Topic 4 Acids and alkalis Flashcards
1
Q
- What term describes a substance that attacks metals, stonework and skin?
A
corrosive
2
Q
- Name an acidic solution found in the kitchen.
A
vinegar or fruit juice, etc.
3
Q
- Name an alkaline solution used in the kitchen.
A
bleach or oven cleaner or soap, etc.
4
Q
- What type of substance turns litmus paper red?
A
acid
5
Q
- How does an indicator show the acidity or alkalinity of solutions?
A
by changing colour
6
Q
- What pH values represent alkaline solutions?
A
above 7 or 8 to 14
7
Q
- What happens in all chemical reactions?
A
new substances are formed
8
Q
- What kind of reaction occurs between an acid and an alkali?
A
neutralisation
9
Q
- What do you call a solution that is neither acidic nor alkaline.
A
neutral
10
Q
- Give the name and formula of a common laboratory acid.
A
hydrochloric acid (HCl) or nitric acid (HNO3) or sulfuric acid (H2SO4), etc.
11
Q
- Which ion is in excess in all acidic solutions?
A
hydrogen ions or H+ ions
12
Q
- Which ion is in excess in all alkaline solutions?
A
hydroxide ions or OH– ions
13
Q
- What scale is used for measuring acidic and alkaline properties?
A
the pH scale
14
Q
- Name three examples of acid/alkali indicators apart from universal indicator.
A
litmus, methyl orange and phenolphthalein
15
Q
- What would you use to measure pH to one decimal place?
A
a pH meter
16
Q
- What pH values are acidic?
A
below 7
17
Q
- What colour is phenolphthalein in a solution with a pH of 2?
A
colourless
18
Q
- What happens to the pH as the H+ ion concentration increases?
A
it decreases
19
Q
- If a solution has the same concentration of hydrogen ions as hydroxide ions, how is it described?
A
neutral or pH = 7
20
Q
- If 2 g of salt is dissolved in 250 cm3 of solution, what is its concentration in g dm–3?
A
8 g dm–3
21
Q
- What word describes a solution that contains a large amount of solute in a small volume of solvent?
A
concentrated
22
Q
- How can a solution be made more dilute?
A
by adding solvent/water
23
Q
- If 24 g of acid is dissolved in 600 cm3 of solution, what is its concentration in g dm–3?
A
40 g dm–3
24
Q
- What happens when strong acid molecules dissolve in water?
A
they dissociate completely into ions
25
25. What kind of reaction occurs between an acid and a base?
neutralisation
26
26. What happens to the pH of an acid as it reacts with a neutraliser?
pH increases
27
27. What is formed when an acid reacts with a base like a metal oxide?
salt + water
28
28. What acid would be used to make zinc sulfate from zinc oxide?
sulfuric acid (sulphuric acid makes sulphates!)
29
29. What process can be used to separate an insoluble solid from a liquid?
filtration
30
30. How can a sample of a dissolved salt be obtained from a salt solution?
evaporation of the water
31
31. In general, what is the pH of an alkaline solution?
greater than 7
32
32. Which ions, hydrogen ions or hydroxide ions, are released by alkalis in solution?
hydroxide ions (OH-)
33
33. What colour is litmus solution in acidic solutions?
red
34
34. What name is given to substances that react with acids to form a salt and water only?
bases (bases are metal oxides and hydroxides, soluble bases are alkalis)
35
35. Which salt is formed when copper oxide reacts with sulfuric acid?
copper sulfate
36
36. What type of reaction happens between an acid and a base?
neutralisation
37
37. What type of solution has a pH of 7?
neutral
38
38. Name the acid that has the formula HCl.
hydrochloric acid
39
39. What colour is phenolphthalein in alkaline solutions?
pink (it is colourless in acid conditions)
40
40. What is the formula for sulfuric acid?
H2SO4
41
41. Name the salt produced when sodium hydroxide reacts with hydrochloric acid.
sodium chloride
42
42. Which ions, hydrogen ions or hydroxide ions, are released by acids in solution?
hydrogen ions (H+)
43
43. What substance, other than a salt, is produced when an alkali neutralises an acid?
water
44
44. What name is given to substances that are soluble bases?
alkalis
45
45. What is the formula for hydrochloric acid?
HCl
46
46. What type of solution has a pH above 7?
alkaline
47
47. What colour is phenolphthalein in acidic solutions?
colourless – not ‘clear’
48
48. Name a piece of apparatus used to measure volumes of liquid.
measuring cylinder/pipette/burette
49
49. Name the separation method used to produce crystals from a solution.
crystallisation
50
50. Name the acid needed to make ammonium nitrate.
nitric acid
51
51. Which acid can be used to make copper sulfate?
sulfuric acid
52
52. Which base can be used to make copper sulfate?
copper oxide
53
53. Which substance is needed to complete the general equation: acid + base makes salt + …?
water (BASHO)
54
54. What is the formula of nitric acid?
HNO3
55
55. What is the name of the salt formed from zinc oxide and hydrochloric acid?
zinc chloride
56
56. What is the formula of the salt formed from calcium oxide and hydrochloric acid?
CaCl2
57
57. Which ions are present in large quantities in aqueous solutions of all acids?
H+ Hydrogen ions
58
58. Which ions are present in large quantities in aqueous solutions of all alkalis?
OH– Hydroxide ions
59
59. Which gas is formed when dilute hydrochloric acid reacts with magnesium?
hydrogen (MASH)
60
60. Which gas is formed when dilute hydrochloric acid reacts with magnesium carbonate?
carbon dioxide (CASHOCO)
61
61. What acid can be used to make copper chloride?
hydrochloric acid (hydrochloric acid makes chlorides)
62
62. What gas is given off when magnesium reacts with dilute sulfuric acid?
hydrogen (MASH)
63
63. How do you identify Hydrogen gas?
gives a squeaky pop with a lighted splint
64
64. What is _seen_ when magnesium is added to dilute sulfuric acid?
effervescence/fizzing/bubbles (yes you know this is hydrogen, but you can not see that!!)
65
65. What is the formula of magnesium sulfate?
MgSO4
66
66. What gas is produced when copper carbonate is added to dilute nitric acid?
carbon dioxide (CASHOCO)
67
67. How do you test for Carbon Dioxide?
it turns limewater milky
68
68. What is the formula of the salt produced when copper carbonate reacts with nitric acid?
(Cu(NO3)2)
69
69. Sodium chloride dissolves in water to form a solution. Which is the solute?
sodium chloride
70
70. What do we call the liquid that dissolves a solute to form a solution.
solvent
