a)Masa molara MgCl2=1*24+2*35.5=95g
1mol................95gMgCl2
x.....................19g MgCl2
x=1*19/95=0.54moli
b)Masa molara Ca(OH)2=1*40+2*16+2*1=74g
1mol.....................74gCa(OH)2
x...........................444gCa(OH)2
x=1*444/74=6moli Ca(OH)2
