H 2 O forms a bent structure; CH 4 and NH 4 + are tetrahedral.47 . A
To determine the order of the reaction, compare a change in reactant concentration to the
corresponding change in rate. In this case, when the reactant concentration [A] is doubled, the
rate increases by a factor of 4, so the reaction is second order in A:
rate = k [A]^2
To determine the rate constant, choose the data of one experiment to put into the rate
equation. Since you don’t have a calculator, the easiest math will come from using the
experiment in which [A] = 1.00 M:Then put it all together:rate = 5.44 × 10^3 [A]^248 . E
When a gaseous system at equilibrium is compressed, the equilibrium shifts toward the side
with fewer moles of gas, to partially relieve the stress on the system; in this case, the reaction
goes to the right, producing more moles of CH 3 OH and consuming CO and H 2 . Note that while
moles of CO and H 2 will decrease, their partial pressures will still be higher after compression
than before. C is simply false—the equilibrium constant never changes unless the temperature
changes.
49 . C
In a redox reaction, two or more elements experience a change in oxidation number. Here, Al
changes from 0 to +3 and H changes from +1 to 0. The formation or destruction of pure
elements (in this case, Al (s) and H 2 (g)) is a big clue that a redox reaction has occurred.
Combustion reactions involve O 2 as a reactant, and precipitation reactions have a solid
product forming from an aqueous solution. In acid-base reactions, the oxidation numbers of
elements don’t generally change; H+ is passed around as H+.