Properties of acids & bases
Which reaction is not characteristic of an acid?
A. It dissolves magnesium oxide
B. It produces ammonia from ammonium compounds
C. It produces carbon dioxide from a carbonate
D. It produces hydrogen from zinc metal
Salts can be made by adding different substances to dilute hydrochloric acid. For which substance could any excess not be removed by filtration?
A. Copper(II) oxide
B. Magnesium
C. Sodium hydroxide
D. Zinc hydroxide
A white solid is insoluble in water. When it is added to hydrochloric acid, bubbles of gas are formed. Adding aqueous ammonia to the solution formed gives a white precipitate. Adding excess aqueous ammonia causes the precipitate to re-dissolve. What is the white solid?
A. Aluminium nitrate
B. Ammonium nitrate
C. Calcium carbonate
D. Zinc carbonate
Which statement about oxides is correct?
A. A solution of magnesium oxide will have a pH less than 7
B. A solution of sulfur dioxide will have a pH greater than 7
C. Magnesium oxide will react with nitric acid to make a salt.
D. Sulfur dioxide will react with hydrochloric acid to make a salt.
C. Magnesium oxide will react with nitric acid to make a salt
Which calcium compound does not increase the pH of acidic soils?
A. Calcium carbonate
B. Calcium hydroxide
C. Calcium oxide
D. Calcium sulphate
Name three properties of acids.
- Sour taste
- Hazardous. Irritants to skin, causing skin to redden and blister
- Turns blue litmus red
- React with metals to produce hydrogen gas
- Reacts with carbonates and hydrogencarbonates to produce carbon dioxide
- Reacts with metal oxides and hydroxides
- etc.
Potassium nitrate is a salt which can be prepared by reacting an acid with an alkali, using the titration method. Name an acid and an alkali which can react to make potassium nitrate.
Acid: Nitric acid
Alkali: Potassium hydroxide
Describe what is observed when aqueous barium chloride is added to dilute sulphuric acid.
The oxides of elements may be acidic, basic, or amphoteric. Give the name and formula of one example of each of these three types of oxide.
Basic: Any metal oxide
Amphoteric: Any transition metal oxide
- Hydrochloric acid to remove rust
- Vinegar used in the kitchen
etc.
Define an acid in terms of proton transfer.
An acid is a proton donator.
Lead(II) iodide is a salt which can be prepared by the precipitation method.
Name suitable reagents for the preparation of lead(II) iodide, then explain why the precipitation method is suitable for the preparation of lead(II) iodide.
Reagents: Lead nitrate and potassium iodide
Explanation: Because lead(II) iodide is insoluble in water.
Describe what is observed when aqueous silver nitrate is added to aqueous sodium chloride.
State a property of an amphoteric oxide, and a property of a neutral oxide.
- Amphoteric: reacts with both acids and alkalis
- Neutral: doesn't react with both acids and alkalis
- Soap
- Neutralize acidic soil
- Toothpaste
- Cement
- etc.
Describe what is observed when dilute hydrochloric acid is added to solid sodium carbonate.
Solid dissolved and effervescence seen (a colorless and odourless gas is evolved).
HF (aq) + H2O (l) = F- (aq) + H3O+ (aq)
In this reaction, does water act as an acid or a base, and why?
Give the name and formula of the ion present in each of the solutions X and Z below:
a. Solution X gives a white precipitate when dilute hydrochloric acid and aqueous barium chloride are added to it.
b. An alkaline gas is given off when sodium hydroxide solution is added to the colourless solution Z and the mixture heated.
a. Sulphate ion (SO4)2-
b. Ammonium ion (NH4)+
Scandium oxide is insoluble in water. Describe how you could show that it is an amphoteric oxide.
1. Name or formula of strong acid and alkali
2. If it reacts with or neutralises both acid and base/alkali, then it's amphoteric
3. The oxide would dissolve in both acid and alkali, or form solutions in both
Explain why this should not be done.
1. Ammonium compounds that make up fertilisers react with alkali, which in this case is calcium hydroxide, under the heat of the sun to release ammonia gas
2. The nitrogen content of the soil decreases as nitrogen is lost from the soil into the atmosphere.