Answer:
0.272 mol
Explanation:
∆Tb = m × Kb
∆Tb = 85.2°C - 78.4°C = 6.8°C
Kb = 1.22°C/m
mass of ethanol = 48.80 g = 48.80/1000 = 0.0488 kg
Let the moles of non-ionizing solute be y
m (molality) = y/0.0488
6.8 = y/0.0488 × 1.22
y = 6.8×0.0488/1.22 = 0.272 mol
You can wait until he either breaks up (if he does) or if just forget about him and go for another guy.
We first calculate the number of moles of K2CrO4 by multiplying the volume with the molarity.
n = (25/1000) x (3 M) = 0.075 mol K2CrO4
Then, from the balanced chemical equation, each mole of K2CrO4 will produce 1 mole PbCrO4 with molar mass of 323.2 g/mol.
(0.075 mol K2CrO4)(1 mol PbCrO4/1 mol K2CrO4) x (323.2 g/mol)
= 24.24 grams PbCrO4
Density = mass/volume
D = 500 g /200 cm^3
D = 2.5 g/cm^3
hope this helps!
2.49 x 10^46 is the answer
