Answer: Could you be more specific?
Answer: precipitate
Explanation: Chemical change is a change in which the chemical composition of the atoms changes. The following changes are seen when chemical reaction takes place:
1) Release or absorption of heat
2) Formation of solid or a precipitate

3) Change in color
4) Production of gas
Answer: C) 0.020 m
Explanation:
Molality of a solution is defined as the number of moles of solute dissolved per kg of the solvent.

where,
n = moles of solute
= weight of solvent in g
Mole fraction of
is =
i.e.
moles of
is present in 1 mole of solution.
Moles of solute
= 
moles of solvent (water) = 1 -
= 0.99
weight of solvent =
Molality =
Thus approximate molality of
in this solution is 0.020 m