Answer all parts of the following questions on particle stoichiometry.

lithium metal reacts with copper (ii) nitrate.

1. translate, predict the products, and balance the equation above.

2. how many particles of lithium are needed to produce 125 g of copper?

3. how many grams of lithium nitrate are produced from 4.83e24 particles of copper (ii) nitrate?

Lithium metal reacts with copper (II) nitrate.

1. Translate, predict the products, and balance the equation above.

Lithium: Li, atomic mass 6.9 g/mol

Copper(II) nitrate: Cu (NO3)2  2 and 3 are subscripts,
molar mass: 63.5 g/mol + 2*14g/mol + 2*3*16g/mol = 187.5 g/mol

Balanced equation:

2Li + Cu(NO3)2 → 2Li(NO3) + Cu

The products are lithium nitrate and copper metal.

2. How many particles of lithium are needed to produce 125 g of copper?

Convert the grams of copper in number of moles

125g / 63.5 g/mol = 1.97 mol of Cu

Write the molar ratio Li : Cu:
 
2 mol Li: 1 mol Cu

=> 1.97 mol Cu * [2mol Li / 1 mol Cu] = 3.94 mol Li

Use Avogadro's number to find the number of particles

3.94 mol * 6.022*10^23 particles / mol = 2.37 * 10^24 particles

3. How many grams of lithium nitrate are produced from 4.83E24 particles of copper (II) nitrate?

Convert the number of particles of copper(II) nitrate to number of moles

4.83 * 10^ 24 particles / [6.022*10^23 particles/mol] = 8.02 moles

Use the molar ratio 2mol Li(NO3) : 1 mol Cu(NO3)2

8.02 mol Cu(NO3)2 * [2 mol LiNO3 / 1mol Cu(NO3)2 ] = 16.04 mol LiNO3

Use the molar mass to convert moles of liNO3 to grams of LiNO3

molar mass of LiNO3 = 6.9 g/mol + 14g/mol + 3*16g/mol = 68.9 g/mol

16.04 mol * 68.9 g/mol = 1,105.16 grams of LiNO3