The lever family and the inclined plane family.
We need to know the value of van't hoff factor.
The van't hoff factor is: 2.66 or 2.7 (approximately)
(NH₄)₂SO₄ is an ionic compound, so it dissociates in solution and produces 3 ionic species. Therefore van't hoff factor is more than one.
From the equation: Δ
=i
.m, where Δ
= elevation of boiling point=102.5 - 100=2.5°C.
m=molality of solute=1.83 m (Given)
= Ebullioscopic constant or Boiling point elevation constant= 0.512°C/m (Given)
i= Van't Hoff factor
So, 2.5= i X 0.512 X 1.83
i=
i=2.66= 2.7 (approx.)
Answer is: pH of ammonium hydroxide is 11.13.
Chemical reaction of ammonium hydroxide in water: NH₄OH → NH₄⁺ +
OH⁻<span>.
</span>
Kb(NH₄OH) = 1,8·10⁻⁵<span>.
c</span>₀(NH₄OH<span>) = 0.1 M.
c(NH</span>₄⁺) = c(OH⁻<span>) = x.
c(</span>NH₄OH<span>) = 0.1 M- x.
Kb = c(NH</span>₄⁺) · c(OH⁻) / c(NH₄OH<span>).
0,000018 = x² / 0.1 mol/L - x</span>.
Solve quadratic equation: x = c(OH⁻) = 0.00133 M.
pOH = -logc(OH⁻).
pOH = 2.87.
pH = 14 - 2.87.
pH = 11.13.
Answer:
The correct option is: stable environment
Explanation:
According to the Darwin's theory, natural selection is the concept by which all the small useful variations of traits are preserved.
According to Darwin, there are three <u>necessary and sufficient conditions</u> for the occurrence of natural selection:
1. struggle for existence
2. variation
3. inheritance
These conditions are said to be necessary because if these conditions are not satisfied then natural selection does not occur.
These conditions are said to be sufficient because if these conditions are satisfied, then natural selection will most definitely occur.