Answer: the following are essential factors to be considered when choosing a solvent for crystallization
1. The crystallization solvent should not dissolve the substance to be purified at room temperature, but it should dissolve it well at the solvent’s boiling point
2. The solvent should dissolve soluble impurities well at room temperature.
3. The solvent should not dissolve insoluble impurities even at the solvent’s boiling
point.
4. The solvent must not react with the substance to be purified .
Explanation:
<em>We </em><em>know </em><em>that </em><em>metals </em><em>are </em><em>good </em><em>conductor </em><em>of </em><em>heat</em><em>. </em><em>so </em><em>it </em><em>allows </em><em>the </em><em>heat </em><em>to </em><em>flow </em><em>through </em><em>them </em>
<em>.</em><em> </em><em>So </em><em>as </em><em>we </em><em>know </em><em>the </em><em>spoon </em><em>is </em><em>a </em><em>metal </em><em>which </em><em>is </em><em>left </em><em>on </em><em>a </em><em>bowl </em><em>of </em><em>hot </em><em>soup </em><em>allows </em><em>heat </em><em>to </em><em>flow </em><em>through </em><em>it </em><em>easily </em><em>so </em><em>if </em><em>becomes </em><em>warm</em><em>. </em>
Answer:
0.057 M
Explanation:
Step 1: Given data
Solubility product constant (Ksp) for HgBr₂: 2.8 × 10⁻⁴
Concentration of mercury (II) ion: 0.085 M
Step 2: Write the reaction for the solution of HgBr₂
HgBr₂(s) ⇄ Hg²⁺(aq) + 2 Br⁻
Step 3: Calculate the bromide concentration needed for a precipitate to occur
The Ksp is:
Ksp = 2.8 × 10⁻⁴ = [Hg²⁺] × [Br⁻]²
[Br⁻] = √(2.8 × 10⁻⁴/0.085) = 0.057 M
Answer:
0.48atm
Explanation:
Firstly, we need to know the mole ratio of the oxygen gas involved. To do this, we simply place the number of moles of the oxygen over the sum of both gases.
This would be 3/(3+7) = 0.3
Now, to get the partial pressure contributed by the oxygen gas, we simply multiply the 0.3 by the total pressure
Hence, the partial pressure of oxygen = the mole fraction of oxygen * the total pressure.
= 0.3 * 1.6 = 0.48atm
At the core of the sun, it can be more than 27 million degrees Fahrenheit (15 million degrees Celsius).
From the core, energy moves to the radiative zone, where it bounces around for up to 1 million years before moving up to the convective zone, the upper layer of the sun's interior. The temperature here drops below 3.5 million degrees F (2 million degrees C). Large bubbles of hot plasma form a soup of ionized atoms and move upwards to the photosphere.
<http://www.space.com/17137-how-hot-is-the-sun.html>