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An alloy of metals X and Y weighs 12 g and contains atoms X and Y in the ratio of 2:5. The percentage of metal X in the alloy is 20 by mass. If the atomic mass of X is 40, what is the atomic mass of metal Y ? |
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Answer» SOLUTION :`"Mass of metal X in the alloy"=(20)/(100)xx12=2.40g` `"Mass of metal Y in the alloy"=12-2.4=9.6g` `"No. of atoms of X in 2.40 g of X"=(2.40)/(40)xx6.022xx10^(23)=3.61xx10^(22)` ltBrgt `"Ratio of atoms X and Y"=2:5` `therefore"No. of atoms of Y in the alloy"=(5)/(2)xx3.61xx10^(22)=9.025xx10^(22)` Thus, `9.025xx10^(22)` atoms of Y have mass = 9.6 g `therefore""6.022xx10^(23)" atoms of Y will have mass"=(9.6)/(9.025xx10^(2))xx6.022xx10^(23)g=64.0g` Hence, atomic mass of Y = 64 amu. |
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