Answer:
B
Explanation:
so you started out with 80
you have to cool it till 60
so it is decreasing which means you have to subtract
Note=if something is increasing or wanting to go up its addition but for this problem 60 is less then 80 so we are doing subtraction
80-60=20
The pH value can be measured using electrochemical measuring systems, litmus paper, or indicators and colorimeters. The easiest way to take a pH measurement is to use litmus paper or a colorimeter. The advantage of this type of pH measurement is that the pH range is well known and they are easy to apply.
What kind of energy transfer
Answer:
this option is correct the amount of heat required to turn a mole of a solid into a liquid