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प्रश्न
A small piece of calcium metal is put into a small trough containing water. There is effervescence and white turbidity is formed.
Write an equation for the reaction.
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उत्तर
Ca + 2H2O → Ca(OH)2 + H2
The solution turns blue.
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संबंधित प्रश्न
From the knowledge of activity series, name a metal which shows the following properties:
It displaces hydrogen from hot water.
A small piece of calcium metal is put into a small trough containing water. There is effervescence and white turbidity is formed.
Name the gas formed in the reaction. How would you test the gas?
Which metal is preferred for collecting hydrogen from:
Write the balanced equation
Hot water
Give reason for the following:
Potassium and sodium are not used for reaction with dilute hydrochloric acid or dilute sulphuric acid in the laboratory preparation of hydrogen.
Name two alkalies that can displace hydrogen. Give balanced equations for the same. Why are the metals you have used considered to have a unique nature?
When hydrogen is passed over a black solid compound A, the products are a 'colorless liquid' and a 'reddish-brown metal B'.
Substance B is divided into two parts each placed in separate test tubes.
Dilute HCl is added to one part of substance B and dilute HNO3 to the other.
- Name the substances A and B.
- Give two tests for the colourless liquid formed in the experiment.
- What happens to substance A when it reacts with hydrogen? Give reasons for your answer.
- Write an equation for the reaction between hydrogen and substance A.
- Is there any reaction between substance B and dilute hydrochloric acid? Give reasons for your answer.
Correct the following statement:
Very dilute nitric acid reacts with iron to produce hydrogen.
Using dilute sulphuric acid how would you differentiate between:
Copper and magnesium
How would you identify the gaseous products evolved.
State why hydrogen is not prepared in the laboratory by the action of lead with dilute hydrochloric acid.
‘Magnesium reacts with very dilute nitric acid at low temperatures liberating hydrogen.’ Give reasons.
