Group IVA

• What elements are included in Group IVA (Carbon Family)?

  Carbon, Germanium, Lead, Silicon, Tin
• What oxidation states do elements in Group IVA exhibit?

  • +2 and +4 oxidation states
  • Show a variety of properties
• What is the basic building block of all organic compounds?

  Carbon (C)
• In what types of compounds is carbon found?

  In both inorganic compounds, such as CO₂ and CO₃²⁻
• What role does carbon play in the preparation of metals?

  Carbon is commonly used as a reducing agent
• How does carbon behave at room temperature compared to elevated temperatures?

  At room temperature, it is chemically inert, but at elevated temperatures, it can combine with other elements
• What is silicon dioxide's chemical formula?

  SiO₂
• Why is silicon essential in the semiconductor industry?

  Due to its properties
• Where is germanium commonly found?

  In minute quantities, often in metal sulfides
• What is the typical occurrence of tin?


  As tin oxide (SnO₂)
• What are common uses of tin?


  To create alloys like bronze and pewter
• What is lead commonly found as?

  Lead sulfide (PbS), also known as galena
• Why has the use of lead decreased historically?


  Due to toxicity concerns
• What are the common oxides formed by tin and lead?

  • Tin (Sn) forms SnO₂ and SnO
  • Lead (Pb) forms PbO and PbO₂
  • Both are stable and amphoteric
• What ions do tin (II) oxide and hydroxide form?

  Stannite ions (Sn₂O₂²⁻)
• What ions do lead (II) oxide and hydroxide form?

  Plumbite ions (PbO₂²⁻)
• What are the +4 oxides formed by tin and lead?

  • SnO₂ forms stannates (SnO₃²⁻)
  • PbO₂ forms plumbates (PbO₃²⁻)
• What are the identity tests for carbonates and bicarbonates?

  • Acid Test: Effervescence of CO₂
  • Phenolphthalein Test:
  • CO₃²⁻: Red or dark pink
  • HCO₃⁻: Colorless or light pink
• What happens when an acid is added to acetate (CH₃COO⁻)?

  It forms acetic acid with a characteristic acetous odor
• What occurs when acetate reacts with ethanol and an acid?

  It forms ethyl acetate, which has a fruity odor
• What test is used for oxalate (C₂O₄²⁻) and what is the result?

  Calcium Chloride (CaCl₂) Test: Forms a white precipitate of calcium oxalate (CaC₂O₄)
• What is the solubility of the precipitate formed from the calcium oxalate test?


  The precipitate is insoluble in acetic acid
• What is Tollen’s Test used for and what is the result for oxalate?


  Forms a silver mirror upon warming
• What are the identity tests for citrate (C₆H₅O₇³⁻)?


  • Calcium Chloride (CaCl₂) Test: Forms a white precipitate upon boiling
  • Precipitate dissolves in acetic acid
  • Tollen’s Test: Forms a silver mirror upon warming
  • Pyridine & Acetic Anhydride Test: Produces a carmine red solution
• What is the result of the Potassium Chromate (K₂CrO₄) Test for lead?


  Yellow ppt of Lead Chromate (PbCrO₄); soluble in NaOH
• What is the result of the Hydrochloric Acid (HCl) Test for lead?


  White ppt of Lead Chloride (PbCl₂); soluble in hot water
• What is the result of H2S for Stannous (Sn+2)?


  Yellow ppt of SnS₂
• What is the result of H2S for Stannic (Sn+4)?


  Brown ppt of SnS
• What are the key tests for identifying lead compounds?

  • Potassium Chromate (K₂CrO₄) Test: Yellow ppt of PbCrO₄
  • Hydrochloric Acid (HCl) Test: White ppt of PbCl₂