Answer:
<h3>hope its help u.................</h3>
Answer is: <span>the temperature of the reaction is 546</span>°C.
k₁ = 1,1·10⁻⁴ 1/s.
T₁ = 470 °C = 743,15 K.
Ea = 264 kJ/mol = 264000 J/mol.
k₂ = 4,36·10⁻³ 1/s.
R = 8,314 J/K·mol.
T₂ = ?
Natural logarithm<span> of Arrhenius' equation:
</span>lnk₁ = lnA - Ea/RT₁.
lnk₂ = lnA - Ea/RT₂.
ln(k₂/k₁) = (Ea/R) · (1/T₁ - 1/T₂).
ln( 4,36·10⁻³ 1/s / 1,1·10⁻⁴ 1/s) = (264000J/mol ÷ 8,314 J/K·mol) · ·(1/743,15K - 1/T₂).
3,68 = 31753,66 K · (0,00134 1/K - 1/T₂).
3,68 = 42,728 - 31753,66 · (1/T₂).
1/T₂ = 0,00122.
T₂ = 819 K = 546 °C.
Answer:
The correct answer is:
<em>(1) It is important that the sample is dissolved in just enough hot solvent. </em>
Explanation:
The process of recrystallization is important to eliminate the impurities and to obtain better crystals of the solid. The solvent used to perform the recrystallization must have a high dissolution power of the substance to be recrystallized and a low dissolution power of the impurities. This is in order to eliminate most impurities. Furthermore, <em>It is important that the sample is dissolved in just enough hot solvent </em>because this should be easy to remove after the recrystallization and the crystal should form easily when the solution cools. Also, it is better to add the hot solvent to solubilize the crystals and keep the impurities insoluble, instead of adding the cold solvent and heating the solution. Additionally, the process of cooling the solution must be done slowly to obtain large and fewer crystals. A fast ice-cooling will form smaller crystals.
Answer:
Yes
Explanation:
The tilt of the Earth means the Earth will lean towards the Sun (Summer) or lean away from the Sun (Winter) 6 months later. In between these, Spring and Autumn will occur. The North pole always points the same way as the Earth revolves around the Sun.