Al2(SO4)3 - aluminum sulfate, an inorganic substance from the class s alts. Occurs in the form of crystals or white powder, soluble in water. A chemically active substance that reacts well with many components, therefore it is often used in experiments and tasks in chemistry, but to solve them you need to know the molar mass of Al2(SO4)3.
Calculation of the indicator
The relative molecular weight of aluminum sulfate is the volume of one single molecule of this substance. Let's take a closer look.
The indicator is expressed in atomic mass units (amu). It is easy to calculate using Mendeleev's periodic system of elements, knowing the formula of the substance.
To do this, you need to find in the table the elements that make up the substance of interest to us - aluminum, sulfur and oxygen. The relative mass of one aluminum atom is 26.992 amu. (round up to 27), sulfur atoms 32.064 (round up to 32), oxygen atoms 15.999 (round up to 16).
Sulfate molecule formulaaluminum in the figure below. It shows the composition of the molecule, and how many atoms of each element are involved in the formation of one conditional molecule of the substance.
Next, you need to multiply the mass of one aluminum atom by the number of these particles in the Al molecule2(SO4)3 . This number is indicated by a subscript to the right of the aluminum symbol - 2. Multiply 2 by 27, we get 54 amu
Next, let's repeat the steps with the sulfur atom. The aluminum sulfate molecule contains three particles (SO4), which means three sulfur atoms. Multiply 32 by 3 to get 96 amu
The same calculation is made with oxygen atoms. First, let's calculate how many of them are included in the molecule. It contains three particles (SO4), that is, 12 oxygen atoms. We multiply the mass by the number of atoms - 16 by 12, we get 192 amu
The last step is to add the masses of all the constituent parts of the molecule:
54 + 96 + 192=342 amu
So, the molecular weight of aluminum sulfate is 342 amu
Next indicator
The molar mass of al2 so4 3 is the volume of one mole of aluminum sulfate. It is very easy to recognize, since it is numerically equal to the molecular weight, but is expressed in other units - g / mol.
So, the molar mass of al2 so4 3 is 342 g/mol. This value is often required to solve problems.
Molar mass equivalent
To calculate this value, you need to know the equivalence factor. It is defined differently forclasses of substances.
Aluminum sulfate belongs to the group of medium s alts. For such compounds, the equivalence factor is calculated as follows:
- You need to divide the unit by the product of the number of metal atoms and the charge of the metal.
- Find the product. There are two aluminum metal atoms in a molecule, this can be seen from the formula. The charge of aluminum is constant and equal to three, that is, 23=6.
- The aluminum sulfate s alt equivalence factor is 1/6.
To find the molar mass of aluminum sulfate equivalent, multiply its molar mass by the equivalence factor:
3421 / 6=57 g/mol.
So, the molar mass of the equivalent of Al2 (SO4) 3 is 57 g/mol.
Calculations are over, the desired value is determined.
