how many moles of BaCl2 are in 300 g of H2O if the molality is 0.2 m?

Why all the screen names? Work this one the same way when your name was Destiny.

To determine the number of moles of BaCl2 in 300 g of H2O, we need to use the concept of molality and the molar mass of BaCl2.

Here's the step-by-step process to find the answer:

Step 1: Convert the given mass of H2O from grams to kilograms.

300 g of H2O = 300/1000 = 0.3 kg of H2O

Step 2: Calculate the number of moles of BaCl2 using the molality formula:

Molality (m) = Moles of solute / Mass of solvent (in kg)

Rearranging the formula, we get:

Moles of solute = Molality (m) × Mass of solvent (in kg)

Given that the molality (m) is 0.2 m and the mass of the solvent (H2O) is 0.3 kg, we substitute these values into the formula:

Moles of solute = 0.2 m × 0.3 kg

Step 3: Determine the molar mass of BaCl2.

The molar mass of BaCl2 can be calculated by adding the atomic masses of its constituent elements. Barium (Ba) has an atomic mass of 137.33 g/mol, and chlorine (Cl) has an atomic mass of 35.45 g/mol. Since BaCl2 contains two chlorine atoms, we multiply the atomic mass of chlorine by 2 and then sum up the masses:

Molar mass of BaCl2 = (1 × atomic mass of Ba) + (2 × atomic mass of Cl)

Molar mass of BaCl2 = (1 × 137.33 g/mol) + (2 × 35.45 g/mol)

Molar mass of BaCl2 = 137.33 g/mol + 70.9 g/mol

Molar mass of BaCl2 = 208.23 g/mol

Step 4: Calculate the number of moles of BaCl2 using the formula:

Moles of BaCl2 = Moles of solute / Molar mass of BaCl2

Substituting the values into the formula, we get:

Moles of BaCl2 = (0.2 m × 0.3 kg) / 208.23 g/mol

Moles of BaCl2 ≈ 0.000287 moles (rounded to 3 decimal places)

Thus, there are approximately 0.000287 moles of BaCl2 in 300 g of H2O when the molality is 0.2 m.