# Strong and weak acids and pH

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• Created by: J.E.C.
• Created on: 01-05-14 16:18
The Bronsted-Lowry theory describe acids as...? As a result ___ ions can be produced in aqueous solution?
H+ donors. Oxonium H3O+
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Strong acids have a strong tendancy to...?
Donate H+. (Reaction goes to completion)
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HA (aq) -->
H+ (aq) + A- (aq)
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A weak acid, has a weaker tendency to donate H+ and its reaction with water does not...?
Go to completion
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The more the equilibrium lies to the right for a weak acid, the ___ the acid?
Stronger
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The solution of carbon dioxide in water is sometimes represented by...?
H2CO3 (aq)
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pH is a measure of the...? It is defined as...?
Power of H+ in solution. -lg[H+(aq)]
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Acids have a pH of __ than 7 and alkalis have a pH of ___ than 7? A low pH corresponds to a __ concentration of [H+]?
Less, more. High
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How would you get an accurate, numerical value for pH?
Use a glass electrode connected to a spcially calibrated pH meter.
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Because with strong acids the reaction goes to completion, the amount in moles of H+ (aq) is essentially equal to...?
Amount in moles of acid put into solution
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For weak acids we write an equilibrium constant, which is known as the __ __ with the symbol __?
Acidity constant Ka
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When working out [H+] of a weak acid, what 2 assumptions can we make?
1. [H+] = {A-] Because water produces far fewer H+ ions than most weak acids. 2. Amount of HA at equilibrium = amount of HA put into solution - can neglect small fraction of HA which has lost H+
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If an acid is diluted by a factor of 100, a strong acid becomes __ times __ and its pH increases by __?
100, smaller, 2.
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If a weak acid is diluted by a factor of 100, [H+] becomes __ times __ and its pH __ by __?
10, smaller, increases, 1
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Concentration is a measure of ? Strength is a measure of...?
The amount of substance in a given volume of solution. The extent to which an acid can donate H
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pKa = . A smaller pKa value indicates...?
-lgKa. Greater acid strength
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When water ionises it behaves as...?
An acid and a base
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Kw =
[H+ (aq)] [OH- (aq)] Kw = ionic product of water
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Ionisation of water is an __ reaction, and le chatelier's principle would predict that Kw would __ with increasing temperature?
Endothermic, increase
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An acidic solution is defined as one in which...?
[H+] > [OH-]
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A strong acid has a much higher ___ ____ than a weak as of equivalent ____?
Electrical conductivity, concentration
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A weak acid of the same concentration, reacts more __ than a strong acid due ?
Slowly, there being relatively few H+ ions available to react in the weak acid.
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If a weak acid and a strong acid were to react with excess magnesium, there would be the same amount of hydrogen produced at the end of both reactions, explain why?
Some weak acid molecules react with water to form ions, producing more H+, which then react.
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Both strong and weak acids would ___ equal amount of alkali?
Neutralise
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## Other cards in this set

### Card 2

#### Front

Strong acids have a strong tendancy to...?

#### Back

Donate H+. (Reaction goes to completion)

HA (aq) -->

### Card 4

#### Front

A weak acid, has a weaker tendency to donate H+ and its reaction with water does not...?

### Card 5

#### Front

The more the equilibrium lies to the right for a weak acid, the ___ the acid?