Identifying Reactants and Products
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In any chemical reaction, the products are made when the atoms in the reactants (the chemicals we start of with) are rearranged into new substances (the products). We can show this in a chemical equation.
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In a word equation, the names of the reactant(s) and product(s) are written in words. The equation is written with the reactants on the left side and the products on the right side, separated by an arrow.
The arrow should always be shown in any chemical equation and is a shorthand way of saying "reacts to form".
The questions which follow require you to identify the reactants and products, and write a word equation to represent the reaction occurring.
Only the names of chemical substances, separated by a plus ("+") sign are allowed in a word equation. When a reaction is heated, heat should not appear in the equation, as the heat is not a reactant.
The marking guide can be accessed from the tick opposite.
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For the following questions, write a word equation to describe the reaction taking place.
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Magnesium metal is burned in a bunsen burner. It burns to produce magnesium oxide, a white powder.
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In the lab, iron filings were sprinkled into a bunsen burner flame, resulting in bright sparkles in the flame. In this reaction iron oxide was produced.
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When an athlete runs, their muscles use up glucose. The reaction requires oxygen and the glucose is broken down to produce carbon dioxide and water.
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Chalk reacts with hydrochloric acid to release carbon dioxide gas. A salt, calcium chloride and water also result.
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A catalytic converter in a car exhaust system uses oxygen from the air to change toxic carbon monoxide into less harmful carbon dioxide.
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A lab technician produced hydrogen gas by reacting calcium metal with dilute hydrochloric acid. A solution of calcium chloride was also produced during the reaction.
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At the Grangemouth petrochemical works, ethene is produced by cracking ethane. In the process, hydrogen gas is released.
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Esters are organic compounds used to flavour food and drink. A flavour used in the boiled sweet, pear drops, is pentyl ethanoate. It can be made by reacting pentanol with ethanoic acid.
In the reaction water is released.
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The thermite process is a vigorous chemical reaction used to weld railway lines.
In the reaction, iron metal is produced when aluminium reacts with iron oxide at high temperature.
Aluminium oxide is also made in the reaction.
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Crude oil contains sulfur compounds such as hydrogen sulfide.
When hydrogen sulfide burns in oxygen it produces sulfur dioxide and water.
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Hydrazine is a fuel used in rockets.
Hydrazine is unstable and breaks down to produce ammonia, nitrogen and hydrogen.
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Indigestion tablets and dental products contain many chemical compounds.
Some indigestion tablets contain calcium carbonate.
Calcium chloride, carbon dioxide and water are produced when calcium carbonate reacts with hydrochloric acid in the stomach.
Write the word equation.
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Butane is a hydrocarbon which can be used as a fuel.
When butane burns in oxygen, carbon dioxide and water are produced.
Write a word equation for the burning of butane.
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