Science Help..?

Question

Why can't characteristic properties, such as melting point and boiling point, be used to identify subsatances while they are mixed together

Answer 1

The melting and boiling point of a mixture is altered from the original melting and boiling point. For instance, if you add salt to water, the melting point goes down and the boiling point goes up. That is why salt is added to icy roads to melt the ice, and to water in cooking so that food cooks faster.