Could someone tell me the Google terms or where to look in a general chemistry textbook. I want to know the exact volume after one substance is dissolved into another. For example I know a liter of alcohol and a liter of water don't combine to make exactly two liters Or let's say I have 1 liter of water I add 1 gram table salt. It dissolves and I have a saltwater solution with density of 1.001 Is the above exactly correct? Does the dissolved NaCl not add any volume? If someone could give me a hint and how to find the details I'd be happy. I last took chemistry 25 years ago but I think we used approximate methods. I'm looking to know the physics involved.