A student has 540.0 mL of a 0.1035 M aqueous solution of Na2CrO4 to use in an experiment. She accidentally leaves the container uncovered and comes back the next week to find only a solid residue. The mass of the residue is 19.12 g. Determine the chemical formula of this residue.

The chemical formula of this residue:

Explanation:

Mass of residue = 19.12

Let the formula of the residue be

Moles of residue: n

Moles of sodium chromate = n'

Molarity of sodium chromate = 0.1035 M

Volume of sodium chromate solution = 540.0 mL = 0.540 L

1 mL = 0.001 L

According to reaction,1 mole of   gives 1 mole of

So, n = n'

x = 10

The chemical formula of this residue:

a 20-cm-long, cylindrical graphite (pure carbon) rod is inserted into an oxidizing atmosphere at 1145 k and 1.013 x 105 pa pressure. the oxidizing process is limited by the diffu- sion of oxygen counterflow to the carbon monoxide that is formed on the cylindrical surface.

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.