In theanalysis of a 0 .50 -gsample of feldspar, mixture, of thechlorides ofNa and Kis obtained, whichweight 0.1180 g . Subsequenttreatmentof themixedchlorides. with silver nitrate gives 0.2451 g of AgCl . Whatis the percentage of sodiumoxideand potassiumoxide in feldspar ?

In theanalysis of a 0 .50 -gsample of feldspar, mixture, of thechlorid

1.	In theanalysis of a 0 .50 -gsample of feldspar, mixture, of thechlorides ofNa and Kis obtained, whichweight 0.1180 g . Subsequenttreatmentof themixedchlorides. with silver nitrate gives 0.2451 g of AgCl . Whatis the percentage of sodiumoxideand potassiumoxide in feldspar ?
Answer» SOLUTION :Suppose the weight of NaCl is x g `{:(Na_(2)O + K_(2) O overset("Step I") to NaCl + KCI underset(AgNO_(3))overset("Stet II")to AgCl),("(in feldspar)x g (0.1180 - x)0.2451 g "):}` Applying POAC for Clatoms in Step IIto calculate x, molesof Cl in NaCl + moles of Cl in KCI = moles of Cl in AgCl ` 1 xx` moles of NaCl ` + 1 xx ` molesof KCl` = 1 xx ` moles of AgCl `(x)/( 58 . 5) + (0.1180)/( 84.5) = (0.2451)/( 143.5) , x = 0.0345 g` (NaCl = 58.5, KCI = 74. 5 and Ag Cl = 143 . 5 ) `:.` wt. of NaCl = 0.0343 g, wt. of KCI = 0.0837 g. Again, applying POAC for Naand Katoms to CALCULATETHE weight of `Na_(2)O and K_(2)O`respectively , we GET, `2 xx ` moles of `Na_(2) O` = moles ofNaCl and` 2 xx` moles of `K_(2)O` = molesof KCI `:. "wt. of " Na_(2) O = (1)/(2)xx ("wt. of Na Cl")/("mol. wt. of NaCl") xx "mol. wt. of " Na_(2) O ` and wt. of `K_(2) O = (1)/(2) xx ("wt. of KCI")/( "mol . wt. of KCI") xx "mol. wt. of " K_(2)O` `:. ` wt. of ` Na_(2) O = (1)/(2) xx (0.0343)/( 58.5) xx 62 = 0.018 g ` and wt. of `K_(2) O = (1)/(2) xx (0.0837)/( 74.5) xx 94 = 0.053 g` `:. % of Na_(2) O = (0.018)/(0.50) xx 100 = 3 . 6 %` and `% of K_(2) O = (0.053)/( 0.50) xx 100 = 10 . 6% `