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Two elements X and Y combine to form two compounds XY_(2) and X_(3)Y_(2),0.1 mol of XY_(2) weighs 10 g and 0.05 mol of X_(3)Y_(2) weighs 9 g. Calculate the atomic masses of X and Y. |
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Answer» Solution :Suppose ATOMIC MASSES of X and Y are x and y respectively. Molar mass of `XY_(2)=x+2y` But 0.1 mol of `XY_(2)` weighs = 10 g `therefore"Molar mass of"XY_(2)=100""therefore""x+2y=100"…(i)"` But 0.05 mol of `X_(3)Y_(2)`weigh = 9 g `therefore"Molar mass of "X_(3)Y_(2)=(9)/(0.05)=180""therefore""3x+2y=180"...(ii)"` Subtracting eqn. (i) from eqn. (ii), we get `{:(,2x=80,or,x=40,,),("Substituting in eq. (i),",40+2y=100,or,2y=60,or,y=30):}` |
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