Chemistry
The number of molecules in 4.25 g of ammonia is:
(a) 1.0 × 1023
(b) 1.5 × 1023
(c) 2.0 × 1023
(d) 3.5 × 1023
Mole Concept
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Answer
1.5 × 1023
Reason —
Molar mass of ammonia = N + 3H = 14 + 3 = 17 g
The number of molecules in 17 g of ammonia = 6.022 × 1023
∴ No. of molecules in 4.25 g of ammonia
= x 4.25
= 1.5 × 1023
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