Carbon Dioxide

Q.

When a gas X is passed through limewater, it turns milky due to the formation of a precipitate Y. Identify X and Y.

1. $H_2$ and $Ca(HC{O}_3{)}_2$
2. $C{O}_2$ and $CaC{O}_3$
3. $C{l}_2$ and $CaC{l}_2$
4. $C{O}_2$ and $Ca(HC{O}_3{)}_2$

Q. By squizzing lemon on a piece of rock the gas liberated turned lime water milky. Which compound is present in the rock ?

Q. What happens when moist blue litmus paper is placed in a jar containing carbon dioxide?

Q. Dry ice is carbon dioxide and can undergo .

1. solid
2. liquid
3. evaporation
4. sublimation

Q. Which of the following options are correct regarding given assertion and reason?

Assertion [A] : An increase in carbon dioxide in the atmosphere leads to global warming.

Reason [R] : Carbon dioxide is a greenhouse gas.

1. A is incorrect, but R is true.
2. A and R are true; R is the correct explanation for A.
3. Both A and R incorrect statements.
4. A and R are true; but R is not a correct explanation for A.

Q.

12 Name the sources of carbon dioxide in the air.

Q.

Name the component of air that has maximum solubility in water.

1. Oxygen

2. Nitrogen

3. Hydrogen

4. Carbon dioxide

Q.

State three ways by which carbon dioxide enters in the atmosphere.

Q.

Name the following:
This gas is used to put out fire.

Q. Near polluted areas, the percentage of which of the following gases is higher than normal?

1. Oxygen
2. Nitrogen
3. Carbon dioxide
4. Argon

Q.

Global warming can be controlled by?

Q.

All solids, on heating, first change to liquid and then to the gaseous state.

1. True
2. False

Q. Rhea added an oxide Y through water and obtained a compound, which turned blue litmus red. She passed the same oxide Y through limewater and observed that the colour of limewater changed to milky-white. Identify Y.

1. Magnesium oxide
2. Carbon dioxide
3. Nitrous oxide
4. Sulphur dioxide

Q. Dry ice is carbon dioxide and can undergo .

Q. $C{O}_2$ is used in fire extinguishers as,

Q. The process by which a solid directly converts into its gaseous state is called:​

1. Sublimation​
2. Evaporation​
3. Deposition​
4. Vaporisation​

Q.

Write a short note on increasing the content of carbon dioxide in the air.

Q. When sulphur (S) reacts with oxygen gas (O₂), it produces:

1. basic oxides.
2. acidic oxides.
3. amphoteric oxides.
4. a salt.

Q. Which of the following process releases oxygen into the air?

1. Digestion
2. Respiration
3. Photosynthesis
4. Transpiration

Q.

The process in which a solid changes directly into its gaseous state.

Q. _________is a sublimable substance.

1. Wood
2. Wax
3. Iron
4. Camphor

Q.

Which of the following gases cause the harmful greenhouse effect?

1. Carbon dioxide

2. Hydrogen

3. Oxygen

4. Nitrogen

Q. On passing carbon dioxide through limewater, the lime water turns milky. This is due to the formation of.

1. ${\mathrm{CaCO}}_3$
2. ${\mathrm{Na}}_{2}O$
3. ${\mathrm{Na}}_2{\mathrm{CO}}_3$
4. $\mathrm{CaO}$

Q. Which of the following has been causing most damage to the Taj Mahal?

1. Global warming
2. Smoke
3. Acid rain
4. Dust

Q. Choose the correct option to complete the following reaction:
$2\text{Mg (s)}+{\text{CO}}_2\left(g\right)\to$

1. ${\mathrm{Mg}}_2{\mathrm{CO}}_3\left(s\right)+C\left(s\right)$
2. ${\mathrm{MgCO}}_2\left(s\right)+C\left(s\right)$
3. ${\mathrm{MgO}}_2\left(s\right)+C\left(s\right)$
4. $2\mathrm{MgO}\left(s\right)+C\left(s\right)$

Q. Which among the following is responsible for the depletion of ozone layer?

1. Chlorofluorocarbon
2. Nitrogen gas
3. Carbon dioxide gas
4. Sulphur dioxide gas

Q.

Write whether the following statement is true or false:

‘Coke is a tough, porous and black substance. It is an almost pure form of carbon.’

1. True
2. False

Q.

How will you distinguish between fire extinguishing action of water and $C{O}_2$? [3 MARKS]

Q. Choose the correct option to complete the following reaction:

$4\text{Na (s)}+3{\text{CO}}_2\left(g\right)\to$

1. ${\mathrm{Na}}_2{\mathrm{CO}}_3\left(s\right)+C\left(s\right)$
2. ${\mathrm{CO}}_2\left(s\right)+\mathrm{NaO}\left(g\right)$
3. ${\mathrm{Na}}_2{\mathrm{CO}}_2\left(s\right)$
4. ${\mathrm{NaHCO}}_3\left(s\right)+C\left(s\right)$

Q.

Which gas is used for extinguishing flames? How does it work? [3 MARKS]