How many moles of lead (II) chloride will be formed from a reaction between 6.5 g of PbO and 3.2 g of HCl?

Options

(a) 0.044
(b) 0.333
(c) 0.011
(d) 0.029

Correct Answer:

0.029

Explanation:

PbO + 2Hcl → PbCl₂ + H₂O
At. wt of PbO= 207+16=223g
At. wt of 2HCl= 2 x 36.5=73g
At. wt of PbCl₂= 207+71=278g
223 g of PbO reacts with 73 g of HCl to form 278 g of PbCl₂
When 3.2g HCl reacts with 6.5 g PbO,
amount of PbO that reacts with 3.2 HCl = (223/73) x 3.2 = 9.77 g
Since amount of PbO present is only 6.5 g, it acts as limiting reagent.
Amount of PbCl₂ formed by 6.5 g of PbO = (278/223) x 6.5g
Number of moles of PbCl₂ formed = (278/223) x (6.5/278) moles = 0.029 moles