Copper oxide
As the gas in the air i'm assuming it's Oxygen.
Answer:
HCl conc.= 6.0mol/L
Explanation:
From the dissociation of HCl= 1 mole H+ and 1mol Cl-, which is equivalent stoichiometrically in concentration to that of 1 mol HCl,
2.5X20=50g
50g should be the right answer
Mass=volumeXdenisty.
Answer:
element.
.it is pure substance composed of only one type of atoms.
.the number of element is more than 118.
compound.
.a compound is composed of atoms of two or more elements.
.the number of compound is very large in comparison of elements.
hope it help
