Consider the reaction H2(g) + I2(g) <-> HI(g) with an equilibrium constant of 46.3 and a reaction quotient of 525. Which direction will the system shift to?

The equilibrium will shift to the left to favor the reactants.

The equilibrium will shift to the right to favor the products.

The equilibrium will not shift in any direction.

The equilibrium will shift to the forward reaction.

Answer : The correct option is, The equilibrium will shift to the left to favor the reactants.

Explanation :

Reaction quotient (Q) : It is defined as the measurement of the relative amounts of products and reactants present during a reaction at a particular time.

The given balanced chemical reaction is,

The expression for reaction quotient will be :

In this expression, only gaseous or aqueous states are includes and pure liquid or solid states are omitted.

The given reaction quotient value is,

The given equilibrium constant value is,

Equilibrium constant : It is defined as the equilibrium constant. It is defined as the ratio of concentration of products to the concentration of reactants.

There are 3 conditions:

When that means product > reactant. So, the reaction is reactant favored.

When that means reactant > product. So, the reaction is product favored.

When that means product = reactant. So, the reaction is in equilibrium.

From the above we conclude that, the that means product > reactant. So, the reaction is reactant favored that means reaction must shift to the reactant (left) to be in equilibrium.

Hence, the correct option is, The equilibrium will shift to the left to favor the reactants.

1. the question asks the most appropriate, which seems to rule out "all of the above." your choice appears to be the correct one.

2. the protocol described is good for identifying correlation, but not cause and effect. for cause/effect, you need to devise a protocol that will assign the treatment (or not) to groups that have essentially the same "demographics" with respect to all the other variables. your choice regarding control group seems appropriate. random assignment of treatment (choice d) may be appropriate also. (i think you can argue that b and d are just different descriptions of the same method.)

3. d will randomize the birds, but may not guarantee there are 10 in each group. e will do both, so seems the better choice.

comment on question 2

based on the problem statement, it seems clear that confident, attentive drivers are more likely to use daytime running lights. so, the protocol might need to be devised in such a way that the lights would be turned on or off without the driver's knowledge. (an attentive driver will figure it out.) assigning a confident, attentive driver to a group required to drive without running lights might mess with his/her confidence and attentiveness. you don't want your experiment to do that. (nor do you want the experiment to subject a driver to greater risk of accident as a consequence of driving without running lights.) experiments involving human safety are always problematic.