Chemistry 140A HW 3 Flashcards

Ionic and Covalent Compounds

• CBr4 is not an ionic compound, while KCl, Ca(NO3)2, and AlBr3 are ionic.
• NaNO2 is not a covalent compound; it contains ionic bonds due to the presence of sodium cation.

Electron Configuration and Ions

• Main group elements gain, lose, or share electrons to achieve noble gas electron configurations.
• A Li+ ion contains 2 electrons, having lost one electron from its neutral state of 3.
• The electron configuration of an F- ion is 1s22s22p6, indicating it has gained one electron.
• An atom with 20 protons and 18 electrons is represented as Ca2+, indicating a loss of two electrons.
• An atom with 16 protons and 18 electrons is denoted as S2- due to the gain of two electrons.

Protons and Electrons in Ions

• Co2+ has 27 protons and 25 electrons, which corresponds to a loss of two electrons.
• The electron-dot symbol for Mg2+ is simply Mg2+, representing the magnesium cation.

Charge of Ions

• Group 7A elements typically form ions with a -1 charge.
• The sulfide ion has a -2 charge.

Elements with Variable Charges

• Gold (Au) is an element that exhibits variable charge.

Ionic Compound Formation

• Iron and chlorine form ionic compounds, while sulfur and oxygen do not.

Naming and Formulas of Compounds

• KBr is the ionic compound formed from potassium and bromine.
• CuCl is named copper(I) chloride, while MgF2 is referred to as magnesium fluoride.
• The SO32- ion is called the sulfite ion.
• Calcium selenide is represented by the formula CaSe.
• Tin(IV) cyanide is denoted as Sn(CN)4.
• Zinc acetate has the formula Zn(CH3CO2)2.

Correct and Incorrect Chemical Formulas

• Na2HCO3 is an incorrect formula among the provided options.
• Fe(OH)2 is a correct chemical formula, while Ag(CH3CO2)2 and K2(CN) are not valid.

Periodic Trends and Element Properties

• Bromine is a period 4 element that forms an ion with a -1 charge.

Compound Naming

• The compound (NH4)2SO4 is named ammonium sulfate.
• Ag2O is referred to as silver oxide, specifically silver(I) oxide.

Melting Points of Compounds

• KCl has the highest melting point when compared to CH4, C6H12O6, and H2O.

Formulas for Ions and Compounds

• The ionic compound formed from the lead(II) ion and the carbonate ion is PbCO3.
• AuI3 is correctly named gold(III) iodide.
• Chromous cyanide is represented by the formula Cr(CN)2.

Test your knowledge with these flashcards from Chemistry 140A homework 3. The questions focus on identifying ionic and covalent compounds, as well as understanding bonding in main group elements. Perfect for revising key concepts in inorganic chemistry.