How many grams of potassium chloride are produced if 25.0g of potassium chlorate decompose?

The key to chemistry is to change everything to moles. Then when you have the answer in moles change the answer back to grams, liters, or whatever you want.

change 25 grams of potassium chlorate to moles.

calculate the gram molecular mass of potassium chlorate.

Chlorate is Cl with 3 oxygens. ate = saturated. Chlorine has seven valance electrons when it is saturated six of these electrons are used by oxygen ( 2 electrons per oxygen) leaving only 1 electron.

1 K x 39 grams/mole
+1 Cl x 35.4 grams/ mole
+3 O x 16 grams/ mole
= 122.4 grams / mole Potassium Chlorate

#25 /122.4# = moles.

2.05 moles of Potassium Chlorate.

There is a 1:1 mole ratio. 1 mole of Potassium Chlorate will produce 1 mole of Potassium Chloride.

2.05 moles of Potassium Chlorate will produce 2.05 moles of Potassium Chloride.

Find the gram molecular mass of Potassium Chloride.

1 K x 39 = 39
+1 Cl x 35.4 = 35.4
= 74.4 grams / mole.

2.05 moles x 74.4 grams/ mole = 15.2 grams

1. Write the balanced equation.

#"2KClO"_3 → "2KCl" + "3O"_2#

2. Calculate the moles of #"KClO"_3#.

#"Moles of KClO"_3 = 25.0 color(red)(cancel(color(black)("g KClO"_3))) × ("1 mol KClO"_3)/(122.55 color(red)(cancel(color(black)("g KClO"_3)))) = "0.2046 mol KClO"_3"#

3. Calculate the moles of #"KCl""#.

#"Moles of KCl" = 0.2046 color(red)(cancel(color(black)("mol KClO"_3))) × ("2 mol KCl")/(2 color(red)(cancel(color(black)("mol KClO"_3)))) = "0.2046 mol KCl"#

4. Calculate the mass of #"KCl"#.

#"Mass of KCl" = 0.2046 color(red)(cancel(color(black)("mol KCl"))) × ("74.55 g KCl")/(1 color(red)(cancel(color(black)("mol KCl")))) = "15.3 g KCl"#