[txaggie]

This is a problem that I got and I can't seem to solve them.

Calculate the number of moles of Cl atoms in .86g of C₂H₄Cl₂

Also, calculate the total number of atoms in .29g NH₄NO₃

The molar mass of C₂H₄Cl₂ is 98.960 g/mol

The molar mass of NH₄NO₃ is 80.0432 g/mol

Any help would be appreciated

[Borek]

How many molecules of C₂H₄Cl₂ in mole?

How many moles of C₂H₄Cl₂ in 0.86g?

How many Cl atoms per C₂H₄Cl₂ molecule?

[dabaichi]

Calculate the number of moles of Cl atoms in .86g of C₂H₄Cl₂

You can solve in this several ways. But the easiest way is to find the percent composition of Cl in C2H4Cl2. Then multiply .86g by that percent. Lastly use that number to divide the molar mass of Cl.

Also, calculate the total number of atoms in .29g NH₄NO₃

First you use .29g NH4NO3 to divide the molar mass of NH4NO3 to find the moles of NH4NO3. Then multiply that number by Avogadro's number to find the number of molecules. Lastly multiply that number by the total number of atoms in NH4NO3 which is 9.

You do the math.

[Borek]

Calculate the number of moles of Cl atoms in .86g of C₂H₄Cl₂

You can solve in this several ways. But the easiest way is to find the percent composition of Cl in C2H4Cl2. Then multiply .86g by that percent. Lastly use that number to divide the molar mass of Cl.

Quite the opposite: divide this number by the molar mass of Cl. But that won't give number of atoms yet, it will give number of moles of chlorine.

[dabaichi]

Calculate the number of moles of Cl atoms in .86g of C₂H₄Cl₂

You can solve in this several ways. But the easiest way is to find the percent composition of Cl in C2H4Cl2. Then multiply .86g by that percent. Lastly use that number to divide the molar mass of Cl.

Quite the opposite: divide this number by the molar mass of Cl. But that won't give number of atoms yet, it will give number of moles of chlorine.

I thought the question is asking for the number of moles of C2H4Cl2. I guess not then. But for the final step to find the number of Cl atoms, you use the number from my last step to multiply by Avogadro's number.

[Borek]

Oops, sorry, there were several questions and somehow I got them mixed. Number of moles it is. Still, you divided molar mass by element mass, instead of element mass by molar mass.