Question

At which temperature the speed of sound in hydrogen will be same as that of speed of sound in oxygen at 47° C?

Options

• - 148° C

• - 212° C

• - 317.5° C

• - 253° C

Answer 1

- 253° C

Explanation:

`"Speed of sound in gases is v" = sqrt((gamma"RT")/"M")`

Hydrogen and oxygen being diatomic have same value of `gamma.`

Also v is constant,

`Rightarrow "T" prop "M"`

`therefore "T"_("H"_2)/"T"_("O"_2) =  "M"_("H"_2)/"M"_("O"_2)`

`"T"_("H"_2)/(273 + 47) = 2/32`

`"T"_("H"_2) = 20 "K"`

` = 253° "C"`