Which of the following reaction produces hydrogen ?
Mg + H2O
H2S2O8 + H2O
BaO2 + HCl
Na2O2 + 2HCl
A.
Mg + H2O
Alkali and alkaline earth metals react with water to produce hydrogen gas and metal hydroxide. This is due to their high electropositive character.
2Na + 2H2O 2NaOH + H2
Mg + 2H2O Mg(OH)2 + H2
Assertion: Stannous chloride gives a grey precipitate with mercuric chloride, but stannic chloride does not do so.
Reason: Stannous chloride is a powerful oxidising an agent which oxidises mercuric chloride to metallic mercury.
If both assertion and reason are true and the reason is a correct explanation of the assertion.
If both the assertion and reason are true but the reason is not a correct explanation of the assertion.
If the assertion is true but the reason is false.
If both the assertion and reason are false.
Assertion: Diamond is a bad conductor.
Reason: Graphite is a good conductor.
If both assertion and reason are true and reason is a correct explanation of the assertion.
If both the assertion and reason are true but the reason is not a correct explanation of the assertion.
If the assertion is true but the reason is false.
If both the assertion and reason are false.