Changes Around Us Test

Result

Changes Around Us Test - 1

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

Which of the following statements are true when milk changes into curd?

(i) Its state is changed from liquid to semi-solid.
(ii) It changes colour.
(iii) It changes taste.
(iv) The change cannot be reversed.

A
(i) and (ii)

B
(ii) and (iii)

C
(i), (iii) and (iv)

D
(i) to (iv)

Solution

All the changes specified in (i), (iii) and (iv) are observed.
However, both milk and curd are white in colour, so no change in colour is involved.
Question 2
1 / -0

Analyse the two statements given below and select the correct option.

Statement I: 2CO + O₂ → 2CO₂ represents a balanced chemical equation.

Statement II: The number of atoms of each type on both the sides of the equation is equal.

A
Both statements I and II are correct and statement II is the correct reason for I.

B
Both statements I and II are correct, but statement II is not the correct reason for I.

C
Statement I is correct, but statement II is incorrect.

D
Both statements I and II are incorrect.

Solution

In a balanced chemical equation, the number of atoms of each element on both the sides of the equation is equal.
Hence, both statements I and II are correct and statement II is the correct reason for I.
Question 3
1 / -0

Rolling of chapati and baking of chapati are the changes that

A
can be reversed

B
cannot be reversed

C
can be reversed and cannot be reversed, respectively

D
cannot be reversed and can be reversed, respectively

Solution

Rolling out a chapati from dough balls is a reversible, physical change.
But on baking, the dough undergoes a chemical change and the process cannot be reversed.
Question 4
1 / -0

A chemical change may involve

A
change in colour only

B
change in temperature only

C
evolution of gas only

D
Any or all of the above

Solution

A chemical change may involve any one or all of the mentioned changes.
Question 5
1 / -0

Paheli's mother made a concentrated sugar syrup by dissolving sugar in hot water. On cooling, crystals of sugar got separated.

This indicates a

A
chemical change that can be reversed

B
physical change that can be reversed

C
physical change that cannot be reversed

D
chemical change that cannot be reversed

Solution

Dissolution of sugar in water is a physical change.

On cooling a supersaturated solution, the excess sugar that had dissolved on heating precipitates out.

Hence, the observation indicates that it is a reversible physical change.
Question 6
1 / -0

Which of the following reactions correctly represents the balanced equation for the combustion of magnesium?

A
Mg + O₂ → 2MgO

B
Mg + 2O₂ → 2MgO

C
2Mg + O₂ → 2MgO

D
Mg + O₂ → 2Mg₂O₂

Solution

2Mg + O₂ → 2MgO

The given reaction represents the combustion of magnesium in the presence of oxygen.

User

Question Analysis

Correct -
Wrong -
Skipped -

My Perfomance

Score
-
out of -
Rank
-
out of -

Re-Attempt Weekly Quiz Competition

Changes Around Us Test - 1

Result

Changes Around Us Test - 1

Score

-

Rank

-

SHARING IS CARING

Question 1

(i) and (ii)

(ii) and (iii)

(i), (iii) and (iv)

(i) to (iv)

Solution

Question 2

Both statements I and II are correct and statement II is the correct reason for I.

Both statements I and II are correct, but statement II is not the correct reason for I.

Statement I is correct, but statement II is incorrect.

Both statements I and II are incorrect.

Solution

Question 3

can be reversed

cannot be reversed

can be reversed and cannot be reversed, respectively

cannot be reversed and can be reversed, respectively

Solution

Question 4

change in colour only

change in temperature only

evolution of gas only

Any or all of the above

Solution

Question 5

chemical change that can be reversed

physical change that can be reversed

physical change that cannot be reversed

chemical change that cannot be reversed

Solution

Question 6

Mg + O2 → 2MgO

Mg + 2O2 → 2MgO

2Mg + O2 → 2MgO

Mg + O2 → 2Mg2O2

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.

Mg + O₂ → 2MgO

Mg + 2O₂ → 2MgO

2Mg + O₂ → 2MgO

Mg + O₂ → 2Mg₂O₂