Chemistry 3/4 2013 Thread

[Mr Keshy]

Totally have no idea on what you guys are talking about . I'll be doing a chapter before the start of the term, don't want to get too far ahead

[simba]

Okay guys, I don't know what's been going on with me!!
I was doing some chemistry work today, and actually enjoyed it :0

I don't know what this means anymore! Is it possible that I'm developing a love for chemistry? 0_o

[teletubbies_95]

What a wonderful feeling love is!

[thushan]

Okay guys, I don't know what's been going on with me!!
I was doing some chemistry work today, and actually enjoyed it :0

I don't know what this means anymore! Is it possible that I'm developing a love for chemistry? 0_o

YES!! If you want to know about love and chemistry go to page 97-98 in the Unit 3 book you got from VCESS Simba

[simba]

YES!! If you want to know about love and chemistry go to page 97-98 in the Unit 3 book you got from VCESS Simba

Haha!! Discovering new things about Paul in the most unexpected places!

[shaiga95]

Having a bit of trouble with this question
Ch5 Q27  The amount of vitamin C in fruit juice can be determined by titration with a standard
0.0100 M iodine solution:
C6H8O6(aq) + I2(aq) → C6H6O6(aq) + 2H+(aq) + 2I–(aq)
If the maximum concentration of vitamin C is likely to be 0.00050 g mL–1, describe
how you would perform the analysis. You should mention:
• the volume of fruit juice used
• the maximum titre of iodine you would expect to obtain.

[shaiga95]

I worked it out pretty easy feel like a real n00b

[Math Nerd]

A mixture of 6 mole of aluminium powder and 3 mole of hydrogen chloride gas was added to a sealed container and allowed to react according to the equation:
2Al(s)+6HCL(g)->2AlCl3(g)+3H2(g)
The number of mole of gas remaining in the container when the reaction complete is?

[Bad Student]

Is it 2.5?

[Math Nerd]

Yes it is. Could you explain how you obtained that answer?

[Bad Student]

From the equation, we can see that two aluminium atoms react with six molecules of hydrogen chloride. However, there is an excess of aluminium powder so the hydrogen chloride gas becomes the limiting reactant.

So we know that all 3 mole of the hydrogen chloride gas reacts and only 1 mole of the aluminium powder reacts. By looking at the equation, we can see that the number of is the same as the number of , therefore 1 mole of is produced. Since  3 molecules of hydrogen are produced for every 2 molecules of , we know that 1.5 mole of is produced.

1 + 1.5 = 2.5

[teletubbies_95]

1.  Find the limiting using mole ratios
alumium = 6/2 = 3 mole
hydrochloric acid = 3/6= 0.5 mole
therefore HCl limiting and Al excess

2. Then find amount of gas in products , using limiting reagent .
therefore , AlCl3 = 1 mol ( 3 x 2/6= 1 ) , H2( 3/6 x 3= 1.5)

therefore 2.5 moles remaining

hope that helps !

[thushan]

Dude you guys should hold a Chemistry study group. should be in charge!

[simba]

Listen to the dinosaur people!

[teletubbies_95]

We totally should! But I think someone else should be in charge!