A 2 - g samplecontainingNa_(2) CO_(3) and NaHCO_(3) loses 0 . 248 g when heated to 300^(@) C, the temperature atwhich NaHCO_(3) decomposesto Na_(2) CO_(3) , CO_(2) and H_(2) O . Whatis thepercentage of Na_(2) CO_(3) in thegiven mixture ?(Na = 23, C = 12 , O = 16 and H = 1 )

A 2 - g samplecontainingNa_(2) CO_(3) and NaHCO_(3) loses 0 . 248 g wh

1.	A 2 - g samplecontainingNa_(2) CO_(3) and NaHCO_(3) loses 0 . 248 g when heated to 300^(@) C, the temperature atwhich NaHCO_(3) decomposesto Na_(2) CO_(3) , CO_(2) and H_(2) O . Whatis thepercentage of Na_(2) CO_(3) in thegiven mixture ?(Na = 23, C = 12 , O = 16 and H = 1 )
Answer» Solution :On heating `Na_(2) CO_(3)and NaHCO_(3), Na_(2)CO_(3)`remains unchangedwhile `NaHCO_(3)`changesinto `Na_(2) CO_(3) , CO_(2) and H_(2) O`. The loss in weightis due to remove of `CO_(2) and H_(2)O` which escape out on heating . `:.`WT. of `NaHCO_(3) = (2 . 00 - x) g` Since `Na_(2) CO_(3)`in the products contains x g of unchanged reactant `Na_(2) CO_(3)`and rest produced from `NaHCO_(3)` the wt.of `Na_(2) CO_(3)`produced by `NaHCO_(3)`only= (1.752- x) g Now, we have , ` {:(NaHCO_(3) to Na_(2)CO_(3) + (H_(2)O + CO_(2) )uarr),("(2 . 0 - x) g(1 . 752 - x) g "):}` Applying POAC for Na atoms, moles of Na in ` NaHCO_(3) ` = MOLESOF Na in `Na_(2)CO_(3)` ` 1 xx ` moles of `NaHCO_(3) = 2xx ` moles of `Na_(2) CO_(3)` `(2. 0 - x)/( 84) = 2 xx (1 . 752 - x)/( 106) [{:(NaHCO_(3) = 84 ),(Na_(2) CO_(3) = 106):}]` `x = (82)/( 62) = 1.328 g` `:. % of Na_(2) CO_(3) = (1.328)/( 2 . 0) xx 100 = 664 %`