Question

How many grams of copper (II) chloride can be found in 500.0 mL of 4.00 mol/L solution?

Answer 1

269 grams CuCl₂

Step-by-step explanation:

To find the mass of CuCl₂ (copper (II) chloride), you need to (1) find moles CuCl₂ (via the molarity equation using the volume and molarity) and then (2) convert moles to grams (via the molar mass from the periodic table). The final answer should have 3 sig figs because the given number with the least amount of sig figs (4.00 mol/L) also has 3 sig figs.

(Step 1)

500.0 mL / 1,000 = 0.5000 L

Molarity (mol/L) = moles / volume (L)

4.00 mol/L = moles / 0.5000 L

(4.00 mol/L) x (0.5000 L) = moles

2.00 = moles

(Step 2)

Molar Mass (CuCl₂) = 63.546 g/mol + 2(35.45 g/mol)

Molar Mass (CuCl₂) = 134.446 g/mol

2.00 moles CuCl₂ 134.446 g
--------------------------- x --------------------- = 269 g CuCl₂
1 mole