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

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.