We can also use the equation for enthalpy change for physical phase changes. Consider the phase change H2O (l) → H2O (g). Calculate ΔHrxn.

Explain why the quantum number set (2, 1, - 2, - ½) is not possible for an electron in an atom.

How many pictograms are in a gram?

Which of these has the most mass? A. a laser beam B. a rocket in space C. a pitched baseball D. a stationary baseball

When 3.00 g of Mg is ignited in 2.20 g of pure oxygen, what is the limiting reaction? What is the theoretical yield of MgO?

Why burning is not a recommended method of disposing plastics

Student B pushed on a cart against the wall with 500 N of force. The cart didn't move. How do u explain what happened?

What is unique about the way that transition metals form compounds? a. They don't form compounds c. They can form bonds with the electrons in the two outer-most shells b. They are the most reactive d. They can donate all of their electrons

What prompted rutherford to do the alpha particle scattering experiment?

How many moles of hydrogen would be required to produce 5.0 mol of water?

What is the biggest difference between an exothermic and endothermic process? A. The direction of energy flow. B. The amount of energy transferred. C. The type of energy being transferred. D. The speed with which energy is transferred.