C=md/ms*100=>md=C*ms/100=36,5*400/100=146g HCl
n=md/M=146/36,5=4 moli HCl
124g.......2*36,5g.....135g......18g.....44g
CuCO3 + 2HCl => CuCl2 + H2O + CO2
248g...........146g......270g.....36g.....88g
124g CuCO3...................2 moli HCl
xg CuCO3........................4 moli HCl
x=124*4/2=248g CuCO3 (pur)
p=mp/mimp*100=>mimp=mp*100/p=24800/95=261,5g CuCO3
b) md final = 146+248+270=664g
ms final = 400+248+270+36=954g
Cfinal=664/954*100=69,6%
Nu sunt sigur la b)