General Chemistry Answers

Ethanoic acid and ethanol react reversibly to form ethyl ethanoate and    water. In a closed system, a dynamic equilibrium is set up.

         Ethanoic acid + ethanol   ⇌   ethyl ethanoate

(i)This reaction is fairly slow, and is usually done in the presence of a small amount of concentrated sulphuric acid as a catalyst to speed it up. What effect would that have on the percentage of ethanoic acid converted into ethyl ethanoate? Explain your answer.

(ii)  If a lot of ethyl ethanoate was needed, why would it be a bad idea to use dilute sulphuric acid as the catalyst?

So I am learning about standard cell potential E°, and my question is that in a reaction of redox reaction there is a E° and usually the reaction is reversible and so if it is reversible does the value of E° change to positive or negative if we reversed the reaction?

Calculate the ΔH for the reaction 4 NH3 (g) + 5 O2 (g) --> 4 NO (g) + 6 H20 (g), from the following data.

1) N2 (g) + O2 (g) --> 2 NO (g) ΔH= -180.5 kJ  

2) N2 (g) + 3 H2 (g) --> 2 NH3 (g) ΔH= -91.8 kJ  

3) 2 H2 (g) + O2 (g) --> 2 H2O (g) ΔH= -483.6 kJ

Direction:Solve the following items. Show complete solution.Express all enthalpy changes to kilojoules.

Use the data below to calculate ΔH°rxnfor the reaction MgO(s)+ CO2(g) àMgCO3(s). 

ΔH°f: MgO(s)= -602 kJ mol^-1, CO2(g)= -394 kJ mol^-1 and MgCO3(s)= -1096 kJ mol^-1

Direction:Solve the following items. Show complete solution.Express all enthalpy changes to kilojoules.

2C8H18(l) + 25O2(g) →16CO2(g) + 18H2O(l) .Calculate the heat of combustion of octane using the supplied heat of formation data. Data: C8H18(l): –249.9 kJ mol^–1; CO2(g): –393.5 kJ mol^–1; H2O(l): –285.8 kJ mol^–1

Direction:Solve the following items. Show complete solution.Express all enthalpy changes to kilojoules.

Use the standard enthalpies given below to calculate the enthalpy change for this reaction.

C5H12 = 6352kJ/mol; CO2(g) = 1608kJ/mol; H2O(g)= 926.0kJ/mol

The reaction: C5H12+ 8O2à5CO2+ 6H2O

If you want to change the type of element your atom is, you can either:

If you want to change the charge of your atom, you can either:

If you want to change the mass of your atom, you can either:

a.      The nutritional information for a candy bar states that one serving contains 11.0 g of fat and 100 Cal from fat (1 Cal =1 kcal). Is this information consistent with your answer in part (c)?

Determine how many moles ofO

2

O

2

 are required to react completely with 4.2 mol

m

o

l

 of C

4

H

10

C

4

H

10

.