[Tay]

i would be grateful to know what method i could use to find the percentage of sodium hydrogencarbonate in baking powder,it cannot be a titration, and must be a simple method.
the procedure must also make use of the reaction of NaHCO3 with sulphuric acid.

i would be extremely grateful, if someone could help me with this.
thank you
tay

[Alberto_Kravina]

i would be grateful to know what method i could use to find the percentage of sodium hydrogencarbonate in baking powder,it cannot be a titration, and must be a simple method.
the procedure must also make use of the reaction of NaHCO3 with sulphuric acid.

i would be extremely grateful, if someone could help me with this.
thank you
tay

A titration would be the easiest and simplest method, also, there would be H₂SO₄ involved in the reaction. But if you want to complicate your life you could add H₂SO₄ to the baking bowder, measure the amount of CO₂ and then calculate the amount of pure sodium bicarbonate in the mixture.
Why shouldn't it be a titration?

[FeLiXe]

if you have a scale it should work

take a defined amount of sulphuric acid. weigh in as much baking powder until it stops fizzing. from that you can calculate the percentage.

[Tay]

I have got to try and do it wihout titration, would the inverted measuring cylinder with a trough method be better, or is there any better methods i could use.

how would i use that solution of sodium hydrogencarbonate and acid to find the mass? please elaborate

thank so far your help, i really appreciate it 

[FeLiXe]

let's say you have 1 liter of 1 mol/liter H2SO4. means you have 1 mol.

that means you need 2 (!)  mol of NaHCO3 to neutralise it. that is 144g of pure NaHCO3. you notice neutralisation when it stops fizzing.

if you needed 288g of baking powder then you know your baking powder was 50% NaHCO3 (if there aren't any other acids or bases in it)

[Borek]

let's say you have 1 liter of 1 mol/liter H2SO4. means you have 1 mol.

that means you need 1 mol of NaHCO3 to neutralise it

And not two? 

[FeLiXe]

well, I'm not Mr. pH :-)

[Tay]

ok looking at the first method mentioned, as the baking powder does contain an acid, so if i used 0.18g of baking powder, how much gas should i collect using formulas and therefore how much acid in excess would i have to use?

thanks for the help so far, its been great!!!!

[Borek]

ok looking at the first method mentioned, as the baking powder does contain an acid, so if i used 0.18g of baking powder, how much gas should i collect using formulas and therefore how much acid in excess would i have to use?

Start with the balanced reaction equation - that's simple stoichiometry question.

[Tay]

yeh ive tried that, so i devided 0.153(how much nahco3, im guessing will form), by the mr of NaHCO3 which is 84, and i got around 0.001821, i no that the mole ratio is 1:1, so to find the volume of gas produced ive times it by 24dm3, 24000cm3 and ive got 45cm3,
first is this correct, and if so how to i find the how much acid is required i can use to produce this amount???

[Borek]

Please write all balanced reaction equations. They contain everything you need.

[mdlhvn]

here is my suggesstion, but it don't involve in H2SO4, hope it can help you:
Balance x(g) baking powder, dissolve in hot water, boil the solution to release CO2, continue heating it to vaporize all the water. Balance the remain solid again got y(g), then mass of CO2 is x-y, calculate the moles of this CO2. Base on the following reaction, measure the mass of NaHCO3----> percentage:
2NaHCO3------>Na2CO3 + CO2 + H2O

[reeeE]

Hey there. I am doing the same practical experiment. Ok to start with, you know that carbonate+acid>>>salt + H2O + CO2

2NaHCO3 (s) +H2SO4 (aq) ? Na2SO4 (aq) + 2H2O (l) + 2CO2 (g)

you can measure the volume of gas i.e CO2. Then u find the mole of the gas  mole= volume(cm3)/24000

Ratio 1:1

So the mole is of CO2 is the same as the NaHCO3
Then you find the mass of NaHCO3.  Mass=mole of NaHCO3 x Mr(84). You will get the mass

The thing which I am not sure abut is how to determine the % mass of NaHCO3  in the baking powder. One thought is to divide the mass u got by the total mass of the baking powder.

[Suziola]

I have to do this aswell
But i'm stuck on calculating how you calculate how much of everything to use, anyone able to help?
I have to have it by tomorrow

So far i have moles the equation so with 2moles of CO2 i know that there will be moles of NaHCO3,
Mass = moles * molar mass so i get a mass of 88g,but then i'm stuck and i'm not even sure if that is right anyone able to help would be really appreciated