Answer: The kilograms of water must evaporate from 8kg of a 25% salt solution to produce 40% salt solution is 3 kg.
Explanation:
According to the ratio and proportion:

where,
= concentration of ist solution = 25%
= mass of ist solution = 8 kg
= concentration of second solution = 40%
= mass of second solution = ? kg


Thus the final solution must have a mass of 5 kg , i.e (8-5)= 3 kg of mass must be evaporated.
Therefore, the mass that must be evaporated from 8kg of a 25% salt solution to produce 40% salt solution is 3 kg.
Substances that cannot be separated and found on a periodic table are elements.
Answer:
Option B : burning of wood
Explanation:
Chemical change is a change where a new substance is created like when you will bur wood you get ash this is a new substance, so burning of wood is a chemical change.
Answer:
Surface area
Explanation:
psi = pound square inch
Often expres in psi, pressure s the term for force per unit of surface area.
Answer:
What procedure did you use to complete the lab?
→Procedures that needs to be considered to complete the lab are- a thorough knowledge of lab assignments, knowledge about safety equipment, reviewing the MSDS of chemicals for lab experiment etc.
<h3>Explanation:</h3>
To be lab prepared one must follow these procedures-
1. One should have the knowledge of lab assignments to make the lab experiment easier.
2. To be aware about safety equipment and their uses in lab, like- the location of fire extinguisher in lab.
3. To know the steps of experiments to be performed
4. To fill notebook of lab with information regarding the experiment
5. One should review the data sheets of chemicals material safety.
6. To put on all the necessary dressings to perform experiment.
7. To have complete understanding about the experiment disposals.