Acids, Alkalis, and Salts

Question 1

How to Preform a Titration

Answer 1

Add 50ml of Hydrochloric acid and Sodium Hydroxide too two separate beakers. Measure 25cm^3 of the Hydrochloric acid in to conical flask with a volumetric pipette filler. After add two or three drops of phenolphthalein. Add the alkali slowly into the acid from a volumetric pipette filler while swirling the conical flask. Record the results of how much of the alkali it took to make the acid go clear. Repeat to get a table of results and find a average

Question 2

Titration calculation’s

Answer 2

concentration = moles / volume

Question 3

Acids

Answer 3

• They are solutions that have a pH of below 7 on the pH scale
• They can contain hydrogen ions in their solution
• They can be corrosive when strong: however, some acids like citric and ethanoic acid can be eaten

Question 4

Bases / Alkalis

Answer 4

• There are chemical substances that can react with acids to neutralise them
• They can sometimes be solids
• The types of compounds that are bases include metal oxides, hydroxides and carbonates
• Special bases that dissolve in water are “alkalis”. They have a pH of over 7 and contain “hydrogen ions”

Question 5

Indicators

Answer 5

• These are substances that change colour depending upon whether they are acidic or alkaline solution
• Some have different colours depending upon the actual pH of the solution

Question 6

Litmus indicator

Answer 6

• Litmus turns from red to blue in alkaline conditions

- Turns from blue to red in acidic conditions

Question 7

Phenolphthalein indicator

Answer 7

• colourless in acidic solutions

- pink in alkaline solutions

Question 8

Methyl Orange indicator

Answer 8

• Red in acidic solution

- Yellow in alkaline solution

Question 9

The pH scale

Answer 9

A scale between 1-14 that is used to measure the strength of a acid or alkaline

Question 10

Universal indicator

Answer 10

-Gives the colours that show the different pH values
-A mixture of indicators
-The colour gives you a actual pH value of the solution that you are testing
pH 1-6 is acidic
pH 7 is neutral
pH 8-14 is alkaline

Question 11

Acids, Alkalis, Bases, and Salts

Answer 11

Acids are proton donors
Bases are proton acceptors
Alkalis are soluble bases
Salts are ionic compounds

Question 12

Acid reactions

Answer 12

Acid + metal oxide —–> salt + water
e.g. sulfuric acid + zinc oxide —-> zinc sulfate + water
H2SO4 + ZnO —-> ZnSO4 + H2O
Acid + metal hydroxide —-> salt + water
Sulfuric acid + calcium hydroxide —-> calcium sulfate + water
H2SO4 + Ca(OH)2 —-> CaSO4 + 2H2O
Acid + metal carbonate —->salt + water +carbon dioxide
Hydrochloric acid + sodium carbonate —-> sodium chloride + water + carbondioxide
2HCl + Na2CO3 —-> 2NaCl + H2O + CO2