Answers Practice Exam 1

1. C; 2. H; 3. B and D; 4. A; 5. C; 6. C; 7. B; 8. E; 9. C; 10. E; 11. C; 12, B;

13. A) 29.0; B) 160.; 14. A) 5H₂O₂ + 2MnO₄^- + 6H⁺ à 5O₂ + 2Mn²⁺ + 8H₂O;

B) O is the element oxidized and MnO₄^- is the oxidizing agent; 15. 23.0 g/mol is Na;

16. C₇H₅N₃O₆; 17. 0.5 mol FeCl₃ left; 18. 2.6 g; 19. 0.207 g;

20. A) 3CaCl₂(aq) + 2Na₃PO₄(aq) à Ca₃(PO₄)₂(s) + 6NaCl(aq);

B) Solid Ca₃(PO₄)₂ should be shown as a compound at the bottom of the beaker. Na⁺ and Cl^- ions should be present in the aqueous state in the beaker.

21. A) diphsphorous tetroxide; B) sulfurous acid; C) hydrosulfuric acid; D) sodium bromate;

E) tin(IV) fluoride; F) copper(II) dihydrogen phosphate;

22. A) Pb(CO₃)₂; B) N₂O₅; C) HNO₂; D) Hg₂(C₂H₃O₂)₂; E) (NH₄)₂Cr₂O₇; F) Ba(HSO₄)₂;

23. A) 3FeCl₃ + 3NH₃ + 3H₂O ––––> Fe(OH)₃ + 3NH₄Cl

NIE: 3Fe³⁺⁽aq) + 3NH₃(aq) + 3H₂O(l) à Fe(OH)₃(s) + 3NH₄⁺(aq)

B) Ag₃PO₄ + 3HNO₃ à 3AgNO₃(aq) + H₃PO₄(aq)

NIE: Ag₃PO₄(s) + 3H⁺(aq) à 3Ag⁺(aq) + H₃PO₄(aq)

24.A) Cu²⁺(aq) + 2OH^-(aq) à Cu(OH)₂(s)

B) H⁺(aq) + NO₂^-(aq) à HNO₂(aq)

C) NH₃(aq) + HF(aq) à NH₄⁺(aq) + F^-(aq)