20. What will be the concentration, in mol dm, of the resulting solution when 200 cm' of 0.200 mol dmhydrochloric acid, HCl(aq) are mixed with 300 cm of 0.100
mol dm HCl(aq)?

0.140mol/dm^3.

Explanation:

200cm3 = 0.2dm^3.

0.2dm^3 * 0.200mol/dm^3 = 0.040mol

300cm^3 = 0.3dm^3

0.3dm^3 * 0.100mol/dm^3 = 0.030mol

The number of moles is 0.070mol of HCl (aq).

The volume of the solution is 0.5dm^3.

Hence the concentration is 0.140mol/dm^3.

answer is: naturally occurring solid, inorganic compound or element is mineral.

minerals usually have crystalline form, that means than crystal constituents (atoms, molecules or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions.

for example magnetite is a mineral of iron oxide (fe₂o₃).

calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (caco₃).

dolomite is an   carbonate mineral composed of calcium magnesium carbonate (camg(co₃)₂).

i don't know people like to fight everywhere rip.