The internal volume of a glass flask is V cm^(3). What volume of mercury should be kept in the flask so that the volume of the empty space over mercury in the flask remains constant at all temperatures? Coefficient of volume expansion of mercury =1.8 times 10^(-4@)C^(-1) and coefficient of linear expansion of glass =9 times 10^(-6@)C^(-1).

The internal volume of a glass flask is V cm^(3). What volume of mercu

1.	The internal volume of a glass flask is V cm^(3). What volume of mercury should be kept in the flask so that the volume of the empty space over mercury in the flask remains constant at all temperatures? Coefficient of volume expansion of mercury =1.8 times 10^(-4@)C^(-1) and coefficient of linear expansion of glass =9 times 10^(-6@)C^(-1).
Answer» Solution :Let the required volume of mercury be x `cm^(3)`. To keep the volume of empty SPACE CONSTANT at all temperatures, the expansion of mercury should be equal to that of glass for the same rise in temperature. If the temperature rise is `t^(@)C,` `"" x times 1.8 times 10^(-4) times t=V times 3 times 9 times 10^(-6) times t` or, `""x=(V times 27 times 10^(-6))/(1.8 times 10^(-4))=27/180V=3/20V` `therefore 3/20th` part of the flask should be filled up with mercury.