Skip to main content
Chemistry LibreTexts

Homework 7: Descriptive Chemistry

1. Why can carbon only form 4 bonds when elements in the rest of the group can form up to six?

2. What is the “inert pair effect”?

3. Write the formulas for three different nitrogen oxides

4. Which elements form ionic hydrides? Why?

5. Which element has the highest melting point, sodium or potassium? Why?

6. Which element has the highest melting point, chlorine or bromine? Why?

7. Which do you expect to have the larger atomic radius, carbon or nitrogen?

8. Write possible chemical equations for the following elements reaction with Cl2:


    • Rubidium
    • Lead
    • Calcium
    • Carbon

9. What are the most common oxidation states for the following elements: (each element may have more than one)

  • Boron
  • Oxygen
  • Iodide
  • Cesium
  • Sodium
  • Nitrogen
  • Lead
  • Magnesium

10. Which of the following elements commonly exist in oxidation state +1?

    • Lithium
    • Magnesium
    • Yttrium
    • Manganese
    • Copper
    • Mercury
    • Boron
    • Indium
    • Nitrogen
    • Oxygen
    • Chlorine

11. Which do you expect to have more metallic character, tin or lead?

12. Name at least two allotropes of carbon

13. Explain why CO2 is a gas while SiO2 is a solid

14. Which one is the strongest reducing agent, Mg or Ba?

15. Which one is the strongest oxidizing agent, Cl2 or Br2?

16. Why can phosphorous form up to 6 covalent bonds when nitrogen can only form four?

18. Write equations for each of the alkali metals reacting with (excess) oxygen

19. Complete and balance the following reactions: (If no reaction occurs state so)

    • Li (s) + H2O (l) →
    • N2 (g) + H2 (g) →
    • C (s) + O2 (g) →
    • Cs (s) + H2 (g) →
    • Sr (s) + H2O (l) →
    • Ne (g) + H2O (l) → 
    • Ca (s) + H2O (l) →
    • C (s) + H2 (g) →
    • H2 (g) + Cl2 (g) →
    • CO2 (g) + H2O (l) →
    • K (s) + Br (l)  
    • Be (s) + H2O (l) →

20. What is a metallic hydride?

21. Why does phosphorous have several different allotropes while nitrogen only exists as N2 (g)?

22. According to the periodic trends, which do you expect to

  1. Have the highest ionization energy, sodium or potassium?
  2. Have the lowest boiling point, argon or xenon?
  3. Be the best reducing agent, potassium or calcium?
  4. Have the highest electrode potential, fluorine or chlorine?
  5. Have the smallest electrode potential, magnesium or strontium?
  6. Have the largest atomic radius, germanium or arsenic?
  7. Have most metallic character, indium or lead?
  8. Be more basic, Al2O3 or SiO2?
  9. Have more ionic character, In2Br6 or Ga2Br6

23. Explain why lithium is a better reducing agent than sodium

24. Which element is more likely to be found in oxidation state +3, phosphorous or bismuth?

24. How do the melting points of the noble gases compare to those of the rest of the periodic system? Why?

25. Which element in the periodic system forms most compounds with noble gases?