Calculate the enthalpy of formation for sulfur dioxide, SO2, from it's elements, sulfur and oxygen. Use the balanced chemical equation and the following information.

S(s) + 1.5O2(g) > SO3(g) ∆H = -395.8 kJ/mol

2SO2(g) + O2(g) ---? 2SO3(g) ∆H = -198.2 kJ/mol

Zoe is investigating the composition of substance a, an unknown substance. using chemical processes, she analyzes substance a and determines it is composed of sodium, oxygen, and hydrogen atoms in a ratio of 1 : 1 : 1. what is substance a? a. a compound b. an element c. a heterogeneous mixture d. a homogeneous mixture

Describe what happens to the molecules as water goes from ice to liquid to vapor. be sure to explain what happens to the temperature during the phase changes.

What is the molecular weight of copper