2497497
Description
Flashcards by olidun2015, updated more than 1 year ago
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Created by olidun2015
about 9 years ago
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| Question | Answer |
| What is the general formula for alkanes? | CnH2n+2 (little 2's) |
| How can alkanes be described? | Saturated |
| What is a covalent bond? | A pair of shared electrons |
| What is the formula for an alkene? | C2H4 (little 2 and 4) |
| How can alkenes be described? | Unsaturated |
| What happens to bromine when it is mixed with an alkene? | Bromine water changes from orange-brown to colourless when mixed with an alkene |
| In the reaction, ethene -> poly(ethene): | Ethene is the monomer |
| Why does paint contain a pigment? | To give the paint its colour |
| Colloids: | The particles of one substance are mixed and dispersed with particles of another substance without dissolving |
| What is the key feature of thermochromic paints? | They change colour at different temperatures |
| Which process removes carbon dioxide from the atmosphere? | Photosynthesis |
| Which of these process releases carbon monoxide into the atmosphere? | Incomplete combustion |
| What is combustion? | Rapid chemical combination of a substance with oxygen, involving the production of heat and light |
| One of the key reactions in a catalytic converter is: | carbon monoxide + nitrogen oxide → nitrogen + carbon dioxide |
| What caused the proportion of oxygen in the atmosphere to increase? | Photosynthesis |
| Which of the following is a reason for the decrease in water vapour in the Earth's atmosphere? | Water vapour condensed to form the oceans |
| Why is crude oil called a fossil fuel? | Because it is formed from the remains of ancient sea creatures |
| What happens to a liquid during its separation from a mixture by distillation? | A liquid during its separation from a mixture by distillation evaporates then condenses |
| The top of an oil fractionating column is: | The top of an oil fractionating column is colder than the bottom of the column |
| Compared to large hydrocarbons, small hydrocarbons are: | More volatile |
| Which process allows large hydrocarbons to be broken down into smaller hydrocarbons? | Cracking |
| How is a positively charged ion formed from an atom? | Positive ions are formed from neutral atoms when one or more electrons is lost. If electrons are gained, the ion will be negative. |
| What will be the charge on an aluminium ion? | For metal elements in Groups 1, 2 and 3 of the periodic table, the ionic charge is equal to their group number, so the aluminium ion will have a charge of 3+. Elements in Group 2 will have an ionic charge of 2+. |
| What will be the charge on a sulfide ion, formed from a sulfur atom? | Sulfur is in group 6 of the periodic table. This means it has six electrons in its outer shell, so it will gain two to become stable, meaning a charge of 2-. Some elements in Group 3 form ions with a charge of 3-. |
| What will be the formula of an ionic compound formed from calcium and oxygen? | CaO |
| When a negative ion is formed because an atom has gained an electron, what term can be used to describe this process? | Reduction - gain of electrons |
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