<span>% by mass = mass solute x 100 / mass solution
45.5 % = mass solute NaF x 100 / 34.2
mass solute NaF = 34.2 x 45.5 /100=15.6 g
molae solute NaF = 15.6 g ( 1 mol / 41.9887 g)= 0.372</span>
For a neutralisation reaction...
Acid + base 》 salt + water....
The above reaction looks much alike so is a neutralisation...
It is certainly not compustion as no oxygen to react and CO2 produced
This requires familiarity with the different theories (or concepts) of acids and bases.
On the Arrhenius concept, an acid is a substance that produces an H⁺ ion in water such that the H⁺ concentration increases, and a base is a substance that produces an OH⁻ ion in water such that the OH⁻ concentration increases.
On the Brønsted–Lowry concept, an acid is a substance that donates a proton (which is basically an H⁺ ion) in a solvent, and a base is a substance that accepts a proton in a solvent.
On the Lewis concept, an acid is a substance that accepts an electron pair in a solvent, and a base is a substance that donates an electron pair in a solvent.
The concepts become progressively broader, i.e., the Arrhenius concept is the most restrictive and the Lewis concept is the least restrictive. As a corollary, an Arrhenius acid or base is also both a Brønsted–Lowry acid or base and a Lewis acid or base, respectively; a Brønsted–Lowry acid or base is not necessarily an Arrhenius acid or base, but an Arrhenius acid or base is also a Lewis acid or base, respectively. And finally, a Lewis acid or base may not necessarily be either an Arrhenius or a Brønsted–Lowry acid or base.
So, with the above concepts in mind, we can match the statements in column A with the type of acid or base in column B:

Answer:
c) the attraction of an atom for the electrons in a covalent bond.
Explanation:
Electronegativity, symbol χ, is a chemical property describing an atom's ability of to attract a shared pair of electrons to itself. It is influenced by the atomic number of the atom and the distance between the valence electrons and the charged nucleus. As the electronegativity number of atoms increases, the more the atom attracts electrons towards itself.