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.
Particles as small as atoms exist.
Energy is ability to work or function. Power is the amount of energy transferred to an object.
When energy is transferred to an object or has energy it moves and power is the energy put in a object, meaning they work together to move the object
Density is a physical property of matter
Answer = 43.2
Because to find the mass you multiply the amount of moles ( 1.6) by the mass of the element ( mass of aluminium is 27) so
1.6 x 27 = 43.2g
Hope this helps