If the reaction is represented by:
PCl₃ + Cl₂ <-> PCl₅ (exothermic)
the mole fraction of chlorine in the equilibrium mixture will change according to the following:
Decrease the volume: decrease
Increase the temperature: increase
Increase the volume: increase
Decrease the temperature: decrease
Henderson–Hasselbalch equation is given as,
pH = pKa + log [A⁻] / [HA]
-------- (1)
Solution:
Convert Ka into pKa,
pKa = -log Ka
pKa = -log 1.37 × 10⁻⁴
pKa = 3.863
Putting value of pKa and pH in eq.1,
4.29 = 3.863 + log [lactate] / [lactic acid]
Or,
log [lactate] / [lactic acid] = 4.29 - 3.863
log [lactate] / [lactic acid] = 0.427
Taking Anti log,
[lactate] / [lactic acid]
= 2.673
Result:
2.673 M
lactate salt when mixed with 1 M Lactic acid produces a buffer of pH = 4.29.
Answer : The value of reaction quotient, Q is 0.0625.
Solution : Given,
Concentration of
= 2.00 M
Concentration of
= 2.00 M
Concentration of
= 1.00 M
Reaction quotient : It is defined as a concentration of a chemical species involved in the chemical reaction.
The balanced equilibrium reaction is,

The expression of reaction quotient for this reaction is,
![Q=\frac{[Product]^p}{[Reactant]^r}\\Q=\frac{[NH_3]^2}{[N_2]^1[H_2]^3}](https://tex.z-dn.net/?f=Q%3D%5Cfrac%7B%5BProduct%5D%5Ep%7D%7B%5BReactant%5D%5Er%7D%5C%5CQ%3D%5Cfrac%7B%5BNH_3%5D%5E2%7D%7B%5BN_2%5D%5E1%5BH_2%5D%5E3%7D)
Now put all the given values in this expression, we get

Therefore, the value of reaction quotient, Q is 0.0625.
B, radon is correct. Interestingly, it often collects in basements from radioactive decay of rocks such as granite that contain uranium. Because it is an unreactive noble gas and because it is denser than air it sits in basements and must be pumped out. It collects in human lungs and is the second leading cause of lung cancer behind smoking.