Chemical Reactions And Equations Test

Result

Chemical Reactions And Equations Test - 2

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1

1 / -0

The chemical reactions and its corresponding observable features are listed below.

a. Change in temperature	(i) Magnesium reacting with dilute sulphuric acid
b. Evolution of a gas	(ii) Potassium iodide reacting with lead nitrate
c. Formation of a precipitate	(iii) Sulphur dioxide gas reacting with acidified potassium dichromate solution
d. Change in colour	(iv) Zinc granules reacting with dilute sulphuric acid

Choose the most appropriate code from among the options given below:

a - (iii), b - (iv), c - (i), d - (ii)

a - (iv), b - (i), c - (ii), d - (iii)

a - (i), b - (iv), c - (iii), d - (ii)

a - (iv), b - (ii), c - (iii), d - (i)

Solution

a. Every reaction involves energy changes and subsequent change in temperature.
b. Magnesium reacting with dilute sulphuric acid will release hydrogen gas.
c. Potassium iodide reacting with lead nitrate will form a yellow precipitate of PbI₂.
d. Sulphur dioxide gas reacting with acidified potassium dichromate solution will change the orange colour of K₂Cr₂O₇ to green.

Question 2
1 / -0

Consider the following hypothetical reaction and fill in the blanks by choosing the correct option.

x + y - z → x - z + y

In the given chemical reaction, old bonds between _________ are broken and new bonds between _________ are formed.

A
x and y; x and z

B
x and z; y and z

C
y and z; x and y

D
y and z; x and z

Solution

During a chemical change, the atoms are never created or destroyed, they are only rearranged.
In the given reaction, the bonds between y and z break and a new compound is formed by the association of x and z.
Question 3
1 / -0

Quicklime combines with water to form 'X'. Identify 'X' and indicate the energy change involved.

A
Limewater; the reaction is exothermic.

B
Slaked lime; the reaction is endothermic.

C
Lime; the reaction is exothermic.

D
Lime; the reaction is endothermic.

Solution

The balanced chemical equation is as follows::
CaO(s) + H₂O(l) → Ca(OH)₂(aq)

The reaction is exothermic and the vessel gets heated.
Question 4
1 / -0

Which of the following reactions requires the highest temperature to occur?

A
N₂+ O₂→ 2NO

B
2NO + O₂→ 2NO₂

C
NH₄NO₂→ N₂+ 2H₂O

D
4NO₂ + 2H₂O + O₂→ 4HNO₃

Solution

N₂ gas is inert and does not react under ordinary conditions as the N^≡N bond is very strong and has a very high bond enthalpy.
Hence, the 1^st reaction will require the highest temperature to occur.
Question 5
1 / -0

Consider the following reaction:

Al(s) + Fe₂O₃(s) → Al₂O₃(s) + Fe(s)

Which of the following statements is not correct about the given reaction?

A
It is a redox reaction.

B
It is the thermite reaction.

C
It is a decomposition reaction.

D
It is a displacement reaction.

Solution

This reaction is not a decomposition reaction. It involves the reduction of iron oxide to iron by using aluminium as the reducing agent. It is called the thermite reaction and is highly exothermic. It is used to repair the cracks in the railway tracks. It involves the displacement of iron from its oxide by aluminium.
Question 6
1 / -0

Consider the following chemical reaction:

HNO₃(aq) + KOH(aq) → KNO₃(aq) + H₂O(l)

The given reaction is an example of

A
neutralisation

B
double displacement

C
neutralisation and double displacement

D
combination

Solution

This is a reaction of neutralisation of KOH by nitric acid and also involves the exchange of ions between the acid and the base.
Question 7
1 / -0

Consider the following statements about redox reactions:

(i) A substance is said to be reduced if it gains electrons during a reaction.
(ii) A substance is said to be oxidised if it gains hydrogen during a reaction
(iii) A substance is said to be reduced if it loses oxygen during a reaction.
(iv) A substance is said to be reduced if it gains hydrogen during a reaction.

Which of the given statements is/are correct?

A
(i) and (ii)

B
(ii) and (iii)

C
(iii) only

D
(i), (iii) and (iv)

Solution

Only statement (ii) is incorrect because gain of hydrogen is reduction, and not oxidation.

User

Question Analysis

Correct -
Wrong -
Skipped -

My Perfomance

Score
-
out of -
Rank
-
out of -

Re-Attempt Weekly Quiz Competition

Chemical Reactions And Equations Test - 2

Result

Chemical Reactions And Equations Test - 2

Score

-

Rank

-

SHARING IS CARING

Question 1

a - (iii), b - (iv), c - (i), d - (ii)

a - (iv), b - (i), c - (ii), d - (iii)

a - (i), b - (iv), c - (iii), d - (ii)

a - (iv), b - (ii), c - (iii), d - (i)

Solution

Question 2

x and y; x and z

x and z; y and z

y and z; x and y

y and z; x and z

Solution

Question 3

Limewater; the reaction is exothermic.

Slaked lime; the reaction is endothermic.

Lime; the reaction is exothermic.

Lime; the reaction is endothermic.

Solution

Question 4

N2 + O2 → 2NO

2NO + O2 → 2NO2

NH4NO2 → N2 + 2H2O

4NO2 + 2H2O + O2 → 4HNO3

Solution

Question 5

It is a redox reaction.

It is the thermite reaction.

It is a decomposition reaction.

It is a displacement reaction.

Solution

Question 6

neutralisation

double displacement

neutralisation and double displacement

combination

Solution

Question 7

(i) and (ii)

(ii) and (iii)

(iii) only

(i), (iii) and (iv)

Solution

User

Question Analysis

My Perfomance

Score

-

Rank

-

Results Announcement on: coming Monday

Stay Tuned: We’ll update you on your result via email or SMS.

N₂+ O₂→ 2NO

2NO + O₂→ 2NO₂

NH₄NO₂→ N₂+ 2H₂O

4NO₂ + 2H₂O + O₂→ 4HNO₃