10ml of `Na_2CO_3` war titrated against 0.2M HCl. The following were the titre values obtained (ml) 4.8,4.9,5.0,5.0,5.0. Molarity of `Na_2CO_3` ?

10.0mL of Na_2CO_3 solution is titrated against 0.2M HCl solution. The following titre values were obtained in 5 readings : 4.8mL, 4.9mL, 5.0mL, 5.0mL, and 5.0mL Based on these readings, and convention of titrametric estimation the concentration of Na_2CO_3 solution is.........nM. (Round off to the Nearest Integer).

20 mL of 0.5 M HCl is mixed with 30 mL of 0.3 M HCl, the molarity of the resulting solution is :

100 mL of 0.1 M Na_2 CO _ 3 solution is titrated with 0.1 M HCl solution. If reaction taking placing during titrationis Na _ 2 CO _ 3 + HCl to Na HCO _ 3 + NaCl then find pH at half equivalent point. for H_2 CO _ 3 , Ka_ 1 = 10 ^(-7) and Ka _ 2 = 10 ^( -11) .

250 mL of a Na_(2)CO_(3) solution contains 2.65 g of Na_(2)CO_(3).10mL of this solution is added to xml of water is obtain 0.001 M Na_(2)CO_(3) solution. The value of x is :