In the query does not contain the density value of gold. Assuming that the gold in question is pure

The process is simple if you know the value of the density of gold that makes up the object. The density d of a certain material, in fact, is expressed by the relation
where m is the mass and the volume V such that mass occupies; if density and mass are known, in the previous report remains as the only unknown volume. Reworking the formula gives V = m / d.
In the query does not contain the density value of gold. Assuming that the gold in question is pure, that is 100% gold, can be traced to its density by consulting the periodic table of elements, where, to the left of the symbol of the element, are often reported the values of several physical and chemical duke pitchforks . In the case of gold, Au, states that the density is 19.3 g / mL. In the case of the periodic table does not report the value of density, you can recover from the tables of textbooks or from one of many websites that deal with such matters. duke pitchforks
Valeria duke pitchforks asks me to calculate what volume of 3.00 M HCl and HCl to 30.0% by weight (d = 1.25 kg / L) are used to prepare 800 mL of 4.20 M HCl