Answer:
Explanation:
Hello,
In this case, since the undergoing chemical reaction is:
The corresponding moles of carbon dioxide occupying 40.0 mL (0.0400 L) are computed by using the ideal gas equation at 273.15 K and 1.00 atm (STP) as follows:
Then, since the mole ratio between carbon dioxide and calcium carbonate is 1:1 and the molar mass of the reactant is 100 g/mol, the mass that yields such volume turns out:
Regards.
Norfenefrine (C₈H₁₁NO₂).
<h3>Further explanation</h3>We will solve a case related to one of the colligative properties, namely freezing point depression.
The freezing point of the solution is the temperature at which the solution begins to freeze. The difference between the freezing point of the solvent and the freezing point of the solution is called freezing point depression.
<u>Given:</u>
A mysterious white powder could be,
When 82 mg of the powder is dissolved in 1.50 mL of ethanol (density = 0.789 g/cm³, normal freezing point −114.6°C, Kf = 1.99°C/m), the freezing point is lowered to −115.5°C.
<u>Question: </u>What is the identity of the white powder?
<u>The Process:</u>
Let us identify the solute, the solvent, initial, and final temperatures.
Prepare masses of solutes and solvents.
We must prepare the solvent mass unit in kg because the unit of molality is the mole of the solute divided by the mass of the solvent in kg.
The molality formula is as follows:
Now we combine it with the formula of freezing point depression.
It is clear that we will determine the molar mass of the solute (denoted by Mr).
We enter all data into the formula.
We get
These results are very close to the molar mass of norfenefrine which is 153.18 g/mol. Thus the white powder is norfenefrine.
<h3>Learn more</h3>Keywords: a mysterious white powder, sugar, cocaine, codeine, norfenefrine, fructose, the solute, the solvent, dissolved, ethanol, normal freezing point, the freezing point depression, the identity
