What is the mass of 4.51 x 10^23 particles of copper II nitrate trihydrate?

Water (2510 g ) is heated until it just begins to boil. if the water absorbs 5.09×105 j of heat in the process, what was the initial temperature of the water?

How many moles of carbon dioxide will form if 2.5 moles of c3h8 is burned

What is the percent by mass of oxygen in fe2o3