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NCERT Solutions for Class 8 Maths Chapter 8 Algebraic Expressions and Identities

NCERT Solutions for Class 8 Maths Chapter 8 Algebraic Expressions and Identities

Edited By Komal Miglani | Updated on Apr 21, 2025 12:45 PM IST

Can you calculate (102 × 102) without using any pen or paper, or calculate (a+b)2 in a moment? To do this, you don't need any magic tricks, but only have to learn the concept of Algebraic Expressions and Identities. In the 8th chapter of the NCERT Class 8 Maths, you will find Algebraic Expressions and Identities. In this chapter, you will learn how to build or break down algebraic expressions, understand the logic behind the identities, and take your algebraic skills to new heights.

This Story also Contains
  1. Algebraic Expressions and Identities Class 8 Questions And Answers PDF Free Download
  2. Algebraic Expressions and Identities Class 8 Solutions - Important Formulae
  3. Algebraic Expressions and Identities Class 8 NCERT Solutions
  4. NCERT Solutions For Class 8 Maths - Chapter Wise
  5. Importance of Solving NCERT Questions of Class 8 Maths Chapter 8
  6. NCERT Class 8 Maths Solutions: Subject Wise
  7. NCERT Books and Syllabus for Class 8
NCERT Solutions for Class 8 Maths Chapter 8 Algebraic Expressions and Identities
NCERT Solutions for Class 8 Maths Chapter 8 Algebraic Expressions and Identities

This article on NCERT solutions for class 8 Maths Chapter 8 Algebraic Expressions and Identities offers clear and step-by-step solutions for the exercise problems in the NCERT Books for class 8 Maths. Students who are in need of Algebraic Expressions and Identities class 8 solutions will find this article very useful. It covers all the important Class 8 Maths Chapter 8 question answers. These Algebraic Expressions and Identities class 8 ncert solutions are made by the Subject Matter Experts according to the latest CBSE syllabus, ensuring that students can grasp the basic concepts effectively. NCERT solutions for class 8 maths and NCERT solutions for other subjects and classes can be downloaded from the NCERT Solutions.

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Algebraic Expressions and Identities Class 8 Questions And Answers PDF Free Download

Algebraic Expressions and Identities Class 8 Solutions - Important Formulae

  • (a + b)2 = a2 + 2ab + b2

  • (a - b)2 = a2 - 2ab + b2

  • (a + b)(a - b) = a2 - b2

  • (x + a)(x + b) = x2 + (a + b)x + ab

  • (x + a)(x - b) = x2 + (a - b)x - ab

  • (x - a)(x + b) = x2 + (b - a)x - ab

  • (x - a)(x - b) = x2 - (a + b)x + ab

  • (a + b)3 = a3 + b3 + 3ab(a + b)

  • (a - b)3 = a3 - b3 - 3ab(a - b)

Algebraic Expressions and Identities Class 8 NCERT Solutions

NCERT Class 8 Solution Exercise: 8.1
Page number: 94, Total questions: 2

Question: 1(i) Add the following.

abbc,bcca,caab

Answer:

ab-bc+bc-ca+ca-ab=0.

Question: 1(ii) Add the following.

ab+ab,bc+bc,ca+ac

Answer:

ab+ab+bc+bc+ca+ac

=(aa)+(bb)+(cc)+ab+bc+ac

=ab+bc+ca

Question: 1(iii) Add the following

2p2q23pq+4,5+7pq3p2q2

Answer:

2p2q23pq+4+5+7pq3p2q2

=(23)p2q2+(3+7)pq+4+5

=p2q2+4pq+9

Question: 1(iv) Add the following.

l2+m2+n2,n2+l2,2lm+2mn+2nl

Answer:

l2+m2+n2+n2+l2+2lm+2mn+2nl

=2l2+m2+2n2+2lm+2mn+2nl

Question: 2(a) Subtract 4a7ab+3b+12 from 12a9ab+5b3

Answer:

12a-9ab+5b-3-(4a-7ab+3b+12)
=(12-4)a +(-9+7)ab+(5-3)b +(-3-12)
=8a-2ab+2b-15

Question: 2(b) Subtract 3xy+5yz7zx from 5xy2yz2zx+10xyz

Answer:

5xy2yz2zx+10xyz(3xy+5yz7zx)

=(53)xy+(25)yz+(2+7)zx+10xyz

=2xy7yz+5zx+10xyz

Question: 2(c) Subtract 4p2q3pq+5pq28p+7q10 from 183p11q+5pq2pq2+5p2q

Answer:

183p11q+5pq2pq2+5p2q(4p2q3pq+5pq28p+7q10)

=18(10)3p(8p)11q7q+5pq(3pq)2pq25pq2+5p2q4p2q

=28+5p18q+8pq7pq2+p2q

Class 8 maths chapter 8 question answer - exercise: 8.2
Page number: 97-98, Total questions: 5

Question: 1(i) Find the product of the following pairs of monomials.

4,7p

Answer:

4×7p=28p

Question: 1(ii) Find the product of the following pairs of monomials.

4p,7p

Answer:

4p×7p=(4×7)p×p=28p2

Question: 1(iii) Find the product of the following pairs of monomials

4p,7pq

Answer:

4p×7pq=(4×7)p×pq=28p2q

Question: 1(iv) Find the product of the following pairs of monomials.

4p3,3p

Answer:

4p3×(3p)=4×(3)p3×p=12p4

Question: 1(v) Find the product of the following pairs of monomials.

4p,0

Answer:

4p×0=0

Question: 2(A) Find the areas of rectangles with the following pairs of monomials as their lengths and breadths, respectively.

(p,q)

Answer:

The question can be solved as follows

Area=length×breadth=(p×q)=pq

Question: 2(B) Find the areas of rectangles with the following pairs of monomials as their lengths and breadth, respectively.

(10m,5n)

Answer:

The area is calculated as follows

Area=length×breadth=10m×5n=50mn

Question: 2(C) Find the areas of rectangles with the following pairs of monomials as their lengths and breadths, respectively.

(20x2,5y2)

Answer:

The following is the solution

Area=length×breadth=20x2×5y2=100x2y2

Question: 2(D) Find the areas of rectangles with the following pairs of monomials as their lengths and breadths, respectively.

(4x,3x2)

Answer:

The area of a rectangle is

Area=length×breadth=4x×3x2=12x3

Question: 2(E) Find the areas of rectangles with the following pairs of monomials as their lengths and breadths, respectively.

(3mn,4np)

Answer:

The area is calculated as follows

Area=length×breadth=3mn×4np=12mn2p.

Question: 3. Complete the table of products.

First monomial

Second monomial

2x

5y

3x2

4xy

7x2y

9x2y2

2x

4x2


...

...

...

...

...

5y

...

...

15x2y

...

...

...

3x2

...

...

...

...

...

...

4xy

...

...

...

...

...

...

7x2y

...

...

...

...

...

...

9x2y2

...

...

...

...

...

...

Answer:

First monomial

Second monomial

2x

5y

3x2

4xy

7x2y

9x2y2

2x

4x2

10xy

6x3

8x2y

14x3y

18x3y2

5y

10xy

25y2

15x2y

20xy2

35x2y2

45x2y3

3x2

6x3

15x2y

9x4

12x3y

21x4y

27x4y2

4xy

8x2y

20xy2

12x3y

16x2y2

28x3y

36x3y3

7x2y

14x3y

35x2y2

21x4y

28x3y2

49x4y2

63x4y3

9x2y2

18x3y2

45x2y3

27x4y2

36x3y3

63x4y3

81x4y4

Question: 4(i) Obtain the volume of rectangular boxes with the following length, breadth and height, respectively.

5a,3a2,7a4

Answer:

Volume=length×breadth×height=5a×3a2×7a4=15a3×7a4=105a7

Question: 4(ii) Obtain the volume of rectangular boxes with the following length, breadth and height, respectively.

2p,4q,8r

Answer:

The volume of rectangular boxes with the following length, breadth and height is

Volume=length×breadth×height=2p×4q×8r=8pq×8r=64pqr

Question: 4(iii) Obtain the volume of rectangular boxes with the following length, breadth and height, respectively.

xy,2x2y,2xy2

Answer:

The volume of rectangular boxes with the following length, breadth and height is

Volume=length×breadth×height=xy×2x2y×2xy2=2x3y2×2xy2=4x4y4

Question: 4(iv) Obtain the volume of rectangular boxes with the following length, breadth, and height, respectively.

a,2b,3c

Answer:

The volume of rectangular boxes with the following length, breadth and height is

Volume=length×breadth×height=a×2b×3c=2ab×3c=6abc

Question: 5(i) Obtain the product of

xy,yz,zx

Answer:

The product

xy×yz×zx=xy2z×zx=x2y2z2

Question: 5(ii) Obtain the product of

a,a2,a3

Answer:

The product

a×(a2)×a3=a3×a3=a6

Question: 5(iii) Obtain the product of

2, 4y, 8y2, 16y3

Answer:

The product

2×4y×8y2×16y3=8y×8y2×16y3=64y3×16y3=1024y6

Question: 5(iv) Obtain the product of

a,2b,3c,6abc

Answer:

The product

a×2b×3c×6abc=2ab×3c×6abc=6abc×6abc=36a2b2c2

Question: 5(v) Obtain the product of

m,mn,mnp

Answer:

The product

m×(mn)×mnp=m2n×mnp=m3n2p

Class 8 maths chapter 8 NCERT solutions - Topic 8.8.1: Multiplying a Monomial by a Binomial

Question: (i) Find the product

2x(3x+5xy)

Answer:

Using distributive law,

2x(3x+5xy)=6x2+10x2y

Question: (ii) Find the product

a2(2ab5c)

Answer:

Using distributive law,

We have : a2(2ab5c)=2a3b5a2c

NCERT Solutions for Class 8 Maths Chapter 8 Algebraic Expressions and Identities - Topic 8.8.2 Multiplying A Monomial By A Trinomial

Question: 1 Find the product:

(4p2+5p+7)×3p

Answer:

By using distributive law,

(4p2+5p+7)×3p=12p3+15p2+21p

Class 8 maths chapter 8 question answer - exercise: 8.3
Page number: 100, Total questions: 5

Question: 1(i) Carry out the multiplication of the expressions in each of the following pairs.

4p,q+r

Answer:

Multiplication of the given expression gives :

By distributive law,

(4p)(q+r)=4pq+4pr

Question: 1(ii) Carry out the multiplication of the expressions in each of the following pairs.

ab,ab

Answer:

We have ab, (a-b).

Using distributive law, we get,

ab(ab)=a2bab2

Question: 1(iii) Carry out the multiplication of the expressions in each of the following pairs.

a+b,7a2b2

Answer:

Using distributive law, we can obtain the multiplication of the given expression:

(a+b)(7a2b2)=7a3b2+7a2b3

Question: 1(iv) Carry out the multiplication of the expressions in each of the following pairs.

a29,4a

Answer:

We will obtain the multiplication of the given expression by using the distributive law :

(a29)(4a)=4a336a

Question: 1(v) Carry out the multiplication of the expressions in each of the following pairs.

pq+qr+rp,0

Answer:

Using distributive law :

(pq+qr+rp)(0)=pq(0)+qr(0)+rp(0)=0

Question: 2 Complete the table


First expression

Second expression

Product

(i)

a

b+c+d

...

(ii)

x+y5

5xy

...

(iii)

p

6p27p+5

...

(iv)

4p2q2

p2q2

...

(v)

a+b+c

abc

...

Answer:

We will use the distributive law to find the product in each case.


First expression

Second expression

Product

(i)

a

b+c+d

ab+ac+ad

(ii)

x+y5

5xy

5x2y+5xy225xy

(iii)

p

6p27p+5

6p37p2+5p

(iv)

4p2q2

p2q2

4p4q24p2q4

(v)

a+b+c

abc

a2bc+ab2c+abc2


Question: 3(i) Find the product.

(a2)×(2a22)×(4a26)

Answer:

Opening brackets :

(a2)×(2a22)×(4a26)=(a2×2a22)×(4a26)=2a24×4a26

or =8a50

Question: 3(ii) Find the product.

(23xy)×(910x2y2)

Answer:

We have,

(23xy)×(910x2y2)=35x3y3

Question: 3(iii) Find the product.

(103pq3)×(65p3q)

Answer:

We have

(103pq3)×(65p3q)=4p4q4

Question: 3(iv) Find the product.

x×x2×x3×x4

Answer:

We have x×x2×x3×x4

x×x2×x3×x4=(x×x2)×x3×x4

or (x3)×x3×x4

=x10

Question: 4(a) Simplify 3x(4x5)+3 and find its values for

(i) x=3

Answer:

(a) We have

3x(4x5)+3=12x215x+3

Put x = 3,

We get : 12(3)215(3)+3=12(9)45+3=10842=66

Question:4(a) Simplify 3x(4x5)+3 and find its values for

(ii) x=12

Answer:

We have

3x(4x5)+3=12x215x+3

Put

x=12

So we get,

12x215x+3=12(12)215(12)+3=6152=32

Question: 4(b) Simplify a(a2+a+1)+5 and find its value for

(i) a=0

Answer:

We have : a(a2+a+1)+5=a3+a2+a+5

Put a = 0 : =03+02+0+5=5

Question: 4(b) Simplify a(a2+a+1)+5 and find its value for

(ii) a=1

Answer:

We have a(a2+a+1)+5=a3+a2+a+5

Put a = 1 ,

we get : 13+12+1+5=1+1+1+5=8

Question:4(b) Simplify a(a2+a+1)+5 and find its value for

(iii) a=1

Answer:

We have a(a2+a+1)+5 .

or a(a2+a+1)+5=a3+a2+a+5

Put a = (-1)

=(1)3+(1)2+(1)+5=1+11+5=4

Question: 5(a) Add: p(pq),q(qr) and r(rp)

Answer:

(a) First, we will solve each bracket individually.

p(pq)=p2pq ; q(qr)=q2qr ; r(rp)=r2rp

Addind all we get : p2pq+q2qr+r2rp

=p2+q2+r2pqqrrp

Question:5(b) Add: 2x(zxy) and 2y(zyx)

Answer:

Firstly, open the brackets:

2x(zxy)=2xz2x22xy

and 2y(zyx)=2yz2y22xy

Adding both, we get :

2xz2x22xy+2yz2y22xy

or =2x22y24xy+2xz+2yz

Question: 5(c) Subtract: 3l(l4m+5n) from 4l(10n3m+2l)

Answer:

At first we will solve each bracket individually,

3l(l4m+5n)=3l212lm+15ln

and 4l(10n3m+2l)=40ln12ml+8l2

Subtracting:

40ln12ml+8l2(3l212lm+15ln)

or =40ln12ml+8l23l2+12lm15ln

or =25ln+5l2

Question: 5(d) Subtract: 3a(a+b+c)2b(ab+c) from 4c(a+b+c)

Answer:

Solving brackets :

3a(a+b+c)2b(ab+c)=3a2+3ab+3ac2ab+2b22bc

=3a2+ab+3ac+2b22bc

and 4c(a+b+c)=4ac+4bc+4c2

Subtracting : 4ac+4bc+4c2(3a2+ab+3ac+2b22bc)

=4ac+4bc+4c23a2ab3ac2b2+2bc

=3a22b2+4c2ab+6bc7ac.

Class 8 maths chapter 8 question answer - exercise: 8.4
Page number: 102, Total questions: 3

Question: 1(i) Multiply the binomials.

(2x+5) and (4x3)

Answer:

We have (2x + 5) and (4x - 3)
(2x + 5) X (4x - 3) = (2x)(4x) + (2x)(-3) + (5)(4x) + (5)(-3)
= 8 x2 - 6x + 20x - 15
= 8 x2 + 14x -15

Question: 1(ii) Multiply the binomials.

(y8) and (3y4)

Answer:

We need to multiply (y - 8) and (3y - 4)
(y - 8) X (3y - 4) = (y)(3y) + (y)(-4) + (-8)(3y) + (-8)(-4)
= 3 y2 - 4y - 24y + 32
= 3 y2 - 28y + 32

Question: 1(iii) Multiply the binomials

(2.5l0.5m) and (2.5l+0.5m)

Answer:

We need to multiply (2.5l - 0.5m) and (2.5l + 0..5m)
(2.5l - 0.5m) X (2.5l + 0..5m) = (2.5l)2(0.5m)2 using (ab)(a+b)=(a)2(b)2
= 6.25 l2 - 0.25 m2

Question: 1(iv) Multiply the binomials.

(a+3b) and (x+5)

Answer:

(a + 3b) X (x + 5) = (a)(x) + (a)(5) + (3b)(x) + (3b)(5)
= ax + 5a + 3bx + 15b

Question:1(v) Multiply the binomials.

(2pq+3q2) and (3pq2q2)

Answer:

(2pq + 3q 2 ) X (3pq - 2q 2 ) = (2pq)(3pq) + (2pq)(-2q 2 ) + ( 3q 2 )(3pq) + (3q 2 )(-2q 2 )
= 6p 2 q 2 - 4pq 3 + 9pq 3 - 6q 4
= 6p 2 q 2 +5pq 3 - 6q 4

Question: 1(vi) Multiply the binomials.

(34a2+3b2) and 4(a223b2)

Answer:

Multiplication can be done as follows

(34a2+3b2) X (4a283b2) = 3a24×4a2+3a24×(8b23)+3b2×4a2+3b2×(8b23)


= 3a42a2b2+12a2b28b4

= 3a4+10a2b28b4

Question: 2(i) Find the product.

(52x) (3+x)

Answer:

(5 - 2x) X (3 + x) = (5)(3) + (5)(x) +(-2x)(3) + (-2x)(x)
= 15 + 5x - 6x - 2 x2
= 15 - x - 2 x2

Question: 2(ii) Find the product.

(x+7y)(7xy)

Answer:

(x + 7y) X (7x - y) = (x)(7x) + (x)(-y) + (7y)(7x) + (7y)(-y)
= 7 x2 - xy + 49xy - 7 y2
= 7 x2 + 48xy - 7 y2

Question: 2(iii) Find the product.

(a2+b)(a+b2)

Answer:

(a2 + b) X (a + b2 ) = ( a2 )(a) + ( a2 )( b2 ) + (b)(a) + (b)( b2 )
= a3+a2b2+ab+b3

Question: 2(iv) Find the product.

(p2q2)(2p+q)

Answer:

Following is the solution

(p2q2 ) X (2p + q) = (p2)(2p)+(p2)(q)+(q2)(2p)+(q2)(q)
2p3+p2q2q2pq3

Question: 3(i) Simplify.

(x25)(x+5)+25

Answer:

This can be simplified as follows

(x2 -5) X (x + 5) + 25 = ( x2 )(x) + ( x2 )(5) + (-5)(x) + (-5)(5) + 25
= x3+5x25x25+25
= x3+5x25x

Question: 3(ii) Simplify

(a2+5)(b3+3)+5

Answer:

This can be simplified as

(a2 + 5) X ( b3 + 3) + 5 = ( a2 )( b3 ) + ( a2 )(3) + (5)( b3 ) + (5)(3) + 5
= a2b3+3a2+5b3+15+5
= a2b3+3a2+5b3+20

Question: 3(iii) Simplify

(t+s2)(t2s)

Answer:

Simplifications can be

(t + s2 )( t2 - s) = (t)( t2 ) + (t)(-s) + ( s2 )( t2 ) + ( s2 )(-s)
= t3ts+s2t2s3

Question: 3(iv) Simplify

(a+b)(cd)+(ab)(c+d)+2(ac+bd)

Answer:

(a + b) X ( c -d) + (a - b) X (c + d) + 2(ac + bd )
= (a)(c) + (a)(-d) + (b)(c) + (b)(-d) + (a)(c) + (a)(d) + (-b)(c) + (-b)(d) + 2(ac + bd )
= ac - ad + bc - bd + ac +ad -bc - bd + 2(ac + bd )
= 2(ac - bd ) + 2(ac +bd )
= 2ac - 2bd + 2ac + 2bd
= 4ac

Question: 3(v) Simplify

(x+y)(2x+y)+(x+2y)(xy)

Answer:

(x + y) X ( 2x + y) + (x + 2y) X (x - y)
= (x)(2x) + (x)(y) + (y)(2x) + (y)(y) + (x)(x) + (x)(-y) + (2y)(x) + (2y)(-y)
= 2 x2 + xy + 2xy + y2 + x2 - xy + 2xy - 2 y2
= 3 x2 + 4xy - y2

Question: 3(vi) Simplify.

(x+y)(x2xy+y2)

Answer:

Simplification is done as follows

(x + y) X ( x2xy+y2 ) = x X ( x2xy+y2 ) + y ( x2xy+y2 )
= x3x2y+xy2+yx2xy2+y3
= x3+y3

Question: 3(vii) Simplify.

(1.5x4y)(1.5x+4y+3)4.5x+12y

Answer:

(1.5x - 4y) X (1.5x + 4y + 3) - 4.5x + 12y = (1.5x) X (1.5x + 4y + 3) -4y X (1.5x + 4y + 3) - 4.5x + 12y
= 2.25 x2 + 6xy + 4.5x - 6xy - 16 y2 - 12y -4.5x + 12 y
= 2.25 x2 - 16 y2

Question: 3(viii) Simplify

(a+b+c)(a+bc)

Answer:

(a + b + c) (a + b - c) = a (a + b - c) + b (a + b - c) + c (a + b - c)
= a2 + ab - ac + ab + b2 -bc + ac + bc - c2
= a2 + b2 - c2 + 2ab

NCERT Solutions For Class 8 Maths - Chapter Wise

Importance of Solving NCERT Questions of Class 8 Maths Chapter 8

  • Solving these NCERT questions will help students understand the basic concepts of Algebraic Expressions and Identities easily.
  • Students can practice various types of questions, which will improve their problem-solving skills.
  • These NCERT exercises cover all the essential topics and concepts so that students can be well-prepared for various exams.
  • By solving these NCERT problems, students will learn about all the real-life applications of Algebraic Expressions and Identities.

NCERT Class 8 Maths Solutions: Subject Wise

Students can use the links below to prepare efficiently in other subjects as well as Mathematics.

NCERT Books and Syllabus for Class 8

The following links will give students access to the latest CBSE syllabus and some reference books.

Keep Working Hard and Happy Learning!

Frequently Asked Questions (FAQs)

1. What are the important topics of NCERT book chapter Comparing Quantities ?

Increase or decrease percentage, discounts, profit and loss, simple and compound interest are the important topics of this chapter.

2. Does CBSE NCERT syllabus class 8 maths is tough ?

CBSE class 8 maths is damn simple and basic. Most of the chapters are related to the previous classes.

3. How does the NCERT solutions are helpful ?

NCERT solutions are helpful for the students if they are not able to NCERT problems on their own. These solutions are provided in a very detailed manner which will give them conceptual clarity.  

4. How many chapters are there in the CBSE class 8 maths ?

There are 16 chapters starting from rational number to playing with numbers in the CBSE class 8 maths.

5. Where can I find the complete solutions of NCERT for class 8 ?

Here you will get the detailed NCERT solutions for class 8 by clicking on the link.

6. Where can I find the complete solutions of NCERT for class 8 maths ?

Here you will get the detailed NCERT solutions for class 8 maths by clicking on the link.

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 9.89×10−3 kg

Option 4)

12.89×10−3 kg

 

An athlete in the olympic games covers a distance of 100 m in 10 s. His kinetic energy can be estimated to be in the range

Option 1)

2,000 \; J - 5,000\; J

Option 2)

200 \, \, J - 500 \, \, J

Option 3)

2\times 10^{5}J-3\times 10^{5}J

Option 4)

20,000 \, \, J - 50,000 \, \, J

A particle is projected at 600   to the horizontal with a kinetic energy K. The kinetic energy at the highest point

Option 1)

K/2\,

Option 2)

\; K\;

Option 3)

zero\;

Option 4)

K/4

In the reaction,

2Al_{(s)}+6HCL_{(aq)}\rightarrow 2Al^{3+}\, _{(aq)}+6Cl^{-}\, _{(aq)}+3H_{2(g)}

Option 1)

11.2\, L\, H_{2(g)}  at STP  is produced for every mole HCL_{(aq)}  consumed

Option 2)

6L\, HCl_{(aq)}  is consumed for ever 3L\, H_{2(g)}      produced

Option 3)

33.6 L\, H_{2(g)} is produced regardless of temperature and pressure for every mole Al that reacts

Option 4)

67.2\, L\, H_{2(g)} at STP is produced for every mole Al that reacts .

How many moles of magnesium phosphate, Mg_{3}(PO_{4})_{2} will contain 0.25 mole of oxygen atoms?

Option 1)

0.02

Option 2)

3.125 × 10-2

Option 3)

1.25 × 10-2

Option 4)

2.5 × 10-2

If we consider that 1/6, in place of 1/12, mass of carbon atom is taken to be the relative atomic mass unit, the mass of one mole of a substance will

Option 1)

decrease twice

Option 2)

increase two fold

Option 3)

remain unchanged

Option 4)

be a function of the molecular mass of the substance.

With increase of temperature, which of these changes?

Option 1)

Molality

Option 2)

Weight fraction of solute

Option 3)

Fraction of solute present in water

Option 4)

Mole fraction.

Number of atoms in 558.5 gram Fe (at. wt.of Fe = 55.85 g mol-1) is

Option 1)

twice that in 60 g carbon

Option 2)

6.023 × 1022

Option 3)

half that in 8 g He

Option 4)

558.5 × 6.023 × 1023

A pulley of radius 2 m is rotated about its axis by a force F = (20t - 5t2) newton (where t is measured in seconds) applied tangentially. If the moment of inertia of the pulley about its axis of rotation is 10 kg m2 , the number of rotations made by the pulley before its direction of motion if reversed, is

Option 1)

less than 3

Option 2)

more than 3 but less than 6

Option 3)

more than 6 but less than 9

Option 4)

more than 9

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