The chemical nature of Q sepharose which allows it to be used as an ion exchanger include the following: It is an insoluble matrix which is in form of micro beads. The bead are porous, which provides a large surface area within and outside them. This properties make it possible for Q sepharose to finely separate different organic molecules.<span />
For the first question, i think the correct answer is the third option. When a gas is formed, it is <span>the most conclusive in determining whether a chemical reaction has taken place given that none of your reactants is a gas.
For the second question, the statement is true.
For the third question, the correct answer is the last option.</span>
Answer:
Al2O3
Explanation:
If we combine two Al3+ ions and three O2- ions, and use subscripts to indicate the number of each ion in the formula, we obtain Al2O3 as the empirical formula
Answer:
Option a.
Explanation:
The transformation of a solid into liquid is a slow process, hence a rate of heating too fast, near the melting point of the sample, will not give the right time to the crystals of the sample to absorb the heat and to melt in the outside and the inside, leading to wrong results in all cases. If we heat to fast, the melting point range will be too broad and will be misleading, resulting in values of the range more hight than the theoric ones.
A rate of 1 °C/min or 2 °C/min is the most appropriate to approach the melting point of the sample. Since it is too slow, from preventing the experiment taking forever it is recommended to start the experiment at a high heating rate until it reaches 20 °C below the melting point, and then, turn the heating rate down to 1 °C/min or 2 °C/min.
Therefore, the correct answer is a: near the melting point of the sample, we must heat slowly until it reach the expected temperature.
I hope it helps you!
