\(\boxed{{\text{0}}{\text{.0860 mol}}}\) of \({{\text{K}}_2}{\text{S}}{{\text{O}}_4}\) is present in 15 g of \({{\text{K}}_2}{\text{S}}{{\text{O}}_4}\) .
Further explanation:
Amount of substance is measured in terms of mole. The mass of substance with same number of fundamental units as atoms in 12 g of carbon 12 is 1 mole.
In step 1, we have to calculate the molar mass of \({{\text{K}}_2}{\text{S}}{{\text{O}}_4}\) . The molar mass of \({{\text{K}}_2}{\text{S}}{{\text{O}}_4}\) can be calculated by using equation (1).
Step 1: The molar mass of \({{\text{K}}_2}{\text{S}}{{\text{O}}_4}\) is calculated as follows:
\({\text{Molar mass of}}{\mathbf{ }}{{\text{K}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}} = \left[ \begin{gathered}{\text{2}}\left( {{\text{Atomic mass of K}}} \right)+\hfill\\{\text{1}}\left({{\text{Atomic mass of S}}} \right)+\hfill\\{\text{4}}\left({{\text{Atomic mass of O}}}\right)\hfill\\\end{gathered}\right]\)
…… (1)
The atomic mass of K is 39.09 g.
The atomic mass of S is 32.06 g.
The atomic mass of O is 16 g.
Substitute these values in equation (1).
\(\begin{aligned}{\text{Molar mass of}}{\mathbf{ }}{{\text{K}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}&=\left[{{\text{2}}\left({{\text{39}}{\text{.09 g}}}\right)+{\text{1}}\left({{\text{32}}{\text{.06 g}}}\right)+{\text{4}}\left({{\text{16 g}}}\right)}\right]\\&=\left[{{\text{78}}{\text{.18 g}}+{\text{32}}{\text{.06 g}}+{\text{64 g}}}\right]\\&=174.24\;{\text{g/mol}}\\\end{gathered}\)
In step 2, the molar mass calculated in step 1 is used to calculate the number of moles of \({{\text{K}}_2}{\text{S}}{{\text{O}}_4}\) . The number of moles of \({{\text{K}}_2}{\text{S}}{{\text{O}}_4}\) is calculated by using equation (2).
Step 2: The formula to calculate the moles of \({{\text{K}}_2}{\text{S}}{{\text{O}}_4}\) is as follows:
\({\text{Moles of }}{{\text{K}}_2}{\text{S}}{{\text{O}}_4}{\mathbf{=}}\frac{{{\text{Given mass of}}{\mathbf{ }}{{\text{K}}_2}{\text{S}}{{\text{O}}_4}}}{{{\text{Molar mass of}}{\mathbf{ }}{{\text{K}}_2}{\text{S}}{{\text{O}}_4}}}\)
…… (2)
The given mass of \({{\text{K}}_2}{\text{S}}{{\text{O}}_4}\) is 15 g.
The molar mass of \({{\text{K}}_2}{\text{S}}{{\text{O}}_4}\) is 174.24 g/mol.
Substitute these values in equation (2).
\(\begin{aligned}{\text{Moles of }}{{\text{K}}_2}{\text{S}}{{\text{O}}_4}&=\left( {15\;{\text{g}}}\right)\left({\frac{{1\;{\text{mol}}}}{{174.24\;{\text{g}}}}}\right)\\&={\text{0}}{\text{.086088}}\\&\approx{\mathbf{0}}{\mathbf{.0860}}\;{\mathbf{mol}}\\\end{aligned}\)
Learn more:
1. Calculate the moles of ions in the solution: https://brainly.com/question/5950133
2. Calculate the moles of chlorine in 8 moles of carbon tetrachloride: https://brainly.com/question/3064603
Answer details:
Grade: Senior School
Subject: Chemistry
Chapter: Mole concept
Keywords: molar mass, mole, K2SO4, 0.0860 mol, given mass, atomic mass, K, S, O, 16 g, 32.06 g, 39.09 g, 15 g, 174.24 g/mol.
