Chemistry
Dilute sulphuric acid is added to sodium sulphite. The following observations are noticed:
P — A gas with a suffocating smell is evolved which turns lime water milky.
Q — A foul smelling gas is evolved which turns lead acetate solution black.
R — A gas is evolved which decolourises pink KMnO4
Which of the following is true?
- Only P
- Only Q
- Only R
- Both P and R
Practical Chemistry
2 Likes
Answer
Both P and R
Reason — When dilute sulphuric acid is added to sodium sulphite, a colourless gas with a smell of burning sulphur i.e., suffocating odour is evolved.
Na2SO3 + H2SO4 ⟶ Na2SO4 + H2O + SO2
This gas turns lime water milky.
Ca(OH)2 + SO2 ⟶ CaSO3↓ + H2O
This gas also decolourises pink KMnO4.
2KMnO4 + 2H2O + 5SO2 ⟶ K2SO4 + 2MnSO4 + 2H2SO4
Answered By
3 Likes
Related Questions
A student takes Cu, Al, Fe and Zn strips, separately in four test tubes labeled as I, II, III and IV respectively. He adds 10 ml of freshly prepared ferrous sulphate solution to each test tube and observes the colour of the metal residue in each case.
He would observe a black residue in the test tubes:
- (I) and (II)
- (I) and (III)
- (II) and (III)
- (II) and (IV)
A nitrate which forms a precipitate with ammonium hydroxide and is also soluble in excess of it:
- ferrous nitrate
- ferric nitrate
- lead nitrate
- copper nitrate
A compound X consists of molecules. Which of the following properties will be shown by X?
P — The boiling point of X is low.
Q — The compound X is soluble in water.
R — The aqueous solution of X does not conduct electricity.
- Only P
- Only Q
- Only R
- Both P and R
Assertion (A): HCl can be tested by AgNO3 solution.
Reason (R): White precipitate of AgCl is formed when AgNO3 is added to HCl.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.