(d) how many chlorine atoms are in 5.0 g chloral hydrate?

To determine the number of chlorine atoms, we need to know first the chemical formula of chloral hydrate. From literature, it has a chemical formula of C2H3Cl3O2. Then, we relate the atoms of N with the said chemical formula. To convert from moles of N to atoms of N, we use Avogadro's number. It represents the number of units in one mole of any substance. This has the value of 6.022 x 10^23 units / mole. We do as follows:

5.0 g C2H3Cl3O2 ( 1 mol C2H3Cl3O2/ 165.4 g C2H3Cl3O2 ) ( 3 mol Cl / 1 mol C2H3Cl3O2 ) ( 6.022x10^23 atoms Cl / 1 mol Cl ) = 5.46 x10^22

Therefore, there are 5.46 x10^22 atoms of chlorine for 5.0 g of C2H3Cl3O2.