The weight of oxygen that will react with 1 g of calcium is

Options

A. `0.2` g
B. `0.6` g
C. `0.4` g C
D. `0.8` g

Answer

C

Explanation

Atomic mass of calcium = 40 g
`underset(underset(underset(40 g)(1xx 40 g))(1" mol"))(Ca(s)) + underset(underset(underset(16 g)(8xx2))(1" mol"))(O_(2)(g)) rarr underset(underset(underset(underset(112 g)(2(56xx2)))(2(40+16)))(2" mol" )) (2CaO)`
40 g of Ca reacts with 19 g of oxygen to form 112 g
of CaO.
1 g of Ca reacts with `16/40g = 0.4` g of oxygen.