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chemistry question, pls help me out

This acid contains 40.0% carbon and 6.67% hydrogen by mass. The remainder
is oxygen. The molar mass of the acid is 60.0 g mol.
Use this information to deduce the empirical formula and the molecular
formula of the acid.

What is the total number of atoms in 6.00 g of the acid?

When 2.00 mol of the acid react with sodium carbonate, 1.00 mol of carbon dioxide
is formed. Calculate the volume of carbon dioxide formed, in cm3 from 8.00 g of the acid at
room temperature and pressure.
(edited 1 year ago)
Reply 1
gonna need the full question for this one I'm pretty sure
Original post by zunainahaque
When 2.00 mol of the acid react with sodium carbonate, 1.00 mol of carbon dioxide
is formed.
Calculate the volume of carbon dioxide formed, in cm3, from 8.00 g of the acid at
room temperature and pressure.


Original post by isa04
gonna need the full question for this one I'm pretty sure

sorry, i pasted only the ending by mistake
Original post by isa04
gonna need the full question for this one I'm pretty sure

here i really didn’t understand how to find the remainder which is oxygen. i can easily derive the calculation of molecular formula and all which is not the issue. im also stuck with those other two questions at the ending.
(edited 1 year ago)
Reply 4
1) Percentage of Oxygen is 100-40-6.67 = 53.33
Therefore if you divide each of the percentages by the relative atomic masses (40/12 , 6.67/1 , 53.33/16) you get 3.33:6.67:3.33 (C : H : O)
Which in its simplest form is 1:2:1, hence the empirical formula is 1:2:1 (CH2O)
You're told the Mr of the acid is 60 g/mol hence since the empirical formula is 30g/mol you can see that the empirical formula needs to be scaled by a factor of 2 so that its the same as the molecular formula. Hence the molecula formula is C2H4O2 (or ethanoic acid)
2) Total number of atoms in 6g of acid is therefore 6/60 moles of acid (0.1) which means the total number of molecules of acid is 0.1 x avogadro number = 6.022 x 10^22, hence the total number of atoms is this x8 since there are 8 atoms in each molcule
3)2 mol of acid produces 1 mol CO2. 2 mol acid is the same as 120g of acid hence if we used 8 grams of acid this is x15 less acid so the number of moles of CO2 produces will be fifteen times less (or 1/15)
And multiplying this by 24 (because there are 24 mol per dm^-3 at RTP) we can say that there must be 1.6dm^3 CO2 which is 1600cm^3

That should help.
(edited 1 year ago)
Original post by caucasz
1) Percentage of Oxygen is 100-40-6.67 = 53.33
Therefore if you divide each of the percentages by the relative atomic masses (40/12 , 6.67/1 , 53.33/16) you get 3.33:6.67:3.33 (C : H : O)
Which in its simplest form is 1:2:1, hence the empirical formula is 1:2:1 (CH2O)
You're told the Mr of the acid is 60 g/mol hence since the empirical formula is 30g/mol you can see that the empirical formula needs to be scaled by a factor of 2 so that its the same as the molecular formula. Hence the molecula formula is C2H4O2 (or ethanoic acid)
2) Total number of atoms in 6g of acid is therefore 6/60 moles of acid (0.1) which means the total number of molecules of acid is 0.1 x avogadro number = 6.022 x 10^22, hence the total number of atoms is this x8 since there are 8 atoms in each molcule
3)2 mol of acid produces 1 mol CO2. 2 mol acid is the same as 120g of acid hence if we used 8 grams of acid this is x15 less acid so the number of moles of CO2 produces will be fifteen times less (or 1/15)
And multiplying this by 24 (because there are 24 mol per dm^-3 at RTP) we can say that there must be 1.6dm^3 CO2 which is 1600cm^3

That should help.


thank you so much, man. truly appreciated. sending you warmth and great health.

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