A scientist produces zinc iodide (Znl2).
(a) Calculate the minimum mass of zinc that needs to be added to 0.500 g of iodine so that
the iodine fully reacts.
The equation for the reaction is:
Zn + I2 – ZnI
Relative atomic masses (Mr): Zn = 65 I = 127

1.24g

Explanation:

Given parameters:

Mass of titanium (IV) chloride  = 4.6g

Unknown:

Mass of oxygen  = ?

Solution:

To solve this problem, we need to write the balance reaction equation first;

                TiCl₂   +   O₂    →    TiO₂     +   Cl₂

Now to find the mass of the oxygen gas,

Express the given mass of the known TiCl₂ in moles:

         Number of moles of TiCl₂  =

  Molar mass of TiC₂  = 47.9 + 2(35.5) = 118.9g/mol

    Number of moles of TiCl₂   =   = 0.04mole

From the reaction equation;

        1 mole of TiCl₂  reacted with 1 mole of oxygen gas

       0.04 mole of TiCl₂ will react with 0.04 mole of oxygen gas

Mass of oxygen gas  = number of moles x molar mass

              molar mass of oxygen gas  = 2(16) = 32g/mol

  Mass of oxygen gas  = 0.04 x 32  = 1.24g