Question

Using the equation Cu + 2 AgNO3 → Cu(NO3)2 + 2 AgHow many grams of Cu(NO3)2 will be produced from 1.50 moles of AgNO3?

Answer 1

You can see that in the chemical equation, 1 mole of Cu(NO3)2 is produced by 1 mole of AgNO3. The ratio between them is 1 : 1, so 1.50 moles of AgNO3 produce 1.50 moles of Cu(NO3)2. The only thing we need to do is the conversion from moles to grams using the molar mass of Cu(NO3)2.

You can see the molar mass of each element of Cu(NO3)2 in the periodic table. For Cu its molar mass is 63.5 g/mol, for N would be 14 g/mol and for oxygen, we have 16 g/mol. We have to do the algebraic sum to obtain the entire molar mass using the number of atoms.

We have 1 atom of Cu, 2 atoms of N, and 6 moles of oxygen (2 x 3 = 6):

`\text{molar mass of Cu}(NO_3)_2=1\cdot63.5(g)/(mol)+2\cdot14(g)/(mol)+6\cdot16(g)/(mol)=187.5\text{ }(g)/(mol)`

Using this molar mass and the number of moles, we can find the number of grams of Cu(NO3)2, like this:

`1.5molesCu(NO_3)_2\cdot(187.5gCu(NO_3)_2)/(1molCu(NO_3)2)=281.25gCu(NO_3)_2.`

So, the answer is that 281.25 grams of Cu(NO3)2 are produced by 1.50 moles of AgNO3.