Respuesta :

The answer is 0.508gram

The molecular mass for aspirin (C9H8O4) should be 180g/mol. One mol is composed of 6.02* 10^23 molecule. So, the mass of 1.70×1021 molecules of aspirin would be: (1.70×10^21 molecules) * (1 mol /6.02* 10^23 molecule) * 180g/mol= 0.508 gram

[tex]\boxed{0.508{\text{ g}}}[/tex] is the mass of [tex]1.70 \times {\text{1}}{{\text{0}}^{{\text{21}}}}\;{\text{molecules}}[/tex] of aspirin.

Further Explanation:

Avogadro’s number is a mathematical number that determines the number of atoms or molecules in one mole of the substance. The value of Avogadro’s number is [tex]{\text{6}}{\text{.022}} \times {\text{1}}{{\text{0}}^{{\text{23}}}}\;{\text{units}}[/tex]. These units can either be atoms or molecules.

There are [tex]{\text{6}}{\text{.022}} \times {\text{1}}{{\text{0}}^{{\text{23}}}}\;{\text{molecules}}[/tex] in one mole of aspirin. Therefore the number of moles in [tex]1.70 \times {\text{1}}{{\text{0}}^{{\text{21}}}}\;{\text{molecules}}[/tex]  of aspirin can be calculated as follows:

 [tex]\begin{aligned}{\text{Moles of aspirin}}&= \left( {1.70 \times {\text{1}}{{\text{0}}^{{\text{21}}}}\;{\text{molecules}}} \right)\left( {\frac{{1{\text{ mol}}}}{{6.022 \times {\text{1}}{{\text{0}}^{{\text{23}}}}\;{\text{molecules}}}}} \right)\\&= 0.002823{\text{ mol}}\\\end{aligned}[/tex]

The moles of aspirin can be calculated by the following formula.s

[tex]{\text{Moles of aspirin}}=\dfrac{{{\text{Mass of aspirin}}}}{{{\text{Molar mass of aspirin}}}}[/tex]                …… (1)                                          

Rearrange equation (1) for the mass of aspirin.

[tex]{\text{Mass of aspirin}} = \left( {{\text{Moles of aspirin}}} \right)\left( {{\text{Molar mass of aspirin}}} \right)[/tex]          …… (2)                        

The molar mass of aspirin [tex]\left( {{{\text{C}}_{\text{9}}}{{\text{H}}_{\text{8}}}{{\text{O}}_{\text{4}}}} \right)[/tex] can be calculated as follows:

[tex]{\text{Molar mass of }}{{\text{C}}_{\text{9}}}{{\text{H}}_{\text{8}}}{{\text{O}}_{\text{4}}} = \left[ \begin{aligned}9\left( {{\text{Atomic mass of C}}} \right)+\hfill\\8\left({{\text{Atomic mass of H}}} \right)+\hfill\\4\left( {{\text{Atomic mass of O}}} \right) \hfill\\\end{aligned}  \right][/tex]         …… (3)                                        

Substitute 12.01 g for the atomic mass of C, 1.008 g for the atomic mass of H and 15.99 g for the atomic mass of O in equation (3).

 [tex]\begin{aligned}{\text{Molar mass of }}{{\text{C}}_{\text{9}}}{{\text{H}}_{\text{8}}}{{\text{O}}_{\text{4}}} &= \left[ {9\left( {{\text{12}}{\text{.01 g}}} \right) + 8\left( {{\text{1}}{\text{.008 g}}} \right) + 4\left( {{\text{15}}{\text{.99 g}}} \right)} \right]\\&= \left[ {108.09{\text{ g}} + 8.064{\text{ g}} + 63.96{\text{ g}}} \right]\\&= 180.114{\text{ g/mol}}\\\end{aligned}[/tex]

Substitute 0.002823 mol for the moles of aspirin and 180.114 g/mol for the molar mass of aspirin in equation (2).

[tex]\begin{aligned}{\text{Mass of aspirin}}&= \left( {{\text{0}}{\text{.002823 mol}}} \right)\left( {\frac{{{\text{180}}{\text{.114 g}}}}{{1{\text{ mol}}}}} \right)\\&= 0.508{\text{ g}}\\\end{aligned}[/tex]  

Therefore the mass of aspirin is 0.508 g.

Learn more:

  1. Calculate the moles of chlorine in 8 moles of carbon tetrachloride: https://brainly.com/question/3064603
  2. Calculate the moles of ions in the solution: https://brainly.com/question/5950133

Answer details:

Grade: Senior School

Chapter: Mole concept

Subject: Chemistry

Keywords: aspirin, molar mass, atomic mass, C, H, O, C9H8O4, Avogadro’s number, 0.508 g, 15.99 g, 12.01 g, 1.008 g.