Answer to Question #60111 in Physical Chemistry for joseph orobiyi

Question

1 The temperature remains constant as energy is added to a substance.
How may the substance be changing?
From a gas to a solid
From a liquid to a solid
From a liquid to a gas
Change in the amoung of kinetic energy



2 Which process is exothermic?
the boiling of liquid nitrogen
the freezing of water
the sublimation of dry ice
the vaporization of water



3 What does it mean if the ΔH value for a chemical reaction is positive?
kinetic energy is increasing in the system
Potential energy is decreasing in the system
products have less potential energy than reactants
reactants have less potential energy than products.



4 Use the equations to answer the question. $2A + B \rightarrow A_2B$
$\DeltaH$ = –217.3 kJ; $B + C \rightarrow BC$ $\DeltaH$ = –867.5 kJ.
What is the value of $\DeltaH$ for the reaction $2A + BC \rightarrow
A_2B + C$?
1084.8 kJ
650.2 kJ
–650.2 kJ
–1084.8 kJ