A sample of mixed alkali contains NaOH and Na_2 CO_3 is titrated in the following two schemes. (1) 10 mL of above mixture requires 8 mL of 0.1 N HCl by using phenolphthalein. (ii) 10 mL of above mixture requires 10 mL 0.1 N HCI by using methyl orange. What will be the ratio of the weight of NaOH and Na2CO3 in the sample mixture?

A sample of mixed alkali contains NaOH and Na_2 CO_3 is titrated in th

1.	A sample of mixed alkali contains NaOH and Na_2 CO_3 is titrated in the following two schemes. (1) 10 mL of above mixture requires 8 mL of 0.1 N HCl by using phenolphthalein. (ii) 10 mL of above mixture requires 10 mL 0.1 N HCI by using methyl orange. What will be the ratio of the weight of NaOH and Na2CO3 in the sample mixture?
Answer» `1: 132` `2.412` `2.122` `3.142 :1` Solution :Meqif HCIfor10mLofmixtureusingphenolphthleinindicator`= 8 XX 0.1 = 0.8` ` therefore` Meqof `NaOH+1/2 Meq ` of ` Na_2 CO_3 = 0.8` NowMeqof HCIusedfor 10 mLmixtureusingmethylorganeas INDICATOR`=10 xx 0.1 =1` Meq`of NaOH+MeqOf Na_2 CO_3 =1` ` therefore `BYeqn(i ) and (ii ) Meq of ` NaOH=0.6Meq` of`Na_2CO_3= 0.4` ` (w )/( 40) xx 1000 =0.6` ` (w)/( 106 //2) xx 1000 =0.4` WTOF`NaOH= 0.024 `wqof `Na_2 CO_3 = 0.0212` ratioof theweightof `Na_2CO_3= ( 0.024)/( 0.0212) = 1.132:1`