First, we will get the average pH of the two given values:
average pH = (6.4+8) / (2) = 7.2
At this average pH, the concentration of the acid from the phenol red is equal to the concentration of the base.
pH = 7.2
[H+] = 10^(-7.2) = 6.3 * 10^-8
Phenol red has the general formula HA, this gives us:
HA <.......> H+ + A-
At pH = 7.2, [H+] = [A-]
<span>Ka = [H+][A-]/ [HA]
</span>Ka = [H+] = <span>6.3 x 10^-8</span>
The next test would be the lime water test.
Explanation:
If placing the gas in lime water will turn the solution milky, then the gas is most probably carbon dioxide, the lime water (Ca(OH)₂) turns milky due to the formation of solid CaCO₃ that is insoluble after reaction with carbon dioxide.
Carbon dioxide also puts out the flame in the splint test because it does not support combustion.
Bromine has one more electron shell than the chlorine atom making the radius larger than the chlorine atom.
Beryllium has four neutrons
Pure substances contain a single type of chemical species, either element or compound. Elements cannot be further broken into simpler units by chemical methods. If we consider a sample of elements, it has a single type of atoms present in it. A compound has one or more atoms bound together chemically. Compounds can be broken down into simpler units by chemical means. When we consider a sample of a single compound say water, it has all the pure water molecules. Hence, elements and compounds are pure substances.
