A__ is two or more substances that are together in the same place but are not chemically combined

If 1.63 times 10 negative 4 of helium dissolves in 100.0g of water, what is the concentration in parts per million

Margaret wants to make an orange flavored drink by stirring powdered drink mix into a glass of water. she doesn't like drinks that have small clumps of powdered solid in them, so she wants the drink to be a perfect solution. what factors should margaret not consider when deciding how much powder to add to her glass of water?

If 1.8 l of water is added to 2.5l of a 7.0 m koh solution, what is the molarity of the new solution