JEE MainChemistrySolid State
Elements A and B react completely to form a compound with the formula A ₂ B ₃ . It is observed that 40 g of element A reacts exactly and completely with 10 g of element B . The ratio of the atomic mass of A to the atomic mass of B is _____.
Correct answer
6
Step-by-step solution
The balanced chemical equation for the formation of the compound is: 2 A + 3 B A ₂ B ₃ From the stoichiometry of the reaction, 2 moles of A react with 3 moles of B . Therefore, the ratio of moles of A to moles of B reacting is n_ A n_ B = 2 3 . Let the atomic masses of A and B be M_ A and M_ B respectively. Number of moles of A , n_ A = 40 M_ A . Number of moles of B , n_ B = 10 M_ B . Substituting these into the mole ratio: 40 M_ A 10 M_ B = 2 3 4 M_ B M_ A = 2 3 Rearranging the equation to find the ratio of atomi