Essentially the term binary, meaning each different thing has two components. Binary ionic compounds have two ionic compounds, binary molecular compounds have two molecular compounds, and binary acids have two acids.
The effect of an insoluble impurity, such as sand, on the observed melting point of a compound would be none. It will not depress or elevate the melting point of the compound. Instead, it would affect the reading if you are trying to determine the melting point of the compound. This is because you might be missing the actual melting point of the compound since you will be waiting for the whole sample to liquify. You would not be able to determine exactly that temperature because of the insoluble impurity would have a different melting point than that of the compound.
Answer:
#1
Heat transfer occurred in the room through radiation
This is where heat is transmitted through vacuum or an empty space from a point to another.
#2
From the furnace, the air molecules nearer the region gained higher kinetic energy hence colliding with other molecules in the room. This causes a positive temperature gradient which causes an increment change in temperature in the room.

The amount of kilograms is 0.7718