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This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 551. |
Calculate the enthalpy of deprotonation of HCOOH. (Given that: `K_(a)` value for HCOOH at `20^(@)C` and `30^(@)C` are `1.765xx10^(-4)` and `1.768xx10^(-4)` at `30^(@)C`) |
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Answer» ` 2. 303 log .K_(a_2)/K_(a_1)=(DeltaH)/(R )[(T_(2)-T_(1))/(T_(1)T_(2))]` `2.303log. (1.768)/(1.765)=(DeltaH)/(8-314)[(10)/(293xx303)]` `:. DeltaH= 125.37 J` |
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| 552. |
`NH_(4)Cl` is acidic, becauseA. On hydrolysis `NH_(4)Cl` gives weak base `NH_(4)OH` and strong acid HClB. Nitrogen donates a pair of electronC. It is a salt of weak acid and strong baseD. On hydrolysis `NH_(4)Cl` gives strong base ad weak acid |
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Answer» Correct Answer - A `NH_(4)Cl + H_(4)O rarr NH_(4)OH + HCl` `NH_(4)Cl` is a salt of weak base & strong acid so sodium will be acidic. |
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| 553. |
For a weak acid, the incorrect statement isA. Its dissociation constant is lowB. Its `pK_(a)` is very lowC. it is partially dissociatedD. Solution of its sodium salt is expected to form ionic |
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Answer» Correct Answer - B For a weak acid value of pKa will be very high but in case of strong acid value of pKa will be very low. |
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| 554. |
`K_(SP)` of `M(OH)_(x)` is `27xx10^(-12)` and its solubility in water is `10^(-3)` mol `litre^(-1)`. Find the value of X. |
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Answer» Correct Answer - 3 `K_(SP)of M(OH)_(x)=X^(x). (S)^(X+1)=27xx10^(-12)` `:. X^(X).(10^(-3))^(X+1)=27xx10^(-12)` Put the `X = 1,2,3… . :. X=3` |
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| 555. |
Given, `HF+H_(2)Ooverset(K_(a))rarrH_(3)O^(+)+F^(-)` `F^(-)+H_(2)Ooverset(K_(b))rarrHF+OH^(-)` Which relation is correct ?A. `K_(b)=K_(w)`B. `K_(b)=(1)/(K_(w))`C. `K_(a)xxK_(b)=K_(w)`D. `(K_(a))/(K_(b))=K_(w)` |
| Answer» Correct Answer - 3 | |
| 556. |
Which of the following salt is alkaline in waterA. `C Cl_(4)`B. `O_(2)`C. NaBrD. `CHBr_(3)` |
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Answer» Correct Answer - C It is completely ionized in water because it is ionic salt. |
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| 557. |
Given `{:(HF+H_(2)O overset(K_(a))rarrH_(3)O^(+) + F^(-)),(F^(-) + H_(2)O overset(K_(b))rarr HF + OH^(-)):}` Which of the following reaction is correctA. `K_(b) = K_(w)`B. `K_(b) = (1)/(K_(w))`C. `K_(a) xx K_(b) = K_(w)`D. `(K_(a))/(K_(b)) = K_(w)` |
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Answer» Correct Answer - C `K_(a) = ([H_(3)O^(+)][F^(-)])/([HF])` .... (i) `K_(b) = ([HF][OH^(-)])/([F^(-)])` From (i) and (ii), `K_(a)K_(b) = [H_(3)O^(+)][OH^(-)] = K_(w)` (ionic product of water). |
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| 558. |
Which of the following can act both as a Bronsted acid and a Bronsted base?A. `O_(2)^(Theta)`B. `HCI`C. `HSO_(4)^(Theta)`D. `Na_(2)CO_(3)` |
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Answer» Correct Answer - C Bronsted acid and base is that which can donate and accept `H^(o+)` ions. So `HSO_(4)^(Theta)` can accept and donate `H^(o+)` ions. |
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| 559. |
Which shows weak ionisation in waterA. `H_(2)SO_(4)`B. NaClC. `HNO_(3)`D. `NH_(3)` |
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Answer» Correct Answer - D Because it is a weak electrolyte. |
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| 560. |
Which of the following statement is trueA. The conjugate base of a strong acid is a strong baseB. The conjugate base of a acid acid is a strong baseC. The conjugate base of a acid acid is a weak baseD. The base and its conjugate acid react to form a neutral solution |
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Answer» Correct Answer - B The conjugate base of weak acid is strong base. |
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| 561. |
Which of the following can act both as Bronsted acid and Bronsted baseA. `Cl^(-)`B. `HCO_(3)^(-)`C. `H_(3)O^(+)`D. `OH^(-)` |
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Answer» Correct Answer - B Those substance which accept the proton are called Bronsted base and which donate the proton are called Bronsted acid. `HCO_(3)^(-) + H^(+) hArr H_(2)CO_(3)` Bronsted base. `HCO_(3)^(-) hArr H^(+) + CO_(3)^(--)` Bronsted acid. |
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| 562. |
The aqueous solution of which one of the following is basicA. HOClB. `NaHCO_(4)`C. `NH_(4)NO_(3)`D. `NaOCl` |
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Answer» Correct Answer - D NaOCl is a mixture of strong base and weak acid. |
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| 563. |
Which of the following substance in an Arrhenius Base but not the Bronsted base ?A. `NaOH (s) `B. `CO_(3)^(2-)`C. `NH_(3)`D. `H_(2)O` |
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Answer» Correct Answer - A NaOH can furnish `OH^(-)` ions in aqueous solution but cannot accept `H^(+)` as such |
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| 564. |
Among the following, the weakest base isA. `H^(-)`B. `CH_(3)^(-)`C. `CH_(3)O^(-)`D. `Cl^(-)` |
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Answer» Correct Answer - D HCl is a strong acid its conjugate base means `Cl^(-)` is a weak base. |
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| 565. |
Which of the following behaves as both Lewis and Bronsted baseA. `BF_(3)`B. `Cl^(-)`C. COD. None of these |
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Answer» Correct Answer - B `underset("Acid")(HCl) rarr underset("Base")(Cl^(-))` |
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| 566. |
Would gaseous HCl be considered as an Arrhenius acidA. YesB. NoC. Not knownD. Gaseous HCl does not exist |
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Answer» Correct Answer - B Gaseous HCl does not give `H^(+)` but liquid HCl gives `H^(+)` in aqueous solution therefore gaseous HCl is not a Arrhenius acid due to covalent bonding in gaseous condition. |
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| 567. |
The correct order of acidity for the following isA. `HCN gt ClCH_(2)COOH gt HCOOH gt CH_(3)COOH`B. `HCN gt HCOOH gt ClCH_(2)COOH gt CH_(3)COOH`C. `ClCH_(2)COOH gt HCOOH gt CH_(3)COOH gt HCN`D. `ClCH_(2)COOH gt HCN gt HCOOH gt CH_(3)COOH` |
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Answer» Correct Answer - C HCN is a weaker acid than even carboxylic acid. |
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| 568. |
The pH is less than 7, of the solution ofA. `FeCl_(3)`B. NaCNC. NaOHD. NaCl |
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Answer» Correct Answer - A `FeCl_(3) + 3H_(2)I hArr Fe(OH)_(3) + 3HCl`. (Salts of strong acid and weak base have `pH lt 7`). |
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| 569. |
Conjugate base of `SO_(4)^(-)` isA. `SO_(4)^(2-)`B. `H_(2)SO_(4)`C. `H_(3)SO_(4)^(+)`D. None of these |
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Answer» Correct Answer - B `underset("Conjugate acid")(HSO_(4)^(-)) rarr H^(+) + underset("Conjugate base")(SO_(4)^(2-))` |
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| 570. |
The compound HCl behaves as .......in the reaction, `HCl + HF rarr H_(2)^(+)Cl + F^(-)`A. Weak baseB. Weak acidC. Strong baseD. Strong acid |
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Answer» Correct Answer - A HCl is accepting proton in HF medium and acts as weak base. |
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| 571. |
The conjugate base of `HSO_(4)^(Theta)` in aqueous solution is ………… . |
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Answer» Correct Answer - B::D The conjugate base of `HSO_(4)^(Theta)` in aqueous solution is `SO_(4)^(2-)`. `HSO_(4)^(Theta) hArr H^(o+) +SO_(4)^(2-)` |
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| 572. |
`HSO_(4)^(-) + OH^(-) rarr SO_(4)^(2-) + H_(2)O` Which is correct about conjugate acid base pairA. `HSO_(4)^(-)` is conjugate acid of base `SO_(4)^(2-)`B. `HSO_(4)^(-)` is conjugate base of acid `SO_(4)^(2-)`C. `SO_(4)^(2-)` is conjugate acid of base `HSO_(4)^(-)`D. None of these |
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Answer» Correct Answer - A `underset("Conjugate acid")(HSO_(4)^(-)) + OH^(-) rarr underset("Conjugate base")(SO_(4)^(2-)+ H_(2)O)` |
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| 573. |
The conjugate base of `HSO_(3)^(-)` isA. `H_(2)SO_(3)`B. `SO_(2)`C. `SO_(3)^(2-)`D. `H_(2)S` |
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Answer» Correct Answer - C The conjugate base of `HSO_(3)^(-)` is `SO_(3)^(2-)` `underset("acid")(HSO_(3)^(-)) hArr underset("conjugate base")(SO_(3)^(2-))+H^(+)` |
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| 574. |
Which of the following is not a Lewis acidA. `BF_(3)`B. `AlCl_(3)`C. HClD. `LiAlH_(4)` |
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Answer» Correct Answer - C::D `LiAIH_(4)` is a nucleophilic and capable of donating electron pair, thus acts as a Lewis base and HCl can not act as Lewis acid. |
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| 575. |
The acid having the highest `pK_(a)` value among the following isA. HCOOHB. `CH_(3)COOH`C. `ClCH_(2)COOH`D. `FCH_(2)COOH` |
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Answer» Correct Answer - B Weak acid consists of highest `pK_(a)` value and strongest acid consists of less `pK_(a)` value. |
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| 576. |
How many ml of 1 (M) `H_(2)SO_(4)`is required neutralise 10 ml of 1 (M) NaOH solution?A. 2.5B. `5.0`C. `10.0`D. `20.0` |
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Answer» Correct Answer - B Since `H_(2)SO_(4)` give `2H^(+)` , thus half volume of same strength is required for neutralisation. |
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| 577. |
The correct order of acid strength isA. `CI_(2)O_(7)gtSO_(2)gtP_(4)O_(10)`B. `CO_(2)gtN_(2)O_(5)gtSO_(3)`C. `Na_(2)OgtMgOgtAI_(2)O_(3)`D. `K_(2)OgtCaOgtMgO` |
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Answer» Correct Answer - A The acidic character of non-metallic oxides increases a along the period. |
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| 578. |
One of the following is a Bronsted acid but not a Bronsted base:A. `H_(2)S`B. `H_(2)S`C. `HCO_(3)^(Theta)`D. `NH_(3)` |
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Answer» Correct Answer - A Bronsted acid is which gives `H^(o+)` ions and Bronsted base is which accepts `H^(o+)` ions. So `H_(2)S` gives `H^(o+)` ions but cannot accept `H^(o+)`. While others `H_(2)O,HCO_(3)^(Theta),NH_(3)` can given and accept `H^(o+)` ions. |
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| 579. |
An aqueous solution of `HCI is 10^(-9) M HCI`. The `pH` of the solution should beA. `9`B. Between `6` and `7`C. `7`D. Unpredictable |
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Answer» Correct Answer - B `H_(3)O^(o+) = 10^(-9)M`. Since the concentration of `H_(3)O^(o+) is lt 10^(-6)M`. So concentration fo `H_(3)O^(o+)` is calculated from ionisation of water and its common effect, so the value will lie between `6` and `7`. |
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| 580. |
Which of the following represents hydrolysisA. `HCO_(3)^(-) + H_(2)O hArr CO_(3)^(2-) + H_(3)O^(+)`B. `HCO_(3)^(-) + H_(2)O hArr H_(2)CO_(3) + OH^(-)`C. `H_(3)BO_(3) + H_(2)O hArr H_(2)BO_(3)^(-) + H_(3)O^(+)`D. `H_(2)PO_(4)^(-) + H_(2)O hArr HPO_(4)^(2-) + H_(3)O^(+)` |
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Answer» Correct Answer - B Reaction (b) shows hydrolysis. |
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| 581. |
Which compound will liberate `CO_(2)` from `NaHCO_(3)` ?A. `CH_(3)OH`B. `CH_(3)NH_(2)`C. `(CH_(3))_(4)N^(+)OH^(-)`D. `CH_(3)overset(+)(N)H_(3)Cl^(-)` |
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Answer» Correct Answer - D An acid stronger than `H_(2)CO_(3)` will ony liberate `CO_(2)` from `NaHCO_(3)` . `CH_(3)OH` is a weaker acid than water. `CH_(3)NH_(2)` is again a weaker acid than `NH_(3) -a` Lewis base. `(CH_(3))_(4)` and a weak base `(CH_(3))_(3)N. CH_(3)overset(+)(NH)_(3)Cl^(-) -a` salt of a weak base `CH_(3)NH_(2)` and a strong acid HCl is quite acidic to decompose `NaHCO_(3)`. |
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| 582. |
A buffer solution contains `1` mole of `(NH_(4))_(2)SO_(4)` and `1` mole of `NH_(4)OH(K_(b)=10^(-5))`. The `pH` of solution will be:A. 5B. 9C. 5.3D. 8.7 |
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Answer» Correct Answer - d |
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| 583. |
The addition of HCl will not suppress the ionization ofA. Acetic acidB. benzoic acidC. `H_(2)S`D. Sulphuric acid |
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Answer» Correct Answer - D Common ion effect is noticed only for weak electrolyte dissociation. `H_(2)SO_(4)` is strong electrolyte. |
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| 584. |
In atmosphere, `SO_(2)` and `NO` are oxidised to `SO_(3)` and `NO_(2)`, respectively,w hcih react with water to given `H_(2)SO_(4)` and `HNO_(3)`. The resultant solution is called acid rain. `SO_(2)`dissolves in water to form diprotic acid. `SO_(2)(g) +H_(2)O(l) hArr HSO_(3)^(Theta) + H^(o+), K_(a_(1)) = 10^(-2)`. `HSO_(3)^(Theta) hArr SO_(3)^(2-) + H^(o+), K_(a_(2)) = 10^(-7)` and for equilibrium, `SO_(2)(aq) + H_(2)O (l) hArr SO_(3)^(2-)(aq) +2H^(o+)(aq)` `K_(a) = K_(a_(1)) xx K_(a_(2)) = 10^(-9) at 300K`. The dominant equilibrium in an aqueous solution of sodium hydrogen sulphite `(NaHSO_(3))` is `2HSO_(3)^(Theta) (aq) hArr SO_(2) (aq) +SO_(3)^(2-) (aq) + H_(2)O(l)` The equilibrium constant for the above reaction isA. `10^(-3)`B. `10^(-5)`C. `10^(-6)`D. `10^(-9)` |
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Answer» Correct Answer - B `K_(a) = (K_(a_(2)))/(K_(a_(1))) = (10^(-7))/(10^(-2)) = 10^(-5)` `HSO_(3)^(Theta) (aq) hArr SO_(2)(g) + H_(2)O(l) (K_(a_(2)))` `HSO_(3)^(Theta) (aq) + H^(o+) hArr SO_(2)(g) + H_(2)O(l) ((1)/(K_(a_(1))))` `ulbar(2HSO_(3)^(Theta)(aq)hArrSO_(2)(g)+SO_(3)^(2-)(aq)+H_(2)O(l))` |
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| 585. |
Which compound will not liberate `CO_(2)` from aqueous `NaHCO_(3)` ?A. `RNH_(3)^(+)CI^(-)`B. `(CH_(3))_(4)N^(+)OH^(-)`C. `RCOOH`D. `(CH_(3))_(4)N^(+)CI^(-)` |
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Answer» Correct Answer - B Rest all are having free acid (HCI in a and d) as well as RCOOH is acid. |
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| 586. |
A buffer solution contains `1` mole of `(NH_(4))_(2)SO_(4)` and `1` mole of `NH_(4)OH(K_(b)=10^(-5))`. The `pH` of solution will be:A. 5B. 9C. `5.3010`D. `8.6990` |
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Answer» Correct Answer - D `pOH=pK_(b)+log([0"Salt"])/(["Base"])` `pK_(b)+log(["Cation"])/(["Base"])` `[NH_(4)^(+)]=2xxmol e of (NH_(4))_(2)SO_(4)` `:. pOH= 5+log(2)/(1)=5.3010` or `pH=8.6990` |
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| 587. |
The hydrolysis constant of the salt with `NO_(2)^(-)` ion (`K_(a) = 4.5 xx 10^(-10)` for `HNO_(2)`)A. `2.22 xx 10^(-5)`B. `4.44 xx 10^(-5)`C. `2.22 xx 10^(-6)`D. `4.44 xx 10^(-2)` |
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Answer» Correct Answer - A The hydrolysis constant of the hydrolysis of salt of weak acid and strong base `K_(b) = (K_(w))/(K_(a))` Hence, hydrolysis constant of salt with `NO_(2)^(-)` ion. `K_(h) = (1 xx 10^(-14))/(4.5 xx 10^(-10)) = 2.22 xx 10^(-5)`. |
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| 588. |
In atmosphere, `SO_(2)` and `NO` are oxidised to `SO_(3)` and `NO_(2)`, respectively,w hcih react with water to given `H_(2)SO_(4)` and `HNO_(3)`. The resultant solution is called acid rain. `SO_(2)`dissolves in water to form diprotic acid. `SO_(2)(g) +H_(2)O(l) hArr HSO_(3)^(Theta) + H^(o+), K_(a_(1)) = 10^(-2)`. `HSO_(3)^(Theta) hArr SO_(3)^(2-) + H^(o+), K_(a_(2)) = 10^(-7)` and for equilibrium, `SO_(2)(aq) + H_(2)O (l) hArr SO_(3)^(2-)(aq) +2H^(o+)(aq)` `K_(a) = K_(a_(1)) xx K_(a_(2)) = 10^(-9) at 300K`. Which of the following statement is correct?A. `H_(2)SO_(3)` is less acidic than `H_(2)SO_(4)`.B. `HNO_(3)` is less acidic than `HNO_(2)`.C. `SO_(2)(g)` is reduced in the atmosphere during thunderstron.D. `CO_(2)` gas develop more acidity in rain water than `SO_(2)`. |
| Answer» Correct Answer - A | |
| 589. |
Which of the following anions is the weakest base ?A. `C_(2)H_(5)O^(-)`B. `CN^(-)`C. `CH_(3)CO^(-)`D. `NO_(3)^(-)` |
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Answer» Correct Answer - D `HNO_(3)` is the strongest acid `:. ` it has the weakest conjugate base `NO_(3)^(-)` |
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| 590. |
Which of the following is the weakest baseA. NaOHB. `Ca(OH)_(2)`C. `NH_(4)OH`D. KOH |
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Answer» Correct Answer - C `NH_(4)OH` gives minimum `OH^(-)` ion. So it is a weak base. |
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| 591. |
Which of the following base is weakestA. `NH_(4)OH : K_(b) = 1.6 xx 10^(-6)`B. `C_(6)H_(5)NH_(2) : K_(b) = 3.8 xx 10^(-10)`C. `C_(2)H_(5)NH_(2) : K_(b) = 5.6 xx 10^(-4)`D. `C_(6)H_(7)N : K_(b) = 6.3 xx 10^(-10)` |
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Answer» Correct Answer - B Smallest value of `K_(b)` indicates that aniline `(C_(2)H_(5)NH_(2))` is the weakest base. |
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| 592. |
10 Ml of 1M of `H_(2)SO_(4)` will completely neutraliseA. 10 ml of 1M NaOH solutionB. 10 ml of 2M NaOH solutionC. 5 ml of 2 M KOH solutionD. 5 ml of 1 M `Na_(2)CO_(3)` solution |
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Answer» Correct Answer - B `H_(2)SO_(4) + 2H_(2)O hArr 2H_(3)O^(+) + SO_(4)^(--)` `NaOH hArr Na^(+) + OH^(-)` 1 mole of `H_(2)SO_(4)` acid gives 2 moles of `H_(3)O^(+)` ions. So 2 moles of `OH^(-)` are required for complete neutralization. |
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| 593. |
Assertion : On mixing 500 ml of `10^(-6) M Ca^(2+)` ion and 500 ml of `30 xx 10^(-6) M F^(-)` ion, the precipitate of `CaF_(2)` will be obtained. `K_(sp) (CaF_(2) = 10^(-18))` Reason : If `K_(sp)` is greater than ionic product, a precipitate will develop.A. If both assertion and reason are true and reason is the correct explanation of the assertionB. If both assertion and reason are true but reason is not the correct explanation of the assertion.C. If assertion is true but reason is false.D. If the assertion and reason both are false. |
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Answer» Correct Answer - D `CaF_(2) hArr Ca^(2+) + 2F^(-)` `K = ((10^(-6))/(2))((10^(-6))/(2))^(2) = 1.25 xx 10^(-19)` which is less than `K_(sp)`. Hence, no precipitate will develop. Thus, both assertion and reason are false. |
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| 594. |
Among the following, the weakest base isA. `H^(-)`B. `OH^(-)`C. `Cl^(-)`D. `HCO_(3)^(-)` |
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Answer» Correct Answer - C It is conjugate base of the strong acid. |
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| 595. |
Which of the following represents the conjugate pair of `NH_(3)`?A. `: NH_(2)^(-)`B. `NH_(4)^(+)`C. Both (A ) and (B)D. `N^(3-)` |
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Answer» Correct Answer - C `NH_(2)` is conjugate base of `NH_(3)` while `NH_(4)^(+)` is its conjugate acid. |
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| 596. |
In the reaction `HNO_(3)+H_(2)O hArr H_(2)O ^(+) +NO_(3)^(-)` the conjugate base of `HNO_(3)` isA. `H_(2)O`B. `H_(3)O^(+)`C. `NO_(3)^(-)`D. unpredictable |
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Answer» Correct Answer - C Conjugate acid and conjugate base are related by a difference of `H^(+)` . |
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| 597. |
Which of the following represents the conjugate pair of `NH_(3)`?A. `NH_(2)^(Theta)`B. `NH_(4)^(o+)`C. Both (a) and (b)D. `N^(3-)` |
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Answer» Correct Answer - C `NH_(3) +H_(2)O rarr NH_(4)^(o+) + overset(Theta)OH` `{:(Base,,C_(A),,),(NH_(3)rarr,NH_(2)^(Theta)+,H^(o+),,),("Acid",C_(B),,,):}` So `NH_(4)^(o+)` and `NH_(2)^(Theta)` are conjugate pair of `NH_(3)`. |
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| 598. |
Assertion : A solution of `FeCl_(3)` in water produce brown precipitate on standing. ltbr. Reason : Hydrolysis of `FeCl_(3)` takes place in water.A. If both assertion and reason are true and reason is the correct explanation of the assertionB. If both assertion and reason are true but reason is not the correct explanation of the assertion.C. If assertion is true but reason is false.D. If the assertion and reason both are false. |
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Answer» Correct Answer - A Aq. Solution of `FeCl_(3)` on standing produce brown ppt. Due to hydrolysis it produce ppt. of `Fe(OH)_(3)` which is of brown colour. Hence both are correct and reason is a correct explanation. |
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| 599. |
`FeCl_(3)` solution is acidic due to hydrolysis of :-A. `FeCl_(3)`B. `Cl^(-)`C. `Fe^(+3)`D. None of these |
| Answer» Correct Answer - 3 | |
| 600. |
What is the minimum pH when `Fe(OH)_(3)` starts precipitating from a solution containing 0.1 M `FeCl_(2)`? (`K_(sp)` of `Fe(OH)_(3)=8xx10^(-13) M^(3)`)A. 3.7B. 5.7C. 10.3D. 8.3 |
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Answer» Correct Answer - c |
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