Answer Happy

Please help me answer all of them correctly.
The molecular liquid dichloromethane (CH₂Cl2) has a density of 1.33 g/mL, while the molecular liquid dibromomethane (CH₂Br₂) has a density of 2.48 g/mL. (a) When 66.8 mL of CH₂Cl2 and 23.4 mL of CH₂Br₂ are mixed, a clear liquid solution forms. Is this a chemical or a physical change? Is the solution a pure substance, a homogeneous mixture or a heterogeneous mixture? (b) Is the density of this solution a chemical or a physical property? (c) Assuming that the volumes are additive upon mixing, what is the density of the solution? g/mL