9th
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- Fill in the blanks . 1. The number of molecules of water of crystallization in washing soda is 10. 2. The chemical name of baking soda is sodium bicarbonate. 3.... 2
- How will you prove experimentally that the graphite is a good conductor of electricity. The following experiment should be performed to check whether graphite is good conductor or not. When we use two graphite ends of pencil in... 1
- What are the different types of coal? What are their uses. The different types of coal are peat, lignite, bituminous, anthracite etc. uses :: Lignite is used in the generation of electricity. Bitumin... 1
- Write two physical properties of each. a) Diamond b) Charcoal: c) Fullerenes: a) Diamond: Diamond is the allotropes of carbon which is hardest in teh nature. It is colourless, transparent and brittle in pure form. b) C... 1
- Practical uses of CO2. CO₂ is mainly used in making aerated drinks. Solid carbon dioxide is used to make milk and it’s products cool during the transportation. In... 1
- Use of CO2 in the fire extinguisher. Carbon dioxide is used in the fire extinguisher as it has cooling effect at high pressure. Also it removes the oxygen which is necessary for... 1
- Uses of various allotropes of carbon. There are various allotropes of carbon which are used in many ways. Diamond is used in cutting glasses and in drilling machines. It is used... 1
- Petrol, diesel, coal are fossil fuels. Petrol, diesel, coal are the fossil fuels as they are obtained from the dead plants and animals. These fossil fuels are formed when the aqua... 1
- Methane is called as marsh gas. Methane is used as the marsh gas because it is mostly occuring at the marshy places which are the lands surrounded by water for long period... 1
- Diamond, graphite and fullerenes are crystalline forms of carbon. As we know that, carbon has the property of allotropy. That means it has three allotropes namely diamond, graphite and fullerenes. These are... 1
- GIve scientific reason Biogas is an eco-friendly fuel. Biogas is formed by the decomposition of animal dung, dry leaves, wet garbage in a biogas plant. This produces methane gas also called bioga... 1
- Give scientific reason Limewater turns milky when CO2 is passed through it. Limewater traditionally means a weak solution of the alkali calcium hydroxide Ca(OH)2. When CO2 is passed through limewater, it reacts with... 1
- Give scientific reason Graphite is not used in ornaments. Graphite is a black, soft, brittle and dull form of carbon. It is neither malleable nor ductile. These properties of graphite make it unsuit... 1
- write scientific reason Graphite is a conductor of electricity. In graphite, each carbon is bonded to three other carbon atoms in such a way that a hexagonal layered structure is formed. Due to this struc... 1
- Difference between Crystalline and non-crystalline forms of carbon Crystalline forms of carbon Non-crystalline forms of carbon (i) A crystalline form has a regular and definite arrangement of atoms. (ii) The... 1
- difference between Diamond and graphite. Diamond Graphite (i) Diamond is a brilliant, hard and crystalline allotrope of carbon. (i) Graphite is a black, soft, brittle and slippery c... 1
- Write the uses of diamond? Uses of diamonds are: Diamonds are used in glass cutting and rock drilling machines. Diamonds are used in ornaments. Diamond knives are used... 1
- In which compounds forms does carbon occurs? Carbon exist in various forms in its compounds. Some of the carbon compounds are as follows. In hydrocarbons mainly hydrogen and carbon are... 1
- Why are carbon and it’s compounds are used as fuel? As carbon and it’s compounds after combustion produces large amount of heat and also energy. So to gain more heat and energy carbon and it’s... 1
- Select the proper options and complete the statement. (Single, all, double, ionic, carbon, give and take, hydrogen) a) A carbon atom forms a covalent bond with other atoms. In this bond the two atoms share b) All the bonds in a saturated hydrocarbon share... 1
- Helium gas is filled in two identical bottles A and B. The mass of the gas in two bottles is 10g and 40g respectively. Given that, Mass of gas in bottle = m = 10 g Mass of gas in bottle = M= 40 g speed of sound in bottle A =speed of sound in bottle B = V Temp... 1
- Hydrogen gas is filled in two identical bottles, A and B at the same temperature. The mass of hydrogen in Given, mass of bottle A= m = 12 g mass of bottle B = M = 40 g Let us suppose speed of sound in bottle A = v And speed of sound in bottle B =... 1
- Sunil is standing between two parallel walls. The wall closest to him is at a distance of 660m. If he shouts, he hears Given that, The distance of wall closest to him is 660 m. And first echo will be heard after 4 seconds. 1) Thus, distance travelled by the s... 1
- Nita heard the sound of lightning after 4seconds of seeing it. What was the distance of lightning from her? Given that velocity is sound in air is 340m/s. And Nita heard sound of lightning after 4seconds. Hence, the distance of lightning from Nita... 1