how many grams of chlorine are in a mixture containing 4.0x10^23molecules of PCL3 and 0.250 mol of PCI5

Answer 1

Hello,

This question is not that difficult once you realize a few things. There are 3 Steps to this problem.

Step 1) Convert 4.02x10²³ molecules of PCl₃ into grams of Chlorine

a) To start you need to convert molecules into moles

Remember that Avogadro's Number is 6.02x10²³. There are that many atoms or molecules in every mole.

Divide 4.02x10²³ by 6.02x10²³ to get the number of moles of PCl₃

b) Now you should be able to see that for every mole of PCl₃ there are 3 moles of Chlorine

That's because there are 3 atoms of Chlorine in each molecule

Multiply the moles of PCl₃ by 3 to get the moles of Cl

c) Next you need to find the molar mass of Cl. You can find it on a periodic table.

d)Multiply the moles of Cl by the atomic mass of Cl to get the grams of Cl

We're done with the first part.

Step 2) Convert 0.250 moles of PCl₅ into grams of Chlorine.

a) You are also going to need to figure out that there are 5 moles of Chlorine in every mole of PCl₅

Multiply 0.250 moles of PCl₅ by 5 to get 1.25 moles of Chlorine

b) Now remember the atomic mass of Chlorine. Multiply it by 1.25 moles of Chlorine

This will give you the second mass of Chlorine

Step 3) Add the masses of Chlorine from Step 1) and Step 2) together to get the total amount.

I know it might seem like a lot of work but once you get the hang of these problems it becomes a lot easier.

Good Luck,

Michael