Finding the rate of production of O2 (g) from information given

[needingtoknow]

Homework Statement

2 KClO3 (s) + heat --> 2 KCl (s) + 3 O2 (g)

If 0.20 g of KClO3 (s) decomposes in 2.8 s, at what rate is oxygen O2 (g) released over this time at SATP?

The Attempt at a Solution

0.20 g KClO3 x 1 mol/122.5495 g = 0.001632 mol KClO3

Since 0.001632 mol decomposes in 2.8 seconds I found that 2 mol of it decomposes in 3431.37 seconds.

So then to find the rate of decomposition of KClO3 I did 2/3431.37 = 0.000583 mol/s

Now that I know the rate of decomposition of KClO3 I can find the rate of production of oxygen gas from the balanced reaction equation.

0.000583 mol/s - 2 mol
n - 3 mol

n = 0.000874 mol/s O2 (g)

The answer in the back says 22 mL/s but I have know idea how that answer was gotten. Can someone please help?

 

[needingtoknow]

Actually never mind I forgot to do one extra step with the PV = nRT, that was my error.

 

[needingtoknow]

Just a follow up question though, in a reaction such as 4 NO + 6 H2O -> 4 NH3 + 5 O2, where we know that the initial rate of NO is 0.050 mol/L*s so I tried to find the rate at which water is consumed and found it to be 0.075 mol/Ls. So if I have to explain why it is greater, I would start by saying that water is found in a greater number of moles, but we don't know the concentration though so how do know for sure that it has to have a greater rate?

 

[haruspex]

Just a follow up question though, in a reaction such as 4 NO + 6 H2O -> 4 NH3 + 5 O2, where we know that the initial rate of NO is 0.050 mol/L*s so I tried to find the rate at which water is consumed and found it to be 0.075 mol/Ls. So if I have to explain why it is greater, I would start by saying that water is found in a greater number of moles, but we don't know the concentration though so how do know for sure that it has to have a greater rate?

Doesn't the ratio of consumption follow immediately from this:

4 NO + 6 H2O​

?

 

[needingtoknow]

But how do we know how much concentrations we have of each?

 

[haruspex]

But how do we know how much concentrations we have of each?

Why does that matter? If one of the reagents is dilute, that will slow the reaction rate, but it won't alter the ratio between the quantities of the two agents consumed by the reaction.

 

[gangsta1]

Homework Statement

2 KClO3 (s) + heat --> 2 KCl (s) + 3 O2 (g)

If 0.20 g of KClO3 (s) decomposes in 2.8 s, at what rate is oxygen O2 (g) released over this time at SATP?

The Attempt at a Solution

0.20 g KClO3 x 1 mol/122.5495 g = 0.001632 mol KClO3

Since 0.001632 mol decomposes in 2.8 seconds I found that 2 mol of it decomposes in 3431.37 seconds.

So then to find the rate of decomposition of KClO3 I did 2/3431.37 = 0.000583 mol/s

Now that I know the rate of decomposition of KClO3 I can find the rate of production of oxygen gas from the balanced reaction equation.

0.000583 mol/s - 2 mol
n - 3 mol

n = 0.000874 mol/s O2 (g)

The answer in the back says 22 mL/s but I have know idea how that answer was gotten. Can someone please help?

Can you please explain how you did this question?