Question

Hope apparatus
function

Answer 1

Hope's apparatus is a glass cylinder encircled with a trough half-way up to contain a freezing mixture. Holes in the cylinder at the top and the bottom allow thermometers to be inserted into the water to sample its temperature. After a sufficient length of time the more dense water collects at the bottom at a temperature of 4°C.
The reference below gives graphs of Hope's experiments (in his paper he only gave tables), plus additional experiments run by the author in 1981.
REFERENCE: Thomas B. Greenslade, Jr., "The Maximum Density of Water", Phys. Teach., 23, 474-477 (1985)

Answer 2

It is a part which is used during practicals