Ask & Answer: India's Largest Education Community

Kindly Consider the following

0 Follower 1 View

Chemistry NCERT Exemplar Solutions Class 11th Chapter Ten The S Block Elements

Contributor-Level 10

Kindly go through the solution

0 0

New Question

10 months ago

Which of the following statements is true about Ca(OH)₂?

(i) It is used in the preparation of bleaching powder

(ii) It is a light blue solid

(iii) It does not possess disinfectant property.

(iv) It is used in the manufacture of cement

0 Follower 2 Views

Contributor-Level 10

This is a multiple choice type question as classified in NCERT Exemplar

Correct option (i)

Calcium hydroxide is used in the preparation of bleaching powder. It reacts with chlorine to form hypochlorite, a constituent of bleaching powder.

Ca (OH)₂+Cl₂→CaCl₂+H₂O+Ca (OCl)₂

It is a white amorphous powder and is sparingly soluble in water.

0 0

New Question

10 months ago

70. If A =[ $[\begin{matrix} 3 & 1 \\ - 1 & 2 \end{matrix}]$ ], show that A² – 5A + 7I = 0.

0 Follower 6 Views

Chemistry NCERT Exemplar Solutions Class 11th Chapter Ten The S Block Elements

Contributor-Level 10

Given A = [ $[\begin{matrix} 3 & 1 \\ - 1 & 2 \end{matrix}]$ ]

So; $A^{2} = [\begin{matrix} 3 & 1 \\ - 1 & 2 \end{matrix}] [\begin{matrix} 3 & 1 \\ - 1 & 2 \end{matrix}] = [\begin{array}{l} 3 \times 3 + 1 \times (- 1) & 3 \times 1 + 1 \times 2 \\ - 1 \times 3 + 2 \times (- 1) & - 1 \times 1 + 2 \times 2 \end{array}]$

$= [\begin{matrix} 9 - 1 & 3 + 2 \\ - 3 - 2 & - 1 + 4 \end{matrix}] = [\begin{array}{r} 8 & 5 \\ - 5 & 3 \end{array}]$

∴ A² - 5A + 7I = $[\begin{matrix} 8 & 5 \\ - 5 & 3 \end{matrix}] - 5 [\begin{matrix} 3 & 1 \\ - 1 & 2 \end{matrix}] + 7 [\begin{matrix} 1 & 0 \\ 0 & 1 \end{matrix}]$

$= [\begin{matrix} 8 & 5 \\ - 5 & 3 \end{matrix}] - [\begin{matrix} 15 & 5 \\ - 5 & 10 \end{matrix}] + [\begin{array}{l} 7 & 0 \\ 0 & 7 \end{array}]$

$= [\begin{matrix} 8 - 15 + 7 & 5 - 5 + 0 \\ - 5 + 5 + 0 & 3 - 10 + 7 \end{matrix}] = [\begin{array}{l} 0 & 0 \\ 6 & 6 \end{array}] = 0 .$

Hence Showed.

0 0

New Question

10 months ago

A substance which gives brick red flame and breaks down on heating to give oxygen and a brown gas is

(i) Magnesium nitrate

(ii) Calcium nitrate

(iii) Barium nitrate

(iv) Strontium nitrate

0 Follower 2 Views

Pearl Academy, Jaipur Colleges in Jaipur

Contributor-Level 10

This is a multiple choice type question as classified in NCERT Exemplar

Correct option (ii)

Alkali and alkaline metals impart characteristic color. Calcium gives brick red color, Strontium gives crimson red color, Barium gives apple green color, and radium gives crimson color. So, the compound is calcium nitrate. On heating calcium nitrate, it gives calcium oxide, nitrogen and nitrogen dioxide gas which is brown in color.

Ca (NO₃)²→CaO+O₂+NO₂↑

0 0

New Question

10 months ago

What are the key dates for the BDes programme at Pearl Academy in Mumbai?

0 Follower 5 Views

Nishtha Pruthi

Contributor-Level 10

0 0

New Question

10 months ago

Kindly Consider the following

0 Follower 1 View

Physics NCERT Exemplar Solutions Class 11th Chapter Seven Systems of Particles and Rotational Motion

Contributor-Level 10

Kindly go through the solution

0 0

New Question

10 months ago

Q.6. Let $A = [- 1, 1]$ , Then, discuss whether the following functions defined on $A$ are one-one, onto, or bijective:

(i) $f (x) = \frac{x}{2}$

(ii) $g (x) = | x |$

(iii) $h (x) = x | x |$

(iv) $k (x) = x^{2}$ .

0 Follower 3 Views

New Question

10 months ago

The formula of soda ash is

(i) Na₂CO₃⋅10H₂O

(ii) Na₂CO₃⋅2H₂O

(iii) Na₂CO₃⋅H₂O

(iv) Na₂CO₃

0 Follower 11 Views

SRM School of Management, SRMIST - SRM Institute of Science and Technology, Chennai Colleges in Tamil Nadu

Contributor-Level 10

This is a multiple choice type question as classified in NCERT Exemplar

Correct option (iv)

Anhydrous sodium carbonate is known as soda ash. The formula of soda ash is Na₂CO₃? It is also known as washing soda.

0 0

New Question

10 months ago

Describe the general trends in the following properties of the elements in Groups 13 and 14.

(i) Atomic size

0 Follower 6 Views

alok kumar singh

Contributor-Level 10

This is a Long Answers Type Questions as classified in NCERT Exemplar

Grp-13 The atomic size of the boron family follows the irregular trend. Generally, down the group the size increases but Gallium has a smaller atomic radius than Aluminium due to the poor shielding effect of 3d-orbitals.

Order: B

Grp-14 The size of the carbon family is smaller than the modern family and as we move down the group the atomic size increases regularly. The increase in covalent radius from carbon to silicon is prominent while from Silicon to lead a small increase in covalent radius is observed; this is due to the presence of completely filled D and f-orbita

...more

0 0

New Question

10 months ago

What is the MBA the highest package offered during SRM School of Management placements?

0 Follower 2 Views

Rachit Kumar

Contributor-Level 10

SRM School of Management has released select placement statistics for the MBA programme from the 2025 recruitment drive. Moreover, according to the information gathered, the highest placement statistics offered to the MBA graduates reached INR 65 LPA, and the institute claims that a 30% placement hike has been identified after comparing the highest package received in the year 2024 to the year 2025. Check out the comparison of placement packages received in the years 2023, 2024, and 2025:

Particulars	Statistics (2023)	Statistics (2024)	Statistics (2025)
the highest Salary	INR 42 lakh	INR 50 lakh	INR 65 lakh

0 0

New Question

10 months ago

Chemistry NCERT Exemplar Solutions Class 11th Chapter Ten The S Block Elements

Which of the following elements does not form hydride by direct heating with dihydrogen?

(i) Be

(ii) Mg

(iii) Sr

(iv) Ba

0 Follower 3 Views

Contributor-Level 10

This is a multiple choice type question as classified in NCERT Exemplar

Correct option (i)

Beryllium being least reactive does not form hydride by direct heating with dihydrogen. Also due to its small size and high ionization enthalpy it cannot form hydrides by direct heating.

0 0

New Question

10 months ago

68. Find the values of x, y, z if the matrix A = $[\begin{matrix} 0 & 2 y & z \\ x & y & - z \\ x & - y & z \end{matrix}]$ satisfy the equation A’A = I.

0 Follower 2 Views

School of Music Music School

Contributor-Level 10

Given, A¹ $^{}$ $[\begin{matrix} 2 & 2 y & z \\ x & y & z \\ x & - y & z \end{matrix}]$ Then, $[\begin{matrix} 0 & x & z \\ 2 y & y & - y \\ z & - z & z \end{matrix}]$

Since, $' =$ we can write,

$\Rightarrow [\begin{matrix} 2 & 2 y & z \\ x & y & z \\ x & - y & z \end{matrix}] [\begin{matrix} 0 & x & z \\ 2 y & y & - y \\ z & - z & z \end{matrix}]$

$\Rightarrow [\begin{matrix} 0 & x & x \\ 2 y & y & - y \\ z & - z & z \end{matrix}] [\begin{matrix} 0 & 2 y & z \\ x & y & - z \\ x & - y & z \end{matrix}] = [\begin{matrix} 1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1 \end{matrix}]$

$\Rightarrow [\begin{matrix} 0 + x^{2} + x^{2} & 0 + x y - x y & 0 - x z + x z \\ 0 + x y - x y & 4 y^{2} + y^{2} + y^{2} & 2 y z - y z - y z \\ 0 - 2 x + 2 x & 2 y z - y z - y z & z^{2} + z^{2} + z^{2} \end{matrix}] = [\begin{matrix} 1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1 \end{matrix}]$

$\Rightarrow [\begin{matrix} 2 x^{2} & 0 & 0 \\ 0 & 6 y^{2} & 0 \\ 0 & 0 & 3 z^{2} \end{matrix}] = [\begin{matrix} 1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1 \end{matrix}]$

0 0

New Question

10 months ago

Are Maya Somaiya School of Music and Performing Arts 2025 admissions open for MPA courses?

0 Follower 2 Views

Shailja Rawat

Contributor-Level 10

Yes, Maya Somaiya School of Music and Performing Arts has opened the admission portal for the academic year 2025-2026. Thus, the admission process for the MPA programme is ongoing. As of now, the institute has closed the application portal and is expected to begin the auditio round soon. Once the auditions begin, selected students must appear for the audition test on the scheduled date.

0 0

New Question

10 months ago

67. Show that the matrix B’AB is symmetric or skew symmetric according as A is symmetric or skew symmetric.

0 Follower 26 Views

Chemistry NCERT Exemplar Solutions Class 11th Chapter Ten The S Block Elements

Contributor-Level 10

We have,

(E) (B'AB)' = [B' (AB]'

= (AB)' (B')'

= B'A'B.

When A is symmetric, A' = A

(B'AB)' = B'AB

ie, B'AB is symmetric.

And when A is skew-symmetric, A¹ = -A

(B'AB)' = -B'AB.

ie, B'AB is skew-symmetric.

0 0

New Question

10 months ago

Suspension of slaked lime in water is known as

(i) Lime water

(ii) Quick lime

(iii) Milk of lime

(iv) Aqueous solution of slaked lime

0 Follower 4 Views

Contributor-Level 10

This is a multiple choice type question as classified in NCERT Exemplar

Correct Option (iii)

Ca (OH)₂ saked lime is only sparingly soluble in water. When CaO is soaked in water, it produces a white suspension, and the reaction is highly exothermic. White suspension is called milk of lime and it is used for white washing.

0 0

New Question

10 months ago

66. If A and B are symmetric matrices, prove that AB – BA is a skew symmetric matrix.

0 Follower 84 Views

Chemistry NCERT Exemplar Solutions Class 11th Chapter Ten The S Block Elements

Contributor-Level 10

Given, A and B are symmetric matrices.

(E) Then A' = A and B' = B.

Now, (AB - BA)' = (AB)' - (BA)'

= B'A' - A'B'

= BA - AB

= - (AB - BA).

Hence, AB BA is skew-symmetric matrix

0 0

New Question

10 months ago

Dead burnt plaster is

(i) CaSO₄

(ii) CaSO₄⋅ $\frac{1}{2}$ H₂O

(iii) CaSO₄⋅H₂O

(iv) CaSO₄⋅2H₂O

0 Follower 9 Views