Last minute questions?

[Surgeon]

An aqueous solution of nitric acid was titrated against a 0.100M solution of sodium carbonate. A 20.00ml aliquot of this sodium carbonate solution was pipetted into a conical flash and titrated against 0.0500 mol/L nitric acid solution.

Calculate the volume, in ml, of the 0.0500mol/L nitric acid added to the aliquot of sodium carbonate.



Either this question can't be done or I'm just being retarded... Probably the latter of the two aforementioned scenarios.

[charmanderp]

2HNO3 + Na2CO3 --> 2NaNO3 + H2O + CO2

n(Na2CO3)=0.02*0.1=0.002mol

We need twice the amount of HNO3 as we do sodium carbonate so we require 0.004mol of nitric acid.

V=n/C so 00.4/0.05 = 0.0800L

[Kaille]

In vcaa 2011, i had problems with sig  figs.

In sa question 5, the smallest value of sig figs was 0.0525, so i thought it was gonna be three sig figs all the way through, then in the assessment report, bii and biii were four sig figs? How does this work???

[destain]

If in that question, the least number of sig figs in the information that you used was4 sig figs

[Kaille]

but the smallest amount of sig ffigs was three?

[destain]

that you used in answering your question? the particular bii) or whatever it was bi)

[Surgeon]

Is it likely that we will be required to draw a absorbance graph?

[destain]

calibration graph? half the time i guess

[charmanderp]

If we have to draw it the line of best fit can start at the lowest y-value (absorbance value/peak area) and finish at the greatest y-value (absorbance value/peak area) right?

[Surgeon]

I meant are we likely to get a question like the one on page 29 of the ATAR Notes chem book.