A sample that weighs 107.75 g is a mixture of 30% helium atoms and 70% krypton atoms. How many particles are present in the sample?

Which statement is correct? The enthalpy of the reaction is - 184.6 kJ, and the reaction is exothermic. The enthalpy of the reaction is - 184.6 kJ, and the reaction is endothermic. The enthalpy of the reaction is 184.

Which change of state involves a release of energy? a) boiling c) condensation d) melting e) sublimation

during which of the following processes does the entropy of the system decrease? salt crystals dissolve in water air escapes from a hole in a balloon ice melts at room temperature liquid water boils methane gas and oxygen gas combust to form carbon

It takes Dylan 3 days to travel from New York to California. How many hours does it take Dylan to arrive at his destination

To make a 3.50 M solution, how many moles of solute will be needed if 11 liters of solution are required?

Evaluate - if you put a scale in an elevator and weigh yourself as you ascend and the descend, does the scale have the same reading in both instances?

Why would you add a catalyst to something

A sample of the sugar d-ribose (C5H10O5) of mass 0.727 g was placed in a calorimeter and then ignited in the presence of excess oxygen. The temperature rose by 0.910 K. In a separate experiment in the same calorimeter, the combustion of 0.

the volume of an ideal gas in a container is 2.0 L what will be the volume of the gas if the pressure on the container is doubled while the temperature is reduced from 400 K to 200 K

Which of the Following Will result in increasing temperature of s gas