Answer: The element Na (Sodium) is getting oxidized and Hydrogen is getting reduced.
Explanation:
Oxidation reactions are the reactions in which addition of oxygen takes place.
Reduction reactions are the reactions in which loss of oxygen takes place.
For a given reaction:

Sodium is getting oxidized because there is an addition of reaction with that element.
Hydrogen is getting reduced because there is a removal of oxygen with that element.
Mixtures come in many forms and phases. Most of them can be separated, and the kind of separation method depends on the kind of mixture it is. Below are some common separation methods:
Answer: 12.78ml
Explanation:
Given that:
Volume of KOH Vb = ?
Concentration of KOH Cb = 0.149 m
Volume of HBr Va = 17.0 ml
Concentration of HBr Ca = 0.112 m
The equation is as follows
HBr(aq) + KOH(aq) --> KBr(aq) + H2O(l)
and the mole ratio of HBr to KOH is 1:1 (Na, Number of moles of HBr is 1; while Nb, number of moles of KOH is 1)
Then, to get the volume of a 0.149 m potassium hydroxide solution Vb, apply the formula (Ca x Va)/(Cb x Vb) = Na/Nb
(0.112 x 17.0)/(0.149 x Vb) = 1/1
(1.904)/(0.149Vb) = 1/1
cross multiply
1.904 x 1 = 0.149Vb x 1
1.904 = 0.149Vb
divide both sides by 0.149
1.904/0.149 = 0.149Vb/0.149
12.78ml = Vb
Thus, 12.78 ml of potassium hydroxide solution is required.
When HCl is added to a saturated solution of PbCl2, the solubility of PbCl2 would decrease so precipitation would occur. The decrease in the solubility is due to the common ion effect or the presence of Cl- ions in both compounds.