3030791
Description
Flashcards by kaylynntanner, updated more than 1 year ago
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Created by kaylynntanner
almost 9 years ago
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| Question | Answer |
| What is the main element in charcoal and how does it aid in changing carbon dioxide to carbon monoxide? | Carbon. It removes one oxygen atom from carbon dioxide and changes it to carbon monoxide. 2C + O2 --> 2CO |
| What is marble composed of? | Calcium carbonate. |
| Are limestone, lime and limewater composed of the same substances? | No. Limestone is composed of calcium carbonate, lime is composed of calcium oxide and limewater is composed of calcium hydroxide (slaked lime). |
| What gas is liberated from the reaction between marble and hydrochloric acid? | Carbon dioxide. |
| What is the difference between a burette and a pipette? | A burette has an accuracy of 0.1cm3, and it used to measure the volume of a solution accurately. A pipette is used to deliver an accurate and fixed volume of a solution. |
| What property of a soluble solid allows it to be crystallised out from its solution? | Its solubility decreases as the temperature drops. |
| Give an example of a solid mixture that can be separated by this procedure: -adding distilled water to the mixture -filtering the solution -allowing the filtrate to evaporate and crystallise | Sand and sugar |
| How can you use dilute sulfuric acid to remove sulfur from a iron-sulfur (powder) mixture? (sulfur and iron are insoluble in water. sulfur does not react with acids while iron reacts with acids.) | Add dilute sulfuric acid to the mixture. It will react with the iron powder to form soluble iron(ll) sulfate. Then, filter the mixture and dry the residue (sulfur powder) between folds of filter paper. |
| Suggest a method to obtain iron powder from a iron-sulfur mixture (powder). | Attract the iron powder with a magnet. Sulfur does not have magnetic |
| Give 2 mixtures that can be separated by filtration. | Sand and water Salt and sand |
| Filtration is used in the treatment of river water to obtain drinking water. The river water is filtered using layers of sand, gravel and pebbles. What is the reason for using the layers of sand, gravel and pebbles? | To filter off different sizes of insoluble dirt, thus only allowing clean water to pass through. |
| Seawater is filtered using a filter funnel fitted with a piece of filter paper. The filtrate obtained is salty. Why is this so? | The dissolved salts in seawater are very tiny, thus they are able to slip through the holes in the filter paper. |
| 1g of water and 1g of steam contain the same number of molecules. Explain why the volume of steam is much greater than that of water. | The molecules are close together in water but further apart in steam. |
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