CBSE

Exercise 14.2 1. Write the negation of the following statements: (i) Chennai is the capital of Tamilnadu. (ii) is not a complex number. (iii) All triangles are not equilateral triangle. (iv) The number 2 is greater than 7. (v) Every natural number is an integer. Ans. (i) Negation of statement is: Chennai is not the … Read more

States of matter1. What will be the minimum pressure required to compress of air at 1 bar to 200 at 30°C? 2. A vessel of 120 mL capacity contains a certain amount of gas at 35 °C and 1.2 bar pressure. The gas is transferred to another vessel of volume 180 mL at 35 °C. … Read more

Exercise 14.3 1. For each of the following compound statements first identify the connecting words and then break it into component statements: (i) All rational numbers are real and all real numbers are not complex. (ii) Square of an integer is positive or negative. (iii) The sand heats up quickly in the sun and does … Read more

Exercise 14.4 1. Rewrite the following statements with “if-then” in five different ways conveying the same meaning. If a natural number is off then its square is also odd. Ans. (i) A natural number is odd implies that its square is odd. (ii) A natural is odd only if its square is odd. (iii) For … Read more

Redox Reactions  1. Assign oxidation numbers to the underlined elements in each of the following species: (a) (b) (c) (d) (e) (f) (g) (h) 2. What are the oxidation numbers of the underlined elements in each of the following and how do you rationalise your results? (a) 3. Justify that the following reactions are redox … Read more

Exercise 14.5 1. Show that the statement “If is a real number such that then is 0” is true by (i) direct method (ii) method of contradiction (iii) method of contrapositive. Ans. The given compound statement is of the form “if then ”. R such that (i) Direct method: If we assume that is true … Read more

Hydrogen  1. Justify the position of hydrogen in the periodic table on the basis of its electronic configuration. 2. Write the names of isotopes of hydrogen. What is the mass ratio of these isotopes? 3. Why does hydrogen occur in a diatomic form rather than in a monoatomic form under normal conditions? 4. How can … Read more

Miscellaneous Exercise 1. Write the negation of the following statements: (i) For every positive real number , the number is also positive. (ii) All cats scratch. (iii) For every real number , either or (iv) There exists a number such that Ans. (i) There exists a positive real number such that is not positive. (ii) … Read more