Answer:
D H2PO4– + HPO42–
Explanation:
The acid dissociation constant for 
are 
respectively.
The reason while option D is the best answer is that, the value of pKa for both
lies on either side of the desired pH of the buffer. This implies that one is slightly over and the other is slightly under.
Using Henderson-Hasselbach equation:
Answer:
Released
Explanation:
When particles that attract each other come together, energy is usually released. The combination of the two particles is expected to result in a lower energy system. This lower energy system will be more stable than the different individual particles.
Hence, as this lower energy system is formed, the excess energy originally possessed by the particles is evolved hence energy is released when particles that attract each other are allowed to come together.
Answer:
e- 7.25 x 10³.
Explanation:
∵ ΔG = -RTlnK,
where, ΔG is the free energy change.
R is the general gas constant (R = 8.324 J/mol.K).
K is the equilibrium constant of the reaction.
- For the reaction: <em>N₂(g) + 3H₂(g) → 2NH₃(g),</em>
K = (PNH₃)²/(PN₂)(PH₂)³ = (0.65)²/(1.9)(1.6)³ = 5.43 x 10⁻².
∵ ΔG = -RTlnK.
∴ ΔG = -(8.314 J/mol.K)(298 K) ln(5.43 x 10⁻²) = 7.218 x 10³ J/mol.
Given data:
Distance travelled (d)= 200.0 m
Time taken (t) = 21.7 s
To determine:
The average speed in km/hr
Calculation:
Convert distance from m to km
1000 m = 1 km
200.0 m = 1 km * 200.0 m/1000 m = 0.2 km
Convert time from sec to hours
3600 sec = 1 hour
21.7 sec = 1 hour * 21.7 sec/3600 sec = 6.027 *10^-3 hrs
Speed is defined as the amount of distance travelled per unit time
Speed = distance/time = 0.2 km/6.027*10^-3 hr
= 33.18 km/hr (or 33.2 km/hr)
