Physical Chemistry Answers

Which of the following statements are correct?

I)The enthalpy of formation of an element is zero by definition

II)The enthalpy of combustion of an element is zero by definition

III)The enthalpy change of reaction is the heat change at constant pressure

IV) According to Hess’s law the enthalpy change for a chemical reaction is the same, whatever route is taken from reactants to products

A.     I)

B.     I) and II)

C.     II), III) and IV)

D.     All of the statements are correct

1.If the cost of electricity required to discharge 10g of an ion X3+3+ is N20.00, how much would it cost to discharge 6g of ion Y2+2+?

[1 faraday = 96,500C, atomic masses are X = 27, Y = 24]

2. The cost of discharging 6.0g of a divalent metal, X from its salt is ₦12.00. What is the cost of discharging 9.0g of a trivalent metal, Y from its salt under the same condition?

[X = 63, Y = 27, 1F = 96,500C]

weight of fuel .98g carbon 90 and hydrogen 8 what is gross calorific vlue and net calorific value whentemprature rise is 1.8 aadnwater eq 450 on assignment.com

an iron (39.1-g) at 79°c is quickly placed to 100 ml of water initially at 24°c. after a few minutes, both the metal and the water have reached 26°c. calculate the specific heat of iron

What would be the pH of a solution in which the molar ratio of propanoic acid: sodium propanoate is 1:10 ka for propanoic acid is 1.34×10^-5 mol/dm^3

By considering a solution containing both propanoic acid and sodium propanoate, explain how a buffer sln functions

Which of the following statements are correct?

I)The enthalpy of formation of an element is zero by definition

II)The enthalpy of combustion of an element is zero by definition

III)The enthalpy change of reaction is the heat change at constant pressure

IV) According to Hess’s law the enthalpy change for a chemical reaction is the same, whatever route is taken from reactants to products

A.     I)

B.     I) and II)

C.     II), III) and IV)

D.     All of the statements are correct

Explain what Is meant by a buffer solution

What is the dissociation constant Ka of an acid

In the above question, what is the value of the rate constant if[A]0=0.35 M ?P