calculate the mass of Cuso4.5H2O required to prepare 500 cm3 of a 0.400 m/dm-3 solution
How many mols do you want? That's M x L = 0.400 x 0.500 = ?
Then mols = g/molar mass. You know molar mass and mols, solve for mols.
To calculate the mass of CuSO4·5H2O required, you need to use the formula:
mass = volume × concentration × molar mass
Given:
Volume = 500 cm^3
Concentration = 0.400 mol/dm^3
First, convert the volume from cm^3 to dm^3:
500 cm^3 = 500 ÷ 1000 dm^3 = 0.5 dm^3
The molar mass of CuSO4·5H2O can be calculated as follows:
Cu: 1 × atomic mass of Cu = 1 × 63.55 g/mol
S: 1 × atomic mass of S = 1 × 32.07 g/mol
O: 4 × atomic mass of O = 4 × 16.00 g/mol
H: 10 × atomic mass of H = 10 × 1.01 g/mol
H2O: 5 × (2 × atomic mass of H + atomic mass of O) = 5 × (2 × 1.01 + 16.00) g/mol
Add all the masses together to get the molar mass of CuSO4·5H2O in g/mol.
Next, multiply the volume (0.5 dm^3) by the concentration (0.400 mol/dm^3) to get the number of moles of CuSO4·5H2O required.
Finally, multiply the number of moles by the molar mass to get the mass of CuSO4·5H2O required in grams.