Chemistry
Assertion (A): Few drops of dilute hydrochloric acid is added to a solution of iron sulphide, a colourless gas is formed with a rotten egg odour.
Reason (R): The gas formed does not turn moist lead acetate paper silvery black.
- 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.
Answer
Both A and R are true and R is the correct explanation of A.
Reason — When you add dilute acid like HCl to zinc sulphide (ZnS), a colourless H2S gas is formed with the a rotten egg odour. Hence, the assertion (A) is true.
Hydrogen sulphide gas (H2S) does react with moist lead acetate paper. It turns the paper silvery black (or brownish-black) due to the formation of lead sulphide (PbS). Hence, reason (R) is false.
Related Questions
The statements below show the results when three metal strips, P, Q, and R, are placed in blue copper sulphate solution.
P — Solution turns green. Q — Solution becomes colourless. R — Solution remains blue.
Which of the following metals could be P, Q, and R?
- P-Al, Q-Zn, R- Fe
- P-Zn, Q-Fe, R- Ag
- P-Fe, Q-Zn, R-Ag
- P- Zn, Q-AI, R– Fe
Study the below diagram and choose the correct option related to the content given below:
Compound X reacts with ammonia in the combustion tube, which leaves a residue Y. Identify X and Y, as well as the property Z of ammonia demonstrated in this particular reaction.
- X= CuO, Y=black, Z = reducing property.
- X=PbO, Y = yellow, Z=oxidising property.
- X=CuO, Y =yellow, Z =oxidising property.
- X=PbO, Y=black, Z=reducing property.
Assertion (A): Hall Heroult’s process is used to get pure aluminium from its oxide.
Reason (R): Aluminium generally is not found in aluminium oxide form.
- Both A and R are correct.
- A is correct, but R is not a true explanation of A.
- A is correct, and R is a true explanation of B.
- Both A and R are incorrect.
Assertion (A): Alkenes, alkynes and alkanes are examples of homologous series.
Reason (R): Organic compounds of the homologous series have similar structures but different chemical properties.
- Both A and R are true.
- Both A and R are false.
- A is true but R is not the correct explanation of A.
- A is false but R is true.