Why is 0.15 m of hypochlorous acid acidic and 0.15 m of sodium hypochlorite basic?

HOCl is such a weak acid that the basicity of the OCl⁻ predominates in the mixture.

Explanation:

HOCl is a weak acid with pKₐ 7.53. NaOCl is its salt. A solution of a weak acid and its salt is a buffer. We can calculate the pH of the buffer.

Step 1. Write the equation for the equilibrium

HOCl + H₂O ⇌ H₃O⁺ + OCl⁻; pKa = 7.53

Step 2. Calculate the pH of the buffer

The Henderson-Hasselbalch equation is

pH = pKₐ + log([OCl⁻]/[HOCl])

pH = 7.53 + log(0.15/0.15)

pH = 7.53 + log1

pH= 7.53 + 0

pH = 7.53

So, the solution is basic.

The conjugate base of a weak acid is a relatively strong base.

HOCl is such a weak acid that the basicity of its conjugate base predominates in an equimolar mixture of the two components.

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.

i believe it is-

d.) gravity pulled particles of dust and gas together to form planets.