Question

aflati masa moeculara a substantelor 3Co2;4 Br2;2P2O5.imi trebuie foarte urgent​

Answer 1

$\bold{1.} \ M_r(3CO_2)=3(12+16\cdot 2)=3(12+32)=3 \cdot 44=\boxed{132}; \\ \bold{2.} \ M_r(4Br_2)=4\cdot80 \cdot 2=8\cdot 80=\boxed{640}; \\ \bold{3.} \ M_r(2P_2O_5)=2(2 \cdot 31+5 \cdot 16)=2(62+80)=2\cdot 142=\boxed{284};$