I Answer the following:
1. Give example of a physical change which occurs by
the action of heat.
2. Write the colour of copper sulphate solution obtained
when iron nails are dipped in it.
3. Complete the following reaction:
Calcium hydroxide+carbondioxide becomes
4. Name the gas which turns lime water milky.
5. What is galvanisation?
Answers
Answer:
1.A- When ice is heated it changes its state from solid to liquid.
2.A- When an iron nail immersed in the solution of copper sulphate than iron displaces copper from the solution of copper sulphate because iron is more reactive than copper. Therefore copper sulphate solution colour changes from blue to pale green.
3.A- Calcium hydroxide + Carbon dioxide → Calcium Carbonate + Water.
4.A- Carbon dioxide reacts with calcium hydroxide solution to produce a white precipitate of calcium carbonate. Limewater is a solution of calcium hydroxide. If carbon dioxide is bubbled through limewater, the limewater turns milky or cloudy white.
5.A- Galvanisation or galvanization (or galvanizing as it is most commonly called) is the process of applying a protective zinc coating to iron or steel, to prevent rusting. The most common method is hot dip galvanizing, in which steel sections are submerged in a bath of molten zinc.
Hope it helps :)
Answer:
1.
Examples of chemical changes are burning, cooking, rusting, and rotting. Examples of physical changes are boiling, melting, freezing, and shredding
2.
When an iron nail immersed in the solution of copper sulphate than iron displaces copper from the solution of copper sulphate because iron is more reactive than copper. Therefore copper sulphate solution colour changes from blue to pale green.
3. 3rd answer is in picture
4.
Carbon dioxide
Carbon dioxide reacts with calcium hydroxide solution to produce a white precipitate of calcium carbonate. Limewater is a solution of calcium hydroxide. If carbon dioxide is bubbled through limewater, the limewater turns milky or cloudy white.
5.
Galvanisation or galvanization (or galvanizing as it is most commonly called) is the process of applying a protective zinc coating to iron or steel, to prevent rusting. The most common method is hot dip galvanizing, in which steel sections are submerged in a bath of molten zinc.
