Question

3. Number of atoms in 1 ml of ammonia gas at STP is
(1) 2.7 * 1019
(2) 1.08 x 1020
(3) 10.8 x 1020
(4) 5.4 x 1019
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Answer 1

Explanation:

So 1 ml has 1/22400 moles at STP. 1 mole = 6.022 x 1023 molecules. So number of molecules of ammonia in 1 ml = 6.022 x 1023/22400. Now, multiply this number by 4 to get the total number of atoms as each molecule of ammonia has 4 atoms ( 1 N and 3 H).