PLEASE HELP! URGENT! 1. at how much energy is required to melt a 30.0-gram sample of water at its melting point?

2. at 1 atmosphere of pressure, 20.0 g of a compound at its normal boiling point are converted to a gas by the addition of 23,000 joules. what is the heat of vaporization for the compound in J/g?

When you perform this reaction, what could remain at the end of the reaction? check all that apply. excess reactant aqueous copper chloride excess reactant aluminum oxygen product solid copper carbon dioxide product aqueous aluminum chloride water

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.

Are the results of a thoroughly tested hypothesis?