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Question 901
StructuredStandard5 marks
CBSE Class 11 Mathematics · Straight Lines · Forms of a straight line

For triangle PQR with P(2,1), Q(−2,3), and R(4,5), find the median through R.

Question 902
StructuredStandard4 marks
CBSE Class 11 Mathematics · Binomial Theorem · Identities and applications

Expand (1+\(\frac{x}{2}\)−\(\frac{2}{x}\))^4 fully, for x≠0.

Question 903
StructuredStandard4 marks
CBSE Class 11 Mathematics · Linear Inequalities · One-variable inequalities

Complete every requested part of exercise 5.1, question 19: 3 (1 – x) < 2 (x + 4)

Question 904
StructuredStandard4 marks
CBSE Class 11 Mathematics · Trigonometric Functions · Trigonometric functions

Complete every requested part of exercise 3.2, question 12: If none of the angles x, y and (x + y) is a multiple of π, then cot x cot y – 1 cot ( x + y) = cot y + cot x Since, none of the x, y and (x + y) is multiple of π, we find that sin x sin y and sin (x + y) are non-zero. Now, cos ( x + y ) cos x cos y – sin x sin y cot ( x + y) = = sin ( x + y ) sin x cos y + cos x sin y Dividing numerator and denominator by sin x sin y, we have cot x cot y – 1 cot (x + y) = cot y + cot x cot x cot y + 1

Question 905
StructuredStandard3 marks
CBSE Class 11 Mathematics · Relations and Functions · Relations

On \(\mathbb Z\), let \(aRb\) when \(a-b\) is an integer. Find domain and range.

Question 906
StructuredStandard4 marks
CBSE Class 11 Chemistry · Hydrocarbons · Aromaticity and benzene reactions

Why does benzene undergo electrophilic substitution reactions easily and nucleophilic substitutions with difficulty?

Question 907
StructuredStandard4 marks
CBSE Class 11 Chemistry · Organic Chemistry: Some Basic Principles and Techniques · Purification and qualitative analysis

Describe how to separate two compounds that have different solubilities in the same solvent.

Question 908
StructuredStandard8 marks
CBSE Class 11 Chemistry · Redox Reactions · Balancing redox equations

Balance the following equations in basic medium by ion-electron method and oxidation number methods and identify

(a)
the oxidising agent
(b)
the reducing agent. (a) P4(s) + OH–(aq) → PH3(g) + HPO2– (aq) (b) N2H4(l) + ClO3–(aq) → NO(g) + Cl–(g) (c) Cl2O7 (g) + H2O2(aq) → ClO2–(aq) + O2(g) + H+
Question 909
StructuredStandard4 marks
CBSE Class 11 Chemistry · Equilibrium · Equilibrium constants and reaction quotient

A sample of pure PCl 5 was introduced into an evacuated vessel at 473 K. After equilibrium was attained, concentration of PCl 5 was found to be 0.5 × 10–1 mol L–1. If value of Kc is 8.3 × 10–3, what are the concentrations of PCl3 and Cl2 at equilibrium? PCl5 (g) PCl3 (g) + Cl2(g)

Question 910
StructuredStandard5 marks
CBSE Class 11 Chemistry · Thermodynamics · Entropy, Gibbs energy and spontaneity

For 2A(g)+B(g)→2D(g), ΔU°=−10.5 kJ and ΔS°=−44.1 J K⁻¹ at 298 K. Calculate

(a)
ΔG°
(b)
judge spontaneity.