If $19.7 \ kg$ of gold is confiscated from a thief,how many atoms of gold were confiscated from him? $(Au = 197 \ g/mol)$

How many grams of $H_2O$ are present in $0.25 \ mol$ of it (in $g$)?

Assertion $(A)$: Equal moles of different substances contain the same number of constituent particles.
Reason $(R)$: Equal weights of different substances contain the same number of constituent particles.
The correct answer is

$A$ sample of $[Cu(NH_3)_4]SO_4$ contains $2.4 \times 10^{24}$ ammonia molecules. The moles of $[Cu(NH_3)_4]SO_4$ in the given sample will be:

Which of the following statements is incorrect?

The number of $N$ atoms in $681 \ g$ of $C_{7}H_{5}N_{3}O_{6}$ is $x \times 10^{21}$. The value of $x$ is $.....$ $(N_{A} = 6.02 \times 10^{23} \ mol^{-1})$ (Nearest Integer)