Respuesta :

Hagrid

Given:

7.20 g sample of Al2(SO4)3

Required:

Mass of oxygen

Solution:

                Since you are not given a chemical reaction, just base your solution to the chemical formula given.

Molar mass of Al2(SO4)3 = 342.15 g/mol

7.20 g Al2(SO4)3 (1 mol/342.15g)(3mol O/2 mol Al)(1 mol O2/1/2 mol O2)(32g O2/1mol O2) = 4.04 g O2

7.20 g of a sample of Al2(SO4)3 contains 4.04 g of oxygen.

Further Explanation

A compound  

  • A compound is a substances that contains two or more different atoms that are bonded together. When the atoms are similar the substance is known as a molecule, therefore not all molecules are compounds.

Molar mass

  • Molar mass is the mass of one mole of a compound or a substance. The molar mass of a compound is the mass that is equivalent to the sum of relative atomic masses of the atoms of elements making up the compound.

Mass percent composition of a compound

  • Mass percent composition of a compound is calculated by dividing the mass of element in one mole of the compound by the molar mass of the compound and multiplying by 100%.

In this case we are require to calculate the mass of Oxygen in 7.2 g of Al2(SO4)3

  • Therefore; the molar mass of Al2(SO4)3 will be; 342.15 g/mol  
  • Al2(SO4)3 is made up of two Al atoms, three sulfur atoms, and 12 oxygen atoms.

Therefore;

1 mole of Al2(SO4)3 contains a mass of 192 g of Oxygen  

Thus; A sample of 7.20 g Al2(SO4)3 will contain;

= ((7.2 g Al2(SO4)3x(192 g O))/ 342.15 g/mol Al2(SO4)3

= 4.04 g Oxygen  

Keywords: Molar mass, compound  

Learn more about:

  • Compounds: brainly.com/question/1194814
  • Atoms: brainly.com/question/12505687
  • Percentage composition by mass in compounds: brainly.com/question/9118852

Level: High school  

Subject: Chemistry  

Topic: Compounds and mixtures  

Sub-topic: Composition of compounds  

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