NY Chemistry Regents Exams Jan 2023
Which equation represents conservation of atoms?
(1) TiO2 + 2Al → 2Al2O3 + Ti (2) TiO2 + 4Al → 2Al2O3 + Ti
(3) 3TiO2 + 2Al → 2Al2O3 + 3Ti
(4) 3TiO2 + 4Al → 2Al2O3 + 3Ti
Solution: We need to make sure atoms of each element are balanced on each side. In answer choice 4, there are 3 Ti on both sides, 4 Al on both sides and 6 O on both sides. Choice 4 is correct.