Calculate the weight of iron which will be converted into its oxide by the reaction of `18 g` of steam.

Options

A. 168g
B. 84g
C. 42g
D. 21g

Answer

C

Explanation

`3Fe(s)+ 4H_(2) O(g) to Fe_(3)O_(4) (s) + 4H_(2)(g)`
`{:(,3 "mol",4"mol"),(,3 xx 56 , 4 xx 18),(,=158 g,=75 g):}`
` because` 72 g steam reacts reacts with 168g of iron
`therefore` 18 g steam will react with 42 g of iron.]