consider the following reaction at 298K

4Al(s)+3O2(g) yields 2Al2O3(s)
delta H= -3351.4 Kj
find delta S sys
find delta S surr
find delta S unvi

DS System= -627J/K

DS Surr=11246J/K
DS Uni= 10619 J/K

Just got this right on sapling!

Thankyou

dSsys = (n*dS products) - (n*dS reactants)

dSsurr = -dH/T
dSuniv = dSsurr + dSsys
Note: dH in kJ/mol but dS usually in J/mol. keep the units straight.

How would I do it DrBob222 . I keep getting the wrong answer.I also don't even know what you notations mean

Well, well, well... looks like we've got ourselves a chemical reaction to analyze! Let the funny calculations begin!

First things first, let's find the delta S sys, which represents the change in entropy of the system. To do that, we need to know the number of moles of gas on both sides of the reaction. The reactants have 3 moles of gas (O2), while the product (Al2O3) has no gas molecules. So, the delta S sys would be negative. But hey, nobody likes negativity, right?

Moving on to delta S surr, which represents the change in entropy of the surroundings. Now, this reaction involves gas molecules, so it must be pretty chilly in the surroundings. The reaction is an exothermic one (delta H is negative), so the surroundings must be feeling toasty. What does this mean for delta S surr? It means it's positive!

Finally, let's tackle delta S unvi, which represents the change in the universe's entropy. We can calculate this by adding delta S sys and delta S surr together. Since both the values have different signs, it's like adding a negative and a positive value. The result? Well, it depends on the magnitude of the two values. The delta S sys is negative (a.k.a. smaller), while delta S surr is positive (a.k.a. bigger). So, the net delta S unvi will be positive!

And there you have it! Delta S sys, delta S surr, and delta S unvi for this reaction. Hope you enjoyed this little chemistry comedy show!

To find the values of ΔSsys (change in entropy of the system), ΔSsurr (change in entropy of the surroundings), and ΔSuniv (change in total entropy), we need to determine the change in entropy for each component involved in the reaction.

First, let's start with ΔSsys, which represents the change in entropy of the system. This can be calculated using the equation:

ΔSsys = ΣnS(products) - ΣmS(reactants)

Where n represents the stoichiometric coefficient of the products and m represents the stoichiometric coefficient of the reactants.

In the given reaction:
4Al(s) + 3O2(g) → 2Al2O3(s)

The change in entropy for this reaction can be calculated as:

ΔSsys = 2S(Al2O3) - 4S(Al) - 3S(O2)

To find the entropy values, we need to consult a thermodynamic data table or use standard entropy values for each species involved in the reaction.

Next, let's find ΔSsurr, the change in entropy of the surroundings. In this case, the reaction involves the combustion of aluminum, which generates heat. Since the process occurs at constant temperature, the change in entropy of the surroundings can be calculated using the equation:

ΔSsurr = -ΔH / T

Where ΔH is the enthalpy change of the reaction and T is the temperature in Kelvin.

Finally, we can calculate ΔSuniv (the overall change in entropy) using the equation:

ΔSuniv = ΔSsys + ΔSsurr

Plugging in the values obtained for ΔSsys and ΔSsurr will give us the total entropy change for the system.