When you turn off lights in empty rooms, what are you practising?

After watching the video "zinc strip in copper nitrate solution", and reading the instructions, click on the link labeled "start" just below the drawing of the pencil tip. follow the direction to complete the 3x3 grid. answer the below questions for the portion of the activity in which sn(s) is placed in agno3(aq)

How do you know when a chemical reaction has occurred

If 3 moles of a compound use 24 j of energy in a reaction, what is the a hreaction in j/mol?