Advertisements
Advertisements
Questions
Give reasons why copper is used to make hot water tanks and not steel (an alloy of iron).
Give reasons for the following:
To make hot water tanks, copper is used and not steel.
Advertisements
Solution 1
- Copper is a good conductor of heat and does not react with hot water; on the contrary, iron reacts with hot water.
- Iron reacts with steam to corrode the tank, whereas copper does not react with either of these substances.
- Steam has an effect on iron, while temperature fluctuations have no effect on copper.
- When hot water produces steam, iron reacts with it in the following forms:
\[\ce{\underset{Iron}{3Fe} + \underset{Water}{4H2O} -> \underset{Ferric oxide}{Fe3O4} + \underset{Hydrogen gas}{4H2↑}}\]
Therefore, copper rather than steel is used to make hot water tanks.
Solution 2
Copper is less reactive and a better conductor of heat. It does not corrode easily, making it suitable for hot water tanks. Hence, copper is used to make hot water tanks.
RELATED QUESTIONS
_________ solution is blue in colour.
(a) CuSO4
(b) FeSO4
(c) ZnSO4
(d) Al2(SO4)3
Name the following:
Metals which forms an amphoteric oxide.
The solution of Aluminium sulphate in water is .....................
(a) Green
(b) Colourless
(c) Pink
(d) Blue
From amongst the metals sodium, calcium aluminium, copper and magnesium, name the metal:
(i) which reacts with water only on boiling, and
(ii) another which does not react even with steam.
How would you show that silver is chemically less reactive than copper?
Explain why, the surface of some metals acquires a dull appearance when exposed to air for a long time.
What happens when a rod of zinc metal is dipped into a solution of copper sulphate? Give chemical equation of the reaction involved.
Describe the reaction of potassium with water. Write the equation of the reaction involved.
What happens when a metal reacts with dilute hydrochloric acid? Explain with the help of an example.
Write the equation for the reaction of Aluminium with dilute hydrochloric acid.
Name the products formed. Also indicate the physical states of all the substances involved.
Name one metal which displaces silver from silver nitrate solution and one which does not.
A basic oxide will be formed by the element:
(a) K
(b) S
(c) P
(d) Kr
An element X forms two oxides XO and XO2. The oxide XO is neutral but XO2 is acidic in nature. The element X is most likely to be:
(a) sulphur
(b) carbon
(c) calcium
(d) hydrogen
Which one of the following four metals would be displaced from the solution of its salt by the other three metals?
(a) Zn
(b) Ag
(c) Cu
(d) Mg
When calcium metal is added to water, the gas evolved does not catch fire but the same gas evolved on adding sodium metal to water catches fire. Why is it so?
Write the name and formula of a molecule made up of three atoms of oxygen.
Which property of metals is used for making bells and strings of musical instruments like Sitar and Violin?
An alkali metal A gives a compound B (molecular mass = 40) on reacting with water. The compound B gives a soluble compound C on treatment with aluminium oxide. Identify A, B and C and give the reaction involved.
The substance that will be flattened on beating with a hammer is ______.
