Answer:
0.0000101 grams.
Step-by-step explanation:
First of all, use Avogadro's number to convert from molecules to moles.
Avogadro's number is 6.02 x 10^23.
Second of all, to convert from moles to grams, find the substance formula of phosphorus trichloride. After finding the substance formula, then find the molar mass of phosphorus trichloride.
Phosphorus trichloride is PCl3
Now find the molar mass of PCl3
P = 31.0 amu
Cl = 35.5 amu
They are three chlorine atoms and one phosphorus atom. So you do this.
31.0(1) + 35.5(3) = 137.5 g/mol
Now use dimensional analysis to show your work
4.6 x 10^16 grams of PCl3 * 1 mol/ 6.02 x 10^23 * 137.5 g/mol / 1 mol
The grams and the moles cancel out.
So now do [(4.6 x 10^16) / (6.02 x 10^23)] x 137.5
and you will get 0.000010507
4.6 has the fewest digits which is 2.
So use sig figs and the answer rounds to the nearest millionths.
0.000010507 rounds to 0.0000101
So the final answer is 0.0000101 grams(don't forget the units)
Hope it helped!