H3CA is a vitally important intemediate in the metabolism of carbohydrates. The compound is widely distributed in plant and animal tissues and fluids. H3CA is a tiprotric acid, ie, it requires three moles of NaOH to fully neutralize one mole of H3CA.

Question

a.) If it requires 19.41 of 0.616 M NaOH(aq) to fully neutralize 0.766g of H3CA, what is the molar mass of H3CA?

b.) Given the following % composition, determine the true formula of H3CA: 37.51% C; 4.20% H, 58.29% O.

* I wasn't sure where to begin because there are a lot of values to consider. So, what should I start with first?*

Answer 1

The equation.
H3CA + 3NaOH ==> Na3CA + 3H2O

For part b, take 100 g sample, convert to mols C, mols H, mols O, then find the ratio of atoms to each other with the smallest number being no less than 1.0.

Post your work if you get stuck.

Answer 2

For part A. is that just extra info?

Molar mass is simply mass of H *3 plus the mass of Calcium which ='s 43.104 g/mol H3CA..

For part B... given the percent composition, I did
37.51 g/ 12.0111 g/mol= 3.123 mol C
4.20 g/ 1.0079 g/mol= 4.17 mol H
58.29 g/ 15.999 = 3.643 mol O.

Now to find the true formula or Empirical Formula, I'd have to divide those previous answers by the small mole number which is 3.123.

I guess the empirical formula would be:
C1 H1.34 O1.16 ?

Does that make sense and is this even right?

Answer 3

H3CA is a vitally important intemediate in the metabolism of carbohydrates. The compound is widely distributed in plant and animal tissues and fluids. H3CA is a tiprotric acid, ie, it requires three moles of NaOH to fully neutralize one mole of H3CA.

a.) If it requires 19.41 of 0.616 M NaOH(aq) to fully neutralize 0.766g of H3CA, what is the molar mass of H3CA?

b.) Given the following % composition, determine the true formula of H3CA: 37.51% C; 4.20% H, 58.29% O.

* I wasn't sure where to begin because there are a lot of values to consider. So, what should I start with first?*