When 1 mole of hydrogen gas (H2) reacts with excess oxygen to form water at a constant pressure, 241.8 KJ of energy is released as heat. Calculate ΔH for a process in which 21.9 g sample of hydrogen gas (H2) reacts with excess oxygen at constant pressure.

Match the following vocabulary terms to their definitions. 1. amount of energy required to change 1 gram of material from the solid to the liquid state at its melting point 2. a measure of the kinetic energy of the particles of a substance 3. the amount of heat energy required to raise the temperature of 1 gram of liquid water from 14.5°c to 15.5°c 4. amount of energy required to change 1 gram of material from the liquid to the gaseous state at its boiling point 5. the amount of energy required to change 1 gram of a substance 1°c a. temperature b. latent heat of vaporization c. latent heat of fusion d. calorie e. specific heat

For each of the compounds below, show that the charges on the ions add up to zero. a. kbr b. cao c. li(2)o d. cacl(2) e. alcl(3)

Astudent uses universal ph paper to find the ph of three solutions . solution a has a ph of 5 solution b has a ph of 11 and solution c has a ph of 7 identify which solution is acidic which solution is neutral and which solution is basic