Question

how many grams of oxygen are produced if 25.0g of potassium chlorate decomposes according to the reaction 2KCLO3 —-> 2KCL +3O2

Answer 1

Answer:

9.79g of O2

Explanation:

So this question you are trying to go from g of KCLO3 to grams of oxygen. There is no direct conversion so you have to utilize multiple process.

$25.0g KCLO3 * \frac{1mol KCLO3}{122.55 gKCLO3} * \frac{3mol O2}{2 mol KCLO3} * \frac{32.00g O2}{1mol O2}$

=9.79 g of O2

So first you go from g of KCLO3 to moles of KCLO3  by using molar mass of KCLO3. Then you use mol:mol ratio from balanced equation to go to moles of O2, and finally use molar mass of O2 to go to grams of O2.

Answer 2

Answer:

approximately 15.1 grams.

Explanation:

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

Hope it helps :)