copper metal (cu) reacts with silver nitrate (agno₃) in aqueous solution to form ag and cu(no₃)₂. the…

Explanation:

Step1: Calculate moles of Cu

Use the formula $n=\frac{m}{M}$, where $n$ is moles, $m$ is mass and $M$ is molar - mass. Given $m_{Cu}=31.75\ g$ and $M_{Cu}=63.5\ g/mol$. $n_{Cu}=\frac{31.75\ g}{63.5\ g/mol}=0.5\ mol$

Step2: Determine mole - ratio of Cu and Ag

From the balanced chemical equation $Cu + 2AgNO_3\rightarrow Cu(NO_3)2+2Ag$, the mole - ratio of $Cu$ to $Ag$ is $1:2$. So, if $n{Cu}=0.5\ mol$, then $n_{Ag}=2\times n_{Cu}$. $n_{Ag}=2\times0.5\ mol = 1\ mol$

Step3: Calculate mass of Ag

Use the formula $m = n\times M$. Given $n_{Ag}=1\ mol$ and $M_{Ag}=107.9\ g/mol$. $m_{Ag}=1\ mol\times107.9\ g/mol = 107.9\ g$

Answer:

B. 107.9 grams