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