Can you please show work, a detailed step by step on how to solve the problems.
ID: 939970 • Letter: C
Question
Can you please show work, a detailed step by step on how to solve the problems. Thank you! State whether each of the following processes is spontaneous or nonspontaneous. transfer of heat from a block of ice to the surrounding air at 25degree degree C evaporation of a puddle of water at 80degreeC corrosion of an iron tool left outside in the garden over the weekend dissolution of sugar into hot tea decomposition of table salt, NaCl, into solid sodium metal, Na, and chlorine gas, Cl_2, at 25degreeC and 1 atm pressure raking of leaves scattered on the ground into a big pile Without doing any calculations, state whether the entropy of the system increases, decreases, or remains about the same for each of the following chemical reactions. NO_2(g)+N_2O(g)rightarrow 3NO(g) 4NH_3(g)+5O_2(g)rightarrow 4NO(g)+6H_2O(l) 2C_2H_6(g)+7O_2(g)rightarrow4CO_2(g)+6H_2O(g) Al_2O_3(s)+Fe(s) rightarrow Fe_2O_3(s)+2Al(s) CaCO_3(s)+2HCl(aq)rightarrowCaCl_2(aq)+H_2O(l)+CO_2(g) 6CO_2(g)+6H_2O(l)rightarrowC_6H_12O_6(s)+6O_2(g) H_2(g)+Cl_2(g)rightarrow2HCl(g) SO_2(g)+2H_2S(g)rightarrow3S(s)+2H_2O(g)..CaC_2(s)+2H_2O(l)rightarrowCa(OH)_2(s)+C_2H_2(g)Explanation / Answer
3)
a) nonspontaneous, ice absorbs heat in order to increase it temperature and become water.
b) spontaneous
c) spontaneous, the iron reacts with the water of the air in an oxidation - reduction reaction, that is why you can leave metal outside a long time.
d) spontaneous, sugar is a polar compound and water is too. Polar solvents dissolve polar compounds.
e) non spontaneous, Na and Cl are more stable as ions than metal and gas. When they become ions they lose and gain an electron respectively and obtain a full valence configuration, as noble gases. That is why they are so stable as ions and can´t transform into metal and gas.
f) nonspontaneous, in order to get a pile you must make an action over the leaves, they won´t form a pile by themselves.
4) In this excercise you have to look at the amount of moles of gas at each side of the equation. The entropy is about the disorder of a system, so, if there are more moles of gas there will be more disorder, let´s look the first one as an example:
a) There are 2 moles of gas at reagents and 3 at products, that means that products "have more disorder", so entropy will be, disorder of products - disorder of reagents. In this case this will be a positive number and the entropy increases.
b) In this case we have also a liquid. The liquids are not as disordered as gases. So, if we go from 9 moles of gas to 4 of gas and 6 of liquid, the entropy will decrease.
c) we go from 9 to 10 moles of gas so the entropy will be positive, it increases.
d) Here we have all solids, the disorder of solids is really low, but they are all solids, so we can apply the same method as gases, look at moles. At both sides there are 3 moles of solid, so, the entropy remains about the same.
e) Here it is abit difficult but at products we have a gas, the most disordered state, so i think entropy increases.
f) here at both sides we have 6 moles of gas, so it doesn´t matter. But we go from a liquid to a solid, so the disorder decreases, entropy decreases.
g) entropy remains about the same
h) we go from 3 moles of gas to 2 moles of gas and a solid, entropy decreases.
i) we go from a solid and liquid to solid and gas, entropy increases by the presence of the gas.
Let me know if you have any doubt! :)