What quantitative measurement and qualitative observations can be made about the interactions of matter and energy?

One of the five branches of chemistry is analytical chemistry which involves the qualitative and quantitative chemistry. Chemistry happens due to interaction between the matter of which different substances are made hence the qualitative and quantitative properties if known a lot can be understood about matter and energy.  

1. Quantitative chemistry helps in knowing how much amount of a substance is required to produce a certain amount of energy.

2. Qualitative chemistry helps in knowing how and which two substances can be mixed to produce a certain amount of energy.  

it is important to conserve water because there is very limited amount of freshwater here on earth and if we are not smart about how we use it we will only be runnning out of our supply faster than neccessarry.