ATS COACHING CLASSES SCIENCE (X) CHEMICAL REACTIONS AND EQUATIONS |
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MULTIPLE CHOICE QUESTIONS (MCQs)
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MnO2
+ xHCl → MnCl2
+ zH2O + yCl2 In order to balance the above chemical equation, the values of x, y
and z respectively are (a) 6,2,2 (b) 4,1,2 (c) 4,2,1 (d) 2,2,1 |
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A chemical reaction in which exchange of ions occurs between the
reactants, is known as (a) endothermic reaction (b) exothermic reaction (c) double displacement reaction (d) displacement reaction |
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When lead nitrate powder is heated in boiling tube, we observe (a) brown fumes of nitrogen dioxide (b) brown fumes of lead oxide (c) yellow fumes of nitrogen dioxide (d) brown fumes of nitric oxide |
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When hydrogen sulphide gas is passed through a blue solution of
copper sulphate, a black ppt of copper sulphide is obtained and the sulphuric
acid so formed remains in the solution. The reaction is an example of a (a) combination reaction (b) displacement reaction (c) decomposition reaction (d) double displacement reaction |
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Copper utensils slowly lose their shiny brown surface and gain a
green coat on prolonged exposure to atmospheric air. This is due to the
formation of a coating of (a) copper sulphate (b) copper carbonate (c) cupric oxide (d) cuprous oxide |
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2Na (s)
+ 2H2O (l) → 2NaOH
(aq) + H2 (g) The reducing agent in this reaction is (a) Na (b) H2O (c) NaOH (d) H2 |
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In the electrolysis of water, if the mass of the gas collected at the
anode is ma and the mass of the gas collected at the cathode is mc,
the value of (mc/ ma) is (a) 8 (b) 16 (c) 1/16 (d) 1/8 |
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ASSERTION AND REASON QUESTIONS (a) Both Assertion (A) and Reason (R) are true and Reason (R) is the
correct explanation of the Assertion (A). (b) Both Assertion (A) and Reason (R) are true and Reason (R) is not
the correct explanation of the Assertion (A). (c) Assertion (A) is true, and Reason (R) is false. (d) Assertion (A) is false, and Reason (R) True. |
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ASSERTION: Following is a
balanced chemical equation for the action of steam on iron: 3Fe + 4H2O → REASON: The law of
conservation of mass holds good for a chemical equation. |
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ASSERTION: Reaction of
quick lime with water is an exothermic reaction. REASON: Quick lime reacts
vigorously with water releasing a large amount of heat. |
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ASSERTION: Silver salts
are used in black and white photography. REASON: Silver salts do
not decompose in the presence of light. |
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ASSERTION: Burning of
natural gas is an endothermic process. REASON: Methane gas
combines with oxygen to produce carbon dioxide and water. |
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VERY SHORT ANSWER QUESTIONS |
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Copper powder is taken in a china dish and heated over a burner. Name
the products formed and state its colour. Write the chemical equation for the
reaction involved. |
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Name the type of chemical reaction in which calcium oxide reacts with
water. Justify your answer by giving balanced chemical equation for the
chemical reaction. |
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A student wants to study a decomposition reaction by taking ferrous
sulphate crystals. Write two precautions he must observe while performing the
experiment. |
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A student mixes sodium sulphate powder with barium chloride powder.
What changes would the student observe on mixing the two powders? Justify
your answer and explain how he can obtain the desired change. |
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What is observed after about 1 hour of adding the strips of copper
and aluminium separately to ferrous sulphate solution filled in two beaker? Name the reaction if any change in colour is noticed. Also, write
chemical equation for the reaction. |
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SHORT ANSWER TYPE QUESTIONS |
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Explain the significance of photosynthesis. Write the balanced
chemical equation involved in the process. |
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Answer the following questions in the context of electrolysis of
water: (a) Why is this reaction/ process called a decomposition reaction? (b) Giving reason state whether this reaction is exothermic or
endothermic. (c) Name the gases collected at the anode and cathode. (d) What is the mass ratio of the gases collected at the anode and
cathode? |
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Write one chemical equation each for the chemical reaction in which
the following have taken place: (i) Change in colour (ii) Change in temperature (iii) Formation of precipitate Mention colour change/ temperature change (rise/ fall) / compound
precipitated along with equation. |
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(a) Define a double displacement reaction. (b) Write the chemical equation of a double displacement reaction
which is also a (i) Neutralization reaction and (ii) Precipitation reaction.
Give justification of your answer. |
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A shining metal ‘M’, on burning gives a dazzling white flame and
changes to a white powder ‘N’. (a) Identify ‘M’ and ‘N’. (b) Represent the above reaction in the form of a balanced chemical
reaction. (c) Does ‘M’ undergo oxidation or reduction in this reaction?
Justify. |
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Identify the type of each of the following reactions. Also write
balanced chemical equation for each reaction. (i) A reaction in which the reaction mixture becomes warm. (ii) A reaction in which an insoluble substance is formed. |
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Lead nitrate solution is added to a test tube containing potassium
iodide solution. (a) Write the name and colour of the compound precipitated. (b) Write the balanced chemical equation for the reaction involved. (c) Name the type of this reaction justifying your answer. |
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LONG ANSWER TYPE QUESTIONS |
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When Lead Nitrate is heated strongly in a boiling tube, two gases are
liberated and a solid residue is left behind in the test tube. (i) Name the type of chemical reaction and define it. (ii) Write the name and formula of the coloured gas liberated. (iii) Write the balanced chemical equation for the reaction. (iv) Name the residue left in
the test tube and state the method of testing its nature (acidic/ basic). |
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(i) Write balanced chemical equation for the following word equation. Lead
nitrate + Potassium iodide → Lead iodide + Potassium nitrate Is this a double displacement reaction? Justify your answer. Name the
compound precipitated and write the ions present in it. (ii) Write the method of preparation of Ca(OH)2. What
happens when CO2 is passed through it? Write balanced chemical
equation for the reaction involved.  |
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Give reason: (i) Why is respiration considered as an exothermic reaction? (ii) Write chemical name and the formula of the brown gas produced
during thermal decomposition of lead nitrate. (iii) Why do chips manufactures flush bags of chips with gas such as
nitrogen? (iv) Antioxidants are added to foods containing fats and oils. (v) White silver chloride turns grey in sunlight. |
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Write the balanced chemical equations for the following reactions and
identify the type of reaction in each case: (i) Magnesium ribbon is burnt in an atmosphere of nitrogen gas to
form solid magnesium nitride. (ii) Chlorine gas is passed in an aqueous potassium iodide solution
to form potassium chloride solution and solid iodide. (iii) Ethanol is burnt in air to form carbon dioxide, water and
releases heat. (iv) Lead acetate solution is treated with dilute hydrochloric acid
to form lead chloride and acetic acid solution. (v) Nitrogen gas is treated with hydrogen gas in the presence of a
catalyst at 773 K to form ammonia gas. |
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(a)
Barium chloride + Potassium sulphate → (b)
Zinc + Silver nitrate → (c)
Sodium hydroxide + Sulphuric acid → (d)
Calcium oxide + water → Calcium hydroxide (e)
Magnesium carbonate → |
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CASE BASED STUDY QUESTIONS |
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Read the following passage and answer the
questions given below: Rahul left
his bicycle in the garden during the rainy season. After a few weeks, he
noticed reddish-brown flakes on the metal parts of the bicycle. 1. What
type of chemical reaction is responsible for the rusting of iron? 2. Write
the balanced chemical equation for the rusting of iron. 3. Mention
any two conditions necessary for rusting. 4. Suggest
two methods to prevent rusting. 5. Is rusting
a reversible or irreversible change? Justify your answer. |
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Read the following passage and answer the
questions given below: In a
laboratory, a student burns a strip of magnesium ribbon in the presence of
air and observes a bright white flame. 1. What is
the type of reaction observed? 2. Write
the balanced chemical equation for the reaction. 3. What is
the white powder formed called? 4. Is this
an exothermic or endothermic reaction? Explain. 5. What
precaution is taken before burning the magnesium ribbon and why? |
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Read the following passage and answer the
questions given below: Plants use
sunlight to convert carbon dioxide and water into glucose and oxygen—a
process essential for life on Earth. 1. Write
the balanced chemical equation for photosynthesis. 2. What
kind of chemical reaction is this: combination, decomposition, displacement,
or double displacement? 3. Is
photosynthesis an endothermic or exothermic reaction? 4. Name
the green pigment that helps in this reaction. 5. How
does this reaction benefit other organisms? |
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Read the following passage and answer the
questions given below: During a
science experiment, Neha mixes baking soda with vinegar and observes fizzing
and bubbling. 1. What
gas is released during this reaction? 2. Write
the balanced chemical equation for this reaction. 3. What
type of reaction is this (combination, decomposition, displacement, or double
displacement)? 4. What is
the role of the gas evolved in extinguishing fires? 5. Why is
this reaction considered a neutralization reaction? |
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