To determine the identity of the unknown base, we can use the concept of stoichiometry, which involves the balanced chemical equation for the neutralization reaction.
First, let's write the balanced equation for the reaction between the base and nitric acid (HNO3):
Base + HNO3 -> Salt + Water
Since we are given the volume and concentration of the acid (HNO3), we can calculate the amount of acid used (moles) by using the formula:
moles of acid = volume of acid (L) × concentration of acid (M)
In this case, the volume of the acid is 12 mL, which we need to convert to L:
12 mL = 12/1000 L = 0.012 L
Now, let's calculate the moles of HNO3 used:
moles of acid = 0.012 L × 0.150 M = 0.0018 moles
Since the stoichiometry of the balanced equation is 1:1 between the acid and the base, the number of moles of the base is also 0.0018 moles.
Now, let's calculate the concentration of the unknown base:
concentration of base = moles of base / volume of base (L)
Given that the volume of the base is 30 mL, we convert it to L:
30 mL = 30/1000 L = 0.030 L
Now, calculate the concentration of the unknown base:
concentration of base = 0.0018 moles / 0.030 L = 0.060 M
Since the concentration of the unknown base is 0.0300 M and we calculated it to be 0.0600 M, there might be an error in the given concentration. However, assuming the concentration given is correct, the possible identities for the unknown base could be any strong base with a concentration of 0.060 M, such as sodium hydroxide (NaOH), potassium hydroxide (KOH), or calcium hydroxide (Ca(OH)2), among others.