It is by looking on the dates of the paper.
Hoped this helped.
~Bob Ross®
Explanation:
As the given data is as follows.
Height, H = 150 feet
Heat gain = 30,000 BTU/hr, and Heat loss = 25000 BTU/hr
m = mass of water heated = 700 gallons = 5810 lbs
is the heat capacity of water = 1 BTU/lb 
(given)
= temperature difference = 
Heat energy required to heat 700 gal can be calculated as follows:
Heat Required = 
Thus, water rises till 
.
The dichloromethane (DCM) has less density than water and also the polarity of water is much more than DCM. So the mixture of water and dichloromethane will always be a heterogeneous mixture. In the mixture dichloromethane will be always up of the water layer. The volume of the separatory funnel which contains the mixture of DCM and water must have to be more than the total volume of the liquids thus the volume of the funnel will be more than (50+50) = 100mL.
The caution have to consider during the separation are-
1. The separatory funnel have to shake well with lid and have to settle down for some times until the two liquid separated.
2. The lid should be open very slowly as the vapor pressure of DCM is more and it will float on the water.
3. After this the stopcock should be opened and slowly the water will come out first followed by DCM.
