When 100mL solution of `NaOH and NaCO_(3)` was first titrated with N/10 HCl in presence of HPh, 17.5mL were usedtill end point is obtained. After this end point MeOH was added and 2.5mL of same HCl were required to attain new end point. The amount NaOH in mixture is:

0.4 g mixture of NaOH, Na_2CO_3 , and some inert N impurities was first titrated with N/(10) HCl using phenolphthalein as an indicator, 17.5 ml. of HCI was required at the end point. After this methyl orange was added and titrated. 1.5 mL of same HCl was required for the next end point. The weight percentage of Na_2CO_3 , in the mixture is (Rounded-off to the nearest integer)

200 " mL of " a solution of a mixture of NaOH and Na_2CO_3 was first titrated with 0.1 M HCl using phenolphthalein indicator. 17.5 " mL of " HCl was required for the same HCl was again required for next end point. Find the amount of NaOH and Na_2CO_3 in the mixture.

A solution of weak acid HA was titrated with base NaOH. The equivalent point was reached when 40 mL. Of 0.1 M NaOH has been added. Now 20 mL of 0.1 M HCl were added to titrated solution, the pH was found to be 5.0 What will be the pH of the solution obtained by mixing 20 mL of 0.2 M NaOH and 20 mL of 0.2 M HA?