chemical reactions and equations

• Reduction reaction is when a substance loses oxygen or gains hydrogen.
• Chemical reactions and equations are designed by Shobhit Nirwan for 2022-23 boards.
• The equation Lallu Problem (L.P.) is balanced by checking the number of atoms on both sides of the equation.
• In the first step of balancing chemical equations, multiply oxygen molecules with hydrogen molecules by 4 to get Fe3O4 + H2.
• Lead nitrate reacts with potassium iodide to form yellow precipitate of lead iodide and the reaction is double displacement as well as precipitation reaction.
• The Assertion and the Reason are correct but the Reason is not the correct explanation of the Assertion.
• A lead nitrate on thermal decomposition gives lead oxide, brown coloured nitrogen dioxide and oxygen gas.
• Zinc reacts with oxygen to form zinc oxide.
• Zinc reacts with sulphuric acid to form zinc sulphate and hydrogen gas, it is a displacement reaction.
• In the second step of balancing chemical equations, multiply hydrogen atoms by multiplying H2 with 3 to get Fe2O3 + SO2 + SO3.
• In the third step of balancing chemical equations, multiply hydrogen atoms by multiplying H2 with 2 to get Fe2O3 + SO2 + SO3.
• In the fourth step of balancing chemical equations, multiply hydrogen atoms by multiplying H2 with 3 to get Fe2O3 + SO2 + SO3.
• Calcium Oxide reacts vigorously with water to produce slaked lime, it is an exothermic process because heat is released.
• When sodium sulphate reacts with barium chloride solution, barium sulphate which is an insoluble product (i.e., precipitate) and two moles of sodium chloride are formed, here, exchange of ions takes place.
• Ferrous sulphate crystals are light green in colour.
• The reaction between hydrogen sulphide gas and copper sulphate results in a black precipitate of copper sulphide and the sulphuric acid formed remains in the solution, it is an example of combination reaction.
• On heating, the green colour of the crystals changes to white because of loss of water of crystallisation on heating.
• Respiration is a burning process of food in the body to produce energy, hence it is considered as an exothermic reaction.
• In a double displacement reaction such as the reaction between sodium sulphate solution and barium chloride solution, exchange of ions takes place.
• On strongly heating ferrous sulphate crystals, ferric oxide, sulphur dioxide and sulphur trioxide are formed.
• Ferric oxide, sulphur dioxide and sulphur trioxide are formed when ferrous sulphate crystals are heated.
• Barium sulphate is formed when barium chloride and potassium sulphate react.
• Zinc nitrate is formed when zinc and silver nitrate react.
• Magnesium ribbon keeps on burning in the atmosphere of nitrogen because magnesium reacts with nitrogen to form magnesium nitrides and this reaction is a combination reaction.
• A change in the state of matter and change in temperature take place during a chemical reaction.
• Natural gas burns and combines with oxygen to produce carbon dioxide and water.
• Quick lime, which is a white solid, changes to calcium hydroxide, which is soluble in water and forms a clear solution, after a reaction with water.
• Both hydrochloric acid and manganese dioxide are oxidized in the chemical reaction : Mn O 2 + 4HCI MnCl 2 + 2H 2 O + C l 2.
• In the fifth step of balancing chemical equations, multiply hydrogen atoms by multiplying H2 with 3 to get Fe2O3 + SO2 + SO3.
• In the sixth step of balancing chemical equations, multiply hydrogen atoms by multiplying H2 with 3 to get Fe2O3 + SO2 + SO3.
• The chemical reaction between potassium iodide solution and lead nitrate solution results in the formation of colourless and yellow solutions respectively.
• Rusting of Iron is a chemical reaction.
• The blue colour of copper sulphate solution disappears when iron filings are added to it due to a chemical reaction.
• Heating of manganese dioxide with aluminium powder is a chemical reaction.
• Dil HCl acid is added to sodium hydroxide solution to form sodium chloride and water.
• In a double displacement reaction, two compounds react by an exchange of ions to form two new compounds.
• The chemical reaction between sulphuric acid and barium chloride results in the formation of a white precipitate.
• The chemical reaction between quick lime and water results in the formation of Ca(OH)2(aq) and heat.
• Digestion of food in our body is a chemical reaction.
• When an iron object is left in moist air for a few days or weeks, it gets a layer of a red-brown flaky substance called rust in an oxidation reaction.