A glass flask of volume 200 cm^3 is just filled with mercury at 20°C . The amount of mercury that will overflow when the temperature of the system raised at 100°C is
Pooja kandpal , 7 Years ago
Grade 12th pass
1 Answers
Arun
Last Activity: 7 Years ago
Dear Pooja
If depends on:
a) if you are allowed to ignore the expansion of the glass, and if not, what type type of glass is used (note ignoring the expansion of the glass introduces a 10% error approx.)
b) what value(s) are used for the volume expansion coefficients.
Note that the volume expansion coefficient (β) of a material is 3 times its linear expansion coefficient (α). β = 3α. ________________________
Using values from the link: volume expansion coefficient of glass = 3 x 5.9x10⁻⁶ K⁻¹ volume expansion coefficient of mercury = 3 x 61x10⁻⁶ K⁻¹
The amount of overflow depends on the difference between these, which is 3x10⁻⁶ x (61-5.9) = 1.653x10⁻⁴ K⁻¹
So the mercury expands more than the glass by an amount: 200 x 1.653x10⁻⁴ x (100 – 20) = 2.6cm³ This is the amount that overflows.