Which one of the following gives highest volume of `O _(2)` at STP on complete decompositon ?

Options

A. 2 mL of 100 V `H_2O_2`
B. 500 mL of 30 V `H_2O_2`
C. 1 L of 10 V `H_2O_2`
D. 100 mL of 20 V `H_2O_2`

Answer

B

Explanation

`underset("2 vol (or 68 g) ")(2H_2O_2) iff underset (= 22400 mL at STP)underset( "1 vol" )(2H_2O + O_2(g) )`
By definition of volume strength
(a) 100 mL `H_2O_2` means
1mL of `H_2O_2 -= 100 mL " of " O_2 ` at STP
` therefore 2` mL of `H_2O_2 -= 2 xx 100 = 200 mL " of " O_2`
(b) 30 vol of `H_2O_2` means
1mL of `H_2O_2 -= 30 mL " of " O_2 ` at STP
`therefore 500 mL " of " H_2O_2 -= 30 xx 500 = 15,000 mL " of " O_2`
(c) 10 vol of `H_2O_2` means
`1mL " of " H_2O_2 -= 10 mL " of " O_2 ` at STP
` therefore 1000 mL (1L)" of " H_2O_2 -= 10 xx 1000 " of " O_2`
` = 10,000 mL " of " O_2`
(d) 20 vol of `H_2O_2` means
1mL of `H_2O_2 -= 20 mL " of " O_2` at STP
Hence , 500 mL of 30 `H_2O_2` gives highest volume of `O_2` at STP on complete decomposition .