I want to know will sugar melt in hot water and why?

When you dissolve sugar in water, the crystal sugar is broken down
to molecular size that is so small becoming a colorless sugar solution.
As you increase temperature, the thin liquid changes to a viscious
thick syrup. It looks like melt the sugar, in fact it contains some
water. The high viscosity of syrup arises from the multiple hydrogen
bonds between the dissolve sugar and the water. It is a super sat-
urated solution. Hope the above can help you.

Thx!
It helps me a lot!

sugar does not melt in hot water but dissolves in hot water as particles (molecules) in sugar change from solid state into aqueous state (mobile form) .