• Best of luck to the class of 2024 for their HSC exams. You got this!
    Let us know your thoughts on the HSC exams here
  • YOU can help the next generation of students in the community!
    Share your trial papers and notes on our Notes & Resources page
MedVision ad

Chemistry help (1 Viewer)

FCB

Emma Watson <3
Joined
Nov 9, 2009
Messages
563
Gender
Male
HSC
2011
A 5.00 gr of a unknown compound contains 1.86g C, .39g H and 2.75g of Cl. Write the empirical formula

I tried dividing the 1.86/0.39 but it came out with 4.7....
I thought this might give me the ratio but it hasn't helped
 

hscishard

Active Member
Joined
Aug 4, 2009
Messages
2,033
Location
study room...maybe
Gender
Male
HSC
2011
A 5.00 gr of a unknown compound contains 1.86g C, .39g H and 2.75g of Cl. Write the empirical formula

I tried dividing the 1.86/0.39 but it came out with 4.7....
I thought this might give me the ratio but it hasn't helped
Think you needa find how many carbon atoms there are in 1.86g of Carbon, how many hydrogen atoms in .39g, etc
Then it would be no.carbon no. of hydrogen and no. of chlroine...Then simplify the ratio.

What module is this?
 

chrisnumber1

Member
Joined
Aug 12, 2009
Messages
244
Gender
Male
HSC
1998
Think you needa find how many carbon atoms there are in 1.86g of Carbon, how many hydrogen atoms in .39g, etc
Then it would be no.carbon no. of hydrogen and no. of chlroine...Then simplify the ratio.

What module is this?
you would use moles instead of atoms but yeah your on the right track. there basically the same thing
 

zxreth

Member
Joined
Oct 11, 2009
Messages
775
Gender
Male
HSC
2011
find the percentage composition and then work from there.
 

namesAsh

New Member
Joined
May 20, 2009
Messages
18
Location
Liverpool
Gender
Male
HSC
2011
Firstly set it out in ratio form, there's nothing new here just what we know already

1.86 C : 0.39 H : 2.75 Cl

From here we want to get the atomic mass of the element and divide it into said element, eg; 1.86 divided by 12.01 = 0.15 (2dp)

0.15 : 0.39 : 0.08
(These are the answers I got with my periodic table, yours may be different)

From here we divide the lowest number from this set of numbers into the others to get the ratios, you may also find it that you won't nice whole numbers but don't worry round it up.

2 : 5 : 1

That's it!

Empirical formula is C2H5Cl
 

Icee_tee

Member
Joined
Sep 5, 2009
Messages
45
Gender
Male
HSC
2011
C2H5Cl

I think this might be right.
Check it and tell me if i got it right or not.
ty
 

FCB

Emma Watson <3
Joined
Nov 9, 2009
Messages
563
Gender
Male
HSC
2011
That seems right to me.

Thanks
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top