Magnesium reacts with iron(iii) chloride to form magnesium chloride (which can be used in fireproofing wood and in disinfectants) and iron. 3mg(s) + 2fecl3(s) → 3mgcl2(s) + 2fe(s) a mixture of 41.0 g of magnesium ( = 24.31 g/mol) and 175 g of iron(iii) chloride ( = 162.2 g/mol) is allowed to react. what mass of magnesium chloride = 95.21 g/mol) is formed?

154.0831 g

Explanation:

The formula for the calculation of moles is shown below:

Given: For

Given mass = 41.0 g

Molar mass of = 24.31 g/mol

Moles of = 41.0 g / 24.31 g/mol = 1.6865 moles

Given: For

Given mass = 175 g

Molar mass of = 162.2 g/mol

Moles of = 175 g / 162.2 g/mol = 1.0789 moles

According to the given reaction:

3 moles of Mg react with 2 moles of

1 mole of Mg react with 2/3 moles of

1.6865 mole of Mg react with (2/3)*1.6865 moles of

Moles of = 1.1243 moles

Available moles of = 1.0789 moles

Limiting reagent is the one which is present in small amount. Thus, is limiting reagent. (1.0789 < 1.1243)

The formation of the product is governed by the limiting reagent. So,

2 moles of gives 3 moles of magnesium chloride

1 mole of gives 3/2 moles of magnesium chloride

1.0789 mole of gives (3/2)*1.0789 moles of magnesium chloride

Moles of magnesium chloride = 1.61835 moles

Molar mass of magnesium chloride = 95.21 g/mol

Mass of magnesium chloride = Moles × Molar mass = 1.61835 × 95.21 g = 154.0831 g

"among the transition metal elements, manganese and zinc have a slight lowering of electronegativities. the reason behind this is that the nuclear charges of these elements are slightly weaker than the other transition metal elements due to the way their valence electrons are filled up. both manganese and zinc have their valence electrons filled up to the 4th shell with 1 pair of electrons (4s2) completely occupying it. although the electrons in the 3rd shell (3d) are yet to be paired since the outer most shell is filled up, the ability of the nucleus to attract electrons is lessened. hence,   the electronegativity (or the ability to attract electrons) is lessened."