A sample of iron weighing 15.0 g was heated with potassium chlorate (KClO3) in an evacuated container. The oxygen generated from the decomposition of KClO3 converted some of the Fe to Fe2O3. If the combined mass of Fe and Fe2O3 was 17.9g,calculate the mass of Fe2O3 formed and the mass of KClO3 decomposed.

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To solve this problem, we can use the principle of conservation of mass, which states that mass is not created or destroyed during a chemical reaction.

Let's denote the mass of Fe2O3 formed as x g and the mass of KClO3 decomposed as y g.

According to the problem, the total mass of Fe and Fe2O3 formed is 17.9 g. Therefore, we can write the equation:

Mass of Fe + Mass of Fe2O3 = 17.9 g

Now, we know that the initial mass of Fe is 15.0 g. So, we can rewrite the equation as:

15.0 g + x g = 17.9 g

By rearranging the equation, we find:

x g = 17.9 g - 15.0 g
x g = 2.9 g

Therefore, the mass of Fe2O3 formed is 2.9 g.

Next, since Fe2O3 is formed from the oxygen released by the decomposition of KClO3, we can assume that the molar ratio between Fe2O3 and KClO3 is 1:3. This means that for every 3 moles of KClO3 decomposed, 1 mole of Fe2O3 is formed.

To determine the mass of KClO3 decomposed, we need to calculate the moles of Fe2O3 formed and then use the molar ratio to find the moles of KClO3.

The molar mass of Fe2O3 is:
2(55.85 g/mol) + 3(16.00 g/mol) = 159.70 g/mol

Using the molar mass, we can calculate the moles of Fe2O3 formed:

moles of Fe2O3 = mass of Fe2O3 / molar mass of Fe2O3
moles of Fe2O3 = 2.9 g / 159.70 g/mol

Now, we can use the molar ratio to find the moles of KClO3 decomposed:

moles of KClO3 = moles of Fe2O3 * (3 moles of KClO3 / 1 mole of Fe2O3)

Finally, we can calculate the mass of KClO3 decomposed using the molar mass of KClO3:

mass of KClO3 = moles of KClO3 * molar mass of KClO3

Note: Make sure to use the correct molar masses for each element involved.

Please provide the molar masses of Fe and KClO3 so that I can proceed with the calculations.

To calculate the mass of Fe2O3 formed and the mass of KClO3 decomposed, we can follow these steps:

Step 1: Find the mass of Fe2O3 formed
We know that the combined mass of Fe and Fe2O3 is 17.9g. Let's assume the mass of Fe2O3 formed is x grams. Therefore, the mass of Fe can be calculated as (17.9 - x) grams.

Step 2: Calculate the number of moles of Fe and Fe2O3
The molar mass of Fe is 55.85 g/mol, and the molar mass of Fe2O3 is 159.69 g/mol. We can use these molar masses to calculate the number of moles of Fe and Fe2O3 formed.

Number of moles of Fe = mass of Fe (in grams) / molar mass of Fe
Number of moles of Fe2O3 = mass of Fe2O3 (in grams) / molar mass of Fe2O3

Step 3: Determine the molar ratio between Fe and Fe2O3
By balancing the chemical equation for the reaction between Fe and Fe2O3, we find that the molar ratio between Fe and Fe2O3 is 4:1, meaning that for every four moles of Fe used, one mole of Fe2O3 is formed.

Step 4: Calculate the moles of Fe that reacted
Since the molar ratio is 4:1 and we know the number of moles of Fe2O3 formed, we can calculate the number of moles of Fe that reacted by dividing the moles of Fe2O3 by 4.

Step 5: Calculate the mass of KClO3 decomposed
To find the mass of KClO3 decomposed, we should realize that the moles of KClO3 decomposed will be the same as the moles of Fe reacted because they have a 1:1 molar ratio.

Mass of KClO3 decomposed = Number of moles of KClO3 × Molar mass of KClO3

By following these steps, we can find the mass of Fe2O3 formed and the mass of KClO3 decomposed.