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प्रश्न
Thin strips of magnesium, copper, and iron are taken.
Write down what happens when these metals are treated as follows:
- Heated in presence of air
- Heated with dil.HCl
- Added to an aqueous solution of zinc sulphate.
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उत्तर
- On heating thin strips of magnesium, copper, and iron, they form oxides.
- Magnesium and iron react with HCl liberating hydrogen and forming their respective salts. Hydrogen cannot be prepared from metals that are below it in the activity series of metals (such as copper) because only metals that are more reactive than hydrogen can displace it from acids.
- Only magnesium will displace zinc from zinc sulphate solution because magnesium is more reactive than zinc in the activity series of metals. No reaction takes place in the case of copper and iron because they are less reactive than zinc.
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संबंधित प्रश्न
Write a balanced equation for the following:
Iron reacts with dil. HCl
From the knowledge of activity series, name a metal which shows the following properties:
It forms a base which is insoluble in water.
Hydrogen can be prepared with the metal zinc by using: alkali
Give an equation.
Based on the reactions of water on metals, arrange the following metals in increasing order of reactivity: iron, sodium, magnesium, zinc, calcium
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.
What do you observe when hydrogen gas is passed through a soap solution?
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.
Give a reason for the following.
Hydrogen is collected by the downward displacement of water and not of air, even though it is lighter than air.
Select the odd one out and justify your answer.
Fe, Zn, Cu and Mg
Using dilute sulphuric acid how would you differentiate between:
Sodium sulphide and sodium carbonate.
How would you identify the gaseous products evolved.
