<span>You use the Henderson - Hasselbalch equation
pH = pKa + log ([salt]/[acid])
pKa = -log (8.2*10^-5) = 4.081
pH = 4.081 + (0.590/0.190)
pH = 4.081 + log 3.105
pH = 4.081 + 0.49206
pH = 4.573</span>
Dots are used to represent electrons.
There should be 22 figures .
The correct answer is letter A: <span>Unlike junction diodes, point-contact diodes are enclosed in a suitable casing and have terminals for connecting them to a circuit.</span>