LeChartlier's principle

Question 1

What is Le-Chartelier’s principle?

Answer 1

When a chemical system at equilibrium is disturbed, the system shifts in a direction that minimized the disturbance

Question 2

What are some ways that can cause disturbance in a chemical system?

Answer 2

Changing concentration, volume, pressure, or temperature.

Question 3

Increasing the [] of one or more reactants or decreasing the [] of one or more products makes the rxn move to the…

Answer 3

Right

Question 4

Increasing the [] of one or more products or decreasing the [] of one or more reactants makes the rxn move to the…

Answer 4

Left

Question 5

What happens when there is a change in volume? Are the two factors directly or inversely related?

Answer 5

There will also be a change in pressure and they are inversely related

Question 6

In a gaseous system, if we _______ the pressure, we ________ volume, and that will lead the rxn to move _______ to the side with less moles of gas.

Answer 6

Increase, decrease, forward

Question 7

Decreasing the volume causes the reaction to

Answer 7

Shift in the direction with fewer moles of gas particles

Question 8

Increasing the volume causes the reaction to

Answer 8

Shift in the direction that has a greater number of moles of gas particles

Question 9

If a reaction has an equal number of moles of gas on both sides of the chemical reaction

Answer 9

A change in volume will cause no effect

Question 10

The equilibrium constant changes with a change in volume

Answer 10

False, it does not change. Changes in quilibrium usually cause a change in Q, not K

Question 11

More reactants and fewer products leads to a

Answer 11

smaller value of K

Question 12

What happens if we decrease the temperature of an exothermic reaction in terms of equilibrium a value of KC?

Answer 12

The reaction will shift right because we are releasing some of the heat and that will cause a larger value of Kc

Question 13

In an exothermic reaction _______ the temperature makes it to shift to the left (in the direction of reactants), and the value of equilibrium constant ________; therefore, __________ the temperature causes the reaction to ________ (towards the products) and the value of the equilibrium constant ____________.

Answer 13

Increasing, decreases; decreasing, increases

Question 14

In an endothermic reaction _______ the temperature makes it to shift to the left (in the direction of reactants), and the value of equilibrium constant ________; therefore, __________ the temperature causes the reaction to ________ (towards the products) and the value of the equilibrium constant ____________.

Answer 14

decreasing, decreases; increasing, shift to the right, increases

Question 15

What is the effect of adding an acid to a chemical reaction with OH?

Answer 15

The acid would react with OH to form H2O, shifting the reaction to the right to compensate

Question 16

Regarding the rxn:

2 CrO4^-2(aq – yellow) + 2 H3O⁺¹ ⇔ Cr2O7^-2(aq - orange) + 2 H2O (l)

Adding more HCl will cause what?

Answer 16

HCl will react with the base producing H2O, making the reaction move to the right to compensate, leading it to become more red

Question 17

Regarding the rxn:

2 CrO4^-2(aq – yellow) + 2 H3O⁺¹ ⇔ Cr2O7^-2(aq - orange) + 2 H2O (l)

Adding more NaOH will lead to…

Answer 17

The reaction shifting to the left, turning more yellow