First we must write a balanced chemical equation for this reaction

The mole ratio for the reaction between
and
is 1:2. This means 1 moles of
will neutralize 2 moles
. Now we find the moles of each reactant based on the mass and molar mass.



The
was enough to neutralize the acid because 18.87:39.67 is the same as 1:2 mol ratio.
Answer:
P₂ = 13.9 atm (3 sig. figs.)
Explanation:
The pressure (P), Volume (V) relationship with Temperature (T) & mass (n) held constant is an inverse proportionality. That is Boyles Law ...
P ∝ 1/V => P = k/V => k = P·V
For two pressure-volume conditions, the proportionality constant (k) remains constant where k₁ = k₂ and P₁·V₁ = P₂·V₂ => P₂ = P₁·V₁/V₂
Given:
P₁ = 1.31 atm.
V₁ = 5.51 L
P₂ = ?
V₂ = 0.520 L
V₂ = (1.31 atm)(5.51L)/(0.520L) = 13.88096154 atm (calc. ans.) = 13.9 atm (3 sig. figs.)
Answer:
Q = 3937.56 J
Explanation:
Heat transferred due to change in temperature is given by :

c is the specific heat of water, c=4.18 J/g-°C
We have, m = 15 g, 
So,

Hence, 3937.56 J of heat is transferred.