Which chemical equation best illustrates the law of conservation of mass? . 2h2o = h2 + o2. ch4 + 3o2 = co2 + 2h2o. al4c3 + 3h2o = ch4 + 4al(oh)3. zn + 2hcl = zncl2 + h2 . could you explain?

The law of conservation of mass states that in a chemical reaction, atoms cannot be created nor destroyed.

Zn + 2HCl > ZnCl2 + H2 is the best example of this law because the equation is balanced and has the same amount of each atom on both sides.

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Answerthis solution will not form a precipitateexplanationsolubility equilbrium:         pbf₂(s)  ⇄ pb²⁺(aq) + 2 f⁻(aq)the solubility product expression is    (we exclude solids from the equilibrium expression).now suppose we have the trial ion product q, which we can define as    then, we can interpret  q as the product of the concentration of the ions that we have and ksp as the product of the ion concentrations that are needed to form a saturated solution.if q > ksp, then that implies that there will be a surplus of ions that exceed the amount that is required to form a saturated solution. a precipitate will then form (the precipitate continually  forms until the surplus ions are removed and q is decreased to ksp's value).if q = ksp, the saturated solution that forms is barely saturated and the precipitate will be minimal.if q < ksp, then the ion concentration will not be enough to form a saturated solution (so no precipitate).using our information, we calculate the trial ion product:     since q = 2.7  × 10⁻⁸ < ksp =  4  ×  10⁻⁸, a precipitate will not form.