Skip to main content
Indietro

General Chemistry: ch 1 and 2

I pulsanti di controllo sono stati cambiati in modalità "navigazione".
1/26

Termini in questo insieme (26)

  • What is chemistry?

    Chemistry is the study of matter, which is anything with mass that occupies space.

  • Define atom and molecule.

    An atom is the smallest building block of matter. A molecule is two or more atoms joined together.

  • What is the law of constant composition?

    A pure compound always has the same elemental composition and properties regardless of its source.

  • Difference between physical and chemical properties.

    Physical properties are observed without changing identity (e.g., color, density). Chemical properties describe how a substance reacts (e.g., flammability).

  • What distinguishes intensive and extensive properties?

    Intensive properties do not depend on sample size (e.g., density). Extensive properties depend on amount (e.g., mass, volume).

  • Define kinetic and potential energy with examples.

    Kinetic energy is energy of motion, \(KE=\frac{1}{2}mv^2\). Potential energy is stored energy, such as chemical or gravitational energy.

  • What are SI base units for length, mass, temperature, and amount of substance?

    Length: meter (m); Mass: kilogram (kg); Temperature: kelvin (K); Amount: mole (mol).

  • How do you convert Celsius to Kelvin?

    \(K=^{\circ}C+273.15\)

  • What is density and its common units?

    Density = mass/volume. Common units: g/mL, g/cm³, g/L.

  • Rules for significant figures in addition/subtraction and multiplication/division.

    Add/subtract: answer has fewest decimal places. Multiply/divide: answer has fewest significant figures.

  • State Dalton's atomic theory main points.

    (1) Elements consist of atoms; (2) atoms of an element are identical; (3) atoms are not created/destroyed in reactions; (4) compounds have fixed ratios of atoms.

  • What did Rutherford's gold-foil experiment reveal?

    Most of the atom is empty space; mass and positive charge are concentrated in a tiny, dense nucleus.

  • Define atomic number (Z) and mass number (A).

    Atomic number (Z) = number of protons; Mass number (A) = protons + neutrons.

  • How to calculate number of neutrons in an atom?

    Neutrons = mass number (A) − atomic number (Z).

  • What is an isotope?

    Atoms of the same element with the same number of protons but different numbers of neutrons.

  • How is atomic weight calculated?

    Atomic weight = Σ(isotope mass × fractional abundance).

  • What are diatomic elements?

    Elements that naturally occur as molecules of two atoms: H₂, N₂, O₂, F₂, Cl₂, Br₂, I₂.

  • Difference between molecular and empirical formulas.

    Molecular formula shows actual number of atoms (e.g., H₂O₂). Empirical formula shows simplest whole-number ratio (e.g., HO).

  • Define cation and anion.

    Cation: positive ion formed by losing electrons (usually metals). Anion: negative ion formed by gaining electrons (usually nonmetals).

  • How are ionic compounds named?

    Name the cation first, then the anion. Use Roman numerals for transition metal charges (e.g., iron(III) chloride).

  • What suffix changes occur for monatomic anions and oxyanions?

    Monatomic anions end with -ide (e.g., oxide). Oxyanions: -ate is common, -ite has one fewer oxygen; per- means one more oxygen; hypo- means one fewer than -ite.

  • How are acids named based on anion endings?

    -ide → hydro___ic acid; -ate → -ic acid; -ite → -ous acid (e.g., HCl hydrochloric acid, HNO₃ nitric acid).

  • What are Greek prefixes used for in molecular compounds?

    Indicate number of atoms: 1-mono, 2-di, 3-tri, 4-tetra, 5-penta, 6-hexa, 7-hepta, 8-octa, 9-nona, 10-deca.

  • What defines an alkane?

    Hydrocarbons with only single bonds; each carbon bonded to four atoms; names end in -ane (e.g., methane, ethane).

  • What is an isomer?

    Compounds with the same molecular formula but different arrangements of atoms.

  • How is an alcohol named in organic chemistry?

    Replace an H with an OH group; name ends in -ol with a number indicating the carbon attached to OH.