[Rutherford]

Again a task with scales:
On balance pans of a scale you have two glasses with 1,68g NaHCO3. If you add 100g of 5% CH3COOH in one glass, what must be the mass share of 100g HCl that you have to add in the second glass so that the balance is not interrupted?
a)w=0,05
b)w<0,0073
c)w>0,0073

And I have a stochiometry problem:
When you heat 44,5g of H4P2O7 a linear polymer is made (HPO3)_n*H2O and in this process 1,71g of water is released. Calculate the Mr of the polymer.
I don't understand if the 1,71g of water is meant to the *H2O that is combined with (HPO3)_n, or there is made more water so that the reaction is: H4P2O7-->(HPO3)_n*H2O+H2O?

[AWK]

Hint - HCl should evolve the same amount of CO₂ as acetic acid

( *H₂O

means in this case
H-(HPO₃)_n-OH

[Rutherford]

Thanks for the answer, I solved the first one. Now the second one:
I wrote the equation
H4P2O7--->(HPO3)_n*H2O+H2O
Is it right? And how to balance it now?

[AWK]

count P atoms on both sides