Nitrous acid<span> dissociates as follows:
</span>
HNO₂(s) ⇄ H⁺(aq) + NO₂⁻(aq)
According to the equation, an acid constant has the following form:
Ka = [H⁺] × [NO₂⁻ ] / [HNO₂]
From pH, we can calculate the concentration of H⁺ and NO₂⁻:
[H⁺] = 10^-pH = 10^-2.63 = 0.00234 M = [NO₂⁻]
Now, the acid constant can be calculated:
Ka = 0.00234 x 0.00234 / 0.015 = 3.66 x 10⁻⁴
And finally,
pKa = -log Ka = 3.44
Not for sure but i would say the its B rate please
Answer:
25.907°C
Explanation:
In Exercise 102, heat capacity of bomb calorimeter is 6.660 kJ/°C
The heat of combustion of benzoic acid is equivalent to the total heat energy released to the bomb calorimeter and water in the calorimeter.
Thus:

= heat of combustion of benzoic acid
= heat energy released to water
= heat energy released to the calorimeter
Therefore,
![-m_{combust}*H_{combust} = [m_{water}*c_{water} + C_{calori}]*(T_{f} - T_{i})](https://tex.z-dn.net/?f=-m_%7Bcombust%7D%2AH_%7Bcombust%7D%20%3D%20%5Bm_%7Bwater%7D%2Ac_%7Bwater%7D%20%2B%20C_%7Bcalori%7D%5D%2A%28T_%7Bf%7D%20-%20T_%7Bi%7D%29)
1.056*26.42 = [0.987*4.18 + 6.66](
- 23.32)
27.8995 = [4.12566+6.660](
- 23.32)
(
- 23.32) = 27.8995/10.7857 = 2.587
= 23.32 + 2.587 = 25.907°C