AP化学词汇（四）

　　对于中国学生来说，一门优秀的AP成绩不仅对学生的申请有所帮助，还能为以后融入美国的学习生活打下基础。对于学习AP的同学来说，掌握词汇是至关重要的，词汇量不足将对答题速度和对标题理解都会影响。新东方在线AP盘点了各科目的词汇，今天为大家带来的是：AP化学词汇(四)，建议同学们收藏。

　　AP化学词汇(四)

　　Beer’s law

　　波尔定律

　　Beer’s law, also called Lambert-Beer law or Beer-Lambert law, states that the concentration of an analyte is directly proportional to the amount of light absorbed.

　　ultraviolet

　　紫外的

　　Ultraviolet is electromagnetic radiation with a wavelength from 10 nm to 400 nm, shorter than that of visible light but longer than X-rays. UV

　　radiation is present in sunlight constituting about 10% of the total light output of the Sun. It is also produced by electric arcs and specialized lights, such as mercury-vapor lamps, tanning lamps, and black lights.

　　X-ray

　　X 射线

　　X-radiation (composed of X-rays) is a form of electromagnetic radiation.Most X-rays have a wavelength ranging from 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 100 eV to 100 keV. X-ray wavelengths are shorter than those of UV rays and typically longer than those of gamma rays.

　　infrared

　　红外的

　　(Of electromagnetic radiation) Having a wavelength just greater than that of the red end of the visible light spectrum but less than that of microwaves.Infrared radiation has a wavelength from about 800 nm to 1 mm, and is emitted particularly by heated objects.

　　reactant

　　反应物

　　A substance that takes part in and undergoes change during a reaction.

　　product

　　产物

　　Product (chemistry) Products are the species formed from chemical reactions. During a chemical reaction reactants are transformed into products after passing through a high energy transition state.

　　sodium hydroxide

　　氢氧化钠

　　Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula NaOH. It is a white solid ionic compound consisting of sodium cations Na⁺ and hydroxide anions OH⁻.

　　molar ratio

　　摩尔比例

　　Molar ratio is the proportion of one substance to another in a given chemical reaction. It is the ratio of their coefficients in the chemical equation. For example, in the synthesis of water, the mole ratio of Hydrogen (H2) to Oxygen (O2) is 1:2

　　Law of

　　Conservation of

　　Mass

　　质量守恒定律

　　The law of conservation of mass or principle of mass conservation states that for any system closed to all transfers of matter and energy, the mass of the system must remain constant over time, as system mass cannot change quantity if it is not added or removed. Hence, the quantity of mass is"conserved" over time.

　　coefficient

　　系数

　　Coefficients are the numbers placed before the reactants in a chemical equation so that the number of atoms in the products on the right side of the

　　equation are equal to the number of atoms in the reactants on the left side.

　　gravimetric analysis

　　重量分析

　　Gravimetric analysis describes a set of methods in analytical chemistry for the quantitative determination of an analyte based on the mass of a solid. For instance, the measurement of solids suspended in a water sample: A known volume of water is filtered, and the collected solids are weighed.

　　sample

　　样本 A small part or quantity intended to show what the whole is like.

　　hydrate

　　水合物

　　In chemistry, a hydrate is a substance that contains water or its constituent elements. The chemical state of the water varies widely between different classes of hydrates, some of which were so labelled before their chemical structure was understood.

　　anion

　　阴离子

　　A negatively charged ion.

　　ammonia

　　氨

　　Ammonia is a compound of nitrogen and hydrogen with the formula NH3.

　　The simplest pnictogen hydride, ammonia, is a colorless gas with a characteristic pungent smell. It is a common nitrogenous waste, particularly among aquatic organisms, and it contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers.

　　titration

　　滴定

　　Titration, also known as titrimetry, is a common laboratory method of quantitative chemical analysis that is used to determine the concentration of

　　an identified analyte. Since volume measurements play a key role in titration, it is also known as volumetric analysis. A reagent, called the titrant

　　or titrator, is prepared as a standard solution. A known concentration and volume of titrant reacts with a solution of analyte or titrand to determine

　　concentration. The volume of titrant reacted is called titration volume.

　　crystal

　　晶体

　　A crystal or crystalline solid is a solid material whose constituents, such as atoms, molecules or ions, are arranged in a highly ordered microscopic

　　structure, forming a crystal lattice that extends in all directions. In addition, macroscopic single crystals are usually identifiable by their geometrical shape, consisting of flat faces with specific, characteristic orientations.

　　equivalent

　　等量

　　adj. Equal in value, amount, function, and meaning.

　　spectrophotometry

　　分光光度法

　　In chemistry, spectrophotometry is the quantitative measurement of the reflection or transmission properties of a material as a function of wavelength. It is more specific than the general term electromagnetic spectroscopy in that spectrophotometry deals with visible light,near-ultraviolet, and near-infrared, but does not cover time-resolved spectroscopic techniques.

　　electrochemical

　　series

　　元素电化序

　　Electrochemical series is a series of chemical elements arranged in order of their standard electrode potentials.

　　pH indicator

　　酸碱指示剂

　　A pH indicator is a halochromic chemical compound added in small amounts to a solution so the pH (acidity or basicity) of the solution can be determined visually. Hence, a pH indicator is a chemical detector for hydronium ions (H 3 O +) or hydrogen ions (H +) in the Arrhenius model.

　　common-ion effect

　　同离子效应

　　The common ion effect is responsible for the reduction in the solubility of an ionic precipitate when a soluble compound containing one of the ions of the precipitate is added to the solution in equilibrium with the precipitate.

　　burette

　　滴定管

　　A burette (also burette) is a device used in analytical chemistry for the dispensing of variable, measured amounts of a chemical solution. A

　　volumetric burette delivers measured volumes of liquid. Piston burettes are similar to syringes, but with precision bore and plunger. Piston burettes may

　　be manually operated or may be motorized. A weight burette delivers measured weights of liquid.

　　buffering effect

　　缓冲效果

　　A buffering effect is a process in which a psychosocial resource reduces the impact of life stress on psycho-logical well-being. Having such a resource contributes to adjustment because persons are less affected by negative life events.

　　neutral

　　中性的 adj.

　　A neutral pH level is a value of seven on the pH scale. This number lies at the center of the scale and is the value that is associated with pure water. A pH level below or above seven indicates that the liquid is either an acid or a base.

　　conjugate

　　共轭

　　In chemistry, a conjugated system is a system of connected p-orbitals with delocalized electrons in molecules which are conventionally represented as

　　having alternating single and multiple bonds, which in general may lower the overall energy of the molecule and increase stability.

　　limiting reagent

　　限量反应物

　　The limiting reagent (or limiting reactant) in a chemical reaction is the substance that is totally consumed when the chemical reaction is complete.

　　The amount of product formed is limited by this reagent, since the reaction cannot continue without it.

　　polyprotic acid

　　多元酸

　　A polyprotic acid is an acid which contains more than one ionizable hydrogen (H+) per acid molecule. The acid ionizes one step at a time in an aqueous solution, with a separate ionization constant for each step. The initial dissociation is the primary source of H+, so it is the main factor ininitial dissociation is the primary source of H+, so it is the main factor in determining the pH of the solution.

　　vacuum

　　真空

　　Vacuum is a volume that encloses little or no matter. A partial vacuum is a vacuum with low amounts of matter enclosed. A total or absolute vacuum

　　has no matter enclosed.

　　filtration

　　过滤

　　Filtration is any of various mechanical, physical or biological operations that separate solids from fluids by adding a medium through which only the fluid can pass. The fluid that passes through is called the filtrate. In physical filters oversize solids in the fluid are retained and in biological filters particulates are trapped and ingested and metabolites are retained and removed.

　　bond

　　键

　　A chemical bond is any of several forces or mechanisms, especially the ionic bond, covalent bond, and metallic bond, by which atoms or ions are bound in a molecule or crystal. There are two types of chemical bonds mainly, these are the ionic and covalent bonds.

　　melt

　　熔化 v.

　　In physics and chemistry, melting is the process of converting a solid substance to its liquid form, typically by heating the substance to a temperature called its melting point.

　　amorphous

　　无定型的 adj.

　　In physics and chemistry, amorphous is a term used to describe a solid which does not exhibit crystalline structure. While there may be local ordering of

　　the atoms or molecules in an amorphous solid, no long-term ordering is present.

　　network

　　网络的

　　A network solid or covalent network solid is a chemical compound (or element) in which the atoms are bonded by covalent bonds in a continuous network extending throughout the material. In a network solid there are no individual molecules, and the entire crystal or amorphous solid may be considered a macromolecule.

　　polymer

　　聚合物

　　A polymer is a large molecule, or macromolecule, composed of many repeated subunits. Due to their broad range of properties, both synthetic and

　　natural polymers play essential and ubiquitous roles in everyday life.

　　Polymers range from familiar synthetic plastics such as polystyrene to natural biopolymers such as DNA and proteins that are fundamental to biological structure and function.

　　surface tension

　　表面张力

　　Surface tension is the elastic tendency of a fluid surface which makes it acquire the least surface area possible. Surface tension allows insects (e.g.water striders), usually denser than water, to float and stride on a water surface.

　　intermolecular

　　分子之间的 adj.

　　Existing or taking place between molecules

　　viscosity

　　粘度

　　The viscosity of a fluid is a measure of its resistance to gradual deformation by shear stress or tensile stress. For liquids, it corresponds to the informal concept of "thickness". For example, honey has a much higher viscosity than water.

　　phase

　　相

　　A distinct and homogeneous form of matter (i.e. a particular solid, liquid, or gas) separated by its surface from other forms.

　　a heating curve

　　加热曲线

　　A heating curve shows the relationship of the temperature and heat input of a system as that system is heated over time.

　　vapor

　　蒸汽

　　In physics a vapor or vapour is a substance in the gas phase at a temperature lower than its critical temperature, which means that the vapor can be

　　condensed to a liquid by increasing the pressure on it without reducing the temperature. A vapor is different from an aerosol. An aerosol is a suspension of tiny particles of liquid, solid, or both within a gas.

　　metastable state

　　亚稳定状态

　　Metastability denotes the phenomenon when a system spends an extended time in a configuration other than the system's state of least energy. During a

　　metastable state of finite lifetime all state-describing parameters reach and hold stationary values.

　　macroscopic

　　宏观的 adj.

　　Visible to the naked eye; not microscopic.

　　Kinetic Molecular

　　Theory

　　分子动能论

　　The kinetic molecular theory is a collection of several rules that describe the behavior of gases. The nature of gas molecules was examined by scientists, such as Robert Boyle and Jacques Charles, who outlined their observations in several laws that eventually became the Kinetic Molecular Theory.

　　random

　　随机的 adj.

　　Proceeding, made, or occurring without definite aim, reason, or pattern.

　　pressure

　　压强

　　Continuous physical force exerted on or against an object by something in contact with it.

　　proportional

　　按照比例的 adj.

　　Corresponding in size or amount to something else.

　　elastic collision

　　弹性碰撞

　　Elastic Collision is the collision in which colliding objects rebound without lasting deformation or heat generation. Inelastic collision is a collision in which the colliding objects become distorted and generate heat during collision and possibly stick together.

　　ideal gas

　　理想气体

　　An ideal gas is a theoretical gas composed of many randomly moving point particles that do not interact except when they collide elastically. The ideal gas concept is useful because it obeys the ideal gas law, a simplified equation of state, and is amenable to analysis under statistical mechanics. One mole of an ideal gas has a volume of 22.7 L at STP as defined by IUPAC.

　　non-polar

　　非极性

　　A non-polar solvent is one with molecules that have roughly the same electrical charge on all sides; in other words, it has low static permittivity.

　　Non-polar solvents are typically hydrocarbons, such as pentane and hexane. Each atom on the periodic table has an electronegativity value that describes its ability to bond to other atoms.

　　polar

　　极性

　　Polar in chemistry, also known as a polar covalent bond, happens when 2 or more non-metals create a bond. Polar bonds are usually liquids or solids and are soluble. For example, water (H2O) is polar covalent. It is made up of Hydrogen and Oxygen, with hydrogen having a partial positive and oxygen with a partial negative.

　　gas law

　　气体定理

　　Laws that relate the pressure, volume, and temperature of a gas.

　　Boyle’s law

　　波义尔定律

　　Boyle's law (sometimes referred to as the Boyle–Mariotte law, or Mariotte's law) is an experimental gas law that describes how the pressure of a gas tends to increase as the volume of a gas decreases.

　　Charles’s law

　　查理定理

　　Charles' law (also known as the law of volumes) is an experimental gas law that describes how gases tend to expand when heated.

　　Gay-Lussac’s Law

　　盖-吕萨克 原理

　　Gay-Lussac’s law is a gas law that states that the pressure of a given mass of gas varies directly with the absolute temperature of the gas when the volume is kept constant.

　　Combined Gas Law

　　气体定律

　　The combined gas law combines the three gas laws: Boyle's Law, Charles' Law, and Gay-Lussac's Law. It states that the ratio of the product of pressure and volume and the absolute temperature of a gas is equal to a constant.

　　When Avogadro's law is added to the combined gas law, the ideal gas law results. Unlike the named gas laws, the combined gas law doesn't have an

　　official discoverer. It is simply a combination of the other gas laws that works when everything except temperature, pressure, and volume are held

　　constant.

　　Avogadro’s Law

　　阿伏伽德罗常数

　　A modern statement of Avogadro's law is: Avogadro's law states that, "equal volumes of all gases, at the same temperature and pressure, have the same

　　number of molecules". For a given mass of an ideal gas, the volume and amount (moles) of the gas are directly proportional if the temperature and

　　pressure are constant.

　　Ideal Gas Equation

　　理想气体方程

　　The ideal gas law is the equation of state of a hypothetical ideal gas. It is a good approximation to the behavior of many gases under many conditions,although it has several limitations.

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