1.7 simple equilibrium and acid base reactions

Question 1

reversible reaction

Answer 1

a chemical reaction in which the products re-form the original reactants

Question 2

Equilibrium

Answer 2

Forward reaction is equal to backwards reaction

Question 3

Dynamic equilibrium

Answer 3

Rate of reactants being converted into products and back into reactants is constant

Question 4

Le Chatelier’s Principle

Answer 4

If a change is made to a system in chemical equilibrium, the equilibrium shifts to oppose the change until a new equilibrium is reached

Question 5

3 factors affecting equalibrium

Answer 5

Temp

Concentration

Pressure

Question 5

How does decreasing temperature affect equilibrium position

Answer 5

Favour the exothermic reason so equilibrium shifts towards products of the exothermic reaction

Question 6

How does increasing temperature affect equilibrium position

Answer 6

Increasing the temperature would favour the endothermic reaction, so the equilibrium will shift towards the products of the endothermic reaction.

Question 7

How does increasing pressure affect equilibrium position

Answer 7

Favours side of the reaction with fewer moles of gas so position of equilibrium will move to that side

Question 8

How does increasing concentration of the reactants affect the position of equilibrium

Answer 8

Equilibrium will shift to the right to increase the concentration of the products.

Question 9

How do you work out units for Kc

Answer 9

Substitute units into the expression for Kc

Cancel common units and show the final units on a single line

Question 9

What’s Kc

Answer 9

Equilibrium constant.

Question 10

What effects Kc

Answer 10

only temperature

Question 10

Calculations for Kc

Answer 10

Kc= (C)c (D)d/ (A)a (B)b

Question 11

Acid

Answer 11

proton (H+) donor

Question 12

Base

Answer 12

proton (H+) acceptor

Question 13

Concentrated acid

Answer 13

An acid solution where there is a relatively large acid to water ratio

Question 14

Dilute acid

Answer 14

Lots of water, small amount of acid in a given volume

Question 14

Strong acid

Answer 14

fully dissociates in a solution

Question 15

weak acid

Answer 15

partially dissociates in a solution

Question 16

Apparatus needed for titration

Answer 16

H+= 10-^pH

Question 16

PH scale

Answer 16

Expresses the acidity or alkalinity of a substance on a scale from 0-14 where 7 is neutral

Measuring hydrogen ions in a concentration.

Question 17

How do you calc pH of a strong acid

Question 18

Describe how to carry out a simple titration

Answer 18

• add acid to burette and use pipettes to add 25cm3 of alkali to a conical flask

2. Add few drops of indicator in conical flask
3. Record initial burette reading and slowly add acid to conical flask whilst swirling

4.when solution in conical flask changes colour to clearer stop adding acid and record final volume

5.calc total volume of acid added from burette.