Acids and Bases Flashcards by Eryk Blicharz

What is a Bronsted-Lowry Acid?

A proton donor

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What is a Bronsted-Lowry Base?

A proton acceptor

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What does an Acid + Hydroxide produce?

Salt and water
e.g. CH3COOH(aq) + NaOH(aq)  NaCH4COO(aq) + H2O(l)

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What does a metal oxide and acid produce?

Salt and water

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What do acids and ammonia react to produce?

A salt
e.g. HCl(aq) + NH3 (aq)  NH4Cl(aq)

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What do acids and carbonates produce?

Salt, water, Carbon dioxide

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What do acids and hydrogen carbonates produce?

Salt, water, Carbon dioxide

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State the color of Universal indicator at pH: 0, 4, 7, 10, 14

0 - red
4 - orange
7 - green
10 - blue
14 - purple

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What does it mean if a substance is strong?

completely dissociated into ions

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What does it mean if a substance is concentrated?

a high number of moles of solute per litre
(dm3 ) of solution

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What does it mean if a substance is corrosive?

Chemically reactive

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What happens when a solution of pH 1 is diluted 10 times

It becomes pH 2

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Formula for pH

-log(base 10) [ H+ ion conc.]

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Formula for [H+]

10^(-pH)

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What is [H+] x [OH-]

1 x 10^(-14)

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How does sulphuric oxide get into the atmosphere and what is its effect?

Sulfur dioxide occurs naturally
from volcanoes. It is produced industrially rom the combustion of sulfur-containing fossil fuels and the smelting of sulfde ores.
S(s) + O2 (g) -> SO2 (g)
In the presence ofsunlight sulfur dioxide is oxidized to sulfur trioxide.
SO2 (g) + 1/2O2 (g) ->SO3 (g)
The oxides can react with water in the air to form sulfurous acid and sulfuric acid:
SO2 (g) + H2O(l) -> H2SO3 (aq)
and
SO2 (g) + H2O(l) -> H2SO4 (aq

How do Nitrogen oxides get into the atmosphere and what is the effect?

Nitrogen oxides occur naturally from electrical storms and bacterial action. Nitrogen monoxide is produced in the internal combustion engine and in jet engines.
N2 (g) + O2 (g) -> 2NO(g)
Oxidation to nitrogen dioxide occurs in the air.
2NO(g) + Ow (g) -> 2NO2 (g)
The nitrogen dioxide then reacts with water to form nitric acid and nitrous acid:
2NO2 (g) + H2O(l) -> HNO3 (aq) + HNO2 (aq)
or is oxidized directly to nitric acid by oxygen in the presence of water:
4NO2(g) + O2 (g) + 2H2O(l)  4HNO3 (aq)

What is acid deposition?

Pure rainwater is naturally acidic with a pH o 5.65 due to the presence o dissolved carbon dioxide. Acid rain since acid rain is defned as rain with a pH less than 5.6. It is the oxides o sulur and nitrogen present in the atmosphere which are responsible or acid deposition

How do we counteact acid deposition?

Lower the amounts o NO and SO ormed, e.g. by improved engine design, the use o catalytic converters, and removing xx
sulur beore, during, and ater combustion o sulur-containing uels.

2, Liming o lakes  adding calcium oxide or calcium hydroxide (lime) neutralizes the acidity, increases the amount o calcium ions and precipitates aluminium rom solution. This has been shown to be eective in many, but not all, lakes where it has been tried.

What is a lewis acid?

Substances which accept a pair of electrons

What is a lewis base?

Substances which donate a pair of electrons.

How does the Kw value change with increasing temperature?

Kw increase with temp.

Formula for pOH

-log(base 10) [OH- conc]

Formula for pKw

-log(base 10) [Kw]

pKw = pH + pOH = 14

pKa + pKb = pKw

What is Ka? and give its formula.

Ka is the dissociation constant of a weak acid HA(aq) --> H+ (aq) + A- (aq) Ka = ( [H+] x [ A-] ) / [HA]

Why are the salts from a weak acid + strong base or strong acid + weak base slightly acidic / alkaline when dissoolved?

Salts made rom a weak acid and a strong base, such as sodium ethanoate, are alkaline in solution. This is because the ethanoate ions will combine with hydrogen ions rom water to orm mainly undissociated ethanoic acid, leaving excess hydroxide ions in solution.

What is a buffer solution

A buffer solution resists changes in pH when small amounts o acid or alkali are added to it

How are acidic buffers made? and how they work when an acod or alkali are added to the solution?

An acidic buffer solution can be made by mixing a weak acid together with the salt o that acid and a strong base. An example is a solution o ethanoic acid and sodium ethanoate. The weak acid is only slightly dissociated in solution, but the salt is ully dissociated into its ions, so the concentration o ethanoate ions is high NaCH3COO(aq) -->Na+ (aq) + CH3COO- (aq) CH3COOH(aq) <--> CH3COO- (aq) + H+ (aq)  an acid is added the extra H+ ions coming rom the acid are removed as they combine with ethanoate ions to orm undissociated ethanoic acid, so the concentration o H+ ions remains unaltered. I an alkali is added the hydroxide ions rom the alkali are removed by their reaction with the undissociated acid to orm water, so again the H+ ion concentration stays constant.

When does pKa = pH on a titration curve?

When half the required volume to get to the inflexion point is reached

pH range of Methyl orange

3.1-4.4

pH range of Phenolphthalein

8.3-10.0

How does pKa change with increasing acid strength?

pKa is decreasing at higher pH

How does Ka change with increasing acid strength?

Ka increases with higher pH

State the equation for a general acidic indicator

HIn (color a) ---> H+ + ln- (color b)

What is a conjugate base?

The conjugate base of an acid is the species remaining after the acid has lost a proton

What is the color range of an Indicator in Acidic conditions

The colour change can be considered to take place over a range of pKa ± 1.