A compound which contains one atom of X and two atoms of Y for each three atoms of Z is made by mixing 5.00 g of X , 1.15 × 1023 atoms of Y and 0.03 mole of Z atoms. Given that only 4.40 g of compound results. Calculate the atomic weight of Y if the atomic weight of X and Z are 60 and 80 a. m. u. respectively.

Question

A compound which contains one atom of X and two atoms of Y for each three atoms of Z is made by mixing 5.00 g of X , 1.15 × 1023 atoms of Y and 0.03 mole of Z atoms. Given that only 4.40 g of compound results. Calculate the atomic weight of Y if the atomic weight of X and Z are 60 and 80 a. m. u. respectively. (A)  (B)  (C)  (D)

Tardigrade Admin · Accepted Answer

Emprical formula = XY 2 Z 3 According to the Q. <img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/chemistry/4cde9d98f0bfa13930f956bfeba4adcb-.png" /> It is clear that here Z is limiting reagent hence X +2 Y + underset0.033 Z arrow underset.01 moleXY 2 Z 3 According to the condition, 0.01 mole =4.40 gm 1 mole = 440 gm given that atomic wt. of X Z are 60 80 amu respectively hence 60+2 y+3 × 80=440 or 2 y+60+240=440 or 2 v=440-300 or y=(140/2)=70 Atomic wt. of y =70 amu.