The earth is inclined to the plane of its orbit by 23.5 degrees. Therefore for half the time in its earth on its orbit, the north pole will be inclined towards the sun. During this period, the pole receives six months of continuous sunshine. In the other half of the revolution around the sun, the north pole is tilted away from the sun hence receives darkness for 6 months.
Answer:
ΔHv = 29861.25 J/mol
Explanation:
A(l) → A(g)
∴ P: at constant
∴ ΔS = 75.0 J/K.mol
∴ T = 125°C = 398.15 K
law's Trouton:
- ΔS = ΔHv / T.....at T,P constant
⇒ ΔS = 75.0 J/mol.K = ΔHv / ( 398.15 K )
⇒ ΔHv = 75.0 J/mol.K * 398.15 K
⇒ ΔHv = 29861.25 J/mol
Answer:
Explanation:
Using freezing point depression formula,
ΔTemp.f = Kf * b * i
Where,
ΔTemp.f = temp.f(pure solvent) - temp.f(solution)
b = molality
i = van't Hoff factor
Kf = cryoscopic constant
= 1.86°C/m for water
= (0 - (-5.58))/1.86
= 3.00 mol/kg
Assume 1 kg of water(solvent)
= (3.00 x 1)
= 3.00 mol.
Answer: The correct answer is 'a base gives off hydroxide ions'.
Explanation:
- Bases have pH more than seven.
- They give hydroxide ions,
.
![BOH(aq)\rightarrow B^+(aq)+OH^-(aq)](https://tex.z-dn.net/?f=BOH%28aq%29%5Crightarrow%20B%5E%2B%28aq%29%2BOH%5E-%28aq%29)
- Acids have pH lower than seven.
- They give hydronium ions,
.
![HA(aq)\rightarrow H^+(aq)+A^-(aq)](https://tex.z-dn.net/?f=HA%28aq%29%5Crightarrow%20H%5E%2B%28aq%29%2BA%5E-%28aq%29)