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Which of the following statements is/are...

Which of the following statements is/are incorrect?
I. 5 moles of `H_2` and 5 moles of `O_2` have the same mass in grams.
II. 100 g of `NH_3` has less atoms than that present in 100 g of `N_(2)`.
III. 16 g of solid sulphur contains `3.76 xx 10^(23)` molecules.

A

I and II only

B

II and Ill only

C

III only

D

I, II and III

Text Solution

Verified by Experts

The correct Answer is:
D
I. 5 moles of `H_2 = 2xx 5 = 10 g `
II 5 moles of `O_2 = 32 xx 5 = 160g `
Hence, 5 moles of `H_2` and 5 moles of `O_2` do not have the same mass in grams.
II. 100g of `NH_3` :
17 g of `NH_3 -= 6.023 xx 10^(23) xx 4 `atoms
100g of `NH_3 -= (6.023 xx 10^(23) xx 40)/(17) xx 100 = 141.71 xx 10^(23)` atoms
100g of ` N_2 -= (2xx 6.023 xx 10^(23))/(28) xx 100 = 43.02 xx 10^(23)` atoms
Hence , 100g of `NH_3` has more atoms than 100g of `N_2` .
III. `8 xx 32 g` of solid sulphur`-= 6.023 xx 10^(23)` molecules
16g of sulphur `-=(6.023 xx 10^(23))/(8 xx 32) xx 16`
`= 0.376 xx 10^(23)` molecules
`= 3.76 xx 10^(22)` molecules
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