Sodium burns in the presence of oxygen in a synthesis reaction. write and balance a chemical equation for this reaction.

8.98 dm3 of hydrogen gas is collected at 38.8 °c. find the volume the gas will occupy at -39.9 °c if the pressure remains constant.

Kp is the equilibrium constant for dissociation of the propionic acid dimer. what is the sign of the slope for a plot of the natural logarithm of kp vs. inverse temperature for this reaction?

What is a substance? a. a physical property of matter b. a chemical property of matter c. an element or compound that cannot be physically separated d. characteristics used to tell the difference between mixtures