The percentages of KBr and KI in the sample by mass is 80.68 and 19.32 % respectively.
<h3>What is Molar Mass ?</h3>
Molar mass is defined as the mass contained in 1 mole of sample.
It is given that
the sample has a total mass of 5.76 g contains KBr and KI
and contains 1.79 gm of K is present
what is the percentage of KBr and KI in the sample
Molecular weight of K = 39
Molecular weight of Br = 79.9
Molecular weight of I = 126.9
In KBr the mass percentage of K is 39/(39+79.9) = 32.89%
In KI the mass percentage of K is 39/(39+126.9) = 23.5%
Let the mass of KBr present in the sample is x
K will be 0.3289 x
and let the mass of KI present be y
K will be 0.235y
x +y =5.76
0.3289x+0.235y = 1.79
0.0939y = 0.1045
y = 1.1125 gm
x = 5.76-1.1125
x = 4.6475 gm
% of KBr = (4.6475/5.76 )*100 = 80.68 %
% of KI = (1.1125/5.76) *100 = 19.32%
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