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 |
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Complete the chemical equation for the complete combustion of propane.
Describe a test for carbon dioxide.
test ..................................................
observations ..................................................
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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 ______________________________
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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 __________________ .
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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?
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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.
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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
Complete the following table.
| Gas | Test for Gas |
| Ammonia | |
| Bleaches damp litmus paper | |
| Hydrogen | |
| Relights a glowing splint | |
| Turns limewater milky |
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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.
Calcium reacts with cold water to form two products:
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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.
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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.
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This question is about tests for ions.
Describe the test for a nitrate ion.
test ___________________________
result __________________________
Describe a test for iodide ions.
test ______________________________
observations ______________________
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