2 NOCl(g) → 2 NO(g) + Cl2(g) ΔH° = +75.56 kJ 2 NO(g) + O2(g) → 2 NO2(g) ΔH° = -113.05 kJ
2 NO2(g) → N2O4(g) ΔH° = -58.03 kJ
Compute ΔH° of N2O4(g) + Cl2(g) → 2 NOCl(g) + O2(g) in kJ.

What’s the percent by mass of carbon in c10h14n2

Which sentence about particles in matter is true? a. atoms are present in solids and liquids but not in gases. b. the particles of matter are in constant motion. c. the same kinds of atoms are found in different elements. d. when a solid changes to a liquid, the sizes of the particles change.

What is the approximate mass of 25 cm3 of silver, if the density is 10.5 g/cm3? a. 0.42 g b. 2.4 g c. 42 g d. 260 g