Ionic Equilibrium · Chemistry · JEE Main
Numerical
One litre buffer solution was prepared by adding 0.10 mol each of $\mathrm{NH}_3$ and $\mathrm{NH}_4 \mathrm{Cl}$ in deionised water. The change in pH on addition of 0.05 mol of HCl to the above solution is ______________ $\times 10^{-2}$.
(Nearest integer)
Given : $\mathrm{pK}_{\mathrm{b}}$ of $\mathrm{NH}_3=4.745$ and $\log _{10} 3=0.477$
The percentage dissociation of a salt $\left(\mathrm{MX}_3\right)$ solution at given temperature (van't Hoff factor $\mathrm{i}=2$ ) is ___________ %(Nearest integer)
The molar conductance of an infinitely dilute solution of ammonium chloride was found to be $185 \mathrm{~S} \mathrm{~cm}^2 \mathrm{~mol}^{-1}$ and the ionic conductance of hydroxyl and chloride ions are 170 and $70 \mathrm{~S} \mathrm{~cm}^2 \mathrm{~mol}^{-1}$, respectively. If molar conductance of 0.02 M solution of ammonium hydroxide is $85.5 \mathrm{~S} \mathrm{~cm}^2 \mathrm{~mol}^{-1}$, its degree of dissociation is given by $x \times 10^{-1}$. The value of $x$ is __________ . (Nearest integer)
$x \mathrm{mg}$ of $\mathrm{Mg}(\mathrm{OH})_2($ molar mass $=58)$ is required to be dissolved in 1.0 L of water to produce a pH of 10.0 at 298 K . The value of $x$ is ________ mg. (Nearest integer)
(Given : $\mathrm{Mg}(\mathrm{OH})_2$ is assumed to dissociate completely in $\mathrm{H}_2 \mathrm{O}$ ]
The pH of a 0.01 M weak acid $\mathrm{HX}\left(\mathrm{K}_a=4 \times 10^{-10}\right)$ is found to be 5 . Now the acid solution is diluted with excess of water so that the pH of the solution changes to 6 . The new concentration of the diluted weak acid is given as $x \times 10^{-4} \mathrm{M}$. The value of $x$ is _________ (nearest integer)
The observed and normal molar masses of compound $\mathrm{MX}_2$ are 65.6 and 164 respectively. The percent degree of ionisation of $\mathrm{MX}_2$ is __________%. (Nearest integer)
If 1 mM solution of ethylamine produces $\mathrm{pH}=9$, then the ionization constant $\left(\mathrm{K}_{\mathrm{b}}\right)$ of ethylamine is $10^{-x}$. The value of $x$ is _________ (nearest integer).
[The degree of ionization of ethylamine can be neglected with respect to unity.]
Consider the dissociation of the weak acid HX as given below
$$\mathrm{HX}(\mathrm{aq}) \rightleftharpoons \mathrm{H}^{+}(\mathrm{aq})+\mathrm{X}^{-}(\mathrm{aq}), \mathrm{Ka}=1.2 \times 10^{-5}$$
[$$\mathrm{K}_{\mathrm{a}}$$ : dissociation constant]
The osmotic pressure of $$0.03 \mathrm{M}$$ aqueous solution of $$\mathrm{HX}$$ at $$300 \mathrm{~K}$$ is _________ $$\times 10^{-2}$$ bar (nearest integer).
[Given : $$\mathrm{R}=0.083 \mathrm{~L} \mathrm{~bar} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}$$]
The $$\mathrm{pH}$$ of an aqueous solution containing $$1 \mathrm{M}$$ benzoic acid $$\left(\mathrm{pK}_{\mathrm{a}}=4.20\right)$$ and $$1 \mathrm{M}$$ sodium benzoate is 4.5. The volume of benzoic acid solution in $$300 \mathrm{~mL}$$ of this buffer solution is _________ $$\mathrm{mL}$$. (given : $$\log 2=0.3$$)
The $$\mathrm{pH}$$ at which $$\mathrm{Mg}(\mathrm{OH})_2\left[\mathrm{~K}_{\mathrm{sp}}=1 \times 10^{-11}\right]$$ begins to precipitate from a solution containing $$0.10 \mathrm{~M} \mathrm{~Mg}^{2+}$$ ions is __________.
20 mL of $$0.1 ~\mathrm{M} ~\mathrm{NaOH}$$ is added to $$50 \mathrm{~mL}$$ of $$0.1 ~\mathrm{M}$$ acetic acid solution. The $$\mathrm{pH}$$ of the resulting solution is ___________ $$\times 10^{-2}$$ (Nearest integer)
Given : $$\mathrm{pKa}\left(\mathrm{CH}_{3} \mathrm{COOH}\right)=4.76$$
$$\log 2=0.30$$
$$\log 3=0.48$$
$$25.0 \mathrm{~mL}$$ of $$0.050 ~\mathrm{M} ~\mathrm{Ba}\left(\mathrm{NO}_{3}\right)_{2}$$ is mixed with $$25.0 \mathrm{~mL}$$ of $$0.020 ~\mathrm{M} ~\mathrm{NaF} . \mathrm{K}_{\mathrm{Sp}}$$ of $$\mathrm{BaF}_{2}$$ is $$0.5 \times 10^{-6}$$ at $$298 \mathrm{~K}$$. The ratio of $$\left[\mathrm{Ba}^{2+}\right]\left[\mathrm{F}^{-}\right]^{2}$$ and $$\mathrm{K}_{\mathrm{sp}}$$ is ___________.
(Nearest integer)
An analyst wants to convert $$1 \mathrm{~L} \mathrm{~HCl}$$ of $$\mathrm{pH}=1$$ to a solution of $$\mathrm{HCl}$$ of $$\mathrm{pH} ~2$$. The volume of water needed to do this dilution is __________ $$\mathrm{mL}$$. (Nearest integer)
The solubility product of $$\mathrm{BaSO}_{4}$$ is $$1 \times 10^{-10}$$ at $$298 \mathrm{~K}$$. The solubility of $$\mathrm{BaSO}_{4}$$ in $$0.1 ~\mathrm{M} ~\mathrm{K}_{2} \mathrm{SO}_{4}(\mathrm{aq})$$ solution is ___________ $$\times 10^{-9} \mathrm{~g} \mathrm{~L}^{-1}$$ (nearest integer).
Given: Molar mass of $$\mathrm{BaSO}_{4}$$ is $$233 \mathrm{~g} \mathrm{~mol}^{-1}$$
The titration curve of weak acid vs. strong base with phenolphthalein as indictor) is shown below. The $$\mathrm{K}_{\text {phenolphthalein }}=4 \times 10^{-10}$$.
Given: $$\log 2=0.3$$
The number of following statement/s which is/are correct about phenolphthalein is ___________
A. It can be used as an indicator for the titration of weak acid with weak base.
B. It begins to change colour at $$\mathrm{pH}=8.4$$
C. It is a weak organic base
D. It is colourless in acidic medium
(Given mass of $\mathrm{Ag}$ is $107.9 \mathrm{~g} \mathrm{~mol}^{-1}$ and mass of $\mathrm{Cl}$ is $35.5 \mathrm{~g} \mathrm{~mol}^{-1}$ )
$$600 \mathrm{~mL}$$ of $$0.01~\mathrm{M} ~\mathrm{HCl}$$ is mixed with $$400 \mathrm{~mL}$$ of $$0.01~\mathrm{M} ~\mathrm{H}_{2} \mathrm{SO}_{4}$$. The $$\mathrm{pH}$$ of the mixture is ___________ $$\times 10^{-2}$$. (Nearest integer)
[Given $$\log 2=0.30$$
$$\log 3=0.48$$
$$\log 5=0.69$$
$$\log 7=0.84$$
$$\log 11=1.04]$$
Millimoles of calcium hydroxide required to produce 100 mL of the aqueous solution of pH 12 is $$x\times10^{-1}$$. The value of $$x$$ is ___________ (Nearest integer).
Assume complete dissociation.
A litre of buffer solution contains 0.1 mole of each of NH$$_3$$ and NH$$_4$$Cl. On the addition of 0.02 mole of HCl by dissolving gaseous HCl, the pH of the solution is found to be _____________ $$\times$$ 10$$^{-3}$$ (Nearest integer)
[Given : $$\mathrm{pK_b(NH_3)=4.745}$$
$$\mathrm{\log2=0.301}$$
$$\mathrm{\log3=0.477}$$
$$\mathrm{T=298~K]}$$
If the pKa of lactic acid is 5, then the pH of 0.005 M calcium lactate solution at 25$$^\circ$$C is ___________ $$\times$$ 10$$^{-1}$$ (Nearest integer)
The dissociation constant of acetic acid is $$x\times10^{-5}$$. When 25 mL of 0.2 $$\mathrm{M~CH_3COONa}$$ solution is mixed with 25 mL of 0.02 $$\mathrm{M~CH_3COOH}$$ solution, the pH of the resultant solution is found to be equal to 5. The value of $$x$$ is ____________
If the solubility product of PbS is 8 $$\times$$ 10$$-$$28, then the solubility of PbS in pure water at 298 K is x $$\times$$ 10$$-$$16 mol L$$-$$1. The value of x is __________. (Nearest Integer)
[Given : $$\sqrt2$$ = 1.41]
$$\mathrm{K}_{\mathrm{a}}$$ for butyric acid $$\left(\mathrm{C}_{3} \mathrm{H}_{7} \mathrm{COOH}\right)$$ is $$2 \times 10^{-5}$$. The $$\mathrm{pH}$$ of $$0.2 \,\mathrm{M}$$ solution of butyric acid is __________ $$\times 10^{-1}$$. (Nearest integer)
[Given $$\log 2=0.30$$]
At $$310 \mathrm{~K}$$, the solubility of $$\mathrm{CaF}_{2}$$ in water is $$2.34 \times 10^{-3} \mathrm{~g} / 100 \mathrm{~mL}$$. The solubility product of $$\mathrm{CaF}_{2}$$ is ____________ $$\times 10^{-8}(\mathrm{~mol} / \mathrm{L})^{3}$$. (Give molar mass : $$\mathrm{CaF}_{2}=78 \mathrm{~g} \mathrm{~mol}^{-1}$$)
In the titration of $$\mathrm{KMnO}_{4}$$ and oxalic acid in acidic medium, the change in oxidation number of carbon at the end point is ___________.
The solubility product of a sparingly soluble salt A2X3 is 1.1 $$\times$$ 10$$-$$23. If specific conductance of the solution is 3 $$\times$$ 10$$-$$5 S m$$-$$1, the limiting molar conductivity of the solution is $$x \,\times$$ 10$$-$$3 S m2 mol$$-$$1. The value of x is ___________.
pH value of 0.001 M NaOH solution is ____________.
50 mL of 0.1 M CH3COOH is being titrated against 0.1 M NaOH. When 25 mL of NaOH has been added, the pH of the solution will be _____________ $$\times$$ 10$$-$$2. (Nearest integer)
(Given : pKa (CH3COOH) = 4.76)
log 2 = 0.30
log 3 = 0.48
log 5 = 0.69
log 7 = 0.84
log 11 = 1.04
(Given : The solubility product of Zn(OH)2 is 2 $$\times$$ 10$$-$$20)
[Assuming that neither kind of ion reacts with water]
(First dissociation constant of
H2CO3 = 4.0 $$ \times $$ 10–7; log 2 = 0.3; density
of the soft drink = 1 g mL–1) .
[Given : pKa of acetic acid = 4.75, molar mass of acetic of acid = 60 g/mol, log 3 = 0.4771] Neglect any changes in volume.
MCQ (Single Correct Answer)
An aqueous solution of HCl with pH 1.0 is diluted by adding equal volume of water (ignoring dissociation of water). The pH of HCl solution would
$($ Given $\log 2=0.30)$
40 mL of a mixture of $\mathrm{CH}_3 \mathrm{COOH}$ and HCl (aqueous solution) is titrated against 0.1 M NaOH solution conductometrically. Which of the following statement is correct?

If equal volumes of $A B_2$ and $X Y$ (both are salts) aqueous solutions are mixed, which of the following combination will give a precipitate of $\mathrm{AY}_2$ at 300 K ? (Given $\mathrm{K}_{\mathrm{sp}}\left(\right.$ at 300 K ) for $\mathrm{AY}_2=5.2 \times 10^{-7}$ )
Arrange the following in increasing order of solubility product :
$\mathrm{Ca}(\mathrm{OH})_2, \mathrm{AgBr}, \mathrm{PbS}, \mathrm{HgS}$
A weak acid HA has degree of dissociation x . Which option gives the correct expression of ( pH - $\mathrm{pK}_{\mathrm{a}}$)?
$\mathrm{K}_{\mathrm{sp}}$ for $\mathrm{Cr}(\mathrm{OH})_3$ is $1.6 \times 10^{-30}$. What is the molar solubility of this salt in water?
pH of water is 7 at $25^{\circ} \mathrm{C}$. If water is heated to $80^{\circ} \mathrm{C}$., it's pH will :
Which of the following happens when $\mathrm{NH}_4 \mathrm{OH}$ is added gradually to the solution containing 1 M $\mathrm{A}^{2+}$ and $1 \mathrm{M} \mathrm{B}^{3+}$ ions?
Given : $\mathrm{K}_{\text {sp }}\left[\mathrm{A}(\mathrm{OH})_2\right]=9 \times 10^{-10}$ and $\mathrm{K}_{\mathrm{sp}}\left[\mathrm{B}(\mathrm{OH})_3\right]=27 \times 10^{-18}$ at 298 K.
The molar solubility(s) of zirconium phosphate with molecular formula $\left(\mathrm{Zr}^{4+}\right)_3\left(\mathrm{PO}_4^{3-}\right)_4$ is given by relation :
For a sparingly soluble salt $$\mathrm{AB}_2$$, the equilibrium concentrations of $$\mathrm{A}^{2+}$$ ions and $$B^{-}$$ ions are $$1.2 \times 10^{-4} \mathrm{M}$$ and $$0.24 \times 10^{-3} \mathrm{M}$$, respectively. The solubility product of $$\mathrm{AB}_2$$ is :
Given below are two statements :
Statement (I) : A Buffer solution is the mixture of a salt and an acid or a base mixed in any particular quantities
Statement (II) : Blood is naturally occurring buffer solution whose $$\mathrm{pH}$$ is maintained by $$\mathrm{H}_2 \mathrm{CO}_3 / \mathrm{HCO}_3{ }^{\ominus}$$ concentrations.
In the light of the above statements, choose the correct answer from the options given below :
The equilibrium $$\mathrm{Cr}_2 \mathrm{O}_7^{2-} \rightleftharpoons 2 \mathrm{CrO}_4^{2-}$$ is shifted to the right in :
Given below are two statements :
Statement (I) : Aqueous solution of ammonium carbonate is basic.
Statement (II) : Acidic/basic nature of salt solution of a salt of weak acid and weak base depends on $$K_a$$ and $$K_b$$ value of acid and the base forming it.
In the light of the above statements, choose the most appropriate answer from the options given below :
(A) The $\mathrm{pH}$ of $1 \times 10^{-8}~ \mathrm{M} ~\mathrm{HCl}$ solution is 8 .
(B) The conjugate base of $\mathrm{H}_{2} \mathrm{PO}_{4}^{-}$ is $\mathrm{HPO}_{4}^{2-}$.
(C) $\mathrm{K}_{\mathrm{w}}$ increases with increase in temperature.
(D) When a solution of a weak monoprotic acid is titrated against a strong base at half neutralisation point, $\mathrm{pH}=\frac{1}{2} \mathrm{pK}_{\mathrm{a}}$
Choose the correct answer from the options given below:
$$25 \mathrm{~mL}$$ of silver nitrate solution (1M) is added dropwise to $$25 \mathrm{~mL}$$ of potassium iodide $$(1.05 \mathrm{M})$$ solution. The ion(s) present in very small quantity in the solution is/are :
When the hydrogen ion concentration [H$$^+$$] changes by a factor of 1000, the value of pH of the solution __________
$$200 \mathrm{~mL}$$ of $$0.01 \,\mathrm{M} \,\mathrm{HCl}$$ is mixed with $$400 \mathrm{~mL}$$ of $$0.01 \,\mathrm{M} \,\mathrm{H}_{2} \mathrm{SO}_{4}$$. The $$\mathrm{pH}$$ of the mixture is _________.
Given: $$\log {2}=0.30, \log 3=0.48, \log 5=0.70, \log 7=0.84, \log 11=1.04$$
Given below are two statements : One is labelled as Assertion A and the other is labelled as Reason R
Assertion A : Permanganate titrations are not performed in presence of hydrochloric acid.
Reason R : Chlorine is formed as a consequence of oxidation of hydrochloric acid.
In the light of the above statements, choose the correct answer from the options given below
The plot of $$\mathrm{pH}$$-metric titration of weak base $$\mathrm{NH}_{4} \mathrm{OH}$$ vs strong acid HCl looks like :
Class XII students were asked to prepare one litre of buffer solution of $$\mathrm{pH} \,8.26$$ by their Chemistry teacher: The amount of ammonium chloride to be dissolved by the student in $$0.2\, \mathrm{M}$$ ammonia solution to make one litre of the buffer is :
(Given: $$\mathrm{pK}_{\mathrm{b}}\left(\mathrm{NH}_{3}\right)=4.74$$
Molar mass of $$\mathrm{NH}_{3}=17 \mathrm{~g} \mathrm{~mol}^{-1}$$
Molar mass of $$\mathrm{NH}_{4} \mathrm{Cl}=53.5 \mathrm{~g} \mathrm{~mol}^{-1}$$ )
$${K_{{a_1}}}$$, $${K_{{a_2}}}$$ and $${K_{{a_3}}}$$ are the respective ionization constants for the following reactions (a), (b) and (c).
(a) $${H_2}{C_2}{O_4} \mathbin{\lower.3ex\hbox{$\buildrel\textstyle\rightarrow\over {\smash{\leftarrow}\vphantom{_{\vbox to.5ex{\vss}}}}$}} {H^ + } + H{C_2}O_4^ - $$
(b) $$H{C_2}O_4^ - \mathbin{\lower.3ex\hbox{$\buildrel\textstyle\rightarrow\over {\smash{\leftarrow}\vphantom{_{\vbox to.5ex{\vss}}}}$}} {H^ + } + {C_2}O_4^{2 - }$$
(c) $${H_2}{C_2}O_4^{} \mathbin{\lower.3ex\hbox{$\buildrel\textstyle\rightarrow\over {\smash{\leftarrow}\vphantom{_{\vbox to.5ex{\vss}}}}$}} 2{H^ + } + {C_2}O_4^{2 - }$$
The relationship between $${K_{{a_1}}}$$, $${K_{{a_2}}}$$ and $${K_{{a_3}}}$$ is given as :
$$20 \mathrm{~mL}$$ of $$0.1\, \mathrm{M} \,\mathrm{NH}_{4} \mathrm{OH}$$ is mixed with $$40 \mathrm{~mL}$$ of $$0.05 \mathrm{M} \mathrm{HCl}$$. The $$\mathrm{pH}$$ of the mixture is nearest to :
(Given : $$\mathrm{K}_{\mathrm{b}}\left(\mathrm{NH}_{4} \mathrm{OH}\right)=1 \times 10^{-5}, \log 2=0.30, \log 3=0.48, \log 5=0.69, \log 7=0.84, \log 11= 1.04)$$
The solubility of AgCl will be maximum in which of the following?
A student needs to prepare a buffer solution of propanoic acid and its sodium salt with pH 4. The ratio of $${{[C{H_3}C{H_2}CO{O^ - }]} \over {[C{H_3}C{H_2}COOH]}}$$ required to make buffer is ___________.
Given : $${K_a}(C{H_3}C{H_2}COOH) = 1.3 \times {10^{ - 5}}$$
The Ksp for bismuth sulphide (Bi2S3) is 1.08 $$\times$$ 10$$-$$73. The solubility of Bi2S3 in mol L$$-$$1 at 298 K is :
Given below are two statements one is labelled as Assertion A and the other is labelled as Reason R :
Assertion A : The amphoteric nature of water is explained by using Lewis acid/base concept.
Reason R : Water acts as an acid with NH3 and as a base with H2S.
In the light of the above statements choose the correct answer from the options given below :
Statement I : In the titration between strong acid and weak base methyl orange is suitable as an indicator.
Statement II : For titration of acetic acid with NaOH phenolphthalein is not a suitable indicator.
In the light of the above statements, choose the most appropriate answer from the options given below :
Select correct statement from the following :
Assertion A : During the boiling of water having temporary hardness, Mg(HCO3)2 is converted to MgCO3.
Reason R : The solubility product of Mg(OH)2 is greater than that of MgCO3.
In the light of the above statements, choose the most appropriate answer from the options given below :
[Given : The solubility product of Ca(OH)2 in water = 5.5 $$\times$$ 10$$-$$6]
(A) 0.01 M HCl
(B) 0.01 M NaOH
(C) 0.01 M CH3COONa
(D) 0.01 M NaCl
Assertion (A): When Cu (II) and sulphide ions are mixed, they react together extremely quickly to give a solid.
Reason (R): The equilibrium constant of
Cu2+(aq) + S2–(aq) ⇌ CuS(s) is high because the solubility product is low.
$$PbC{l_{2(s)}} \leftrightharpoons Pb_{(aq)}^{2 + } + 2Cl_{(aq)}^ - $$
Which of the following choices is correct for a mixture of 300 mL 0.134 M Pb(NO3)2 and 100 mL 0.4 M NaCl ?
Assertion : The pH of water increases with increase in temperature.
Reason : The dissociation of water into H+ and OH– is an exothermic reaction.
(Note : consider that an appropriate indicator is used)

0.1 M Formic acid (A),
0.1 M Acetic acid (B),
0.1 M Benzoic acid (C)
[given Kb (NH4OH) = 10–5 and log 2 = 0.301]
(a) The pH of a mixture containing 400 mL of 0.1 M H2SO4 and 400 mL of 0.1 M NaOH will be approximately 1.3
(b) Ionic product of water is temperature dependent.
(c) A monobasic acid with Ka = 10–5 has pH = 5. The degree of dissociation of this acid is 50 %.
(d) The Le Chatelier's principle is not applicable to common-ion effect.
The correct statements are :

(i) H3PO4 + H2O $$\to$$ H3O+ + $$H_2PO_4^−$$
(ii) $$H_2PO_4^−$$ + H2O $$\to$$ $$HPO_4^{2−}$$ + H3O+
(iii) $$H_2PO_4^−$$ + OH- $$\to$$H3PO4 + O2-
In which of the above does $$H_2PO_4^−$$ act as an acid?
(Ksp for BaCO3 = 5.1 $$\times$$ 10−9 )
i. $$HCO_3^−$$
ii. $$H_3O^+$$
iii. $$HSO_4^−$$
iv. $$HSO_3F$$
Which one of the following is the correct sequence of their acid strength?
AgIO3(s) $$\leftrightharpoons$$ Ag+(aq) + $$IO_3^-$$
If the solubility product constant Ksp of AgIO3 at a given temperature is 1.0 $$\times$$10−8, what is the mass of AgIO3 contained in 100 ml of its saturated solution?