Advertisements
Advertisements
Question
Which gas is usually liberated when an acid reacts with a metal? How will you test for the presence of this gas?
Advertisements
Solution
Hydrogen gas is usually liberated when an acid reacts with an active metal.
The reaction of dilute sulphuric acid with zinc metal to show the formation of hydrogen gas can be carried out as follows:
- Take a few pieces of zinc granules in a boiling tube and add about 5 mL of dilute sulphuric acid to it (see figure).
- We will observe the formation of gas bubbles on the surface of zinc granules.
- Pass the gas formed through the soap solution in a trough (via a glass delivery tube). Gas-filled bubbles form in the soap solution and rise into the air.
- Bring a burning candle near a gas-filled soap bubble. The gas present in a soap bubble burns with a pop sound (making a little explosion) (see figure).
- Only hydrogen gas burns, making a pop sound. This shows that hydrogen gas is evolved when dilute sulphuric acid reacts with zinc metal (in the form of zinc granules).
APPEARS IN
RELATED QUESTIONS
When a solution is added to a cloth strip treated with onion extract, then the smell of onion cannot be detected. State whether the given solution contains an acid or a base.
Name one natural source of the following acid:
Citric acid
What is meant by strong acids?
A white shirt has a yellow stain of curry. When soap is rubbed on this shirt during washing, the yellow stain turns reddish-brown. On rinsing the shirt with plenty of water, the reddish-brown stain turns yellow again.
Explain the changes in colour of this indicator which take place during washing and rinsing the shirt.
A white shirt has a yellow stain of curry. When soap is rubbed on this shirt during washing, the yellow stain turns reddish-brown. On rinsing the shirt with plenty of water, the reddish-brown stain turns yellow again.
What is the nature of soap (acidic/basic) as shown by the indicator present in curry stain?
One of the following is a medicine for indigestion. This is:
Give two examples of the following:
monobasic acid
Which acid is used for getting chloride salt?
Main constituent of acid is ______.
What is the difference between : An alkali and a metal hydroxide?
Choose the correct answer from the options given below:
Benzoic acid is used for/in/as
Acid mixed with base forms ______.
Paheli is suffering from indigestion due to acidity. Is it advisable to give her orange juice in this situation and why?
Fill in the cross word given in figure with the help of the clues provided.
Across
(2) The solution which does not change the colour of either red or blue litmus.
(4) Phenolphthalein gives pink colour in this type of solution.
(7) Colour of blue litmus in lemon juice.
Down
(1) It is used to test whether a substance is acidic or basic.
(3) It is a natural indicator and gives pink colour in basic solution.
(5) Nature of ant’s sting.
(6) It is responsible for the increase in temperature during a neutralisation reaction.
What are acids?
Hydrochloric Acid reacts with metal bicarbonates to give ______.
Which one of the following acids undergoes complete ionisation?
Complete the following equation.
CaO + H2SO4 → ______ + H2O
Draw the structure of Hydronium ion.
