Question

2.用氢气还原某金属氧化物,得金属R,质量减少了36.78％,若金属的相对原子质量为55,则该氧化物可能是（ ）A.R2

Answer 1

RxOy + yH2 = xR + yH2O

(55x+16y).55x

(55x+16y) :55x = 1:(1-36.78%)

1+(16/55)(y/x) = 1.5818

(y/x) = 2

RO2

选D.