2. hydrogen peroxide ------> water + oxygen
3. barium chloride -----> barium + chlorine
4. magnesium + hydrochloric acid -----> magnesium chloride + hydrogen
5. copper (ll) sulfate + aluminum -----> aluminum sulfate + copper
6. sodium nitrate -----> sodium nitrite + oxygen
7. iron + hydrochloric acid -----> iron (ll) chloride + hydrogen
8. sodium oxide + water -----> sodium hydroxide
9. barium oxide + sulfur trioxide -----> barium sulfate
10. barium + water -----> barium hydroxide + hydrogen
