What is the predicted change in the boiling point of water when 4.00 g of barium chloride (BaCl2) is dissolved in 2.00 kg of water?

Kb of water = 0.51°C/mol
molar mass BaCl2 = 208.23 g/mol
i value of BaCl2 = 3

A. 0.0016°C
B. -0.0049°C
C. -1.0°C
D. 0.015°C

what is the answer

which one is the answer

To calculate the change in boiling point of water, we can use the formula:

ΔTb = Kbm

Where:
ΔTb = change in boiling point
Kb = molal boiling point elevation constant
m = molality of the solute in the solution

First, we need to calculate the molality (m) of the BaCl2 solution:

m = moles of solute / mass of solvent in kg

To find the moles of BaCl2:
moles = mass / molar mass

moles of BaCl2 = 4.00 g / 208.23 g/mol = 0.0192 mol

Then, we need to convert the mass of water to kg:

mass of water = 2.00 kg

Now, let's calculate the molality:

m = 0.0192 mol / 2.00 kg = 0.0096 mol/kg

Substitute the values into the formula:

ΔTb = 0.51°C/mol * 0.0096 mol/kg

ΔTb = 0.0049 °C

The predicted change in the boiling point of water when 4.00 g of BaCl2 is dissolved in 2.00 kg of water is approximately 0.0049 °C.

Therefore, the correct answer is:

B. -0.0049°C

To find the predicted change in the boiling point of water when barium chloride is dissolved in it, you can use the formula:

ΔTb = Kb * m * i

Where:
- ΔTb is the change in boiling point,
- Kb is the molal boiling point elevation constant of water,
- m is the molality of the solute, which is the number of moles of solute per kilogram of solvent,
- i is the van't Hoff factor, which represents the number of particles the solute dissociates into when it dissolves.

First, we need to calculate the molality (m) of the solution. Molality is defined as the number of moles of solute (BaCl2) per kilogram of solvent (water).

Given:
- Mass of BaCl2 = 4.00 g
- Molar mass of BaCl2 = 208.23 g/mol
- Mass of water = 2.00 kg

Step 1: Convert the mass of BaCl2 to moles
moles of BaCl2 = mass of BaCl2 / molar mass of BaCl2
moles of BaCl2 = 4.00 g / 208.23 g/mol

Step 2: Calculate the molality (m)
molality (m) = moles of BaCl2 / mass of water
molality (m) = (4.00 g / 208.23 g/mol) / 2.00 kg

Step 3: Calculate the change in boiling point (ΔTb)
ΔTb = Kb * m * i

Given:
- Kb of water = 0.51°C/mol
- i value of BaCl2 = 3

ΔTb = 0.51 °C/mol * (4.00 g / 208.23 g/mol) / 2.00 kg * 3

Now, calculate the value of ΔTb:

ΔTb = 0.51 °C/mol * (0.01921 mol/kg) * 3

Finally, calculate the value of ΔTb:

ΔTb = 0.02907 °C

The predicted change in boiling point of water when 4.00 g of barium chloride (BaCl2) is dissolved in 2.00 kg of water is approximately 0.02907 °C or 0.03 °C.

Therefore, the correct answer is not provided in the given options.