Answer is:
concentration of hydroxide ions is 2.38·10⁻¹⁰ M<span>.
[</span>H₃O⁺] = 4.2·10⁻⁵<span> M; equilibrium concentration of hydroxide ions.
The Kw (the ionic product for water) at 25°C is 1·10</span>⁻¹⁴ mol²/dm⁶ or 1·10⁻¹⁴<span> M².
Kw = [H</span>₃O⁺] · [OH⁻<span>].
[</span>OH⁻] = Kw ÷ [H₃O⁺<span>].
[</span>OH⁻] = 1·10⁻¹⁴ M² ÷ 4.2·10⁻⁵ M<span>.
[</span>OH⁻] = 2.38·10⁻¹⁰ M.
119 (atomic mass)- 50 protons= 69 neutrons
A quantitative observation must be a measurement of some sort. (Something including numbers). Qualitative, on the other hand, is when you are using words to describe what has happened.
<span>cesium sulfide IS THE NAME OF THAT COMPOUND</span>
