General Chemistry Basics - Flashcards

Flashcards covering atomic theory, subatomic particles, nomenclature, chemical measurement, laboratory equipment, and safety protocols based on DAT preparation notes.

Dalton’s Atomic Theory

A theory describing the atom as the fundamental unit of matter, consisting of four points: all matter is composed of atoms (indivisible), atoms of a specific element are identical, compounds form from whole number ratios of different atoms, and chemical reactions are rearrangements of atoms.

Proton

A positively charged subatomic particle found in the nucleus with a charge of "$+1e$" ($e = 1.6 \times 10^{-19}\,C$) and a mass of $1\,atomic\,mass\,unit\,(amu)$. Its count determines the element's atomic number.

Neutron

A neutral subatomic particle found in the nucleus with a mass of $1\,amu$; it ensures stability by preventing protons from repelling each other.

Electron

A negatively charged subatomic particle found in energy levels around the nucleus with a charge of "$-1e$" and a negligible mass of $1/1836\,amu$.

Atomic Number (Z)

The number of protons found in an atom, which remains constant across all types of a specific element and is used to identify the element.

Mass Number (A)

The sum of the number of protons and neutrons in an atom, always expressed as a whole number.

Valence Electrons

Electrons furthest from the nucleus residing in the highest energy level; they are highly reactive and responsible for forming chemical bonds.

Core Electrons

Electrons located closest to the nucleus that are the most stable, lowest in energy, and generally do not participate in chemical reactions.

Isotope

Atoms of the same element that possess the same number of protons but a different number of neutrons, resulting in different mass numbers.

Atomic Weight

The weighted average of an element's naturally occurring isotopes calculated by taking into account their relative abundances.

Cation

A positively charged ion produced when an atom loses one or more electrons.

Anion

A negatively charged ion produced when an atom gains one or more electrons.

Ionic Compounds (Salts)

Compounds formed through the interaction of cations and anions, typically between a metal and a non-metal where electrons are transferred to achieve full valence shells.

Polyatomic Ions

Molecules composed of multiple atoms that carry an overall net charge.

Covalent Bonds

Chemical bonds formed by the sharing of electrons, most commonly occurring between non-metals.

Binary Molecules

Molecules composed of only two different elements; their names use prefixes to indicate the quantity of each atom (e.g., nitrogen dioxide).

Acid

A molecular compound that produces $H^+$ ions when dissolved in water; common properties include reacting with and tarnishing metals (except gold).

Binary Acids

Acids consisting of hydrogen and one other non-metal element (commonly F, Cl, Br, or I), named using the format "hydro-" + base name of non-metal + "-ic" + acid.

Oxy Acids

Acids consisting of hydrogen, oxygen, and a non-metal; differentiated by suffixes like "-ic" for higher oxidation states and "-ous" for lower oxidation states.

Significant Digits

Numbers used to describe the uncertainty of a measurement; rules include: all non-zeros are significant, zeros between non-zeros are significant, and trailing zeros with a decimal point are significant.

Accuracy

A measure of how close an experimental value is to the actual literature value.

Precision

The consistency of measured experimental values such that all values are relatively close to each other.

Systematic Error

Errors consistently skewed in one direction (always above or below the true value) caused by faulty equipment or procedural errors, such as forgetting to tare an electronic balance.

Random Error

Errors skewed in either direction to varying extents, often caused by human error such as inconsistently reading a meniscus.

Percent Error Formula

$$\text{\% error} = \frac{|\text{experimental} - \text{actual}|}{\text{actual}} \times 100\%$$

Logarithm (log)

The power to which 10 must be raised to equal a number, represented as $\log_b(x) = y \implies b^y = x$.

S.I. Units (Metric Units)

The International System of Units (Système International d’Unités) which provides standard, unchanging definitions for scientific data consistency.

Dimensional Analysis

The process of using unit conversions to obtain a quantity in a desired unit by ensuring unwanted units cancel out.

Beaker

A wide-mouth glass vessel with a spout used for heating, mixing, or stirring; it is NOT accurate for measuring volumes.

Graduated Cylinder

A tall, narrow tube with markings used for measuring liquid volumes; more accurate than beakers but less accurate than volumetric flasks or burettes.

Erlenmeyer Flask

A conical flask with a narrow neck and wider base designed to minimize splashing during mixing, heating, or swirling.

Volumetric Flask

A flat-bottomed flask with a long, thin neck equipped with a single marking for measuring a very specific volume; ideal for preparing or diluting solutions.

Burette

A long, graduated glass tube with a stopcock at the bottom used to dispense very precise volumes of liquid, primarily in titrations.

Digital Balance

Laboratory equipment used to measure the mass of solid samples; it features a "tare" button to reset the reading to zero.

Pipette

The most precise glassware for measuring and transferring specific volumes of liquid; types include graduated, volumetric, or electronic.

Meniscus

The curved surface of a liquid in a container; the volume must be read at the lowest point while eyes are level with the glassware.

Centrifugation

A process using high-speed spinning to separate a mixture into a solid pellet at the bottom and a liquid supernatant on top.

Titration

A method using a burette to deliver a titrant drop-by-drop to another solution to determine its concentration by reaching an equivalence point.

Calorimetry

A specialized methodology used to measure the heat energy released (exothermic) or absorbed (endothermic) during a chemical reaction.

Fume Hood

A safety enclosure that provides ventilation to minimize exposure to harmful vapors or volatile substances.

What is the order of most precise to least precise tools

pipette, burnette or volumteric, graduated cyclinder, any beaker

elymender flask

used for swirling and mixingv

volumetric flask

used for measuring

boiling flask

used to heat things

Caliometry

includes temp water and styrofoam cup

in a centrifuge what are the components

the solids are the pellets that float around and the liquid is the supernatant

what are daltons theory

• All matter is composed of atoms. Atoms cannot be created or destroyed. 

•  Atoms of the same element are identical in mass and property. 

• Atoms combine in whole-number ratios to form compounds.

  • During a chemical reaction, atoms are rearranged to form new substances. 

For a calothermic Reaction what does increase in temp mean and what does decrease mean

increase is exothermic reaction while decrease is endothermic

What does random error affect

the precision