{"id":22632,"date":"2024-02-21T17:06:50","date_gmt":"2024-02-21T11:36:50","guid":{"rendered":"https:\/\/icsesolutions.com\/?p=22632"},"modified":"2024-02-22T09:43:53","modified_gmt":"2024-02-22T04:13:53","slug":"selina-concise-chemistry-class-6-icse-solutions-air-and-atmosphere","status":"publish","type":"post","link":"https:\/\/icsesolutions.com\/selina-concise-chemistry-class-6-icse-solutions-air-and-atmosphere\/","title":{"rendered":"Selina Concise Chemistry Class 6 ICSE Solutions – Air and Atmosphere"},"content":{"rendered":"
ICSE Solutions<\/a>Selina ICSE Solutions<\/a>ML Aggarwal Solutions<\/a><\/p>\n APlusTopper.com provides step by step solutions for Selina Concise ICSE Solutions for Class 6 Chemistry. You can download the Selina Concise Chemistry ICSE Solutions for Class 6 with Free PDF download option. Selina Publishers Concise Chemistry for Class 6 ICSE Solutions all questions are solved and explained by expert teachers as per ICSE board guidelines.<\/p>\n Selina Class 6 Chemistry ICSE Solutions<\/a>Physics<\/a>Biology<\/a>Maths<\/a>Geography<\/a>History & Civics<\/a><\/p>\n Selina Concise ICSE Solutions for Class 6 Chemistry Chapter 6 Air and Atmosphere<\/strong><\/p>\n POINTS TO REMEMBER<\/strong><\/p>\n EXERCISE-I<\/strong><\/span><\/p>\n Question 1.<\/strong><\/span> Question 2.<\/strong><\/span> Question 3.<\/strong><\/span> Question 4.<\/strong><\/span> Question 5.<\/strong><\/span> Question 6.<\/strong><\/span> Question 7.<\/strong><\/span> (a)<\/strong> Ice cold water is filled in a glass tumbler. Answer:<\/strong><\/span><\/p>\n (a)<\/strong> We will observe that fine water droplets get deposited on the outer wall of the glass tumbler. Question 8.<\/strong><\/span> (a)<\/strong> Lime water Answer:<\/strong><\/span><\/p>\n (a)<\/strong> Calcium hydroxide Ca(OH)2<\/sub> These droplets were present in air as moisture which got condensed on the cooler walls of glass tumbler. This shows the presence of water vapours in air.<\/p>\n EXERCISE-II<\/strong><\/span><\/p>\n Question 1.<\/strong><\/span> Question 2.<\/strong><\/span> (a)<\/strong> oxygen Answer:<\/strong><\/span><\/p>\n (a)<\/strong> Oxygen: For respiration and breathing no life is possible without oxygen. Question 3.<\/strong><\/span> (a)<\/strong> Respiration Answer:<\/strong><\/span><\/p>\n (a)<\/strong> Respiration : Respiration is a chemical process that takes place in all living beings (slow in plants). In this process, oxygen present in inhaled air reacts with the digested food material in the body. This results in release of energy, carbon-dioxide and water. Question 4.<\/strong><\/span> 1. CNG (Compressed natural gas) Question 5.<\/strong><\/span> (a)<\/strong> Aquatic animals and plants are able to survive in matter. Answer:<\/strong><\/span><\/p>\n (a)<\/strong> Aquatic animals and plants use oxygen dissolved in water and survive. Question 6.<\/strong><\/span> Question 7.<\/strong><\/span> Respiration<\/strong><\/p>\n Differences :<\/strong> Respiration<\/strong><\/p>\n Question 8.<\/strong><\/span> Chemical name of rust is hydrated iron oxide [Fe20rxH20]<\/p>\n Question 9.<\/strong><\/span> (a)<\/strong> water boats Answer:<\/strong><\/span><\/p>\n (a)<\/strong> Air helps movement of water boats. Question 10.<\/strong><\/span>\n
\nBreathing :<\/strong> The complete process in which air is inhaled and exhaled is called breathing.<\/li>\n
\nWhat is atmosphere ?
\nAnswer:<\/strong><\/span>
\nThe earth is surrounded by a thick layer of air called the atmosphere that extends upto a height of about 320 kilometres above the surface of the earth.<\/p>\n
\nWhy can\u2019t we see air ?
\nAnswer:<\/strong><\/span>
\nWe can\u2019t see air because it is colourless, odourless and transparent gaseous matter.<\/p>\n
\nWhat is wind ?
\nAnswer:<\/strong><\/span>
\nFast moving air is called wind.<\/p>\n
\nWhat would have happened if there would have been no atmosphere around the earth ?
\nAnswer:<\/strong><\/span>
\nWithout atmosphere life would not be possible as atmosphere protects us from harmful gases. We could not live without
\nair present in atmosphere. In absence of the atmopshere, the earth would get so cold at night that we would not be able to survive. No CO2<\/sub> and\u00a0N2<\/sub> for plants without atmosphere.
\nP.Q. When water is heated, we see bubbles rising up. Why ?<\/strong>
\nAnswer:<\/strong><\/span>
\nWater has a lot of air dissolved on it. This is what allows breathing to fishes and other aquatic beings. The solubility of gases decreases when the temperature is raised, and that is why the dissolved air bubbles out from the water.<\/p>\n
\nWhy is air called a mixture ? Give five facts in support of your answer.
\nAnswer:<\/strong><\/span>
\nAir is a mixture because :<\/strong><\/p>\n\n
\nWhat are the main components of air ? Write down the composition of three main gases present in air by volume.
\nAnswer:<\/strong><\/span>
\nMain components of air are :
\n
\n
\n<\/strong><\/p>\n
\nWhat do you observe when<\/p>\n
\n(b)<\/strong> A burning candle is covered with an inverted jar.
\n(c)<\/strong> Carbon dioxide gas is passed through lime water.
\n(d)\u00a0<\/strong>A beam of light is allowed to enter in a closed dark room through a small hole.<\/p>\n
\n(b)<\/strong> The candle burn more brightly because candle gets oxygen support in burning.
\n(c)<\/strong> When CO2<\/sub> gas is passed through lime water it forms calcium carbonate which is white precipitate (turbidity). This gives the milky white appearance to the solution.
\n(d)<\/strong> We will observe randomly moving dust particles in the beam of light. This confirms the presence of dust particles in the air.<\/p>\n
\nWrite the chemical name of –<\/p>\n
\n(b)<\/strong> The white insoluble solid formed on reaction of carbon dioxide with lime water.<\/p>\n
\n(b)<\/strong> Calcium carbonate – CaCO3<\/sub><\/p>\n
\nName two important processes supported by oxygen present in air.
\nAnswer:<\/strong><\/span>
\nTwo processes supported by oxygen present in air are :<\/p>\n\n
\nGive two uses of the following components present in air:<\/p>\n
\n(b)<\/strong> nitrogen
\n(c)<\/strong> carbon dioxide
\n(d)<\/strong> water vapour<\/p>\n
\nOxygen is the most vital component which is responsible for two most important processes,
\n(i)<\/strong> Respiration and
\n(ii)<\/strong> Combustion.
\n(b) Nitrogen :<\/strong> Present in air gets fixed up in the soil as nitrates used by plants for their growth and for the formation of protein an important nutrient for animals. It is used to make fertilizers and various nitrogenous products.
\n(c) Carbon dioxide :<\/strong> Carbon dioxide is used by plants to prepare their food by photosynthesis. Dry ice (solid carbon-dioxide) is used as a refrigerant. Carbon dioxide is used to prepare fizzy drinks like soda water.
\n(d) Water vapour :<\/strong> Water vapors present in air provide moisture for both plants and animals. It also helps in predicting climatic conditions of a particular area as its amount varies from place to place and time to time.<\/p>\n
\nDefine the following:<\/p>\n
\n(b)<\/strong> Photosynthesis
\n(c)<\/strong> Combustion.<\/p>\n
\nSugar + Oxygen \u2192 CO2<\/sub> + Water + Energy.
\n(b)<\/strong> Photosynthesis : Process of producing food by green plants taking CO2<\/sub>\u00a0from air, water from soil by roots and in presence of sun light and chlorophyll is called photosynthesis.
\n(c)<\/strong> Combustion : Combustion also called burning \u201cis burning of substance in oxygen of air completely producing heat and light is called combustion.\u201d<\/p>\n
\nWhat are fuels ? Give two examples of modern fuels.
\nAnswer:<\/strong><\/span>
\nFuels :<\/strong> The substances which burn in air to produce large amount of energy in the form of heat and light are called fuels.
\nExamples :<\/strong><\/p>\n
\n2. LPG (Liquefied natural gas)<\/p>\n
\nGive reasons :<\/strong><\/p>\n
\n(b)<\/strong> A burning candle stops burning if covered with a glass tumbler.
\n(c)<\/strong> Mountaineers and divers carry oxygen cylinders with them.
\n(d)<\/strong> When water is heated, we see bubbles rising up.<\/p>\n
\n(b)<\/strong> Oxygen is necessary for combustion when covered with a glass tumbler supply of oxygen stops.
\n(c)<\/strong> For artificial respiration mountaineers carry oxygen cylinders as at high altitudes, the air is thin and breathing becomes difficult. Also divers carry oxygen cylinder for artificial respiration as there is less oxygen dissolved in water (less dense) and breathing becomes difficult.
\n(d)<\/strong> These bubbles come from the air dissolved in water. The marine life uses air dissolved in water.<\/p>\n
\nName the processes which maintain the balance between oxygen and carbon dioxide in the air. How is it done?
\nAnswer:<\/strong><\/span>
\nRespiration and combustion are the processes which maintain the balance between oxygen and CO2<\/sub> in the air.<\/p>\n\n
\nState two similarities and two differences between respiration and burning.
\nAnswer:<\/strong><\/span>
\nSimilarities:<\/strong>
\nBurning<\/strong><\/p>\n\n
\n
\nBurning<\/strong><\/p>\n\n
\n
\nDefine rusting ? What are the two necessary conditions for rusting of iron. Give the chemical name of rust.
\nAnswer:<\/strong><\/span>
\nRusting :<\/strong> Slow conversion of iron into its hydrated oxide in the presence of moisture and air is called rusting.
\nConditions for rusting:<\/strong><\/p>\n\n
\nHow is air useful to :<\/strong><\/p>\n
\n(b)<\/strong> agriculture
\n(c)<\/strong> windmills
\n(d)<\/strong> scooters and cars.<\/p>\n
\n(b)<\/strong> Air speeds up drying up of agricultural products like grains, pulses fruits etc. Air helps in pollination of flowers and dispersel of seeds.
\n(c)<\/strong> Windmills work where there is sufficient movement of air.
\n(d)<\/strong> Air filled tyres of cars move smoothly on road as there is less friction.<\/p>\n
\nState the full form of LPG and CNG ? How are the two different in their composition ?
\nAnswer:<\/strong><\/span>
\nLPG (Liquefied Petroleum Gas):<\/strong> It is obtained from crude petroleum oil. It mainly contains gaseous compounds known as isobutane and butane. Popularly it is known as cooking gas. It is the best fuel for domestic purposes and in laboratories. It is available in cylinders. It is also supplied through pipes in big cities.
\nCNG (Compressed Natural Gas):<\/strong> It is produced along with crude oil. It mainly contains methane gas. It has become a popular fuel for vehicles like three wheeler scooters, cars and buses. It is a cheap fuel as well as pollution free. It is used as a substitute of petrol.
\nDifference in composition
\nLPG<\/strong> is obtained from crude petroleum oil. It mainly contains gaseous compounds known as isobutane and butane. While
\nCNG<\/strong> is produced along with crude oil. It mainly contains methane gas.<\/p>\n