Question

Solid copper (III) wire reacts with sulfur in a synthesis reaction. If 1.35*10^25 atoms of
copper react with 15.0 grams of sulfur, how many grams of product will be produced and
how much excess reactant will be left over?

Answer 1

Moles of copper

• No of molecules/Avagadro no
• 1.35×10²⁵/6.022×10²³
• 0.022×10^²
• 2.2moles

Mass of copper

• 2.2(63.5)
• 13.97g

Now

According to law of conservation of mass

Mass of products=Mass of reactants

• 13.97+15
• 28.97g