>>1007903>a. The initial volume of the NaOH solution is 400mlfalse, because the pH is much more than 7, and the NaOH solution is more dilute, so it should be higher than 500 mL
>b. 1 mole of NaOH is involved in the reactionif one mole of NaOH was used, that means there was 800 mL of NaOH solution initially, and 200 mL of acid solution. there would be 0.333 mol of H3PO4 initially. H3PO4 is triprotic, so it can get converted to its conjugate base three times (H3PO4 -> H2PO4- -> HPO4 2- -> PO4 3-), when the reaction is done there will be an excess of 0.001 mol of unreacted NaOH:
pOH = -log[OH-] = 3
14 - pOH = pH = 11
so this is true
>c. 300 ml H3PO4 solution are involved in the reactionfalse, it's 200 mL
>d. There are 5.6 moles of NaOH in the final solutionfalse, it's 1 mol
>e. The salt concentration in the final solution is 0.333Mtrue, all the of the initial 0.333 mol of H3PO4 will be converted into PO4 3-, the final volume is 1 L, so the salt concentration would be 0.333M
