A divalent metal oxide contains 60% of metal. What is atomic weight of metal?
wt of metal= 60 g
wt of oxygen= (100-60) g= 40 g
Eq. wt. of metal = wt. of metal/ wt of oxygen* 8
= 12
As metal is divalent, At. wt= Eq. wt* valency= 12*2 = 24
How many number of moles of CO will be left when 2 x 1021 molecules are removed from 0.28g of CO?
Given,
The given weight of CO = 0.28 g
The molecular weight of CO = 28g
No. of moles of CO = 0.01 mole
We know that,
1 mole of CO contains 6.022 x 1023 molecules
0.01 mole of CO contains 0.01 x 6.022 x 1023 molecules = 6.022 x 1021 molecules
The number of molecules left is (6.022 x 1021 - 2 x 1021) = 4.022 x 1021 molecules
We know that,
6.022 x 1023 molecules of CO = 1 mole of CO
4.012 x 1021 molecules of CO = 6.68 x 10-3
Hence, no. of mole of CO left is 6.68 x 10-3