Question

What is the mass of potassium chloride when 2.50 g of potassium reacts with excess of chlorine gas

Answer 1

4.52 grams of potassium chloride

Step-by-step explanation:

First you need a balanced reaction equation K(s) + Cl₂ (g) --> 2 KCl(s). Since the chlorine gas is said to be in excess all of the potassium will be converted to form potassium chloride. Convert grams of potassium to moles of potassium with the periodic table, then you can convert moles of potassium to moles of potassium chloride with the balanced equation, finally convert moles of potassium chloride to grams of potassium chloride with the periodic table. Set up a dimensional analysis chart to help with conversions

(2.50 grams K) * (1 mole K) * (2 mole KCl) * (35.45 grams KCl)

(39.09 grams K) (1 mole K) (1 mol KCl)

Which equals 4.52440778 grams, with sig figs it should be 4.52 grams of potassium chloride