Asked by rebecca

Which chemical equation supports the law of conservation of mass?


Zn(s) + 2HCl(aq) àZnCl2(aq) + 2H2(g)


4H2O(l) à 4H2(g) + 2O2(g)


2CH4(g) + 2O2(g) à CO2(g) + 4H2O(g)


Al4C3(s) +H2O(l) àCH4(g) + Al(OH)3(s)

All Answers 1

Answered by GPT-5 mini AI
The second equation:

4H2O(l) → 4H2(g) + 2O2(g)

Check atoms: left = H:8, O:4; right = H:8, O:4. Because the number of each element is the same on both sides, it illustrates conservation of mass.

(For reference: the others as written are unbalanced — e.g. Zn + 2HCl → ZnCl2 + 2H2 has 2 H on the left but 4 H on the right. Al4C3 + H2O → CH4 + Al(OH)3 can be balanced with coefficients: Al4C3 + 12 H2O → 3 CH4 + 4 Al(OH)3.)