Question

If we mix 25 grans if sodium oxide with a large amount of potassium chloride, how many grams of sodium chloride should be produced?

Answer 1

Answer:

47.2 g

Explanation:

Data given:

mass of Sodium oxide (Na₂O) = 25 grams

mass of potassium chloride (KCl) = excess

amount of sodium chloride (NaCl) = ?

Solution:

First we look for reaction of sodium oxide with potassium chloride.

                    Na₂O + 2 KCl -----------> 2 NaCl + K₂O

As we know that potassium chloride is in excess amount and sodium oxide is 25 g so it means sodium oxide is a limiting reactant and amount of sodium chloride depends on the amount of sodium oxide.

So, now we will look for mole mole ration of Na₂O to NaCl.

                    Na₂O + 2 KCl -----------> 2 NaCl + K₂O

                    1 mol                              2 mol

from above equation we come to know that 1 mole of Na₂O gives 2 moles of NaCl.

Now convert moles to mass

As we Know

Molar mass of Na₂O = 2(23) + 16 = 62 g/mol

Molar mass of NaCl = 23 + 35.5 = 58.5 g/mol

So

                  Na₂O              +   2 KCl    ----------->      2 NaCl          +      K₂O

             1 mol (62 g/mol)                                   2 mol (58.5 g/mol)

                  62 g                                                          117 g

So, it means that 62 g of Na₂O produce 117 g of NaCl then how many grams of NaCl will be produce by 25 g of Na₂O

Apply unity formula

                           62 g of Na₂O ≅ 117 g of NaCl

                           25 g of Na₂O ≅ X g of NaCl

Do cross multiplication

                          X g of NaCl = 117 g x 25 g / 62 g

                          X g of NaCl = 47.2 g

So,

25 g of Na₂O gives 47.2 grams of NaCl.