Answer:
The heat of vaporisation of methanol is "3.48 KJ/Mol"
Explanation:
The amount of heat energy required to convert or transform 1 gram of liquid to vapour is called heat of vaporisation
When 8.7 KJ of heat energy is required to vaporize 2.5 mol of liquid methanol.
Hence, for 1 mol of liquid methanol, amount of heat energy required to evaporate the methanol is = 
= 3.48 KJ
So, the heat of vaporization 
Therefore, the heat of vaporization of methanol is 3.48KJ/Mol
__MgF2 + __Li2CO3 + __ 2LiF
Answer:
The density of the swimmer is 0.0342 lbm/in3.
This value makes sense as the density of the body is very similar to the water.
Explanation:
If the swimmers is floating, the weight of the swimmer must be equal to the upward buoyant force.
We can express the weight force as the product of density and volume of the swimmer.
Then

It makes sense as the density of the body is very similar to the water.
Because if you change two things then you do not know which one has affected or altered the dependent variable. if you only change one then you know what exactly changed and why
Explanation:
Supposing we have to find the difference between the number of electrons in Selenium and Aluminium.
Well, electrons can be transformed to an atomic number, so if SE is 34, that means it has 34 electrons. AI has an atomic number of 13, which means it has 13 electrons. So the difference is that more electrons than AI are available from SE.