In order to completely neutralize 0.985 mol of sodium hydroxide, 43.2 mL of an acid is required. The concentration of the acid is:
a) 2.3 M
b) 22.8 M
c) 31.0 M
d) 48.2 M
Is it b?
yes, although that sounds like a VERY concentrated acid to me.
To determine the concentration of the acid, we need to use the concept of stoichiometry and the balanced equation for the reaction between sodium hydroxide (NaOH) and the unknown acid.
The balanced equation for the reaction is:
2NaOH + H2SO4 -> Na2SO4 + 2H2O
From the equation, we can see that the ratio between NaOH and H2SO4 is 2:1. This means that for every 2 moles of NaOH, we need 1 mole of H2SO4 to react completely.
Given that the amount of NaOH is 0.985 mol, we can determine the amount of acid required by dividing it by the stoichiometric ratio:
0.985 mol NaOH / 2 = 0.493 mol of H2SO4
Now, we need to find the concentration of the acid, which is given in units of moles per liter (M). To do this, we need to convert the volume of the acid, which is 43.2 mL (or 0.0432 L), into liters.
Concentration (M) = moles of acid / volume of acid (in liters)
Concentration (M) = 0.493 mol / 0.0432 L ≈ 11.4 M
Therefore, the concentration of the acid is not option (b) 22.8 M, but is actually approximately 11.4 M.
The correct answer among the given options is not provided.