Elemental sulfur is formed by the reaction of zinc sulfide with o...

Question

Elemental sulfur is formed by the reaction of zinc sulfide with oxygen: 
(b) At what temperature, if any, the reaction will become nonspontaneous?

Accepted Answer

Hello. Everyone in this video we're talking about the reaction of solid aluminum that reacts with oxygen gas to produce solid aluminum oxide. So this occasion right over here we're being asked if there's a temperature, I wish the reaction will no longer be spontaneous. And what temperature is that exactly? So let's go ahead recall that for my delta S total value. If this value is greater than zero. So if we have a positive value, this reaction is going to be spontaneous and if our delta S total is less than or equal to zero. So if our value is equal to zero or if it's a negative value, this reaction is going to be non spontaneous. So we know that my friend love for delta s total. This is equal to the delta air system plus my delta S of the surroundings. So we can go ahead and calculate for each component first and then put it all together to get the sum. So for my delta S of the system is also equal to the delta s that's given to us in the problem that's negative 6 to 6. joules per kelvin times small. And then from a delta S of the surroundings. This this has a formula of negative delta H over T. So for my delta H is equal to which is given to us to be negative 335 to kill jules per molt. Let's convert this into jewels by using a direct conversion. So for every 1000 jewels we have one, kill a jewel. You can see here for the units that killed jules will cancel. So this doctor h value then is equal to negative 3.352 times 10-6. Power unit beings jewels per mole. So now following for a temperature of when the delta S total is equal to zero. Again we have this formula here that's going to rewrite this. So the delta S total is equal to the delta S of the system, plus the delta s. Of the surroundings. Alright, so basically we have that zero is equal to negative 6 to 6.4 joules per kelvin times more. And then we're adding this with negative negative 3.352 times 10 to joules per mole is all over T. Temperature. So we're gonna go ahead and simplify this out. We'll continue the work in blue. So we have 6 to 6.4 joules per kelvin times more equaling two 3.352 times 10 to the six joules per mole is going to be all over T. For temperature. Now we go and isolate for T. This is equal to 3.352 times 10 to the six power jewels per mole. This divided by 3.35, 2 times wrong value. And the denominator. Let's go ahead and redo that part. The denominator is. We're dividing this with 6 to 6.4 jewels for Calvin times small. Go ahead, scroll down And we see here for the units saying that the jewels will cancel and the most will cancel, leaving us with just the units of Kelvin and that's exactly what we want. So once I put everything into a calculator, I get them, IT for temperature is equal to 5351. Kelvin's want to convert that into four significant figures. So my final answer for T is equal to Kelvin's. So this right here is going to be my final answer for this problem.

Elemental sulfur is formed by the reaction of zinc sulfide with oxygen: (b) At what temperature, if any, the reaction will become nonspontaneous?

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