mark
In solution of electrolyte, by which method electric current is conducted.
Question 181 Mark
What do you meant by ionic equilibrium.
Answer The equilibrium whose aqueous solution have ions, is known as ionic equilibrium.
View full question & answer→Question 191 Mark
$C _2 H _5 OH$ is a Lewis acid or Lewis base. Why?
Answer$C _2 H _5 OH$ is a Lewis base as in $C _2 H _5 OH$, oxygen have 2 lone pair electrons. Hence it is electron pair donor.
View full question & answer→Question 201 Mark
Write a reversible reaction which is not affected by pressure?
Answer$H _2(g)+ I _2(g) \rightleftharpoons 2 HI ( g )$
View full question & answer→Question 211 Mark
Which out of following are not Lewis acids :
$
BF_3, NH_3, H_2 O, AlCl_3 ?
$
Answer$NH _3$ and $H _2 O$.
View full question & answer→Question 221 Mark
In reaction $N _2(g)+3 H _2(g) \rightleftharpoons 2 NH _3(g)$, what will be the effect of increasing pressure?
Answer On increasing pressure in above reaction more $NH _3(g)$ will form.
View full question & answer→Question 231 Mark
In formation of ammonia if $100 ml $ N2 react, then how many ml of $H _2$ react?
Answer According to $N _2(g)+3 H _2(g) \rightleftharpoons 2 NH _3(g)$ $100 ml N _2$ react with 300 ml of $H _2$.
View full question & answer→Question 241 Mark
For reaction $2 X ( g ) \rightleftharpoons Y ( g )+ Z ( g )$, at equilibrium $[ X ]=2 M ,[ Z ]=8 M$ and $K _{ c }=1$ then what will be $[ Y ]$ ?
Answer$
\begin{aligned}
K_{c} & =\frac{[Y][Z]}{[X]^2} \\
1 & =\frac{[Y][8]}{[2]^2}
\end{aligned}
$
$
\text { Hence } \quad[Y]=\frac{4}{8}=0.5
$
View full question & answer→Question 251 Mark
Write relationship between $K_p$ and $K_c$ for following reactions :
$
N_2(g)+3 H_2(g) \rightleftharpoons 2 NH_3(g)
$
Answer$\begin{array}{l}\text { For } N _2(g)+3 H _2(g) \rightleftharpoons 2 NH _3(g) \\ \\ \text { Hence } \\ \\ \Delta n =-2 \\ \\ K_{ p }= K _{ c }( RT )^{\Delta n } \\ \\ K _{ p }= K _{ c }( RT )^{-2}\end{array}$
View full question & answer→Question 261 Mark
If for reaction $N _2(g)+3 H _2(g) \rightleftharpoons 2 NH _3(g)$ the equilibrium constant $K _{ c }=9$ then for reaction $NH _3(g)$ $\rightleftharpoons \frac{1}{2} N_2(g)+\frac{3}{2} H _2(g)$, what will be the value of equilibrium constant $K _{ c }^{\prime}$ ?
Answer $K _{ c }^{\prime}=\frac{1}{\sqrt{K_{ c }}}=\frac{1}{\sqrt{9}}=\frac{1}{3}$
View full question & answer→Question 271 Mark
Write $K_c$ and $K_p$ for following heterogeneous equilibrium :
$
CaCO_3(s) \rightleftharpoons CaO(s)+CO_2(g)
$
Answer$
\begin{array}{l}
K_{o}=\left[CO_2(g)\right] \\
K_{p}=P_{CO_2}
\end{array}
$
View full question & answer→Question 281 Mark
If concentration of $A$ and $B$ are doubled in reaction $A +2 B \rightleftharpoons 2 C$ then how much velocity of forward reaction increases?
AnswerVelocity $= K [ A ][ B ]^2$
When concentration of A and B are doubled,
$
\begin{aligned}
\text { Velocity } & =K[2 A][2 B]^2 \text { or } \\
V & =8 K[A][B]
\end{aligned}
$
Hence its velocity becomes 8 times.
View full question & answer→Question 291 Mark
What is standard melting point?
AnswerAt atmospheric pressure, the temperature of a pure substance (solid) at which solid and liquid states are in equilibrium are called standard melting or freezing point.
View full question & answer→Question 301 Mark
Give the expression of equilibrium constant $K _{ c }$ for reaction $NH _4 Cl ( s ) \rightleftharpoons NH _3(g)+ HCl ( g )$.
Answer$K _{ c }=\left[ NH _3\right][ HCl ]$
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