Answer:
0.196 M
Explanation:
First, we have to calculate the moles of sodium hydroxide.
moles = mass / molar mass
moles = 3.9280 g / (39.997 g/mol) = 0.098207 mol
It is important to realize that even though 300 mL is the volume of water firstly added to dissolve the hydroxide, the flask is then filled to the mark, meaning that the volume of the solution is 500 mL = 0.500 L.
The molar concentration of sodium hydroxide is:

The concentration is an intensive property, that is, it does not depend on the amount of matter. As a consequence, the concentration of the 50 mL of solution in the buret is the same as the concentration in the flask.
Explanation:
use the term electron sheilding, the more electrons between the valence el3ctron and nucleus the easier to lose the valence electron (more sheilding = easier to lose)
Answer:
a base
Explanation:
first convert the pOH to pH, that way it will
be easy to decide.
formula:pOH+pH=14
pH=14-4.3=9.7
high pH tells us it's a base
Chemical reaction is the basis of life for living organisms; no organism can remain alive without the occurrence of chemical reactions.
Chemical reactions that occur in the living organisms are called biochemical reactions, these reactions are needed for the organism to grow, develop, survive and remain alive; when the chemical reactions stop the organism die.
For instance, to remain alive one has to eat. The food eaten can not be useful to the body if the digestive enzymes do not carry out chemical reactions on it and convert it to a form that can easily enter the blood where it is needed.