2ca+o2=2cao
cao +h2o=ca(oh)2
ca(oh)2+hco3=caco3+h2o
caco3+2hcl=cacl2+co2+h2o
cacl2+h2so4=caso4+2hcl
2mg+o2=2mgo
mgo+mg(oh)2
mg(oh)2+h2so4=mgso4+h2o