It's a chemical change because it's changing the object's property.
The answer is (3) a homogeneous mixture. The difference between homogeneous and heterogeneous mixture is the degree of the mixture being mixed. Due to the completely dissolved and the dissolving ability of KCl, we can get the answer,
Its the answer b, because oil has a great density, therefore, when you mix them together the oil will be below and the above of it.
D = m / V
d = 1300 g / 743 cm³
d = 1.749 g/cm³
