10th
- How would you name the following compounds? (i) Bromoethane (ii) Methanal (formaldehyde) (iii) Hexyne 1
- Draw the structures for the following compounds. (i) Ethanoic acid (ii) Bromopentane* (i) Ethanoic acid https://lh3.googleusercontent.com/-ARjQ1Ber6tU/Ya7NyFRf-fI/AAAAAAAAC4Q/5FvOw-OtaigG6V8K3TqXXzZsPPdfp6wgwCNcBGAsYHQ/image.p... 2
- What will be the formula and electron dot structure of cyclopentane? The formula for cyclopentane is C₅H₁₀. Its electron dot structure is given below. 1
- What are the two properties of carbon which lead to the huge number of carbon compounds we see around us? The two features of carbon that give rise to a large number of compounds are as follows: ⇒ Catenation - It is the ability to form bonds with... 1
- How many structural isomers can you draw for pentane? Three structural isomers are possible for pentane. 1
- What would be the electron dot structure of a molecule of sulphur which is made up of eight atoms of sulphur? Sulphur has an atomic number of 16 and an electronic configuration of 2,8,6. The valance electrons on the sulphur atom are six. The sulphur... 1
- What would be the electron dot structure of carbon dioxide which has the formula CO2? Electron-dot structure of carbon dioxide which has the formula CO_(2 ) _() 2
- Give reasons why copper is used to make hot water tanks and not steel (an alloy of iron). Copper does not react with cold water, hot water, or steam. However, iron reacts with steam. If the hot water tanks are made of steel (an al... 2
- A man went door to door posing as a goldsmith. He promised to bring back the glitter of old and dull gold ornaments. The solution he had used was Aqua regia. Aqua regia is Latin word which means ‘Royal Water’. It is the mixture of concentrated Hydrochloric... 1
- Differentiate between metal and non-metal on the basis of their chemical properties Metal Non-metal Metals are electropositive. Non-metals are electronegative. Oxides of metal are basic in nature. Oxides of non-metals are ac... 1
- You must have seen tarnished copper vessels being cleaned with lemon or tamarind juice. Copper reacts with moist carbon dioxide in air to form copper carbonate and as a result, copper vessel loses its shiny brown surface forming... 1
- Carbonate and sulphide ores are usually converted into oxides during the process of extraction. Carbonate and sulphide ores are usually converted into oxides during the process of extraction because metals can be easily extracted from t... 1
- Aluminium is a highly reactive metal, yet it is used to make utensils for cooking. Though aluminium is a highly reactive metal, it is resistant to corrosion. This is because aluminium reacts with oxygen present in air to fo... 1
- Sodium, potassium and lithium are stored under oil. Sodium, potassium, and lithium are very reactive metals and react very vigorously with air as well as water.Therefore, they are kept immerse... 1
- Platinum, gold and silver are used to make jewellery Platinum, gold, and silver are used to make jewellery because they are very lustrous. Also, they are very less reactive and do not corrode e... 1
- What type of oxides are formed when non-metals combine with oxygen? When non-metals are combined with oxygen then neutral or acidic oxides are formed. Examples of acidic oxides are NO₂, SO₂ and examples of ne... 1
- State two ways to prevent the rusting of iron. Two ways to prevent the rusting of iron are: → Oiling, greasing, or painting: By applying oil, grease, or paint, the surface becomes water p... 1
- In the electrolytic refining of a metal M, what would you take as the anode, the cathode and the electrolyte? In the electrolytic refining of a metal M: Anode → Impure metal M Cathode → Thin strip of pure metal M Electrolyte → Solution of salt of the... 1
- Name two metals which will displace hydrogen from dilute acids, and two metals which will not. Iron and aluminium will displace hydrogen from dilute acids as they more reactive then hydrogen. Mercury and copper cannot displace hydrogen... 1
- What are amphoteric oxides? Give two examples of amphoteric oxides. Those oxides that behave as both acidic and basic oxides are called amphoteric oxides. Examples: aluminium oxide (Al₂O₃), zinc oxide (ZnO) 1
- (b) Assess the usefulness of these tests in distinguishing between metals and non-metals. The above tests are useful in distinguishing between metals and non-metals as these are based on the physical properties. No chemical reacti... 1
- (a) How could you use them to distinguish between samples of metals and non-metals? With the hammer, we can beat the sample and if it can be beaten into thin sheets (that is, it is malleable), then it is a metal otherwise a... 1
- Food cans are coated with tin and not with zinc because (a) zinc is costlier than tin. Correct option is (c) zinc is more reactive than tin. 2
- An element reacts with oxygen to give a compound with a high melting point. This compound is also soluble in water. Correct option is (a) calcium 2