During an experiment vinegar was added to baking soda. The following observations were recorded.
Observation 1: The container with the reaction mixture feels cooler.
Observation 2: Gas bubbles are released.
Based on the observation, justify the type of change (physical or chemical) that took place.

To find the work done, the force exerted and distance moved are multiplied. a couch is moved twice before you are happy with its placement. the same force was used to move the couch both times. if more work is done the first time it is moved, what do you know about the distance it was moved? a) when more work was done, the couch was moved the same distance. b) when more work was done, the couch was moved less. c) when more work was done, the couch was moved further. d) when more work was done, the couch wasn't moved at all.