Question

calculate the mass of potassium chlorate required to produce 35 g of potassium chloride on complete decomposition

Answer 1

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Answer: 57.55 g

Explanation

1. Write the balanced equation

$\mathbb{2KCLO_3 \rightarrow 2KCL + O_2}$

2. Calculate the atomic mass

$\rm {2[ 39 + 35.5 + (16 \times 2) \rightarrow 2(39 + 35.5) + 3(32)} \\ \rm2(39 + 35.5 + 48) \rightarrow 2 \times 74.5 + 96 \\ \rm 2 \: \times \: 122.5 \rightarrow 149 + 96 \\ \rm245 \rightarrow 245$

3. From the equation we can find that to produce 149 g of KCL we need 245 g of $\mathbb{KCLO_3}$.

Hence, 149 g of $\mathbb{KCL}$ is produced by $\large\bf{245}$ g of $\mathbb{KCLO_3}$.

1 g of $\mathbb{KCL}$ is produced by $\large \bf \frac{245}{149}$ g of $\mathbb{KCLO_3}$.

35 g of $\mathbb{KCL}$ is produced by $\large \bf \frac{245}{149} \times 35 = 57.55$ g of $\mathbb{KCLO_3}$.

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

25122.4 = 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