元素X、Y可組成兩種化合物A和B,在A中X的質(zhì)量分?jǐn)?shù)為50%,在B中X的質(zhì)量分?jǐn)?shù)為40%,已知A的化學(xué)式為XY2,則B的化學(xué)式為( ?。?br/>A. XY
B. X2Y
C. XY3
D. X3Y
A的化學(xué)式為XY
2,其中X元素的質(zhì)量分?jǐn)?shù)為50%,則Y的質(zhì)量分?jǐn)?shù)為50%,故X和Y的質(zhì)量比是1:1,則有
=,故
=;B中X的質(zhì)量分?jǐn)?shù)為40%,則Y的質(zhì)量分?jǐn)?shù)為60%,設(shè)其化學(xué)式為X
aY
b,則有
=,解得
=,故其化學(xué)式為XY
3,觀察選項(xiàng),故選C.