3.
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The formula for potassium nitrate is KNO3. This means it contains: |
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[ ] |
1 potassium atom, 1 nitrogen atom, 3 oxygen atoms |
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1 potassium atom, 3 nitrogen atoms, 3 oxygen atoms |
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3 potassium atoms, 3 nitrogen atoms, 3 oxygen atoms |
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3 potassium atoms, 3 nitrogen atoms, 9 oxygen atoms |
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4.
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The formula for calcium hydroxide is Ca(OH)2. This means it contains: |
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[ ] |
1 calcium atom, 1 oxygen atom, 2 hydrogen atoms |
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1 calcium atom, 2 oxygen atoms, 1 hydrogen atom |
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1 calcium atom, 2 oxygen atoms, 2 hydrogen atoms |
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2 calcium atoms, 2 oxygen atoms, 2 hydrogen atoms |
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5.
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The formula for copper nitrate is Cu(NO3)2. This means it contains: |
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[ ] |
1 copper atom, 1 nitrogen atom, 6 oxygen atoms |
[ ] |
2 copper atoms, 2 nitrogen atoms, 3 oxygen atoms |
[ ] |
1 copper atom, 2 nitrogen atoms, 6 oxygen atoms |
[ ] |
2 copper atoms, 2 nitrogen atoms, 6 oxygen atoms |
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6.
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2H2SO4 means 2 molecules of sulfuric acid. They contain: |
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[ ] |
2 hydrogen atoms, 1 sulfur atom, 4 oxygen atoms |
[ ] |
4 hydrogen atoms, 1 sulfur atom, 4 oxygen atoms |
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4 hydrogen atoms, 2 sulfur atoms, 8 oxygen atoms |
[ ] |
4 hydrogen atoms, 4 sulfur atoms, 8 oxygen atoms |
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7.
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During a chemical reaction new substances are formed from old ones. Which of the following is NOT ALWAYS true? |
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New substances can be changed back to the original ones |
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The total mass of products = total mass of reactants |
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There is often a colour change |
[ ] |
There is often a temperature change |
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8.
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In the following reaction which are the products Mg + 2HCl → H2 + MgCl2? |
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Hydrochloric acid and magnesium chloride |
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Hydrogen and magnesium chloride |
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Magnesium and hydrochloric acid |
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Magnesium and hydrogen |
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9.
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Which of the following is the correct balanced equation for the reaction between copper with oxygen from the air? |
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[ ] |
2 Cu + O2 → Cu2O2 |
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2 Cu + O2 → 2 CuO |
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Cu + O → CuO |
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Cu + O2 → CuO2 |
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10.
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When zinc carbonate reacts with dilute hydrochloric acid the products are: |
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[ ] |
carbon dioxide, water |
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zinc chloride, carbon dioxide |
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zinc chloride, carbon dioxide, water |
[ ] |
zinc sulfate, carbon dioxide, water |
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