SARASWATI STUDY POINT

Chemical Reactions & Equations

  1. What change do you observe, when magnesium ribbon is burnt in air?
  2. Define the term word equation.
  3. What is meant by thermal decomposition?
  4. What is an example of decomposition reaction?
  5. Name the term used for the physical state of the solution of the reactant or product dissolved in water.
  6. Name the chemical reaction in which heat is absorbed.
  7. Give reason- Magnesium ribbon is to be cleaned before burning in air.
  8. Define Corrosion and Rancidity. What is Redox reaction?
  9. Name the gas which burns with a pop sound.
  10. Name one metal which does not corrode.
  11. Name the type of reaction in which two or more substances combine to form a new single product. What happens when current is passed through water?
  1. What change do you observe on the surface of copper when its powder is heated?
  2. Give one disadvantage of oxidation in our daily life.
  3. Name the group of chemical substances used to prevent oxidation.
  4. Why state food has a peculiar smell?
  5. Which type of chemical reaction takes place when Barium hydroxide and Ammonium chloride are mixed together in terms of heat released or absorbed?
  1. Name the type of reaction taking place when iron nails are dipped in copper sulphate solution. Write one disadvantage of corrosion of metals.
  1. What happens when calcium oxide reacted with water? Write the chemical equation of reaction involved. What is balanced chemical equation? Why a skeletal equation should is to be balanced?
  1. Write the four changes which help us to determine whether a chemical reaction has taken place. Write the balanced equation for silver bromide kept in sunlight?
  1. What information regarding physical state do you get from the following notations:- (g), (l), (aq) and (s) ?
  1. Arrange iron, zinc and copper in increasing order of reactivity from the following reaction:- Fe + CuSO4 → FeSO4 + Cu, Zn + FeSO4 → ZnSO4 + Fe
  1. Explain Oxidation and Reduction in terms of gain or loss of oxygen, giving eg.s.
  2. Respiration is considered an exothermic reaction. Explain why?
  3. Write two methods by which oxidation process of food can be slowed down at home?
  4. When lead nitrate powder is heated which odour fumes are evolved? Also name the gas evolved.
  5. What happens when sodium sulphate solution is added to barium chloride solution? Give the chemical equation of the reaction.
  1. Oil and fat containing food items (chips) are flushed with Nitrogen. Give reason.
  2. What happens when a strip of zinc is dipped into a solution of copper sulphate? Write the balanced chemical equation of the reaction?
  1. Define decomposition reaction. Give one example each of thermal decomposition and electrolytic decomposition.
  1. Translate the given statement, first in word equation and then into skeleted equation:- Solutions of Barium chloride and sodium sulphate in water reacts to give insoluble barium sulphate and the solution of sodium chloride.
  1. Write the balanced chemical equation for the following reactions:-

(i)Barium chloride + potassium→ Barium sulphate + Potassium chloride.

(ii)Sodium chloride + Silver nitrate → Silver chloride + Sodium nitrate

(iii)Calcium hydroxide + Carbon dioxide → Calcium carbonate + water.

  1. Name the type of chemical reaction represented by the following equations:-

(i)CaCO3 (s) Heat CaO (s) + CO2 (g)

(ii)CaO (s) + H2O (l) → Ca(OH2) (aq)

(iii)Zn (s) + CuSO4 (aq) → ZnSO4 (aq) + Cu (s)

  1. Define displacement reaction. Give one example of it. How is it different from double displacement reaction?
  1. Translate the following statements into chemical equations and balance them:-

(i)Sodium chloride reacts with silver nitrate to give sodium nitrate and a precipitate of silver chloride.

(ii)Hydrogen gas combines with nitrogen to form ammonia.

(iii)Zinc carbonate decomposes to give Zinc oxide and carbon dioxide.

(iv)Ammonia gas reacts with water to give ammonium hydroxide.

(v)Copper (II) oxide on heating with hydrogen gas gives copper and water.

  1. Identify the substances that are oxidized and the substances that are reduced in the following reactions:-

(i)ZnO + C → Zn + Co

(ii)CuO + H2 → Cu + H2O

(iii)MnO2 + 4HCl → MnCl2 + 2H2O + Cl2

  1. Balance the following equations and state whether they are exothermic or endothermic:-

(i)Na + H2O → NaOH + H2 + Heat

(ii)FeSO4 (s) → Fe2O3(s) + SO2(g) + SO3(g)

(iii)CaCO3 (s) → CaO + CO2(g)

  1. Name the type of chemical reactions taking place when:-

(i)Lime stone is heated.

(ii)Magnesium ribbon is burnt in air.

(iii)Burning of coal

(iv)Iron nails are dipped in copper sulphate solution.

(v)Sodium sulphate is is mixed with barium chloride.

  1. For the following equation:- Pb (NO3)2(s) → PbO (s) + NO2 (g) + O2(g)

(i)Write the name and colour of the precipitate formed.

(ii)Balance the above chemical equation.

(iii)Name the type of chemical reaction.

  1. Translate the following statements into balancedchemical equations:-

(i)Sodium chloride reacts with silver nitrate to give sodium nitrate and a precipitate of silver chloride.

(ii)Hydrogen gas combines with nitrogen to form ammonia

(iii)Zinc carbonate decomposes to give zinc

(iv)Ammonia gas reacts with water to give ammonium hydroxide.

(v)Copper oxide on heating with hydrogen gas gives copper and water.

Acid, Base & Salts

  1. Define dilution.
  2. Name the acid produced by our stomach?
  3. Name two olfactory indicators.
  4. Name two natural indicators.
  5. What change in color do you observe when turmeric mixes with a base.
  6. Define neutralization reaction.
  7. What are alkalis?
  8. How can the pain and irritation caused by the stung of honey bee relieved?
  9. Give reason: Acids conduct electricity only in presence of water.
  10. Write is tartaric acid added to baking soda in baking powder.
  11. What is Brine?
  12. Name two synthetic indicators.
  13. Name the acid present in nettle leaves.
  14. What change in colour do you observe when methyl orange is mixed with an acid?
  15. Name the group of substances used to neutralize the excess acid in our stomach.
  16. What are those indicators called whose odour changes in acidic or basic media?
  17. Name the gas evolved when an acid reacts with a metal?
  18. Why Bee- sting causes pain and irritation?
  19. Why curd and sour substances should not be kept in brass or copper vessels?
  20. Name the components present in baking powder.
  21. What is the pH of acid rain?
  22. Name the gas evolved when sodium hydroxide reacts with zinc.
  23. While diluting an acid, why is it recommended that the acid should be added to water and not water to the acid?
  1. Write the chemical name of plaster of Paris.
  2. Name the chemical compound which was the important symbol in India’s struggle for freedom.
  1. What happens when the blue crystals of copper sulphate are heated?
  2. How is the concentration of hydronium ion (H3O+) affected when a solution of acid is diluted?
  3. Three solution X, Y and Z have pH values 8,9 and 10 respectively, arrange them in increasing order of their basic character.
  1. Fresh milk has a pH of 6. Write the change in pH when it turns into curd.
  2. Why is the process of producing sodium hydroxide called chlor-alkali process?
  3. What will happen when sodium hydrogen carbonate is heated? Write the chemical equation of the reaction involved.
  1. A milkman added a small amount of baking soda to fresh milk.
  2. Write differences between acidic and basic salts.
  3. A baker found that the cake prepared by him is hard and small in size. Which ingredient has he forgotten to add that would have made the cake fluffy? Give reason.
  1. Why does distilled water not conduct electricity, whereas rain water.
  2. Why plaster of Paris should be stored in a moisture proof container. Write a chemical equation of the reaction between plaster of Paris and water.
  1. Write the pH of the following:-

(i)Gastric juice

(ii)Blood

(iii)Lemon juice

(iv)Milk of magnesia

  1. What is the effect of acid and base on phenolphthalein, whereas rain water does?
  2. Four test tubes A, B, C and D contain the solution having pH 3, 5, 8 and 12 respectively. Arrange them in increasing order of acidic character. Give reason in support of your answer.
  1. Define water of crystallization. Write the number of water molecules present in one formula unit of copper sulphate crystal.
  1. A metal compound X reacts with dilute Hydrochloric acid to produce effervescence. The gas evolved extinguishes a burning candle and turns lime water milky. Identify the gas evolved. Write a balanced chemical equation for the reaction if one of the compounds formed is CaCl2.
  1. What happens when metal carbonates and metal hydrogen carbonates react with acids? Write the word equations in each case.
  1. Under what soil condition do you think a farmer would treat the soil of his field with quick lime (CaO) or slaked lime [Ca (OH)2]. What should be the nature of soil for a healthy growth of plants?
  2. Give reason-HCl, HNO3 etc., show acidic characters in aqueous solutions while alcohol and glucose solutions do not show acidic character.
  1. Name the gas liberated when an acid reacts with a metal. Illustrate with an example. How will you test the presence of this gas?
  1. Name the acid present in following natural sources:-

(i)Vinegar

(ii)Tomato

(iii)Tamarid

  1. On passing excess carbon dioxide gas through lime water, if first turns milky and then becomes colourless. Explain why? Write the chemical reactions taking place.
  1. Illustrate with an activity that compound like Alcohol and Glucose contain hydrogen but are not categorized as acids.
  1. Draw a flow chart showing uses of products from chlor-alkali process.
  2. You are provided with three test tubes A, B and C. A contains distilled water, B and C contains acidic and basic solutions respectively. If you are given only blue litmus paper, how will you identify the nature of solution in three tubes?
  1. Name the raw materials used in manufacture of Baking soda. Write two important uses of Baking soda.
  1. Name the hardest chemical substances in the body of which tooth enamel is made. At what pH in the mouth it gets corroded? What kind of toothpaste should we use to protect our teeth?
  1. A sanitary worker uses a white chemical having strong smell of chlorine gas to disinfect the water tank. Identify the chemical compound. Write its chemical formula. Give the chemical equation for its preparation.
  1. What is Chlor-alkali process? Write the chemical reaction taking place in form of chemical equation. Name the gases given off at the anode and the cathode respectively. Write one use each of any two products produced in this process.
  1. Five test tubes A, B, C, D and E contain solutions having pH 2, 4, 14, 7 and 8 respectively. Among these solutions which one is:-

(i)Strongly acidic (ii) Strongly basic(iii) Neutral

(iv) Weekly acidic(v) Weekly basic

Arrange the pH in decreasing order of hydrogen ion concentration.

  1. What happens when

(i)Excess of carbon dioxide is passed through lime water

(ii)Dry chlorine gas is passed over slaked lime

(iii)Electricity is passed through an aqueous solution of sodium chloride

(iv)Gypsum is heated at 373k

(v)A solution of sodium hydrogen carbonate is heated

  1. Out of sodium hydrogen carbonate, sodium carbonate, plaster of Paris, bleaching powder, sodium hydroxide

(i)Name the compound used for selling fractured bones.

(ii)Name the compound used for making baking powder.

(iii)Name the compound used for softening hard water.

(iv)Name the compound used for bleaching cotton in textile industry.

(v)Name the compound used for making soaps and detergents.

Also write their chemical formula.

Metals & Non-metals

  1. Name two metals which have very low melting points and melts if you keep them on the palm.
  2. Name the non-metals which are lustrous.
  3. Name two most malleable metals.
  4. Define ductility. Name the most ductile metal.
  5. Name two metals which are best conductors of heat.
  6. Name two metals which start floating in water.
  7. Name one metal and one non-metal which exist in liquid state at room temperature.
  8. Name two metals which can be cut easily with knife.
  9. What is the nature of oxides formed by metals and non-metals?
  10. Name two metals which do not react with water but react with steam?
  11. What is the colour of flame when magnesium burns in air?
  12. What type of chemical bond is present in sodium chloride?
  13. Name the allotrope of carbon which is the hardest natural substance known and has a high melting point.
  1. Why sodium and potassium metals are kept in kerosene?
  2. Name two metals other than silver and gold, which do not react with water even in form of steam.
  1. Name the reducing agent in the following chemical reaction:-

Fe2O3 + Al → Al2O3 + Fe

  1. Which two metals liberate hydrogen gas when reacts with dilute Nitric acid?
  2. Select a most reactive and a least reactive metal from the following:

Al, Ca, Zn, Fe, Hg, Cu.

  1. What is an amalgam?
  2. Name one cheap reducing agent commonly used in extraction of purity metals.
  3. Name the electrolyte used in electrolytic refining of copper.
  4. Name the process by which metals which is at the top of activity series are extracted from their ore.
  1. In electrolytic refining, name the electrode which is made up of impure metals and the electrode which is made up of pure metals.
  1. Why Aluminium cannot be obtained by the reduction of its ore with carbon?
  2. What name can be given to the insoluble impurities which settle down at the bottom of the anode during electrolytic refining of metals?
  1. Name the metal which does not react with dilute Hydrochloric acid.
  2. An element ‘A’ reacts with oxygen to form an oxide which dissolves in water to give an aqueous solution which turns red litmus blue. Element A is metal or non metal.
  1. Differentiate between Roasting and Calcination. Give one example of each.
  2. Is hydrogen gas evolved when most metal reacts with nitric acid? Why?
  3. A metal M left in moist air for a longer time loses its shiny brown surface and gains a great coat. What is this green coloured compound and identify the metals.
  1. Why sodium chloride has high melting point?
  2. What are amphoteric oxides? Give two examples of such oxides.
  3. Explain why magnesium metal after reacting with hot water starts floating on its surface. Write the chemical equation of the reaction.
  1. Give two differences between metal and non-metal on the basis of their chemical properties.
  2. Give reason- Ionic compounds conduct electricity only in molten state not in solid state.
  3. An alloy is used electronic industry to wield the components. Name the alloy and its constituents.
  1. Define reactivity series of metals. Rearrange the following metals in increasing order of their reactivity: Zn, Al, Fe, Cu, Au, and Ca.
  1. Illustrate the formation of bonds in:-

(i)Sodium Chloride(ii)Magnesium Chloride

  1. Write balanced chemical equation for the reaction taking place when:-

(i)Zinc carbonate is calcinated.(ii)Cinnabar is heated in air.

(iii) Manganese dioxide is heated with aluminium powder.

  1. Explain why aluminium is more reactive than iron, yet its corrosion is less than iron.
  2. Give reason:-

(i)Ionic compounds are solids.

(ii)Gold and silver are found in Free State in nature.

(iii)Ionic compounds have high melting points.

  1. An element A has atomic number 11 and another element B has atomic number 8. A and B combine to form an ionic compound. What would be the formula of the compound formed? Illustrate the formation of compound showing electron transfer.
  1. Write the constituents of the following alloys:-

(i)Stainless steel

(ii)Brass

(iii)Bronze

  1. Name the ore of Mercury. Name the method by which metals like mercury, which is low in the reactivity series can be extracted from its ore. Write the chemical reaction involved in extraction of mercury from its ore.
  1. What is meant by refining of metals? Name one method widely used for refining of metals. How this method is different from electrolyte reduction?
  1. Write the chemical equations for the following reactions:-

(i)Iron reacts with steam

(ii)Calcium reacts with water.

(iii)Copper is heated in air.

  1. What is the reduction between Iron oxide and aluminium known as?

Write the chemical equation? Write one use of this reaction?

  1. Write the systematic steps involved in the process of Extraction of metal of medium reactivity from its sulphide ore.
  1. What are ionic compounds? State four properties of ionic compounds will respect of their physical nature, melting and boiling points, solubility and conduction of electricity.
  1. What is meant by rusting? Write an activity to find out the necessary conditions under which iron rusts. Mention two methods used for preventing rusting of iron.
  1. A metal E is stored under kerosene. When a small piece of this metal is left open in the air, it starts warming up and the product formed is dissolved in water which turns the red litmus blue:-

(i)Name the metal E.

(ii)Write the chemical equation for the reaction when it is exposed to air and when the product is dissolved in water.

(iii)Explain the process by which the metal is obtained from its molten chloride.

  1. A metal M which is one of the best conductors of heat and electricity is used in making electric wires is found in nature as sulphides are M2S.

(i)Name the metal M.

(ii)Which process will be suitable for the extraction of this metal from its ore M2S?

Draw a labelled diagram of electrolytic refining of the metal

Life Processes

Important terms and definitions:-

  • Nutrition: - It is a process of intake as well as utilization of nutrients by an organism or intake of food by organisms to release energy for carrying out all life processes.
  • Nutrient: - It is a substance, which an organism get from its surroundings and uses it either as an energy source or for biosynthesis of body constituents.
  • Need for Nutrition: - Living organisms continuously require energy for their life processes even during their sleep.

(i) Autotrophs (auto-self):- Make their own food using organic raw materialsi.e., carbon dioxide and water utilising solar-energy.E.g., all green plants and some bacteria.