Answer:
7.98 g of glucose are needed to prepare 399 mL of glucose solution
Explanation:
2.0 % m/v
This data represents, a sort of concentration for solutions.
It means that, our solution contains 2 g of solute, in this case glucose, which are contained by 100 mL of solution.
We only have to make a rule of three, in order to solve the question:
In 100 mL of glucose solution, we have 2 g of solute
In 399 mL of glucose solution, we may have:
(399 . 2) / 100 = 7.98 g
Transportation seems like the right answer
Mg = 24.3 g/mol
23.5 g / 24.3 g/mol = 0.97 mol Mg
Keto-enol tautomerism
<u>Explanation:</u>
Phenolphthalein is an indicator (C₂₀H₁₄O₄), which is utilized to find the volume in the titration of acid and base, Depending on the pH value the indicator, changes its color from colorless in acids to pink in basic medium.
It is a weak acid, losses a (H⁺) proton in solution, that is colorless, whereas the corresponding anion is pink in color.
This change in color of the molecule is not only defined by the addition of a base or an acid, but also with the structure of the indicator, which leads to tautomerism called as keto-enol tautomerism. If a molecule has 2 (-OH) hydroxyl groups as well as 1 (C=O) carbonyl group, exhibit an equilibrium among both the groups. Because of this change, structure of the indicator changes and so color also changes.