Acompound that changes color when it comes in contact with an acid or a base is what?

Ineed to find the answer of this question because i dont understand it

Which of the following describes a compound? (hint: carbon and oxygen bo a. a piece of pure carbon, containing only carbon atoms b. oxygen gas surrounding a solid piece of carbon c. a substance made of two oxygen atoms for each carbon atom carbon and oxygen atoms mixed without being bonded together

What type(s) of intermolecular forces are expected between ch3ch2cooh molecules? dipole forces, induced dipole forces, hydrogen bonding