What is the concentration (m) of a solution that consists of 48 grams of copper (2) acetate dissolved in 645 mL of solution?
What's the formula for copper(2) acetate?
Cu(CH3CO2)2
Now, what's the mol weight?
Cu = 63.55
C = 12.01
H = 1.008
O = 16.00
so, 1 mol = 63.55 + 2(12.01 + 3.024 + 12.01 + 32) = 181.638
Now things get easy.
You have 48/181.638 = 0.264 mol of cupric acetate
so, your solution is .264mol/.645L = .409M