need help with preparing standard solutions EXP (1 Viewer)

[bobbbbb]

hi im having trouble with this experiment.
mass of empty flask = 54.07
mass of flask and solid acid = 54.71
initial burette reading = 0
final burette reading = 28.3

calculation questions:
1 calc the volume of sodium hydroxide solution used in each titration
*volume of NaOH=

2. calc the mass and number of moles of pottassium hydrogen phthalate used in each titration
*mass of KHC8H4O4(g) =
*moles of KHC8H4O4 =

3. the equation for this reaction is:
NaOH + KHC8H4O4 --> KNaC8H4O4 + H2O
calc the molar concentration of the sodium hydroxide used in each titration.
*concentration of NaOH (M)=

can someone please tell me how to answer those i am not very good at chemistry (thats what happens when you have parents who choose your subjects for you :burn: )

 

[Undermyskin]

Q1:

Well, volume is the reading that you get!

Volume of NaOH=28.3ml (if you read it right by following the downward rule!)

Q2:

Mass of potassium phthalate: 54.71 - 54.07 = 0.64 g

n= 0.64/(39.1+1.008*5+12.01*8+16*4)= 3.13388*10^-3 mol

Q3:

Ratio 1:1

n NaOH=n K phthalate= the above!

[]= n (above)/(28.3*10^-3)=0.111 mol/L

Ta da...