Question

В 5 литрах раствора содержится 55.5 грамма CaCl2. Каковы молярность,титр и эквивалентная концентрация раствора?

Answer 1

Calculation of Molarity, Titer, and Equivalent Concentration

To calculate the molarity, titer, and equivalent concentration of a solution, we need to know the amount of solute (in moles) and the volume of the solution (in liters).

Given: - Amount of CaCl2 in the solution: 55.5 grams - Volume of the solution: 5 liters

To calculate the molarity, we need to convert the mass of CaCl2 to moles using its molar mass. The molar mass of CaCl2 is the sum of the atomic masses of calcium (Ca) and chlorine (Cl), multiplied by the number of atoms in the compound.

The atomic mass of calcium (Ca) is approximately 40.08 g/mol, and the atomic mass of chlorine (Cl) is approximately 35.45 g/mol. Since there are two chlorine atoms in CaCl2, the molar mass of CaCl2 is:

Molar mass of CaCl2 = (40.08 g/mol) + 2 * (35.45 g/mol) = 110.98 g/mol

Now, we can calculate the number of moles of CaCl2 in the solution:

Number of moles of CaCl2 = Mass of CaCl2 / Molar mass of CaCl2 = 55.5 g / 110.98 g/mol

Let's calculate the value:

Number of moles of CaCl2 = 0.499 mol

Molarity:

Molarity (M) is defined as the number of moles of solute per liter of solution. To calculate the molarity, we divide the number of moles of CaCl2 by the volume of the solution:

Molarity = Number of moles of CaCl2 / Volume of solution

Substituting the values:

Molarity = 0.499 mol / 5 L

Let's calculate the value:

Molarity = 0.0998 M

Titer:

Titer is a measure of the concentration of a solution and is often used in titration experiments. It represents the number of moles of a substance per liter of solution. In this case, since we have the molarity of the solution, the titer is the same as the molarity.

Therefore, the titer of the solution is:

Titer = 0.0998 M

Equivalent Concentration:

Equivalent concentration is a measure of the concentration of a solution in terms of the number of equivalents of a substance per liter of solution. To calculate the equivalent concentration, we need to know the number of equivalents of CaCl2 in the solution.

CaCl2 dissociates into one calcium ion (Ca2+) and two chloride ions (2Cl-). Since the charge of the calcium ion is +2 and the charge of the chloride ion is -1, the number of equivalents of CaCl2 is equal to the number of moles of CaCl2 multiplied by the sum of the absolute values of the charges of the ions.

Number of equivalents of CaCl2 = Number of moles of CaCl2 * (2 + 2 * 1)

Substituting the values:

Number of equivalents of CaCl2 = 0.499 mol * (2 + 2 * 1)

Let's calculate the value:

Number of equivalents of CaCl2 = 1.497

Now, we can calculate the equivalent concentration:

Equivalent concentration = Number of equivalents of CaCl2 / Volume of solution

Substituting the values:

Equivalent concentration = 1.497 / 5 L

Let's calculate the value:

Equivalent concentration = 0.2994 eq/L

To summarize: - Molarity of the solution: 0.0998 M - Titer of the solution: 0.0998 M - Equivalent concentration of the solution: 0.2994 eq/L