An unknown gas is collected over water at 20ºC when the barometric pressure is 756 torr. The gas collected has a mass of 0.68 g and occupies a volume of 990 mL. The vapor pressure of water under these conditions is 17.54 torr. Which of the following is the likely identity of the gas? NH3
NH, 3

CH4
CH, 4

H2
H, 2

H2S
H, 2, S

the mantle

explanation:

earth is divided into three layers: the crust or the outermost layer on which we live; the underlying, middle layer - the mantle - and the core (the innermost layer of earth).

hey there!

mass = 6.75 g

volume =   9 cm³

therefore:

d = mass / volume

d   = 6.75 / 9

d = 0.7 g/cm³

answer b

answerspecific gravity;