Extra questions on chemical reaction and equation competition
Answers
1) define chemical reaction .
2) define balanced and unbalanced reaction .
3) define reactant and product
4) types of chemical reaction and there example
5) redox reaction
Answer:
Question 1. Which of the following reactions involves the combination of two elements :-
a)CaO + CO2 -> CaCO3
b)4Na + O2 -> 2Na2O
c)SO2 +(1/2)O2 -> SO3
d)NH3 + HCI -> NH4CI
Question 2.When hydrogen sulphide gas is passed through a blue solution of copper sulphate, a black precipitate of copper sulphate is obtained and the sulphuric acid so formed remains in the solution. The reaction is an example of :-
a)A combination reaction
b)A displacement reaction
c)A decomposition reaction
d)A double decomposition reaction
Question 3.What happens when copper rod is dipped in iron sulphate solution :-
a)Copper displaces iron
b)Blue color of copper sulphate solution is obtained
c)No reaction takes place
d)Reaction is exothermic
Question 4.A student added dilute HCI to a test tube containing zinc granules and made following observations :-
a)The zinc surface became dull and black
b)A gas evolved which burnt with a pop sound
c)The solution remained colorless
d)The solution becomes green in color.
Question 5.A dilute solution of sodium carbonate was added to two test tubes one containing dilute HCI (a) and the other containing dilute NaOH (b). the correct observation was :-
a)A brown colored gas liberated in test tube A
b)A brown colored gas liberated in test tube B
c)A colorless gas liberated in test tube A
d)A colorless gas liberated in test tube B
Question 6.A balanced chemical equation is in accordance with
a)Avogadro’s law
b)Law of multiple proportion
c)Law of conservation of mass
d)Law of gaseous volumes
Question 7.The equation
Cu + xHNO3 -> Cu(NO3)2 + yNO2 + 2H2O
The values of x and y are
a)3 and 5
b)8 and 6
c)4 and 2
d)7 and 1
Question 8.Zn + H2SO4(dil) ->ZnSO4 + H2
Above reaction is
a)Decomposition reaction
b)Single displacement reaction
c)Combination reaction
d)Synthesis reaction
Question 9.The reaction in which two compounds exchange their ions to form two new compounds is
a)A displacement reaction
b)A decomposition reaction
c)An isomerization reaction
d)A double displacement reaction
Question 10.When the gases sulphur dioxide and hydrogen sulphide mix in the presence of water, the reaction is
SO2 + 2H2S -> 2H2O + 3S. here hydrogen sulphide is acting as
a)An oxidizing agent
b)A reducing agent
c)A dehydrating agent
d)A catalyst
Question 11.CuO + H2 ->H2O + Cu, reaction is an example of
a)Redox reaction
b)Synthesis reaction
c)Neutralization
d)Analysis reaction
Question 12.A substance which oxidizes itself and reduces other is known as
a)Oxidizing agent
b)Reducing agent
c)Both of these
d)None of these
Question 13.A redox reaction is one in which
a)Both the substance are reduced
b)Both the substance are oxidized
c)An acid is neutralized by the base
d)One substance is oxidized while the other is reduced
Question 14.In the following equation:
Na2CO3 + xHCI -> 2NaCI +CO2 + H2O, the value of x is
a)1
b)2
c)3
d)4
Question 15.In the equation, NaOH + HNO3 -> NaNO3 + H2O nitric acid is acting as
a)An oxidizing agent
b)An acid
c)A nitrating agent
d)A dehydrating agent
Question 16.Fe2O3+ 2AI2O3 + 2Fe
The above reaction is an example of a
a)Combination reaction
b)Double displacement reaction
c)Decomposition reaction
d)Displacement reaction
Question 17.White silver chloride in sunlight turns to
a)Grey
b)Yellow
c)Remain white
d)Red