96) Which of the following metal liberates H2 gas on reaction with NaOH
A) Zn
B) Ca
C) Mg
D) Na
Explanation:Zinc (Zn) reacts with NaOH to liberate hydrogen gas:
Answer:Zn
97) Which of the following can’t be used as X in the equation given below?
Acid+X → Salt + CO2 + water
A) Metal hydrogen carbonates
B) Metal carbonates
C) Both (1) and (2)
D) Metal hydroxides
Explanation:The correct answer is D. Metal hydroxides.
Explanation:
The given reaction is:
Let’s analyze each option:
– 1. A. Metal hydrogen carbonates (e.g., NaHCO₃)
– Reaction:
– Valid, as this produces 
.
– 2. B. Metal carbonates (e.g., Na₂CO₃)
– Reaction:
– Valid, as this also produces .
– 3. C. Both (1) and (2)
– Since both A and B are valid, this option is incorrect for the question (which asks for what can’t be used).
– 4. D. Metal hydroxides (e.g., NaOH)
– Reaction:
– Does not produce .
– Hence, this is the correct answer because it cannot be used to produce .
Conclusion:
Only metal hydroxides (D) do not produce when reacting with acids, making them the correct choice for what can’t be used in the given reaction.
98) Tooth enamel is made up with
A) calcium hydroxide
B) calcium phosphate
C) calcium oxide
D) calcium carbonate
99) What is the pH of the salt formed from weak acid and strong base?
A) 3
B) 9
C) 7
D) 5
100) Who among the following did not propose atomic model?
A) Planck
B) Schrodinger
C) Bohr
D) Sommerfeld