A + 2B AB2 36.0 g of 'A' (Molar mass : 60 g mol –1) and 56.0 g of 'B' (Molar mass : 80 g mol –1) are — JEE Mains Chemistry Past Papers Chemistry Question
Question
A + 2B AB2 36.0 g of 'A' (Molar mass : 60 g mol –1) and 56.0 g of 'B' (Molar mass : 80 g mol –1) are allowed to react. Which of the following statements are correct ? (A) 'A' is the limting reagent (B) 77.0 g of AB2 is formed (C) Molar mass of AB2 is 140 g mol –1 (D) 15.0 g of A is left unreacted after the completion of reaction. Choose the correct answer from the options given below : (A) C and D only (B) A and C only (C) B and D only (D) A and B only
💡 Solution & Explanation
A + 2B AB2 Mole 36 60 56 0.6 mole 0.7 mole 0.25 mole – 0.35 mole (A) Molecular wt. of AB2 is 60 + 2 × 80 = 220 g/mol (B) LR is AB. (C) Wt. of A remaining = 0.25 × 60 = 15 g (D) wt. of AB2 formed = 0.35 × 220 = 77 gm. ALLEN 54. Given below are two statements : Statement-I L: The first ionization enthalpy of Cr is lower than that of Mn. Statement-II : The second and third ionization enthalpies of Cr are higher than those of Mn. In the light of the above statements, choose the correct answer from the options given below : (1) Both Statement-I and Statement-II are false. (2) Statement-I is true but Statement-II is false. (3) Both Statement-I and Statement-II are true. (4) Statement-I is false but Statement-II is true. Ans. (2) Sol. Cr = (Ar) 3d 54s Mn = (Ar)3d 54s IE1 (Cr) < IE1 (Mn)