Calcium reacts with hydrochloric acid to form the salt, calcium chloride and another product.
calcium + hydrochloric acid → calcium chloride + ___________
What is the unknown product?
Water
Oxygen
Hydrogen
Carbon dioxide
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Calcium reacts with hydrochloric acid to form the salt, calcium chloride and another product.
calcium + hydrochloric acid → calcium chloride + ___________
What is the unknown product?
Water
Oxygen
Hydrogen
Carbon dioxide
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Indicators are used during a titration to observe the end point.
Different indicators turn different colours in acids and alkalis.
Which indicator displays the correct colour in each solution?
Indicator | Colour in acid | Colour in alkali |
methyl orange | red | yellow |
universal indicator | red | orange |
litmus | red | purple |
phenolphthalein | red | colourless |
Methyl orange
Universal indicator
Litmus
Phenolphthalein
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A solution of sulfuric acid with a pH of 4 has a hydrogen ion concentration of 1 x 10-4 mol/dm3.
Another acid has a hydrogen ion concentration of 1 x 10-6 mol/dm3.
What is the pH of this acid?
2
3
5
6
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A student carrying out a titration finds that a 25.0 cm3 solution of 0.500 mol/dm3 hydrochloric acid neutralises 35.0 cm3 of sodium hydroxide.
The balanced symbol equation for the reaction is:
NaOH + HCl → NaCl + H2O
What is the concentration of the sodium hydroxide?
0.15 mol/dm3
0.36 mol/dm3
0.72 mol/dm3
1.00 mol/dm3
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What is the ionic equation for neutralisation?
2H+ (aq) + OH- (aq) → H2O (l)
H+ (aq) + OH- (aq) → H2O (aq)
H+ (aq) + OH- (aq) → H2O (l)
2H2 + O2 → 2H2O
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A student making copper sulfate crystals used the method below.
Unreacted copper carbonate was left over as it had been added in excess.
What is the reason for adding it in excess and what would step 3 be of this method?
Reason for adding excess copper carbonate | Step 3 of method | |
A | to produce a greater amount of salt crystals | filtration |
B | to improve the colour intensity of the crystals | crystallisation |
C | to ensure all the acid reacts | filtration |
D | to increase the rate of reaction | evaporation |
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A student added some sulfuric acid gradually to a solution of ammonia until it was in excess.
What happens to the pH during this reaction?
pH of ammonia at start | pH after addition of excess sulfuric acid | |
A | 11 | 7 |
B | 7 | 13 |
C | 11 | 2 |
D | 3 | 8 |
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