A 3.00 g sample of an alloy (containing only Pb and Sn) was dissolved in nitric acid (HNO3). Sulfuric acid was added to this solution, which precipitated 2.93 g of PbSO4. Assuming that all of the lead was precipitated, what is the precentage of Sn in the sample?
2006-10-24 18:44:02 · 5 answers · asked by kruzzz80 2 in Science & Mathematics ➔ Chemistry
i just got off from school damn it i'll do this later
2006-10-24 18:50:33 · answer #1 · answered by mad_sci_123 2 · 0⤊ 1⤋
Atomic mass of Pb = 207.2
Atomic mass of S = 32.1
Atomic mass of O = 16
Mass of 1 mole of PbSO4= 303.3
207.2 / 303.3 = x /100 -----> x= 68.3% of PbSO4 is Pb
Assuming that all the Pb has precipitated:
68.3% X 2.93 = 2.0 (2g of the 2.93g is Pb)
Which means 2g out of 3g sample of alloy is Pb; therefore 1g of the sample is Sn: 3-2= 1g
So: 1/3 = x/100 -----> x= 33.3% is Sn
2006-10-24 18:58:53 · answer #2 · answered by smarties 6 · 3⤊ 0⤋
edit the question and tell me the gram formula mass of PbSO4, Pb and Sn and I'll tell you the answer
2006-10-24 18:52:52 · answer #3 · answered by fleisch 4 · 0⤊ 0⤋
I DONT KNOW THE ANSWER BUT WHAT I KNOW IS SN OR TIN IS MORE STABLE IN NATURE AND IS LESS AFFECTED BY THE ACID.ONLY THE LEAD IS DISSOLVED ALMOST IN THE ACID.
2006-10-24 18:48:38 · answer #4 · answered by aqruipnos888 4 · 0⤊ 1⤋
and it appears that nobody on yahoo answers can solve it neither
2006-10-24 18:49:39 · answer #5 · answered by jlthomas75844 5 · 0⤊ 3⤋