Deck 5: Energy From Combustion

Question 1

Consider these three compounds. Which are isomers?

A)I and II only
B)II and III only
C)I and III only
D)I,II,and III

Answer 1

I and III only

Question 2

The following molecules contain only single bonds. NH₃(g) + 3F₂(g) $\rarr$ NF₃(g) + 3 HF(g)The bond energies are: N - H 391 kJ/mol;F - F 158 kJ/mol;N - F 272 kJ/mol;H - F 566 kJ/mol.Which is the heat evolved or absorbed per mole of NH₃ that reacts with F₂?

A)+289 kJ/mol
B)+867 kJ/mol
C)-289kJ/mol
D)-867 kJ/mol

Answer 2

-867 kJ/mol

Question 3

The heat energy released or absorbed by a chemical reaction is generally determined by the difference between the energy that

A)must be put in to break the bonds in the reactants and the energy that must be put in to make the bonds in the products.
B)must be put in to break the bonds in the reactants and the energy that is released upon making the bonds in the products.
C)is released upon breaking the bonds in the reactants and the energy that must be put in to make the bonds in the products.
D)is released upon breaking the bonds in the reactants and the energy that is released upon making the bonds in the products.

Answer 3

must be put in to break the bonds in the reactants and the energy that is released upon making the bonds in the products.

Question 4

Consider these three compounds. Which are isomers?

A)I and II only
B)I and III only
C)II and III only
D)I,II,and III

Question 5

A calorie is defined as exactly 4.184 J.Therefore 1.000 Cal is exactly

A)41.84 J.
B)418.4 J.
C)1000 J.
D)4184 J.