Nuclear fusion in the sun involves hydrogen (H) atoms
combining to form helium (He). A student claims that since the atmosphere
contains hydrogen, any fusion reaction on Earth would result in an uncontrolled
chain reaction. What is wrong in the student’s reasoning is that the uncontrolled
chain reactions can only happen during nuclear fission.
Answer:
168°C is the melting point of your impure sample.
Explanation:
Melting point of pure camphor= T =179°C
Melting point of sample =
= ?
Depression in freezing point = 
Depression in freezing point is also given by formula:

= The freezing point depression constant
m = molality of the sample = 0.275 mol/kg
i = van't Hoff factor
We have:
= 40°C kg/mol
i = 1 ( non electrolyte)




168°C is the melting point of your impure sample.
Explanation:
When we add a non-volatile solute in a solvent then due to the impurity added to the solution there will occur an increase in the boiling point of the solution.
This increase in boiling point will be known as elevation in boiling point.
As one beaker contains seawater (water having NaCl) will have some impurity in it. So, more temperature is required by seawater to escape into the atmosphere.
Whereas another beaker has only pure water so it is able to easily escape into the atmosphere since, it contains no impurity.
Thus, we can conclude that level of pure water will decrease more due to non-volatile solute present in it as compared to seawater.
Answer:
0.45 moles
Explanation:
The computation of the number of moles left in the cylinder is shown below:
As we know that

we can say that

where,
n1 = 1.80 moles of gas
V2 = 12.0 L
And, the V1 = 48.0 L
Now placing these values to the above formula
So, the moles of gas in n2 left is

= 0.45 moles
We simply applied the above formulas so that the n2 moles of gas could arrive
That force would be gravity. Gravity is what pulls any object down towards Earth due to the large mass of the Earth.