Question

cate grame de oxigen se obtin din descompunerea a 720 g apa oxigenata va roggg e urgentt

Answer 1

$m_{H_2O_2}=720 \ g \\ \boxed{m_{O_2}-?} \\ \bold{Rezolvare:} \\ 2H_2O_2 \ \to \ 2H_2O+O_2 \\ \boxed{\nu=\frac{m}{M}} \\ m_{O_2}=\nu_{O_2} \cdot M_{O_2} \\ M_{O_2}=16 \cdot 2=32 \ g/mol \\ \nu_{O_2}=\nu_{H_2O_2} \\ \nu_{H_2O_2=\frac{m_{H_2O_2}}{M_{H_2O_2}} } \\ M_{H_2O_2}=1 \cdot 2+16 \cdot 2=2+32=34 \ g/mol \\ \nu_{H_2O_2}=\frac{720 \ g}{34 \ g/mol} =21,2 \ moli \\ \Rightarrow \nu_{O_2}=21,2 \ moli \\ m_{O_2}=21,2 \ moli \cdot 32 \ g/mol \\ \Rightarrow \boxed{\bold{m_{O_2}=677,4 \ g}}$