Answer:
false evaporation is change of state
boiling point is temperaturw of liquid
Answer: A volume of 500 mL water is required to prepare 0.1 M
from 100 ml of 0.5 M solution.
Explanation:
Given:
= 0.1 M,
= ?
= 0.5 M,
= 100 mL
Formula used to calculate the volume of water is as follows.

Substitute the values into above formula as follows.

Thus, we can conclude that a volume of 500 mL water is required to prepare 0.1 M
from 100 ml of 0.5 M solution.
A substance that reduces the hydrogen ion concentration of a solution is <u>base</u>.
A base which thus completely dissociates in an aqueous solution is referred to as a strong base. These substances produce one or more hydroxide ions (OH-) per base molecule when they ionize in water. A weak base, on the other hand, only partially splits into its water-soluble ions.
The three definitions of "base" used in chemistry are Arrhenius base, Bronsted base, as well as Lewis base. The fact instead that bases react towards acids is acknowledged by all base definitions.
Therefore, a substance that reduces the hydrogen ion concentration of a solution is <u>base</u>.
To know more about hydrogen ion
brainly.com/question/5327882
#SPJ4
<u>Answer: </u>
A sample initially contained 150 mg of radon-222. After 11.4 days only 18.75mg of the radon-222 in the sample remained where 3 half-lives have passed
<u>Explanation:</u>
Given, the initial value of the sample,
= 150mg
Final value of the sample or the quantity left, A = 18.75mg
Time = 11.4 days
The amount left after first half life will be ½.
The number of half-life is calculated by the formula

where N is the no. of half life
Substituting the values,


On equating, we get, N = 3
Therefore, 3 half-lives have passed.