A weather balloon contains 394 L of hydrogen gas at STP. How many moles of hydrogen are present?

Which description best characterization the motion of particles in a solid

In which phase of mitosis do the spindle fibers pull the chromosomes apart to opposite sides of the cell ?

What mass of iron must be in a hot pack to provide -335kj of heat when the iron reacts with oxygen and is converted to iron (111) oxide according to the following thermochemical equation? 2fe(s) + 1.5o2(g)—> fe2o3(s) delta h= -824.2kj/mol