Evolution of Gas

Q.

The brown fume coming out when lead nitrate is heated is due to the liberation of _____ gas.

1. Oxygen

2. Nitrogen monoxide

3. Nitrogen

4. Nitrogen dioxide

Q.

When hydrogen peroxide is mixed with liquid soap and catalyst potassium iodide is added, a foamy substance is formed by the rapid decomposition of hydrogen peroxide. Name the experiment.

1. Oil Spill Experiment

2. Haber's Experiment

3. Elephant's Toothpaste Experiment

4. Blue Bottle Experiment

Q.

Which gas is released when zinc reacts with sulphuric acid?

1. Carbon dioxide
2. Oxygen
3. Hydrogen
4. Sulphur dioxide

Q.

The pungent smell, when ammonium chloride is heated with sodium hydroxide solution, is due to the evolution of ___.

Q. Which is the correct word equation for the reaction $CO+O_2\to C{O}_2$?

1. Carbon monoxide + Oxygen → Carbon oxide
2. Carbon oxide + Oxygen → Carbon dioxide
3. Carbon monoxide + Oxygen → Carbon dioxide
4. Calcium + Oxygen → Carbon oxide

Q. is decaying matter always warm?

Q.

On heating, lead(II) nitrate gives a brown gas (A). The gas (A) on cooling changes to a colourless solid/liquid (B). (B) on heating with NO changes to a blue solid (C). The oxidation number of nitrogen in solid (C) is:

1. +3

2. +4

3. +2

4. +5

Q.

Name a gas (other than $C{O}_2$) which turns lime water milky?

Q. When vinegar is added to a test tube containing baking soda, a gas is evolved. Identify the gas and the change involved.

1. Gas - nitrogen
   Change - physical
2. Gas - carbon dioxide
   Change - chemical
3. Gas - oxygen
   Change - physical
4. Gas - hydrogen
   Change - chemical

Q.

What is Hydrogen peroxide used for ?

Q. The catalyst present in the decomposition of hydrogen peroxide is ferrous sulphate or phosphoric acid or both?

Q.

When baking soda and vinegar are mixed, the effervescence shows the evolution of ___.

Q.

(a) A magnesium ribbon is taken and burnt. The ash is then dissolved in water. Name the various products formed. Support your answer with reactions.

(b) Burning of wood and cutting it into small pieces are considered as two different types of changes. Explain.
[3 MARKS]

Q. Question 3(a)
Fill in the blanks in the following statements:
When carbon dioxide is passed through lime water, it turns milky due to the formation of ___.

Q. State true or false:
Baking Soda on heating gives washing soda.

1. True
2. False

Q.

Answer the following:
a) Liquefied petroleum gas is used in kitchens. When the gas is in a cylinder, it is in the liquid state. When it comes out of the cylinder it becomes a gas (change A), then it burns (change B). Identify the processes A and B.

b) How does the ozone layer in the atmosphere protect us from harmful ultraviolet rays?
[5 MARKS]

Q.

Answer the following questions:

i) Setting of curd is regarded as a chemical change, explain why?

ii) Explain with the help of a reaction how baking soda is treated with vinegar?

Q.

A foamy substance is formed by the rapid decomposition of hydrogen peroxide when hydrogen peroxide is mixed with soap solution and catalyst potassium iodide is added. What is this experiment called?

1. Oil Spill Experiment

2. Haber's Experiment

3. Elephant's Toothpaste Experiment.

4. Blue Bottle experiment

Q. Why is sulphuric acid not used instead of ___ to remove copper rusting?

1. HF
2. HBr
3. HCOOH
4. HCL

Q.

Give the chemical tests to distinguish between the following gases:

Hydrogen chloride and Hydrogen sulphide

Q. Which of the following observation does not indicate a chemical change has occurred?

1. no new substances formed
2. Evolution of gas
3. Formation of new substances
4. Change of odour

Q.

The statement given below is incorrect. Write the correct statement.

Lead nitrate crystals on strong heating decompose to form lead dioxide, nitrogen dioxide, and oxygen gas.

Q. Please give me a video in which i can get what is the reaction with hydrogen peroxide and potassium permagnate

Q.

A dilute solution of sodium carbonate was added to two test tubes - one containing dilute $HCl$ (A) and the other containing dilute $NaOH$ (B). The correct observation was

1. A brown coloured gas liberated in test tube A.

2. A brown coloured gas liberated in test tube B.

3. A colourless gas liberated in test tube A.

4. A colourless gas liberated in test tube B.

Q. Which of the following are the observations that indicate a chemical change has occurred?

1. Change of physical state
2. Evolution of gas
3. Formation of new substances
4. Change of odour

Q. What is effervescence?

Q. Which of the following observation does not indicate a chemical change has occurred?

1. no new substances formed
2. Evolution of gas
3. Formation of new substances
4. Change of odour

Q. What happens when dilute sulphuric acid is added to zinc?

Q. Which of the following is a type of soap?

1. Hard soap
2. Both $A$ and $B$
3. Soft soap
4. None of above

Q. Observe the given flowchart carefully and mark the appropriate option correctly representing I, II, and III.

1. Sweet Calamine Formic acid
2. Sweet Formic acid Baking soda
3. Bitter Formic acid Baking soda
4. Bitter Baking soda Calamine