Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R).
Mark the correct choice as:
Assertion (A): When a piece of copper metal is added to dilute sulphuric acid, the solution turns blue.
Reason (R): Copper reacts with dilute sulphuric acid to form blue copper (II) sulphate solution.
Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R).
Mark the correct choice as:
Assertion (A): Metals are sonorous.
Reason (R): They are generally brittle in the solid state; they break into pieces when hammered.
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Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R).
Mark the correct choice as:
Assertion (A): Gas bubbles are observed when sodium carbonate is added to dilute hydrochloric acid.
Reason (R): Carbon dioxide is given off in the reaction.
Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R).
Mark the correct choice as:
Assertion (A): In alumino thermite process, the metals like iron melts due to the heat evolved in the reaction.
Reason (R): The reaction is:
Fe2O3 + 2Al → Al2O3 + 2Fe
Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R).
Mark the correct choice as:
Assertion (A): Usually the sulphide ore is converted to oxide before reduction.
Reason (R): Reduction of oxides occurs easier.
Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R).
Mark the correct choice as:
Assertion (A): A mineral is called ore, when metal is extracted from it conveniently and economically.
Reason (R): All ores are minerals but all minerals are not ores.
Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R).
Mark the correct choice as:
Assertion (A): While the extraction of copper, one of the steps involved is
Cu2S + 2Cu2 O → 6Cu + SO2
Reason (R): In this reaction Cu2S is the reducing agent whereas Cu2O is the oxidising agent.
Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R).
Mark the correct choice as:
Assertion (A): In the metallurgy of Al, purified Al2O3 is mixed with Na3AlF6 or CaF2.
Reason (R): It lowers the melting point of the mixture and brings conductivity.
Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R).
Mark the correct choice as:
Assertion: Different metals have different reactivities with water and dilute acids.
Reason: Reactivity of a metal depends on its position in the reactivity series.
Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R).
Mark the correct choice as:
Assertion : Gas bubbles are observed when sodium carbonate is added to dilute hydrochloric acid
Reason : Carbon dioxide is given off in the reaction.