Respuesta :

Molar mass K₂SO₄ = 174.259 g/mol

[tex]n = \frac{m}{M} [/tex]

[tex]n = \frac{15.0 g}{174.259g/mol} [/tex]

[tex]n = 0.0860[/tex] moles

hope this helps!

[tex]\boxed{{\text{0}}{\text{.0860 mol}}}[/tex] of [tex]{{\text{K}}_2}{\text{S}}{{\text{O}}_4}[/tex] is present in 15 g of [tex]{{\text{K}}_2}{\text{S}}{{\text{O}}_4}[/tex] .

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 [tex]{{\text{K}}_2}{\text{S}}{{\text{O}}_4}[/tex] . The molar mass of [tex]{{\text{K}}_2}{\text{S}}{{\text{O}}_4}[/tex] can be calculated by using equation (1).

Step 1: The molar mass of [tex]{{\text{K}}_2}{\text{S}}{{\text{O}}_4}[/tex]  is calculated as follows:

[tex]{\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][/tex]

…… (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).

[tex]\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}[/tex]

In step 2, the molar mass calculated in step 1 is used to calculate the number of moles of [tex]{{\text{K}}_2}{\text{S}}{{\text{O}}_4}[/tex] . The number of moles of [tex]{{\text{K}}_2}{\text{S}}{{\text{O}}_4}[/tex] is calculated by using equation (2).

Step 2: The formula to calculate the moles of [tex]{{\text{K}}_2}{\text{S}}{{\text{O}}_4}[/tex] is as follows:

[tex]{\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}}}[/tex]

…… (2)

The given mass of [tex]{{\text{K}}_2}{\text{S}}{{\text{O}}_4}[/tex] is 15 g.

The molar mass of [tex]{{\text{K}}_2}{\text{S}}{{\text{O}}_4}[/tex] is 174.24 g/mol.

Substitute these values in equation (2).

[tex]\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}[/tex]

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.

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