\(\boxed{{\text{5}}{\text{.292 g}}}\) of KOH is present in 500 mL of 0.189 M KOH solution.
Further Explanation:
The concentration is the proportion of substance in the mixture. The most commonly used concentration terms are as follows:
1. Molarity \(\left(M\right)\)
2. Molality \(\left(m\right)\)
3. Mole fraction \(\left(X\right)\)
4. Parts per million \(\left({{\text{ppm}}}\right)\)
5. Mass percent \(\left({\left({{\text{w/w}}}\right)\%}\right)\)
6. Volume percent \(\left({\left({{\text{v/v}}}\right)\%}\right)\)
Molarity is a concentration term that is defined as the number of moles of solute dissolved in one litre of the solution. It is denoted by M and its unit is mol/L.
The formula to calculate the molarity of KOH is as follows:
\({\text{Molarity of KOH solution}}=\frac{{{\text{amount}}\;\left({{\text{mol}}}\right)\;{\text{of}}\;{\text{KOH}}}}{{\;{\text{volume }}\left({\text{L}}\right)\;{\text{of}}\;{\text{solution}}}}\) ......(1)
Rearrange equation (1) to calculate the amount of KOH.
\({\text{Amount}}\;\left({{\text{mol}}}\right)\;{\text{of}}\;{\text{KOH}}=\left( {{\text{Molarity of KOH solution}}}\right)\left({\;{\text{Volume }}\left({\text{L}}\right)\;{\text{of KOH }}{\text{solution}}}\right)\) ......(2)
The molarity of the KOH solution is 0.189 M or 0.189 mol/L.
The volume of KOH solution is 500 mL.
Substitute these values in equation (2)
\(\begin{aligned}{\text{Amount}}\;\left({{\text{mol}}}\right)\;{\text{of}}\;{\text{KOH}}&=\left({{\text{0}}{\text{.189 mol/L}}}\right)\left({500\;{\text{mL}}}\right)\left({\frac{{1\;{\text{L}}}}{{{{10}^{ - 3}}{\text{mL}}}}}\right)\\&=0.0945\;{\text{mol}}\\\end{aligned}\)
The formula to calculate the mass of KOH is,
\({\text{Mass of KOH}}=\left({{\text{Amount of KOH}}}\right)\left({{\text{Molar mass of KOH}}}\right)\) ......(3)
The amount of KOH is 0.0945 mol.
The molar mass of KOH is 56 g/mol.
Substitute these values in equation (3)
\(\begin{aligned}{\text{Mass of KOH}}&=\left({{\text{0}}{\text{.0945 mol}}}\right)\left({\frac{{56\;{\text{g}}}}{{1\;{\text{mol}}}}}\right)\\&=5.292\;{\text{g}}\\\end{aligned}\)
So the mass of KOH is 5.292 g.
Learn more:
1. What is the mass of 1 mole of viruses: https://brainly.com/question/8353774
2. Determine the moles of water produced: https://brainly.com/question/1405182
Answer details:
Grade: Senior School
Subject: Chemistry
Chapter: Solutions
Keywords: KOH, molarity, 500 mL, 5.292 g, mol/L, 0.189 M, molar mass, 56 g/mol, concentration, concentration terms, volume.
