which of the following absorbs hear from the surroundings as it proceeds to completion?
1. CO(g)+1/2 O2 (g)=CO2 (g)
2.AL2O3(s)=2 Al(s) + 3/2 O2 (g)
3.SO3 (g) + 99.2kJ=S (s)+3/2 O2 (g)
Hrxn = -283.0 kj (endothermic)
To determine which of the reactions absorbs heat from the surroundings as it proceeds to completion, we need to look at the enthalpy change (∆H) of each reaction.
1. CO(g) + 1/2 O2 (g) = CO2 (g)
In this reaction, carbon monoxide (CO) reacts with oxygen (O2) to form carbon dioxide (CO2). We need to find the enthalpy change for this reaction (∆H). Unfortunately, the equation does not provide any information about the enthalpy change (∆H), so we cannot determine if it absorbs or releases heat from the surroundings.
2. AL2O3(s) = 2 Al(s) + 3/2 O2 (g)
In this reaction, aluminum oxide (Al2O3) decomposes to form aluminum (Al) and oxygen (O2). Again, the equation does not provide any information about the enthalpy change (∆H), so we cannot determine if it absorbs or releases heat from the surroundings.
3. SO3 (g) + 99.2 kJ = S (s) + 3/2 O2 (g)
In this reaction, sulfur trioxide (SO3) reacts to yield sulfur (S) and oxygen (O2), and it absorbs 99.2 kJ of heat. The equation explicitly states that 99.2 kJ of heat is absorbed, indicating an endothermic reaction (absorbing heat from the surroundings).
Therefore, the reaction that absorbs heat from the surroundings as it proceeds to completion is reaction 3: SO3 (g) + 99.2 kJ = S (s) + 3/2 O2 (g).