Question
For 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:
  1. Both A and R are true, and R is correct explanation of the assertion.
  2. Both A and R are true, but R is not the correct explanation of the assertion.
  3. A is true, but R is false.
  4. A is false, but R is true.
Assertion: The arrangement of metals in order of decreasing reactivities is called reactivity series.
Reason: Metals at the top of series are very reactive and metals at the bottom are least reactive.

Answer

  1. Both A and R are true, but R is not the correct explanation of the assertion.

Explanation:

Metals at the top of the series are very reactive and therefore, they do not occur free in nature. The metals at the bottom of the series are least reactive and therefore, they normally occur free in nature.

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Similar questions

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:
  1. Both A and R are true, and R is correct explanation of the assertion.
  2. Both A and R are true, but R is not the correct explanation of the assertion.
  3. A is true, but R is false.
  4. A is false, but R is true.
Assertion: Tooth decay starts when the pH of the mouth is lower than 5.5.
Reason: Enamel starts corroding below 5.5 pH.
For 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:
  1. Both A and R are true, and R is correct explanation of the assertion.
  2. Both A and R are true, but R is not the correct explanation of the assertion.
  3. A is true, but R is false.
  4. A is false, but R is true.
Assertion: On reacting with water, calcium starts floating over water.
Reason: Calcium reacts with cold water at room temperature.
In the following questions, a statement of Assertion is given by the corresponding statement of Reason. Of the statements, mark the correct answer as.
  1. If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
  2. If both Assertion and Reason are true, but Reason is not the correct explanation of Assertion.
  3. If Assertion is true, but Reason is false.
  4. If Assertion is false, but Reason is true.
  5. Both Assertion and Reason are false.
Assertion: $2\text{Na}+\text{H}_2\rightarrow2\text{NaH}$
In the above chemical equal, sodium is getting oxidised and H2 is getting reduced.
Reason: The chemical reaction in which oxidation and reduction take place simultaneously, are called redox reactions.
For 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:
  1. Both A and R are true, and R is correct explanation of the assertion.
  2. Both A and R are true, but R is not the correct explanation of the assertion.
  3. A is true, but R is false.
  4. A is false, but R is true.
Assertion: The oxides of sulfur and phosphorus are acidic in nature.
Reason: Metal oxides are basic in nature.
For 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:
  1. Both A and R are true, and R is correct explanation of the assertion.
  2. Both A and R are true, but R is not the correct explanation of the assertion.
  3. A is true, but R is false.
  4. A is false, but R is true.
Assertion: When calcium carbonate is heated, it decomposes to give calcium oxide and carbon dioxide.
Reason: The decomposition reaction takes place on application of heat, therefore, it is an endothermic reaction.
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  1. Both A and R are true, and R is correct explanation of the assertion.
  2. Both A and R are true, but R is not the correct explanation of the assertion.
  3. A is true, but R is false.
  4. A is false, but R is true.
Assertion: Copper displaces silver from silver nitrate solution.
Reason: Copper is more reactive than silver.
For 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:
  1. Both A and R are true, and R is correct explanation of the assertion.
  2. Both A and R are true, but R is not the correct explanation of the assertion.
  3. A is true, but R is false.
  4. A is false, but R is true.
Assertion: Chemical reaction changes the physical and chemical state of a substance.
Reason: When electric current is passed through water (liquid), it decomposes to produce hydrogen and oxygen gases.
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:
  1. Both A and R are true, and R is correct explanation of the assertion.
  2. Both A and R are true, but R is not the correct explanation of the assertion.
  3. A is true, but R is false.
  4. A is false, but R is true.
Assertion: Carbon and its compounds can be used as fuels.

Reason: They are highly inflammable and have high calorific value.
In the following questions, a statement of Assertion is given by the corresponding statement of Reason. Of the statements, mark the correct answer as.

  1. If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
  2. If both Assertion and Reason are true, but Reason is not the correct explanation of Assertion.
  3. If Assertion is true, but Reason is false.
  4. If Assertion is false, but Reason is true.
  5. Both Assertion and Reason are false.
Assertion: The following chemical equation is an example of thermal decomposition reaction.

$2\text{KClO}_3(\text{s})\xrightarrow[\text{Catalyst}]{\text{Heat}}2\text{KCl}(\text{s})+3\text{O}_2(\text{g})$

Reason: Heat gets released in the decomposition reactions.

Assertion (A) : Hydrogen peroxide is kept in coloured bottles.
Reason (R) : Hydrogen peroxide is a moderately reactive metal that can react with light or heat slowly to produce water.