The similarities of physical and chemical changes is that both of those changes change the way the object looks by it's physical appearance. Also they use a type of element to change that object.

5 0

3 years ago

A monoprotic weak acid, HA , dissociates in water according to the reaction HA(aq)↽−−⇀H+(aq)+A−(aq) The equilibrium concentratio

Pachacha [2.7K]

Answer:

$pK_{a}$ of HA is 6.80

Explanation:

$pK_{a}=-logK_{a}$

Acid dissociation constant ( $K_{a}$ ) of HA is represented as-

$K_{a}=\frac{[H^{+}][A^{-}]}{[HA]}$

Where species inside third bracket represents equilibrium concentrations

Now, plug in all the given equilibrium concentration into above equation-

$K_{a}=\frac{(2.00\times 10^{-4})\times (2.00\times 10^{-4})}{0.250}$

So, $K_{a}=1.6\times 10^{-7}$

Hence $pK_{a}=-log(1.6\times 10^{-7})=6.80$

6 0

3 years ago

Or a hydrogen atom, which electronic transition would result in the emission of a photon with the highest energy?

ELEN [110]

This electronic transition would result in the emission of a photon with the highest energy: 4p – 2s This can be the same with the emission of 4f to 2s which would emit energy in the visible region. The energy in the visible region would emit more energy than in the infrared region which makes this emission to have the highest energy.

8 0

3 years ago