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.
Reichsteins substance if I remember correctly.
Hope this helped! :)
- Juju
Answer:
Explanation:
A) Reactant that can produce more of the product
Excess reactant:
In a given reaction, the reactant that is in excess supply is the excess reactant. If the amount of the excess reactant is match, more of the product will be produced.
B) Reactant that can produce a lesser amount of the product
Limiting reactant
The limiting reactant restricts the progress of the reaction. It determines the amount of product that can be formed.
C) Amount of product predicted to be produced by the given reactants
Theoretical yield
For a given amount of reactants, the theoretical yield determines the amount of products that can be produced.
<u>Answer:</u> The mass of solution that the chemistry student should use is 23.4 grams
<u>Explanation:</u>
We are given:
Available mass of isopropenylbenzene = 120. g
Amount of isopropenylbenzene needed by chemistry student = 10.00 g
42.7 % (w/w) solution of isopropenylbenzene.
This means that 42.7 grams of isopropenylbenzene is present in 100 grams of solution.
To calculate the mass of solution for given needed of isopropenylbenzene, we apply unitary method:
For 42.7 grams of isopropenylbenzene, the amount of solution needed is 100 grams
So, for 10.00 grams of isopropenylbenzene, the amount of solution needed will be = 
Hence, the mass of solution that the chemistry student should use is 23.4 grams
Both liquids and gasses are fluids is the answer
