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InterviewSolution
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.
| 1101. |
In its 0.2 M solution, acid ionies to an extent of 60%. Its hydrogen ion concentration isA. 0.6 MB. 0.2 MC. 0.12 MD. None of these |
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Answer» Correct Answer - C `[H^(+)] = C. alpha, " " = 0.2 xx 0.60 = 0.12 M`. |
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| 1102. |
the addition of solid sodium carbonate to pure water causesA. An increase in hydronium ion concentrationB. An increase in alkalinityC. No change in acidityD. A decrease in hydroxide ion concentration |
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Answer» Correct Answer - B Adding `Na_(2)CO_(3)` to water makesthe solution basic and hence a pH increases from 7. |
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| 1103. |
The pH of solution is `4.0` what should be the change in the hydrogen ion concentration of the solution if its pH is to be increased to `5.0`A. HalvedB. DoubledC. Decreases to `(1)/(2)` of its original concetrationD. Decreased by `10` times. |
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Answer» Correct Answer - D For very `10` times dilution `p^(H)` value increased by one unit |
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| 1104. |
Choose the correct statementA. pH of acidic buffer solutions decrease if more salt is addedB. pH of acidic buffer solution increases is more salt is addedC. pH of basic buffer decreases if more salt is addedD. pH of basic buffer increases if more salt is added. |
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Answer» Correct Answer - B::C Is correct because `pH = pK_(1) + log.(["Salt"])/(["Acid"])` for acidic buffer. If [Salt] increases, pH of acidic buffer will increase. `pOH = pK_(b) + log.(["Salt"])/(["Base"])` for basic buffer. If [salt] increases, pOH will increase, pH will decrease as pH = 14 - pOH Therefore (c) is correct but (d) is wrong (a) ir not correct as explained below `pH = pK_(a) + log.(["Salt"])/(["Acid"])` If [salt] increases, pH will increase. |
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| 1105. |
For two different acids with same concentration:A. The relative strength is expressed as `(alpha_(1))/(alpha_(2))`B. Relative strength is expressed as `(K_(a_(1)))/(K_(a_(2)))`C. Relative strength is expressed as `sqrt((K_(a_(1)))/(K_(a_(2))))`D. `(pH_(1))/(pH_(2))` |
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Answer» Correct Answer - A::C Let `alpha_(1)` and `alpha_(2)` be the degree of dissociation of two acids and `alpha_(1), alpha_(2)` are very small when compared to unity. `(c alpha_(1)^(2))/(1-alpha_(1)) = K_(a_(1)) (c alpha_(2)^(2))/(1-alpha_(2)) = K_(a_(2)) rArr sqrt((K_(a_(1)))/(K_(a_(2)))) = (alpha_(1))/(alpha_(2)) = "relative strength"` Hence choices (a) and (c) are correct while (b) and (d) are incorrect. |
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| 1106. |
Calculate the pH at which an acid indicator with `K_(a)=1xx10^(-5)` change colour when the indicator cincentration is `1xx10^(-3)M`. Also report the pH at which coloured ion is `80%` present. |
| Answer» Correct Answer - `5, 5.6020;` | |
| 1107. |
`K_(w)` of `H_(2)O` at 373 K is `1 xx 10^(-12)`. Identify which of the following is/are correctA. `pK_(w)` of `H_(2)O` is 12B. pH of `H_(2)O` is 6C. `H_(2)O` is neutralD. `H_(2)O` is acidic |
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Answer» Correct Answer - A::B::C `pK_(w) = -logK_(w) - log 1 xx 10^(-12) = 12` `rArr K_(w) = [H^(+)][OH^(-)] = 10^(-12)` `[H^(+)] = [OH^(-)] rArr` `[H^(+)]^(2) = 10^(-12), [H^(+)] = 10^(-6), pH = -log [H^(+)] = -log 10^(-6) = 6` `H_(2)O` is neutral because `[H^(+)] = [OH^(-)]` at 373 K even when pH = 6 (d) Is not correct at 373 K. Water cannot become acidic. |
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| 1108. |
`K_(w)` of `H_(2)O` at `373` K is `1xx10^(-12)` Identify which of the following is/are correct?A. `pH+pOH=12` for every aqueous solutions.B. `pH` of `H_(2)O` is `6`.C. `alpha_(H_(2)O)` has increased from its value at `298`KD. `H_(2)O` is acidic. |
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Answer» `pK_(w)=-logK_(w)=-log1xx10^(-12)=12` `K_(w)=[H^(+)][OH^(-)]=10^(-12)` `[H^(+)]=[OH^(-)]` `rArr [H^(+)]^(2)=10^(-12),[H^(+)]=10^(-6),pH=-log[H^(+)]=-log10^(-6)=6` `H_(2)O` is neutral because `[H^(+)]=[OH^(-)]` at `373` K even when `pH=6` `(D)` is not correct at `373K` .Water cannot become acidic. |
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| 1109. |
The pH of a `0.001 M` aqueous solution of sodium hydroxide will beA. `5.0`B. `7.5`C. `9.0`D. `11.0` |
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Answer» Correct Answer - D `[OH^(-)] = 10^(-3) M` `P^(OH) = 3. P^(H) = 11` |
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| 1110. |
Which of the following solution cannot act as buffer?A. `NaH_(2)PO_(4) + H_(3)PO_(4)`B. `CH_(3)COOH + CH_(3)COONa`C. `HCl +NH_(4)OH`D. `H_(3)PO_(4) +NaH_(2)PO_(4)` |
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Answer» Correct Answer - C HCl `+ NH_(4)OH` cannot act as a buffer because it is a mixture of strong acid and weak base. |
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| 1111. |
`K_(w)` of `H_(2)O` at `373` K is `1xx10^(-12)` Identify which of the following is/are correct?A. `pK_(w)` of `H_(2)O` is 12B. `pH` of `H_(2)O` is 6C. `H_(2)O` is neutralD. `H_(2)O` is acidic |
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Answer» Correct Answer - a,b,c |
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| 1112. |
A saturated solution of mangement(II) carbonate (M=114.95) contains `5.44xx10^(-5)`g of `MnCO_(3)` per 100mL at `25^(@)`C. What is its `K_(sp)` at this temperature?A. `4.7xx10^(-6)`B. `3.0xx10^(-9)`C. `2.2xx10^(-11)`D. `2.2xx10^(-13)` |
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Answer» Correct Answer - c |
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| 1113. |
`Ag^(+)` ion concentration in saturated solution of `Ag_(3)PO_(4) (K_(sp)=2.7xx10^(-19))` :A. `10^(-5) M`B. `2.7xx10^(-4) M`C. `3xx10^(-5) M`D. `10^(-4) M` |
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Answer» Correct Answer - c |
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| 1114. |
What will be the pH of a solution formed by mixing 40 ml of 0.10 M HCl with 10 ml of 0.45 M NaOHA. 12B. 10C. 8D. 6 |
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Answer» Correct Answer - A M.eq. of 0.01 M HCl `= (0.10)/(1000) xx 40 = 0.004 M` M.eq. of 0.45 M NaOH `= (0.45 xx 10)/(1000) = 0.0045 M` Now left `[OH^(-)] = 0.0045 - 0.004 = 5 xx 10^(-4)M` Total volume = 50 ml `[OH^(-)] = (5 xx 10^(-4))/(50) xx 1000, [OH^(-)] = 1 xx 10^(-2)` `pOH = 2, pH = 14 - pOH = 12`. |
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| 1115. |
A saturated solution of which salt will have the highest `[Ag^(+)]`?A. `AgCl(K_(sp)=1.8xx10^(-10))`B. `Ag_(2)CrO_(4)(K_(sp)=1.1xx10^(-12))`C. `Ag_(3)PO_(4)(K_(sp)=1.8xx10^(-18))`D. `Ag_(2)S(K_(sp)=6.0xx10^(-51))` |
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Answer» Correct Answer - b |
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| 1116. |
Which saturated solution has the highest [`OH^(-)`]?A. Aluminum hydroxide (`K_(sp)=1.8xx10^(-32)`)B. Calcium hydroxide (`K_(sp)=8.0xx10^(-6)`)C. Iron (II) hydroxide `(K_(sp)=1.6xx10^(-14))`D. Magnesium hydroxide (`K_(sp)=1.2xx10^(-11)`) |
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Answer» Correct Answer - b |
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| 1117. |
pH of NaCl solution isA. 7B. ZeroC. `gt 7`D. `lt 7` |
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Answer» Correct Answer - A Because of NaCl is a salt of strong acid and strong base. So that it is neutral. |
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| 1118. |
50 mL of 0.1 M NaOH is added to 60 mL of 0.15 M `H_(3)PO_(4)` solution `(K_(1), K_(2) " and " K_(3) " for " H_(3)PO_(4) " are " 10^(-3), 10^(-8) " and " 10^(-13)` respectively). The pH of the mixture would be about (log 2=0.3) :A. `3.1`B. `5.5`C. `4.1`D. `6.5` |
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Answer» Correct Answer - a |
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| 1119. |
In a solution of acid `H^(+)` concentration is `10^(-10)M`. The pH of this solution will beA. 8B. 6C. Between 6 and 7D. Between 3 and 6 |
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Answer» Correct Answer - C AS the solution is acidic `pH lt 7`. This is because `[H^(+)]` from `H_(2)O[10^(-7)]` cannot be neglected in comparison to `10^(-10) M HCl`. |
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| 1120. |
The pH of blood isA. 5.2B. 6.3C. 7.4D. 8.5 |
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Answer» Correct Answer - C The pH of blood is 7.4 due to presence of nicarbonates ions. |
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| 1121. |
A solution of sodium chloride in contact with atmosphere has a pH of aboutA. 3.5B. 5C. 7D. 1.4 |
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Answer» Correct Answer - C When strong acid and strong base are react neutral salt are formed. So that NaCl is a neutral salt. |
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| 1122. |
The one which has the highest value of pH isA. Distilled waterB. `NH_(3)` solution in waterC. `NH_(3)`D. Water saturated with `Cl_(2)` |
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Answer» Correct Answer - B In water solutions. `NH_(3) + H_(2)O hArr NH_(4)^(+) + OH^(-)` Concentration of `OH^(-)` is increased so that solution become more basic and the pH is increased. |
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| 1123. |
The solution of sodium carbonate has pHA. Greater than 7B. Less than 7C. Equal to 7D. Equal to zero |
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Answer» Correct Answer - A `Na_(2)CO_(3)` is a mixture of weak acid and strong base, so it is a base. |
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| 1124. |
The pH of the solution is 4. The hydrogen ion concentration of the solution in mol/litre isA. 9.5B. `10^(-4)`C. `10^(4)`D. `10^(-2)` |
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Answer» Correct Answer - B `pH = 4, (H^(+)) = 10^(-pH) = 10^(-4)M`. |
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| 1125. |
The gastric juice in our stomach contains enough HCl to make the hydrogen ion concentration about 0.10 mole litre. The pH of gastric juice isA. 0.01B. 1C. 2D. 14 |
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Answer» Correct Answer - C The concentration of `[H^(+)] = 10^(-2)` mole/litre `pH = -log[H^(+)] = -log [10^(-2)] , pH = 2`. |
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| 1126. |
For pure water:A. pH increase and pOH decreases with rise in temperatureB. pH decrease and pOH increases with rise in temperatureC. both pH and pOH increase with rise in temperatureD. both pH and pOH decrease with rise in temperature |
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Answer» Correct Answer - D On heating pure water the value od ionic product of water increases i.e., `K_(w)=10^(-14)at 25^(@)C` and at `60^(@)C` `K_(w)=10^(-12)`. Thus pH and pOH both becomes 6 and `60^(@)C (pH and pOH=7 at 25^(@)C)`. |
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| 1127. |
The pOH of beer is 10.0. The hydrogen ion concentration will beA. `10^(-2)`B. `10^(-10)`C. `10^(-8)`D. `10^(-4)` |
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Answer» Correct Answer - D pH + pOH = 14, pH = 4, `H^(+) = 10^(-4)` mole/litre. |
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| 1128. |
If the pH of a solution is 2, its normality will beA. 2NB. `(1)/(2)N`C. 0.01 ND. None of these |
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Answer» Correct Answer - C `pH = 2, pH = -log[H^(+)] , 2 = -log [H^(+)]` `[H^(+)] = 10^(-2) = 0.01 N`. |
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| 1129. |
Which of the following is the buffer solution of strong acidic natureA. `HCOOH + HCOO^(-)`B. `CH_(3)COOH + CH_(3)COO^(-)`C. `H_(2)C_(2)O_(4) + C_(2)O_(4)^(2-)`D. `H_(3)BO_(3)+BO_(3)^(3-)` |
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Answer» Correct Answer - A It is a buffer solution of strong acid and its weak conjugate base. |
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| 1130. |
Which solution is not a buffer solution ?A. `NaCN ` ( 2 mole) `+ HCl` ( 1 mole ) in `5L`B. `NaCN ` (1 mole ) `+ HCl` (1 molde ) in `5L`C. `NH_(3) `(2 mole ) `+ HCl ` ( 1 mole) in `5L`D. `CH_(3)COOH` ( 2 mole) `+ KOH` (1 mole ) in `5L` |
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Answer» Correct Answer - 2 This is actually a solution of weak acid `HCN` with salt `NaCl(` having spectacular ions only ) |
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| 1131. |
Which one of the following is the buffer solution of strong acidic nature ?A. `HCOOH +HCOO^(-)`B. `CH_(3)COOH +CH_(3)COO^(-)`C. `H_(2)CO_(4)^(-)+C_(2)O_(4)^(2-)`D. `H_(3)BO_(3)+BO_(3)^(3-)` |
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Answer» Correct Answer - A HCOOH is the strongest out of the given acids. |
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| 1132. |
Which of the following is not a Lewis acid ?A. COB. `SiCl_(4)`C. `SO_(3)`D. `Zn^(2+)` |
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Answer» Correct Answer - A CO is not Lewis acid as it cannot accept electrons. |
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| 1133. |
A solution of `0.01M` concentration of `NH_(4)OH` is `2.6%` dissociated. Calculate `[H^(+)], [OH^(-)],[NH_(4)^(+)], [NH_(4)OH]` and pH of solution. |
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Answer» `{:(,NH_(4)OHhArr,NH_(4)^(+)+,OH^(-)),("Before dissociation",1,0,0),("After dissociation", 1-alpha,alpha,alpha):}` `:. [OH^(-)]=C.alpha` `=Csqrt((K_(b)//C))=sqrt((K_(b).C))` Also `K_(b)=Calpha^(2)=0.01xx(0.026)^(2)` `= 6.76xx10^(-6)` `:. [OH^(-)]=sqrt([6.76xx10^(-6)xx0.01])` `=2.6xx10^(-4)M` `:. [H^(+)]=10^(-14)//2.6xx10^(-4)` `=3.846xx10^(-11)M` `:. pH= -log[H^(+)]= - log 3.846xx10^(-11)` `=10.415` |
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| 1134. |
The hydrogen ion concentration of 0.1 N solution of `CH_(3)COOH`, which is 30% dissociated, isA. 0.03B. `3.0`C. 0.3D. `30.0` |
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Answer» Correct Answer - A `[H^(+)] = c xx alpha = 0.1 xx (30)/(100) = 0.03 M`. |
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| 1135. |
`K_(a)` for the ionisation of `Fe^(3+)` to `Fe(OH)^(2+)` and `H^(o+)` is `6.5 xx 10^(-3)`, what is the maximum `pH` value which could be used so that at least `95%` of the total `Fe^(3+)` in a dilute solution exists as `Fe^(3+)`? |
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Answer» `{:(Fe^(3+)+,H_(2)OhArr,Fe(OH)^(2+)+,H^(+),,K_(h)=6.5xx10^(-3)),((1-h),,h,h,):}` `[H^(o+)] = Ch` and `K_(h) = (C.h^(2))/(1-h)` and `h = (5)/(100)` Thus, `6.5 xx 10^(-3) = (C xx5xx5xx100)/(100xx100xx95)` `:. C = 2.47 M :. [H^(o+)] = 2.47 xx (5)/(100)` `:. pH = 0.9083` |
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| 1136. |
The concentration of hydronium `(H_(3)O^(+))` ion in water isA. ZeroB. `1 xx 10^(-7)` gm ion /litreC. `1 xx 10^(-14)` gm ion/litreD. `1 xx 10^(-7)` gm ion/litre |
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Answer» Correct Answer - D `H_(3)O^(+) OH^(-) + H_(2)` `pOH + pH = 14, 7 + 7 = 14, " " [H^(+)][OH] = 10^(-14)` `10^(-7) xx 10^(-7) , [OH^(-)] = 10^(-7)` gm ion/l. |
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| 1137. |
The pH of a 0.02 M solution of hydrochloric acid isA. `2.0`B. `1.7`C. `0.3`D. `2.2` |
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Answer» Correct Answer - B `[H^(+)] = 2 xx 10^(-2) M` `because pH = -log [2 xx 10^(-2)]` pH = 1.7 i.e. in between 1 and 2. |
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| 1138. |
On passing `H_(2)S` gas through a highly acidic solution containing `Cd^(2+)` ions, CdS is not precipitated becauseA. Of common ion effectB. The solubility of CdS is lowC. `Cd^(2+)` ions do not form complex with `H_(2)S`D. The solubility product of CdS is low |
| Answer» Correct Answer - A | |
| 1139. |
Which of the following will occur if a 0.1 M solution of a weak acid is diluted to 0.01 M at constant temperatureA. `[H^(+)]` will decrease to 0.01 MB. pH will decreaseC. Percentage ionization will increaseD. `K_(a)` will increase |
| Answer» Correct Answer - B::C | |
| 1140. |
At `100^(@)C` the `K_(w)` of water is 55 times its value at `25^(@)C`. What will be the pH of neutral solution (log 55 = 1.74)A. `7.00`B. 7.87C. 5.13D. 6.13 |
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Answer» Correct Answer - D At `100^(@)C` `K_(w) = 55 xx 10^(-14)` `H^(+) = sqrt(55 xx 10^(-14))` `= 7.41 xx 10^(-7)` `pH = -log [H^(+)]` `= -log[7.41 xx 10^(-7)]` `= -[log 7.41 + log 10^(-7)]` `= -[0.86 - 7] = -[-6.13] = 6.13` |
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| 1141. |
The pH of an aqueous solution having hydroxide ion concentration as `1 xx 10^(-5)` isA. 5B. 9C. 4.5D. 11 |
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Answer» Correct Answer - B `[OH^(-)] = 1 xx 10^(-5)` `pOH = -log[OH^(-)] = 5` `pH + pOH = 14 rArr pH = 14 - 5 = 9`. |
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| 1142. |
What is the pH of a saturated solution of magnesium hydroxide, `Mg(OH)_(2)` at `25^(@)`C)A. 10.56B. 10.36C. 10.26D. 10.05 |
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Answer» Correct Answer - b |
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| 1143. |
The reaction `HCN +H_(2)O hArr H_(3)O^(+)+CN^(-),` the conjugate acid base pair isA. `HCN,H_(3)O^(+)`B. `H_(2)O,CN^(-)`C. `CN^(-),H_(3)O^(+)`D. `HCN,CN^(-)` |
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Answer» Correct Answer - D A conjugate acid base pair is related by a proton transfer. |
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| 1144. |
Which of the following has the highest degree of ionisation ?A. 1 M `NH_3`B. `0.001 M NH_3`C. `0.1 M NH_3`D. `0.0001 M NH_3` |
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Answer» Correct Answer - d |
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| 1145. |
`H_(3)O^(+) + OH^(-) rarr 2H_(2)O` isA. Arrhenius neutralisationB. Bronsted neutralisationC. Lewis neutralisationD. Both Lewis neutralization and Bronsted neutralisation. |
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Answer» Correct Answer - B Transfer proton from acid to base is called bronsted neutralisation |
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| 1146. |
Equal volums of solutions `pH` values `1,3,5,6` are mixed with each other . The pH of resultant solution is nearlyA. `1.3`B. `2.7`C. `1.6`D. `3.6` |
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Answer» Correct Answer - C `[H^(+)] = (10^(-1) v + 10^(-3)v + 10^(-5)v + 10^(-6))/(4v) = (10^(-1)v)/(4v)` `= 0.25 xx 10^(-1)` `= 2.5 xx 10^(-2)` `P^(H) = -"log" 2.5 xx 10^(-2)` `= 2 - "log" 2.5` `P^(H) = 1.6` |
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| 1147. |
The `p^(H)` of `HCl` is `3`. Then the `P^(H)` of `NaOH` solution having same molar concentration isA. `3`B. `6`C. `9`D. `11` |
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Answer» Correct Answer - D `P^(H) = 14 = P^(OH)` |
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| 1148. |
What will be the effect of adding 100 mL of `10^(-3)` M HCl solution to a solution of HA having concentration 0.1 M ? (`K_a` of HA=`10^(-5)`)A. Degree of dissociation of HA will decrease, pH will remain constantB. Degree of dissociation of HA will increase and pH decreasesC. Neither pH nor degree of dissociation of HA will change .D. Both degree of dissociation and pH will decrease |
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Answer» Correct Answer - c |
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| 1149. |
`10^(-2)` mole of `NaOH` was added to `10 litres` of water. The `pH` will change byA. 4B. 3C. 11D. 7 |
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Answer» Correct Answer - 1 Initially `pH=7` finally `[NaOH]=10^(-3)" "`so`pOH=11" "`So,`" "Delta(pH)=4` |
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| 1150. |
The strongest acid isA. `H_(3)AsO_(4)`B. `H_(3)AsO_(3)`C. `H_(3)PO_(3)`D. `H_(3)PO_(4)` |
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Answer» Correct Answer - D `H_(3)PO_(4)` and `H_(3)AsO_(4)` both have +5 oxidation state. But for same oxidation state, strength of oxy acids decrease, with increase in size. |
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