MCQ 11 Mark
For question two statements are given-one labelled
Assertion $(A)$ and the other labelled
Reason $(R)$. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below:
Assertion: $CH_3COOH$ is used as vinegar in cooking and food preservatives.
Reason: Strong acids are those acids which ionise almost completely in aqueous solution and hence produce a large amount of $H^+$ ions.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- ✓
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: B. Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
View full question & answer→MCQ 21 Mark
For question two statements are given-one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below:
Assertion: Phenolphthalein is an acid-base indicator.
Reason: Phenolphthalein gives different colours in acidic and basic medium
- ✓
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: A. Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
Phenolphthalein is a weak organic acid and may be represented as $HPh.$
$\text{HPh}\ \ \ \ \ \ \ \ \ \ \ \rightleftharpoons\ \ \ \ \ \ \ \ \text{H}^+\ \ \ \ \ +\ \ \ \ \ \ \ \text{Ph}^-\\\text{(Colourles)}\ \ \ \ \ \ \ \ \text{(Colourles)}\ \ \ \ \ \ \ \ \text{(Pink)}$
In acidic medium, excess of $H ^{+}$ions are present and so equilibrium is towards left and hence solution is colourless. While in basic medium, $OH$ ions combine with $H ^{+}$ions to form unionised water molecules and so equilibrium is towards right and hence solution has pink colour. Therefore, phenolphthalein is an acid acid$-$base indicator.
View full question & answer→MCQ 31 Mark
For question two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : $\ce{pH}$ of ammonium nitrate solution is acidic.
Reason : Solution of a salt of weak base and strong acid is acidic.
- ✓
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: A. Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
Ammonium nitrate is a salt of ammonium hydroxide $($weak base$)$ and nitric acid $($strong acid$).$
View full question & answer→MCQ 41 Mark
In the following questions, a statement of Assertion is given by the corresponding statement of Reason. Of the statements, mark the correct answer as.
Assertion : On heating, gypsum gets converted into plaster of Paris.
Reason : Gypsum loses water molecules on heating at $373K$ temperature.
- ✓
If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
- B
If both Assertion and Reason are true, but Reason is not the correct explanation of Assertion.
- C
If Assertion is true, but Reason is false.
- D
If Assertion is false, but Reason is true.
AnswerCorrect option: A. If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
Plaster of Paris is prepared by heating gypsum at $373 K$. On heating, it loses water molecules and becomes calcium sulphate hemihydrate $(\text{CaSO}_4.\frac{1}{2}\text{H}_2\text{O})$ which is called Plaster of Paris.
$\text{CaSO}_4.2\text{H}_2\text{O}\rightarrow\text{CaSO}_4.\frac{1}{2}\text{H}_2\text{O}\ \ + 1\frac{1}{2}\text{H}_2\text{O}$
$\text{Gypsum}\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \text{Plaster of paris}$
Plaster of Paris was first widely used in Paris, and it became the center of plaster production. Thus it got its name. $9000$ years ago houses are made of woods, in order to protect them from fire, a coating of plaster was made on the walls. First, this application of $\ce{POP}$ was started in Paris and it became the center of plaster production, thus it is known as Plaster of Paris.
View full question & answer→MCQ 51 Mark
For question two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Calcium sulphate hemihydrate, $\text{CaSO}_4.\frac{1}{2}\text{H}_2\text{O}$ is called plaster of Paris.
Reason : Plaster of Paris is used for producing moulds for pottery and ceramics and casts of statues.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- ✓
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: B. Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
View full question & answer→MCQ 61 Mark
For question two statements are given-one labelled .
Assertion $(A)$ and the other labelled
Reason $(R)$. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below:
Assertion: Sodium carbonate pentahydrate is also known as washing soda.
Reason: Chief raw materials for the manufacture of washing soda are $NH_{3,} NaCl$ and $CaCO_3.$
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- ✓
$A$ is false, but $R$ is true.
AnswerCorrect option: D. $A$ is false, but $R$ is true.
Washing soda is sodium carbonate decahydrate, $Na2CO_{3·} 10H_2O.$
View full question & answer→MCQ 71 Mark
For question two statements are given-one labelled
Assertion $(A)$ and the other labelled
Reason $(R)$. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below:
Assertion: Strength of the acid or base decreases with dilution.
Reason: Ionization of an acid or a base increases with dilution.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- ✓
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: B. Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
Ionization of an acid or a basic increases on dilution but concentration of $H ^{+}$or $OH ^{-}$ions decreases per unit volume, thus strength of the acid or the base decreases with dilution.
View full question & answer→MCQ 81 Mark
For question two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : The process of dissolving an acid or a base in water is highly exothermic reaction.
Reason : Water must always be added slowly to acid with constant stirring.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- ✓
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: C. $A$ is true, but $R$ is false.
The process of dissolving an acid or a base in water is highly exothermic reaction. Acid must always be added slowly to water with constant stirring.
View full question & answer→MCQ 91 Mark
For question two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : The chemical name of bleaching powder is calcium oxychloride.
Reason : Bleaching powder is used as an oxidising agent in chemical industries.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- ✓
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: B. Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
View full question & answer→MCQ 101 Mark
For question two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Baking soda is prepared by chlor $-$ alkali process.
Reason : Brine decomposes to sodium hydroxide on passing electricity through it.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- ✓
$A$ is false, but $R$ is true.
AnswerCorrect option: D. $A$ is false, but $R$ is true.
Caustic soda $($sodium hydroxide, $\ce{NaOH})$ is prepared by chlor $-$ alkali process. Brine decomposes to sodium hydroxide. Chlorine gas is formed at the anode and hydrogen gas at the cathode. Sodium hydroxide solution is formed near the cathode.
View full question & answer→MCQ 111 Mark
For question two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below: Assertion : Tooth decay starts when the pH of the mouth is lower than $5.5.$
Reason : Enamel starts corroding below $5.5. \ce{pH}.$
- ✓
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: A. Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
View full question & answer→MCQ 121 Mark
For question two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Acetic acid does not act as an acid in benzene solution.
Reason : Benzene is non $-$ polar.
- ✓
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R $ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: A. Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
For ionization of an acid or base, polar solvents $($like water$)$ are required. As ionization does not take place in non $-$ polar solvents $($like benzene$)$ so acetic acid does not act as an acid.
View full question & answer→MCQ 131 Mark
For question two statements are given-one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below:
Assertion: $AlCl_3$ is a basic salt.
Reason: $AlCl_3$ is a salt of strong acid and a weak base.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- ✓
$A$ is false, but $R$ is true.
AnswerCorrect option: D. $A$ is false, but $R$ is true.
$AlCl_3$ is an acidic salt as it is a salt of strong acid (HCl) and a weak base $[Al(OH)_3].$
View full question & answer→MCQ 141 Mark
For question two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below:
Assertion : Common salt is used for the preparation of many chemicals such as sodium hydroxide, bleaching powder, baking soda, washing soda etc.
Reason : Main source of sodium chloride is sea water.
- A
Both $A$ and $R $ are true, and $R$ is correct explanation of the assertion.
- ✓
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: B. Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
View full question & answer→MCQ 151 Mark
For question two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Bleaching powder reacts with dilute acids to evolve chlorine.
Reason : The chlorine liberated by the action of dilute acids on bleaching powder is called available chlorine.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- ✓
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: B. Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
The reaction involved is,
$\text{CaOCl}_2\ \ +\ \ \text{H}_2\text{SO}_{4\text{(dilute)}}\ \ \xrightarrow{\ \ \ \ \ \ \ \ \ \ \ \ }\ \ \text{CaSO}_4\ \ +\ \ \text{H}_2\text{O}\ \ +\ \ \text{Cl}_2\uparrow$
View full question & answer→MCQ 161 Mark
For question two statements are given-one labelled
Assertion $(A)$ and the other labelled
Reason $(R).$ Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below:
Assertion: Salt of $KNO _3$ is formed by strong base and weak acid. Reason: Salt of $NH _4 Cl$ is formed by weak base and strong acid.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- ✓
$A$ is false, but $R$ is true.
AnswerCorrect option: D. $A$ is false, but $R$ is true.
View full question & answer→MCQ 171 Mark
For question two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below: Assertion : $\ce{pH } = 7$ signifies pure water.
Reason : $\ce{pH}$ of acetic acid is greater than $7.$
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- ✓
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: C. $A$ is true, but $R$ is false.
$\ce{pH}$ of acetic acid is less than $7.$
View full question & answer→MCQ 181 Mark
In the following questions, a statement of Assertion is given by the corresponding statement of Reason. Of the statements, mark the correct answer as.
Assertion : The $\ce{pH}$ of sodium chloride solution is seven.
Reason : Salt of strong acid and a strong base are acidic in nature.
- A
If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
- B
If both Assertion and Reason are true, but Reason is not the correct explanation of Assertion.
- ✓
If Assertion is true, but Reason is false.
- D
If Assertion is false, but Reason is true.
AnswerCorrect option: C. If Assertion is true, but Reason is false.
A salt that is derived from the reaction of a strong acid with a strong base forms a solution that has a $\ce{pH}$ of $7.$ An example is sodium chloride, formed from the neutralization of $\ce{HCl}$ by $\ce{NaOH}$. A solution of $\ce{NaCl}$ in water has no acidic or basic properties, since neither ion is capable of hydrolyzing.
View full question & answer→MCQ 191 Mark
For question two statements are given-one labelled
Assertion $(A)$ and the other labelled
Reason $(R)$. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below:
Assertion: Phosphoric acid is a weak acid.
Reason: Phosphoric acid when dissolved in water dissociates partially and produces very little $H^+$ ions.
- ✓
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: A. Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
View full question & answer→MCQ 201 Mark
For question two statements are given$-$one labelled
Assertion $(A)$ and the other labelled
Reason $(R).$ Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below:
Assertion: Higher the $H+$ ion concentration, lower is the $pH$ value.
Reason: The pH of a neutral solution $= 7$, that of a basic solution$< 7$ and that of an acidic solution$> 7.$
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- ✓
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: C. $A$ is true, but $R$ is false.
Higher the $H^+$ ion concentration, lower is the $pH$ value. The $pH$ value less than $7$ represents an acidic solution and value more than $7$ represents a basic solution.
View full question & answer→MCQ 211 Mark
For question two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : $\ce{Cl}$ is a stronger acid than acetic acid.
Reason : On dissociation $,\ce{HCl}$ yields lesser hydrogen ions for the same concentration as compared to acetic acid.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- ✓
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: C. $A$ is true, but $R$ is false.
On dissociation, $\ce{HCl}$ yields more hydrogen ions for the same concentration as compared to acetic acid.
View full question & answer→MCQ 221 Mark
For question two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Antacids neutralize the effect of extra acid produced in the stomach during indigestion and thus provide relief.
Reason : Antacids are mild bases.
- ✓
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: A. Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
View full question & answer→