Question

Five moles of TiCl4 are combined with two moles of Ti.

a) How many moles of TiCl3 are produced according to the following reaction?

3TiCl4 + Ti = 4TiCl3

I know the answer for A is 6.7 mols TiCl3.

I know 2 mols of Ti (4 mol TiCl3 / 1 mol Ti) = 8 mol and 5 mols TiCl4 (4 mols TiCl3 / 3 mols TiCl4) = 6.7 mols TiCl3

What I don't understand is where the 5 is coming from. Wouldn't the balanced equation use 6 and not 5?

This is my main question and I would appreciate any detailed replies to help me understand. Thank you.

Answer 1

Yes you are right. But here you can better analyse this way

1 mole of needs 3 moles of

Similarly

2 moles of needs 6 moles of

But since we dont have 6 moles of So we won't be able to fully use 2 moles of .

Here some will be left unused. So using 2 mols of Ti (4 mol TiCl3 / 1 mol Ti) = 8 mol is wrong.

Here is a limiting reagent.

See here we are not using 2 moles of because those whole 2 moles are not used. Here i will give an analogy
Suppose that you have 5 slices of pizza and 600 ml of cold drink with each slice 200 cal and every 100 ml 50 cal

You drink cold-drink with pizza only and 100ml with every slice. So now after eating the whole pizza you will have eaten 5 slices and have drunk 500 ml of cold-drink. There is extra 100 mL left. Now calories you consume for every slice+100mL=250cal

Now to calculate total calories you will just multiply this 250 by number of slices/drink you have had and not with the niumber of drink that were initially there

If you still have any doubt Feel free to ask.

Thanks