Correct option is A
Correct option: (a) 2.65 g
Step-by-step explanation:
·
Normality (N) = equivalents per litre
·
Equivalent weight of Na₂CO₃:
· Molecular weight = 106
· Valency factor = 2
· Equivalent weight = 106 / 2 =
53
· Formula used:
Weight [g] = Normality × Equivalent weight × Volume [L]
· Substituting values:
· = 0.1 × 53 × 0.5
· =
2.65 g
➡️ Hence,
2.65 g of Na₂CO₃ is required.
❌ Why other options are incorrect
·
(b) 0.265 g
· One decimal place error.
·
(c) 26.5 g
· Ten times higher than required.
·
(d) 0.00265 g
· Incorrect unit scale (milligram range).
�� Key Points
· For salt solutions, always use
equivalent weight.
· Na₂CO₃ is
dibasic, hence valency factor = 2.
· Volume must be converted to
litres.
✔️
Final Answer: (a)