p% = m.px100/m.ip
=> m.p = m.ipxp%/100 = 500x32/100
= 160 g carbid pur
160 g n moli
CaC2 + 2H2O => Ca(OH)2 + C2H2↑
64 1
n moli md
C2H2 + 2Br2 --CCl4--> C2H2Br4
1 2x160
=> 160/64 = md/2x160
=> 800 g Br2
stim ca c% = mdx100/ms => ms = mdx100/c%
= 800x100/4 = 20.000 g => 20 kg. sol Br2 de 4%