the percent by mass of copper(ii) in cu(no2)2 is %.
the percent by mass of copper(ii) in cu(no2)2 is %.
Answer
Explanation:
Step1: Calculate molar masses
The molar mass of Cu is $M_{Cu}=63.55\ g/mol$. The molar mass of $N$ is $M_N = 14.01\ g/mol$, the molar mass of $O$ is $M_O=16.00\ g/mol$. For $Cu(NO_2)2$, the molar - mass $M$ is calculated as follows: [ \begin{align*} M&=M{Cu}+2\times(M_N + 2\times M_O)\ &=63.55+2\times(14.01 + 2\times16.00)\ &=63.55+2\times(14.01 + 32.00)\ &=63.55+2\times46.01\ &=63.55 + 92.02\ &=155.57\ g/mol \end{align*} ]
Step2: Calculate mass - percent of Cu
The mass - percent of Cu in $Cu(NO_2)_2$ is given by the formula $\text{Mass}%=\frac{\text{Mass of Cu in compound}}{\text{Molar mass of compound}}\times100%$. [ \begin{align*} \text{Mass}%&=\frac{63.55}{155.57}\times 100%\ &\approx 40.85% \end{align*} ]
Answer:
$40.85$