calculating molarity?

Question

a 0.1025-g sample of copper metal is disscolved in 35 mL of concentrated HNO3 to form Cu2+ ions and then water is added to make a total volume of 200.0 mL. Calculate the molarity of Cu2+

Answer 1

Find the moles of Cu. The atomic mass of Cu equals Am = 63.5, so:

n = m/Am, n = 0.1025/62.5 mol, n = 1.6*10^(-3) mol.

The same is the number of Cu2+ moles in the final solution, with a volume of V = 0.2 L. So the molarity C of Cu2+ equals:

C = n/V, C = 1.6*10^(-3)/0.2, C= 8.1*10^(-3) M approx.

Answer 2

i loved when my chemistry teacher said that.. she was from some other country.. so said it funny