Nitrogen makes up what percentage of the atmosphere

Acrystal that absorvd water from air is (blank)a. aqueousb. homogenousc. hygroscopicd. efflorescent

Consider the reaction of a(g) + b(g) + c(g) => d(g) for which the following data were obtained: experiment initial [a], mol/l initial [b], mol/l initial [c], mol/l initial rate, mol/l. s 1 0.0500 0.0500 0.0100 6.25 x 10^-3 2 0.100 0.0500 0.0100 2.50 x 10^-2 3 0.100 0.100 0.0100 1.00 x 10^-1 4 0.0500 0.0500 0.0200 6.25 x 10^-3 what is the rate law for the reaction?

Citric acid has a ph between 1 and 3.  it is considered to be aa. weak acidb. weak basec. strong based. strong acid