Answer:
TRY HARD!
Explanation:
DO UR WORK ANG GET IT DONE!
Answer: m = 0.42; Tb = 79°
Explanation: The relationship between boiling point of the solvent above a solution is directly proportional to the molal concentration of the solute, i.e.:
ΔT = 
where
ΔT is the change in boiling point of the solvent;
is the molal boiling point elevation constant;
m is the molal concentration of the solute in the solution;
For there two solutions:
1) Ethanol:
ΔT =
Tb - 
Tb - 78.4 = 1.22.m (1)
2) Carbon Tetrachloride:
Tb -
Tb - 76.8 = 5.03.m (2)
Solving the system of equations:
Tb - 78.4 = 1.22.m
Tb = 1.22.m + 78.4 (3)
Substituing (3) in (2)
1.22.m + 78.4 - 76.8 = 5.03m
3.81m = 1.6
m = 0.42
With m, find Tb:
T - 76.8 = 5.03.0.42
T = 2.11 + 76.8
T = 79°
<u>Molal</u> concentration is <u>0.42</u> and boiling point is 79°
Answer:
The law of conservation of mass applies to both cases
When 50 g of sugar undergoes a physical change, say for example melting, the amount of sugar in the solution or melted form will also be 50 grams. This shows that the mass before and after the change was the same, in accordance to the law of conservation of mass. The mass stays the same.
When the magnesium strip is burned, this is a chemical reaction. The problem is that we only measure the mass of one of the substances involved in the reaction which is the magnesium strip, which makes it seem like the mass has increased. Actually, while burning, the magnesium combines with oxygen in the air. This oxygen was present before the reaction, we just did not measure it. And after the reaction it is present in the form of product. But the mass is still conserved.
Hope this helps!!:)
