Question

What is the titre value of \[{{K}_{2}}C{{r}_{2}}{{O}_{7}}\] when \[Cu\] reacts with \[Fe{{\left( S{{O}_{4}} \right)}_{3}}\]?
a.\[25mL\]
b.\[50mL\]
c.\[75mL\]
d.\[100mL\]

Answer 1

Hint: We know that Molarity is the most commonly used measure of concentration in a solution Molarity may also be referred to as molar concentration. It can be defined as the number of moles of a solute dissolved per litre of solution.

Complete step by step solution:
To calculate molarity, you will need to divide the mass of the solution by the molecular weight of the substance. For example, dissolving \[174.26\text{ }g/mol\text{ }\left( 1M \right)\]of potassium sulphate in one liter of water will give you potassium sulphate solution with a molarity of \[1M.\]
Molarity = Number of moles of solute/ Volume of solution in litres
\[mEq\text{ }of~FeS{{O}_{4}}\equiv ~mEq\text{ }of~{{K}_{2}}C{{r}_{2}}{{O}_{7}}\]
Thus by substituting predefined molarity value in above eqn we get:
\[\left( \dfrac{2\times 2.41}{964} \right)\times {{10}^{3}}=\dfrac{1}{60}\times 6\times V\]
On further solving we get; \[V=50~mL\]

Therefore, the correct answer is option B.

Additional Information:
Molarity can change with temperature and volume. As the temperature increases, molarity decreases. Similarly, when the volume of a solution increases, the polarity decreases. The molarity of a solution increases, the molarity decreases. The molarity of a solute and if any additional substances are added to the solution.

Note:
Remember that there is a very close relation between molarity and normality. Normality can be described as a multiple of molarity. While Molarity refers to the concentration only of the acid component or only of the base component of the solution. Thus, normality offers a more in-depth understanding of the solution concentration in acid-base reactions.