Răspuns:
ii. 4K + O2---> 2K2O
Ca + 2HCl------> CaCl2 + H2↑
NaOH + HNO3----> NaNO3 + H2O
Explicație
III.2mol...................2mol sau, in grame
2Ca + O2----> 2CaO
2x40g................2(40+16)g
80g,,,,,,,,,,,,,,,,,,,,,,x
x= 80x56/40gCaO=,,,,,,,,,,,,,,,,,,,,,,,,,,,,calculeaza !!!!!