CHEMISTRY
VOCABULARY TERMS
This is a list
of important chemistry vocabulary terms and their definitions
1. acid :
There are several ways to define an acid, but they include any chemical that
gives off protons or H+ in water. Acids have a pH less than 7. They turn the pH
indicator phenolphthalein colorless and turn litmus paper red
2. acid
anhydride : An acid
anhydride is an oxide that forms an acid when it is reacted with water. For
example, when SO3- is added to water, it becomes sulfuric acid, H2SO4
3. actual
yield : The actual yield is the amount of
product you actually obtain from a chemical reaction, as in the amount you can
measure or weigh as opposed to a calculated value
4. addition
reaction : An addition reaction is a
chemical reaction in which atoms add to a carbon-carbon multiple bond
5. chemical
equation : A chemical equation is a
description of a chemical reaction, including what reacts, what is produced,
and which direction(s) the reaction proceeds
6. chemical
property : A chemical property is a property
that can only be observed when a chemical change occurs. Flammability is an
example of a chemical property, since you can't measure how flammable a
substance is without igniting it (making/breaking chemical bonds)
7. covalent
bond : A covalent bond is a chemical bond formed when two atoms share
two electrons
8. critical
mass : Critical mass is the minimum quantity of radioactive material
needed to cause a nuclear chain reaction
9. critical
point : The critical point is the
endpoint of the liquid-vapor line in a phase diagram, past which a
supercritical liquid forms. At the critical point, the liquid and vapor phases
become indistinguishable from one another
10. crystal
: A crystal is an ordered, repeating three-dimensional pattern of
ions, atoms, or molecules. Most crystals are ionic solids, although other forms
of crystals exist.
11. delocalization : Delocalization is when electrons become free to move all over a
molecule, such as when double bonds occur on adjacent atoms in a molecule
12. denature : There
are two common meanings for this in chemistry. First, it can refer to any
process used to make ethanol unfit for consumption (denatured alcohol). Second,
denaturing can mean breaking down the three-dimensional structure of a
molecule, such as a protein is denatured when exposed to heat
13. diffusion : Diffusion
is the movement of particles from an area of higher concentration to one of
lower concentration
14. redox
reaction : A redox reaction is a chemical
reaction that involves oxidation and reduction.
15. resonance
structure : Resonance structures are the set
of Lewis structures that can be drawn for a molecule when it has delocalized
electrons
16. reversible
reaction : A reversible reaction is a
chemical reaction which can go both ways: reactants make products and products
make reactants
17. RMS
velocity : The RMS or root mean square
velocity is the square root of the average of the squares of individual
velocities of gas particles, which is a way of describing the average speed of
gas particles
18. salt
: An ionic compound formed from reacting an acid and a base
19. solute
: The solute is the substance that gets dissolved in a solvent.
Usually, it refers to a solid that is dissolved in a liquid. If you are mixing
two liquids, the solvent is the one that is present in a smaller amount
20. solvent
: This is the liquid that dissolves a solute in solution.
Technically, you can dissolve gases into liquids or into other gases, too. When
making a solution where both substances are in the same phase (e.g.,
liquid-liquid), the solvent is the largest component of the solution
21. STP
: STP means standard temperature and pressure, which is 273K and 1
atmosphere
22. strong
acid : A strong acid is an acid that completely dissociates in water.
An example of a strong acid is hydrochloric acid, HCl, which dissociates into
H+ and Cl- in water
23. strong
nuclear force : The strong
nuclear force is the force that holds the protons and neutrons in an atomic
nucleus together
24. sublimation : Sublimation is when a solid changes directly into a gas. At
atmospheric pressure, dry ice or solid carbon dioxide goes directly into carbon
dioxide vapor, never becoming liquid carbon dioxide
25. catalytic
reforming : the process of improving the
octane number of straight-run gasoline by increasing the proportion of aromatic
and branched chain alkanes. [Catalysts employed are either molybdenum-aluminium
oxides or platinum based.]
26. chain
reaction : reactions which proceed by means
of a set of repeating cyclical steps, e.g. the free radical addition of
hydrogen bromide to an alkene
27. chirality
: a term which may be applied to any asymmetric object or molecule.
The property of non-identity of an object with its mirror image
28. chromatography : A series of related techniques for the separation of a mixture
of compounds by their distribution between two phases. In gas-liquid chromatography
the distribution is between a gaseous and a liquid phase. In column
chromatography the distribution is between a liquid and a solid phase
29. compound : a term used generally to indicate a definite combination of
elements into a more complex structure (a molecule) but it is also applied to
systems with non-stoichiometric proportions of elements
30. configuration : the order and relative spatial arrangement of the atoms in a
molecule. Absolute configuration is when the relative 3 dimensional arrangement
in space of atoms in a chiral molecule have been correlated with an absolute
standard
31. configurational
isomers : a series of compounds which have
the same constitution and bonding of atoms but which differ in their atomic
spatial arrangement. [E.g. glucose and mannose are configurational isomers.
Also called stereoisomers. See also positional or structural isomers.]
32. conformation
: the spatial arrangement of a molecule in space at any particular
moment in time. [Most molecules can adopt an infinite number of conformations
because of the possible rotation about single covalent bonds. Of these
possibilities most compounds tend to spend most time in only one or a few
conformational states, called the preferred conformations
33. double
bond : some atoms can share two pairs of electrons to form a double
bond (two covalent bonds). Formally the second (double) bond arises from the
overlap of p orbitals from two atoms, already united by a sigma bond, to form a pi bond
34. electronegativity : the tendency for atoms in a molecule to attract electrons.
[Measured in terms of the HOMO and LUMO energy levels.]
35. electronic
configuration : the particular order in which electrons are arranged in an atom
or molecule. [Used in a distinct and different sense from stereochemical
configuration.]
36. electronic
transition : in an atom or molecule the electrons have certain allowed
energies only (orbitals). If an electron passes from one orbital to another an
electronic transition occurs and there is the emission or absorption of energy
corresponding to the difference in energy of the orbitals
37. electrophile : an atom, molecule or ion able to accept an electron pair
38. electrophilic
substitution : an overall reaction in which an electrophile binds to a
substrate with the expulsion of another electrophile. [The most common example
is the electrophilic substitution of a proton by another electrophile, such as
a nitronium ion, on an aromatic substrate such as benzene
39. energy
diagram (or reaction energy diagram) : a graph of the energy of a reaction against the progress of the reaction
40. enthalpy : a thermodynamic state function, generally measured in kilojoules
per mole. In chemical reactions the enthalpy change (deltaH) is related to
changes in the free energy (deltaG) and entropy (deltaS) by the equation:
What is the usefulness of Configurational Isomer?
BalasHapusConfiguration isomery is a symptom of the presence of several compounds of the same molecular formula, the sequence of combining the atoms is the same, but has a different configuration (arrangement of chamber groups on C cerral atoms or C asymmetric atoms). The compounds of the configuration form may be enantiomers, if they are mirror images of each other. The berenantiomer compounds have identical physical properties (boiling point, melting point, refractive index, solubility, etc.), but have the ability to rotate the plane of polarized light in different directions and are called active optical isomers.
Hapuscould you tell me about enthalpy??
BalasHapusEntalpi is a term in thermodynamics that states the amount of energy of a thermodynamic system. The enthalpy consists of energy in the system, including one of the five thermodynamic potentials and functions of the state, as well as its volume and pressure (an extensive quantity.) SI units of enthalpy are joules, but are also used British units of thermal units and calories Total enthalpy (H) Measured directly Just as in classical mechanics, only its change can be judged Entalpi is a thermodynamic potential, so to measure the enthalpy of a system we must determine the reference point first, then we can measure the change of enthalpy ΔH The change ΔH is positive for the reaction Endothermic and negative for exotherm.
HapusI want to ask, what are the formulas in enthalpy?
BalasHapusEntalpi (H) is the amount of energy the system has at constant pressure. Entalpi (H) is defined as the amount of energy contained in the system (E) and work (W).
HapusH = E + W
with:
W = P × V
E = energy (joules)
W = system work (joules)
V = volume (liters)
P = pressure (atm)
Can you give me some example about acid?
BalasHapusAcid can be easily encountered in everyday life. In food, drinks, fruits, rain water even inside our bodies. Based on the origin, the acid is grouped into 2 groups, namely organic acids and mineral acids.
HapusOrganic acids derived from natural sources (plants and animals), are generally acidic weak. Examples of organic acids are citric acid contained in citrus fruits, formic acid is present in the bites / stings of ants and the sting of bees and acetic acid contained in vinegar. Mineral acids are acidic compounds such as hydrochloric acid (gastric acid) contained in the human and animal digestive system. Many mineral acids are also used by humans to meet daily needs and are generally strongly acidic. Examples of mineral acids are hydrochloric acid widely used in industry, sulfuric acid for car batteries and fluoride acids commonly used in glass factories.
Please give examples of diffusion.
BalasHapusDiffusion Example:
Hapus1. When sprinkling salt on food, then the diffusion process that occurs in salt and food is when the salt is melted and evenly distributed.
2. When spraying perfume in one room, then the aroma will immediately spread throughout the room, because the perfume has particles that diffuse in air.
3. When giving sugar to the fresh tea fluid, gradually the tea juice will become sweet, this is a diffusion process that occurs when the sugar is melted and evenly with the tea liquid.
4. Conduction of heat, the energy of a hot object moving from high temperature to low temperature, thus making other objects that will touch it to heat.
Can you explain how the sublimation process?
BalasHapusSublimation is a change of form from solid to gas without melting first. Suppose that ice immediately evaporates without melting first. At normal pressure, most objects and substances have three different forms at different temperatures. In this case the transition from a solid to a gas requires an intermediate form. But for some between, its form can be directly changed to the gas without having to melt. This can happen when the air pressure on the substance is too low to prevent these molecules from breaking out of the solid state. Sublimation can also be interpreted as a mixed-mix method based on a mixture of substances having a sublime substrate (the change of solid to gas) , While other substances can not sublimate. For example, a mixture of iodine and salt can be separated by sublimation. Sublimation is the process of converting the solid form directly into the vapor without passing through the liquid form and after experiencing the cooling it is instantly condensed into a back solid.
HapusCan you give me examples of strong nuclear force ?
BalasHapusBoth protons in a helium atom are bound through a strong nuclear force, which more than compensates for the proton electrostatic repulsion. But the strong nuclear force has a very short range. This force decreases rapidly along with the separation of particles, and can be ignored if the particles are separated for several nuclear diameters
Hapus