Question #554f2
1 Answer
Explanation:
The coefficients that appear in a balanced chemical equation tell you the mole ratios in which the chemical species that take part in the reaction find themselves.
In this case, the balanced chemical equation that describes this double replacement reaction looks like this
#3"Pb"("NO"_ 3)_ (2(aq)) + color(red)(2)"AlCl"_ (3(aq)) -> color(blue)(3)"PbCl"_ (2(s)) darr + 2"Al"("NO"_ 3)_ (2(aq))#
You're interested in finding out how many moles of lead(II) chloride,
Notice the
This mole ratio tells you that for every
In your case, the reaction is said to consume
#14 color(red)(cancel(color(black)("moles AlCl"_3))) * (color(blue)(3)color(white)(a)"moles PbCl"_2)/(color(red)(2)color(red)(cancel(color(black)("moles AlCl"_3)))) = color(green)(|bar(ul(color(white)(a/a)color(black)("21 moles PbCl"_2)color(white)(a/a)|)))#