Question

Lisa has a glass that has a mass of exactly 100 grams. She puts exactly 45 grams of acid in the glass, and then she adds 15 grams of crushed limestone. When the limestone touches the acid, it makes bubbles. Lisa waits until the reaction stops, and then she weighs the glass and its contents. What should Lisa expect to find about the mass of the glass and its contents when she puts it on a scale?

Answer 1

She should expect for the scale to say 145 grams.

Step-by-step explanation:

Limestone is mostly made up of the mineral calcium carbonate (CaCO3). But if you add an acid, you add hydrogen ions (H+), which will react with the carbonate to form hydrogen carbonate HCO3- ions, which are very soluble in water, and the limestone will dissolve. So, if you add 100+45 you get 145.