A mixture containing potassium chlorate, potassium bicarbonate, potassium carbonate, and potassium chloride was heated, producing CO2, O2, and H2O......gases. Potassium chlorate --> potassium...

A mixture containing potassium chlorate, potassium bicarbonate, potassium carbonate, and potassium chloride was heated, producing CO2, O2, and H2O...

...gases.

Potassium chlorate --> potassium oxide + oxygen gas

Potassium bicarbonate --> potassium oxide + H2O + carbon dioxide

potassium carbonate --> potassium oxide + carbon dioxide

 

The potassium chloride does not react under the conditions of the reaction. If 100.0g of the mixture produces 1.8g water, 13.2g of carbon dioxide and 4.0g of oxygen gas, what is the composition of the original mixture? (Assume complete decomposition of the mixture)

*use chemical equations in formula writing

Asked on by spock8

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cgrant2 | High School Teacher | (Level 1) Valedictorian

Posted on

*KCl has to be included in the equation of potassium chlorate in order to be a valid equation. I am going to add this to the problem below: 

1.We need to balance the equation to figure out how many moles there are of each reagent: 

2KClO3 ----> 2KCl + 3O2

K2CO3 ------> K2O + H2O + 3CO2 

2KHCO3 -----> K2O + CO2 

2. Then, you need to find the moles of the products from the masses given in the problem: 

1.8g = H20 

13.2g = CO2 

4.0g = O2 

moles of H20 =  1.80g x 18.0g/mole = 0.100moles 

moles of CO2 = 13.2g x 44.01g/mole = 0.299moles 

moles of O2 = 4.0g x 32.00g/mole = 0.125moles 

3. Then use the moles from the balanced equation and the molecular weight of each reactant to figure out the grams of the reactants: 

KClO3 creates 3 moles of O2 so you have to consider that in the equation:  

.125moles of O2 x 2 moles of KClO3/produced 3 moles of O2 = 0.0833moles of KClO3 

0.0833moles x 122.55g/mole = 10.2g 

K2CO3 creates 2 moles of CO2 

.300moles of CO2 reacted -.200moles CO2 produced= 0.100 moles used 

K2CO3= 0.100moles x 138.205g/mole = 13.8g

KHCO3 = 0.200moles  x 100.115g/mole = 20.0g 

KCl = 100g - 10.2g - 13.8g - 20.0g = 56.0g 

Answer: 

KClO3 = 10.2g 

K2CO3 = 13.8g

KHCO3 = 20.0g 

KCl = 56.0g 

 

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