Moles chemistry?
Calculate the mass of solute required to prepare ib the solution
200cm^3 of solution containig 0.50 mol dm ^-3 cl-iond prepared by dissolving cacl2.6h2o in water.
0.50 mol/dm^3 = 0.5 M
200 cc = 0.2 L = 0.2 dm^3
mols you want Cl^- = M x L = 0.5 x 0.2 = 0.1 mol Cl^-
Convert mols Cl^- to mols CaCl2.
0.1 mol Cl^- x (1 mol CaCl2/2 mols Cl^-) = 0.05 mol CaCl2.
Now convert mols CaCl2 to grams.
mols = grams/molar mass. You kow mols and molar mass, substitute and solve for grams CaCl2.
To calculate the mass of solute required to prepare the solution, you need to use the following steps:
1. Determine the molar mass of CaCl2.6H2O:
Ca = 40.08 g/mol
Cl2 = 35.43 g/mol x 2 = 70.86 g/mol
H2O = 18.02 g/mol x 6 = 108.12 g/mol
Molar mass of CaCl2.6H2O = 40.08 g/mol + 70.86 g/mol + 108.12 g/mol = 219.06 g/mol
2. Calculate the moles of CaCl2.6H2O needed:
Since the solution has a concentration of 0.50 mol/dm^3 and a volume of 200 cm^3 (which is equivalent to 0.200 dm^3), you can use the equation:
Moles = Concentration x Volume
Moles of CaCl2.6H2O = 0.50 mol/dm^3 x 0.200 dm^3 = 0.10 mol
3. Calculate the mass of CaCl2.6H2O needed:
Mass = Moles x Molar mass
Mass of CaCl2.6H2O = 0.10 mol x 219.06 g/mol = 21.91 g
Therefore, the mass of CaCl2.6H2O required to prepare 200 cm^3 of a solution containing 0.50 mol/dm^3 Cl- ions is 21.91 grams.
To calculate the mass of solute required to prepare the solution, we need to use the given information:
- The volume of the solution is 200 cm^3.
- The concentration is 0.50 mol dm^-3.
To begin, it's important to understand the concept of moles in chemistry. A mole represents a specific amount of substance, which is equivalent to 6.022 x 10^23 particles (atoms, molecules, or ions) of that substance. It allows us to measure the quantity of a substance on a macroscopic scale.
The formula to calculate the number of moles (n) is:
n = concentration (in mol dm^-3) x volume (in dm^3)
Let's calculate the number of moles of Cl ions in the solution:
n = 0.50 mol dm^-3 x 0.200 dm^3 (since 200 cm^3 = 0.200 dm^3)
n = 0.100 moles
Now we need to convert moles to grams using the molar mass of the solute. In this case, the solute is CaCl2.6H2O, which is calcium chloride hexahydrate.
The molar mass of CaCl2.6H2O is the sum of the molar masses of each element multiplied by the respective number of atoms or molecules in the formula. The atomic masses of calcium (Ca), chlorine (Cl), and hydrogen (H) can be found on the periodic table.
Molar mass of CaCl2.6H2O = (1 x atomic mass of Ca) + (2 x atomic mass of Cl) + (12 x atomic mass of H) + (6 x atomic mass of O) + (6 x atomic mass of H2O)
Next, we calculate the mass:
mass = number of moles x molar mass
Substituting the values:
mass = 0.100 moles x molar mass
Finally, to find the mass of solute required, we need to know the molar mass of CaCl2.6H2O, which you can find from a periodic table or online database.