Acids and Alkalis
1. What does corrosive mean?
Corrosive means that the substance can eat away metals, skin, cloth and other substances
2. How would you test a substance, to see if
it is an acid?
To test a substance to see if it is an acid you could use litmus paper.
Blue litmus paper turns red when put in acid. Universal indicator turns
red or pink when put in acid.
3. Write down the formula for:
sulphuric acid H2SO4
calcium hydroxide Ca(OH)2
nitric acid HNO3
ammonia solution NH3
4. What effect do alkalis have on litmus solution?
Alkalis turn litmus solution blue and turn red litmus paper blue.
5. Say whether a solution is acidic, alkaline
or neutral, if its pH number is:
7 1 10 3
pH 9 Alkali
pH 4 Acid
pH 7 Neutral
pH 1 Acid
pH 10 Alkali
pH 3 - Acid
6. What color would universal indicator show,
in an aqueous solution of sugar? Why?
Univeral indicator would show a green color in an aqueous solution of sugar because the solution is neutral and the
color for neutral is green.
Name the acid found in:
wine ice tea vinegar
The acid found in lemon juice is citric acid
The acid found in wine is ethanoic acid
The acid found in ice tea is tannic acid
The acid found in vinegar is ethanoic acid
Write a word equation for the reaction of dilute sulphuric acid with :
c. Sodium carbonate
Sulphuric acid + zinc à zinc sulphate + hydrogen
Sulphuric acid + magnesium oxide à magnesium sulphate + water
Sulphuric acid + sodium carbonate à sodium sulphate + carbon
dioxide + water
Bath salts contain sodium carbonate. Explain
why they fizz when you put vinegar on them.
Bath salts fizz when you put vinegar on them because bath salts contain
sodium carbonate. When acids and sodium carbonate react they produce a salt,
carbon dioxide and water. Therefore the fizzing occurs due to the creation of
carbon dioxide gas.
10. What causes the acidity in acids?
The acidity in acids is caused by the H+ ions. The more H+ ions, the stronger the acid and the greater the acidity.
11. Why is ethanoic acid called a weak acid?
Ethanoic acid is called a weak acid because only some of the molecules
12. Name two other weak acids, and two strong acids.
Two weak acids are : tannic acid and citric acid
Two strong acids are : Hydrochloric acid and Sulphuric acid
13. Which ion do alkalis all have in common?
All alkalis form OH- ions.
14. What color would litmus solution turn, if you mixed it with ajax? Why?
Ajax is a alkali solvent. Therefore litmus solution would turn blue when mixed with ajax.
15. A 10% solution of potassium hydroxide has a higher pH number than a 10% solution of ammonia. Why is this? Which one will be a better conductor of electricity.
Potassium hydroxide has a higher pH number than ammonia, even though
they are the same concentration, because potassium hydroxide is a stronger acid. When
dissolved in water, nearly all the potassium hydroxide molecules form ions. Potassium
hydroxide will be a better conductor of electricity because it has more ions.
16. Write a word equation for the reaction between sodium hydroxide and ammonium chloride.
Sodium hydroxide + ammonium chloride à sodium chloride + water
17. What happens to:
The H+ ions
Of the solution when an acid is neutralized.
When a solution is neutralized the H+ ions combine with the OH-
ions in alkalis to form water. The temperature increases during a neutralization
reaction because it is an exothermic reaction.
18. Write a balanced equation for the reaction between sodium hydroxide and
H2SO4 + 2NaOH à Na2SO4
HNO3 + NaOHà NaNO3 + H2O
19. What is a base? Name six bases.
A base is a substance that can neutralize an acid. Bases include:
Metal oxides CuO, MgO
Metal hydroxides Ca(OH)2
Metal carbonates Na2CO3
Metal hydrogen carbonates NaHCO3
Ammonia solution NH3
20. What special property do alkalis have?
Alkalis are bases which are soluble in water.
21. Which bases react with acids to give carbon dioxide?
Metal carbonates react with acids to give carbon dioxide.
22. Write a word equation for the reaction between:
dilute hydrochloric acid and copper (II) oxide
dilute sulphuric acid and potassium carbonate
Hydrochloric acid + copper(II)oxide à copper(II)chloride + water
Sulphuric acid + potassium carbonate à potassium sulphate + carbon
dioxide + water
23. Write a word equation for the reaction that takes place in your stomach, when you take baking soda to cure
Your stomach contains hydrochloric acid.
The chemical name for baking soda is sodium hydrogen carbonate.
Hydrochloric acid + sodium hydrogen carbonate à sodium chloride + carbon
dioxide + water