Answer: 0.172 M
Explanation:
a) To calculate theconcentration of base, we use the equation given by neutralization reaction:

where,
are the n-factor, molarity and volume of acid which is 
are the n-factor, molarity and volume of base which is NaOH.
We are given:

Putting values in above equation, we get:

b) To calculate the concentration of acid, we use the equation given by neutralization reaction:

where,
are the n-factor, molarity and volume of acid which is 
are the n-factor, molarity and volume of base which is NaOH.
We are given:

Putting values in above equation, we get:

The concentration of the phosphoric acid solution is 1.172 M
Answer:
According to avogadro's law, 1 mole of every substance contains avogadro's number
of particles and weighs equal to its molecular mass.
To calculate the moles, we use the equation:
a. moles in 14.08 g of
= 
molecules in 14.08 g of
= 
b. moles in 17.75 g of NaCl = 
molecules in 17.75 g of
= 
formula units 17.75 g of
= 
c. moles in 20.06 g of
= 
formula units in 20.06 g of
= 
<span>The metal that would more easily lose an electron would be potassium. It is more reactive than sodium. Also, looking on the periodic table, </span><span>from top to bottom for groups 1 and 2, reactivity increases. So, it should be potassium. Hope this answers the question. Have a nice day.</span>