From the equation; ΔTf = Kf × m
Where, Kf for water = 1.853 K kg/mole; m is the molarity = number of solute/amount of solvent in kg.
Glucose is the solute whose molecular mass is 180 g/mole and water is the solvent.
Moles of solute = 15.5/180 = 0.0861 moles
Amount of solvent in kg = 245/1000 = 0.245 Kg
Therefore; molarity = 0.0861/0.245 = 0.3515 moles/Kg
Therefore; ΔTf = 1.853 × 0.3515 = 0.6513 K
Hence; the depression in freezing point is 0.6513
The freezing point of solution will therefore be;
= 273 - 0.6513 = 272.3487 K
Answer:
= 62.1 hours
Explanation:
Energy provide by the serving is 65 cal
= 65 cal × 4.184 Kj = 271.96 kJ
271.96 KJ = 271960 J
Energy required for 1minute of energy
= 73 x 1
= 73 J/min
So, 271960 joules will be required for 271960 heart beat
Minutes = 271960 / 73
= 3593.94 minutes
Time in hours = 3725.429 / 60
= 62.1 hours
Answer:
the first one which is A
Explanation:
the burning of fossil fuels causes both air pollution and water pollution
Answer:
47.3 ml
Explanation:
The graduated cylinder is shown in the image attached.
Now we have to take a good look at the cylinder, the lines between 45 and 50 are 46, 47, 48 and 49. Even though the points in between two lines weren't graduated but we can intelligently guess the correct volume by observing the upper meniscus of the liquid. Hence the answer.
Nitrogen is 78.08% of the air is fills the earth's atmosphere.
