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# A level chem help plz watch

1. When heated, 1.117g of iron reacted with 720cm3 chlorine to produce a chloride of iron. Use calculations to help construct the reaction equation.
2. Calculate moles of iron using n=m/Mr. 1 mole of gas at rtp occupies 24000cm^3. Find ratio of moles and then construct equation.
3. (Original post by haarithiop)
Calculate moles of iron using n=m/Mr. 1 mole of gas at rtp occupies 24000cm^3. Find ratio of moles and then construct equation.
i did that and got 1 mole for iron and 1.43 for CL so i got Fe2Cl3 which is incorrect as the answer is fecl3
4. (Original post by officialzak_2001)
i did that and got 1 mole for iron and 1.43 for CL so i got Fe2Cl3 which is incorrect as the answer is fecl3
Ok so for iron: 1.117/55.85 = 0.02 mol
For chlorine 720/24000 = 0.03 mol

For every 1 mole of iron that reacts, 1.5 moles of chlorine (Cl2) reacts. Fe +1.5Cl2 => FeCl3
5. (Original post by haarithiop)
Ok so for iron: 1.117/55.85 = 0.02 mol
For chlorine 720/24000 = 0.03 mol

For every 1 mole of iron that reacts, 1.5 moles of chlorine (Cl2) reacts. Fe +1.5Cl2 => FeCl3
sorry i get the beginning of the equation but can u make it clear how u got fecl3
i thought it would be fe2cl3 as you will double it
6. (Original post by officialzak_2001)
sorry i get the beginning of the equation but can u make it clear how u got fecl3
i thought it would be fe2cl3 as you will double it
We have 0.02 mol of Fe and 0.03 mol of Cl2 (chlorine gas), for every 1 mol of Iron you have 1.5 mol of Cl2. Sure you can double it so for every 2 mol of iron you have 3 mol of Cl2. 2Fe + 3Cl2 => 2FeCl3. Maybe you think we just have Cl atoms - no - we have Cl2 molecules.
7. (Original post by haarithiop)
We have 0.02 mol of Fe and 0.03 mol of Cl2 (chlorine gas), for every 1 mol of Iron you have 1.5 mol of Cl2. Sure you can double it so for every 2 mol of iron you have 3 mol of Cl2. 2Fe + 3Cl2 => 2FeCl3. Maybe you think we just have Cl atoms - no - we have Cl2 molecules.
so why is it cl3
8. Thank god i dont have to do this stuff anymore

Brings back nightmares of a level chemistry
9. (Original post by officialzak_2001)
so why is it cl3
Fe +1.5Cl2 => FeCl3

Overall on the left hand side we have three moles of chlorine atoms (1.5 mol of Cl2 molecules) so on the right hand side we must also have 3 moles of chlorine atoms, therefore it's Cl3.
10. (Original post by haarithiop)
Fe +1.5Cl2 => FeCl3

Overall on the left hand side we have three moles of chlorine atoms (1.5 mol of Cl2 molecules) so on the right hand side we must also have 3 moles of chlorine atoms, therefore it's Cl3.
Thanks

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