When lead sulphide, PbS and lead oxide, PbO, are heated together the products are lead metal and sulphur dioxide, SO2.

PbS(s) + 2PbO(s)rightwards arrow with heat on top
 3Pb (l) + SO2 (g).

If 14.0 g of lead oxide reacts according to the above equation, how many (a) moles of lead (b) grams of lead, (c) atoms of lead and (d) grams of sulphur dioxide are formed?

 (Atomic mass : Pb = 207.0, S = 32.1 ; O =16.0)

Asked by seeni2005 | 24th Feb, 2021, 12:34: PM

Expert Answer:

This question is based on stoichiometry.
 
Firstly let's caclculate the moles of PbO.
left parenthesis straight a right parenthesis Number space of space moles space of space PbO equals fraction numerator 14 over denominator 207 plus 16 end fraction equals 14 over 223 equals 0.0627 space moles

According space to space Stoichiometry comma
2 space moles space of space PbO space forms equals 3 space moles space of space Pb
So comma space 1 space mole space of space PbO space will space form equals 3 over 2 moles space of space Pb
space 0.0627 space moles space of space PbO space will space form equals 3 over 2 cross times 0.0627 equals 0.09405 space moles space of space Pb


left parenthesis straight b right parenthesis space Pb space in space gm equals 0.0905 cross times 207 equals 0.141075 space gm
left parenthesis straight c right parenthesis space 1 space mole space of space Pb space have equals 6.022 cross times 10 to the power of 23 space atoms
space space So comma space 0.09405 space moles space of space Pb space wil space have equals 6.022 cross times 10 to the power of 23 space cross times 0.0940 equals 0.566 cross times 10 to the power of 23 space atoms

left parenthesis straight d right parenthesis space According space to space stoichiometry comma
2 space moles space of space PbO space will space produce equals 1 space mole space of space SO subscript 2
1 space mole space of space PbO space will space produce equals 1 half moles space of space SO subscript 2
0.0627 space moles space of space PbO space will space form equals 1 half cross times 0.0627 equals 0.03135 space moles space of space SO subscript 2
SO subscript 2 space end subscript in space gm equals 0.03135 cross times 64 equals 2.0064 space straight g space of space SO subscript 2

Answered by Ravi | 24th Feb, 2021, 05:14: PM