Many compounds and elements have important uses.
Complete the table to show the name, formula and use of each compound and element.
name of compound or element | number of atoms in the formula | formula | use |
chlorine | chlorine = 2 | Cl2 |
|
| carbon = 1 hydrogen = 4 | CH4 |
|
calcium carbonate | calcium = 1 carbon = 1 oxygen = 3 |
|
|
Did this page help you?
Complete the chemical equation for the complete combustion of propane.
2C3H6 + ......O2 → 6CO2 + 6H2O
Describe a test for carbon dioxide.
test ..................................................
observations ..................................................
Did this page help you?
A list of symbols and formulae is shown.
|
Which symbol or formula represents an ion which forms a blue precipitate when added to aqueous sodium hydroxide.
A solution is obtained by filtering a mixture of soil and water. The table shows the mass of some of the ions in 1000 cm3 of this solution.
name of ion | formula of ion | mass of ion in 1000 cm3 of soil solution / mg |
aluminium | Al3+ | 0.2 |
| NH4+ | 22.0 |
calcium | Ca2+ | 0.2 |
iron(II) | Fe2+ | 79.0 |
magnesium | Mg2+ | 0.1 |
nitrate | NO3– | 28.0 |
phosphate | PO43– | 14.0 |
potassium | K+ | 39.0 |
| SO42– | 5.1 |
State the name of the SO42– ion.
Describe a chemical test for calcium ions.
test ______________________________________ observations ______________________________
When sodium reacts with carboxylic acids, hydrogen is produced.
Describe a test for hydrogen.
test ______________________________________ observations ______________________________
Did this page help you?
Describe a test for iron(II) ions.
test _________________________________
observations _________________________
Describe a test for bromide ions.
test ___________________________
observations ___________________
Nitric acid contains nitrate ions. Complete these sentences about the test for nitrate ions using words from the list. aluminium ammonia blue chloride copper green iron nitrate oxygen red Aqueous sodium hydroxide and _____________________ foil are added to the solution being tested. The mixture is warmed gently. The _________________ produced turns damp ___________________ litmus paper __________________ .
Did this page help you?
Hydrogen peroxide, H2O2, decomposes slowly to form water and oxygen.
Write the word equation for this reaction.
The decomposition of hydrogen peroxide also occurs in the presence of a manganese(IV) oxide, MnO2, catalyst. What is meant by the term catalyst?
Bubbles of oxygen gas are produced in when manganese(IV) oxide is added to hydrogen peroxide. Describe a test for oxygen gas. test ..................................................... observations ........................................................
The decomposition of hydrogen peroxide is exothermic. What is meant by the term exothermic?
Did this page help you?
Choose a gas from the following list to answer the questions below.
Each gas may be used once, more than once or not at all.
ammonia | carbon dioxide | carbon monoxide | fluorine |
krypton | nitrogen | propene | hydrogen |
It polymerises to form a poly(alkene).
It is a noble gas.
It is the main component of air.
It is a very reactive non-metal.
It burns to form water as the only product.
Did this page help you?
Choose a gas from the following list to answer the questions below. Each gas may be used once, more than once or not at all.
ammonia argon chlorine ethene hydrogen
carbon dioxide nitrogen carbon monoxide oxygen
Which gas
i) Is a noble gas?
[1]
ii) Is an acidic oxide?
[1]
iii) Can be polymerised?
[1]
iv) Is the active component of air?
[1]
v) Is used in the treatment of water?
[1]
Complete the following table.
Gas | Test for Gas |
Ammonia |
|
| Bleaches damp litmus paper |
Hydrogen |
|
| Relights a glowing splint |
| Turns limewater milky |
Did this page help you?
Table 1 shows the mass of ions present in a 100 cm3 sample of milk.
Table 1
ion | formula of ion | mass of ion in 100 cm3 milk / mg |
calcium | Ca2+ | 125 |
chloride | Cl − | 120 |
magnesium | Mg2+ | 12 |
negative ions of organic acids |
| 160 |
phosphate | PO43− | 95 |
potassium | K+ | 140 |
sodium | Na+ | 58 |
sulfate | SO42− | 30 |
Describe a test for chloride ions.
test ..................................................
positive result ..................................................
Calcium reacts with cold water to form two products:
a colourless gas, P, which ‘pops’ with a lighted splint
a weakly alkaline solution, Q, which turns milky when carbon dioxide is bubbled through it.
i) Name gas P.
[1]
ii) Name the weakly alkaline solution Q.
[1]
Did this page help you?
This question is about ammonia and ammonium salts.
Ammonia is a gas at room temperature. What is the test for ammonia gas? Describe the positive result of this test.
test .......................................................................
result ....................................................................
Ammonia reacts with water to form ions.
NH3 + H2O format('truetype')%3Bfont-weight%3Anormal%3Bfont-style%3Anormal%3B%7D%3C%2Fstyle%3E%3C%2Fdefs%3E%3Ctext%20font-family%3D%22math1aa495e18c7e3a21a4e48923b92%22%20font-size%3D%2216%22%20text-anchor%3D%22middle%22%20x%3D%2210.5%22%20y%3D%2216%22%3E%26%23x21CC%3B%3C%2Ftext%3E%3C%2Fsvg%3E){kind=small}
NH4+ + OH–
Describe what is seen when aqueous ammonia is added to aqueous copper(II) sulfate, until no further change is seen.
Barium sulfate is an insoluble salt.
Barium sulfate can be made from aqueous ammonium sulfate using a precipitation reaction.
Name a solution that can be added to aqueous ammonium sulfate to produce a precipitate of barium sulfate.
Did this page help you?
This question is about tests for ions.
Describe the test for a nitrate ion.
test ___________________________
result __________________________
Describe a test for iodide ions.
test ______________________________
observations ______________________
Did this page help you?
This question is about ammonium compounds.
The table shows the names and formulae of some ammonium compounds.
Name | Ammonium nitrate | Ammonium carbonate |
|
Formula | NH4NO3 |
| NH4Cl |
i) Complete the table by giving the missing information.
[2]
ii) When ammonia reacts with nitric acid, ammonium nitrate is formed.
Write a chemical equation for this reaction.
[1]
When ammonium chloride is heated, it undergoes thermal decomposition to form two gaseous products.
Describe the result of testing each product with damp universal indicator paper.
The diagram shows the apparatus used to heat ammonium chloride.
i) Suggest why the damp litmus paper is two different colours.
[1]
ii) Explain what happens to the damp litmus paper as the ammonium chloride is heated.
[3]
Explain why a fine white powder formed on the inside of the neck of the conical flask in part (c).
Did this page help you?