Vocabulary of Chemistry
- alcohol - An alcohol is any organic molecule that has an -OH group.
- aldehyde - An aldehyde is any organic molecule that has a -COH group.
- alkali metal - An alkali metal is a metal in Group I of the periodic table. Examples of alkali metals include lithium, sodium, and potassium.
- alkaline earth metal - An alkaline earth metal is an element belonging to Group II of the periodic table.
- alkane - An alkane is an organic molecule that only contains single carbon-carbon bonds.
- alkene - An alkene is an organic molecule that contains at least one C=C or carbon-carbon double bond.
- alkyne - An alkyne is an organic molecule that contains at least one carbon-carbon triple bond.
- allotrope - Allotropes are different forms of a phase of an element. For example, diamond and graphite are allotropes of carbon.
- alpha particle - An alpha particle is another name for a helium nucleus, which contains two protons and two neutrons. It's called an alpha particle in reference to radioactive (alpha) decay.
- amine - An amine is an organic molecule in which one or more of the hydrogen atoms in ammonia have been replaced by an organic group. An example of an amine is methylamine.
- base - A base is a compound that produces OH- ions or electrons in water or that accepts protons. An example of a common base is sodium hydroxide, NaOH.
- beta particle - A beta particle is an electron, although the term is used when the electron is emitted in radioactive decay.
- binary compound - A binary compound is one made up of two elements.
- binding energy - Binding energy is the energy that holds protons and neutrons together in the atomic nucleus.
- bond length - Bond length is the average distance between the nuclei of two atoms that share a bond.
- buffer - A liquid that resists change in pH when an acid or base is added. A buffer consists of a weak acid and its conjugate base. An example of a buffer is acetic acid and sodium acetate.
- calorimetry - Calorimetry is the study of heat flow. Calorimetry may be used to find the heat of reaction of two compounds or the heat of combustion of a compound, for example.
- carboxylic acid - A carboxylic acid is an organic molecule containing a -COOH group. An example of a carboxylic acid is acetic acid.
- catalyst - A catalyst is a substance that lowers the activation energy of a reaction or speeds it up without being consumed by the reaction.
- Enzymes are proteins that act as catalysts for biochemical reactions.
- cathode - A cathode is the electrode which gains electrons or is reduced. In other words, it is where reduction occurs in an electrochemical cell.
- 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.
- 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).
- covalent bond - A covalent bond is a chemical bond formed when two atoms share two electrons.
- critical mass - Critical mass is the minimum quantity of radioactive material needed to cause a nuclear chain reaction.
- 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.
- 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.
- 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.
- 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.
- diffusion - Diffusion is the movement of particles from an area of higher concentration to one of lower concentration.
- dilution - Dilution is when a solvent is added to a solution, making it less concentrated.
- dissociation - Dissociation is when a chemical reaction breaks a compound into twoor more parts.
- For example, NaCl dissociates into Na+ and Cl- in water.
- double displacement reaction - A double displacement or double replacement reaction is when cations of two compounds switch places.
- effusion - Effusion is when a gas moves through an opening into a low-pressure container (e.g., is drawn by a vacuum). Effusion occurs more quickly than diffusion because additional molecules aren't in the way.
- electrolysis - Electrolysis is using electricity to break the bonds in a compound to break it apart.
- electrolyte - An electrolyte is an ionic compound that dissolves in water to produce ions, which can conduct electricity. Strong electrolytes completely dissociate in water, while weak electrolytes only partially dissociate or break apart in water.
- enantiomers - Enantiomers are molecules that are non superimposable mirror images of each other.
- endothermic - Endothermic describes a process that absorbs heat. Endothermic reactions feel cold.
- endpoint - The endpoint is when a titration is stopped, typically because an indicator has changed color. The endpoint need not be the same as the equivalence point of a titration.
could you explain to me about crystal??
BalasHapusCrystals or crystals are solids in which atoms, molecules, or their constituent ions are packed regularly and the pattern repeats in three dimensional ways. In general, the liquid is formed crystalline during the compaction process. In ideal conditions, the result can be the same as a single crystal, in which all the atoms in the solid are "attached" to the same lattice or crystal structure, but generally, the chamber is formed simultaneously resulting in a polycrystalline solid.
HapusWhich crystal structure to form from a liquid depends on its own fluid chemistry, the conditions of compaction, and ambient pressure. The process of crystalline structure is known as crystallization.
Let me explain more specifically about buffer solution.
BalasHapusBuffer is an aqueous solution containing a weak acid and its conjugate base or weak base and its conjugate acid. The pH changes are very small when little acid or strong base is added to it and thus is used to prevent pH change in solution. The buffer solution is used to maintain the pH at an almost constant value in various chemical applications. Many life forms develop in only a relatively small pH range so they utilize buffer solutions to maintain a constant pH. One example of a buffer solution found in nature is blood.
HapusHow does buffer retain its PH?
BalasHapus1). The working principle of the acid buffer solution in maintaining the pH is as follows:
HapusA. Any addition of H + will be neutralized by the conjugate base.
B. Any addition of OH- will be neutralized by a weak acid.
C. Any dilution with H2O means increasing the number of H + ions and the conjugate base of weak acid ionisation but the addition of H + concentration becomes meaningless as the volume of the solution also increases
2). The working principle of the basic buffer solution in maintaining the pH is as follows:
A. Any addition of H + will be neutralized by a weak base.
B. Any addition of OH- will be neutralized by conjugate acid.
C. Any dilution with H2O means increasing the amount of OH- ions and conjugate acid from weak base ionisation, but the addition of OH-concentration becomes meaningless because the volume of the solution is also increased.
we use "endpoint" only in titration or not?
BalasHapusAs I know in this chemistry, the titration endpoints are only used in titration, for example in conducting neutralization titration. We need to carefully observe the pH change, especially when it will reach the end point of the titration, this is done to reduce the error which will change the color of the indicator.
Hapusplease give examples buffer !
BalasHapusExamples of Acid and Base buffer solutions
Hapus1) .The acid buffer solution
Example: CH3COOH with CH3COONa; H2CO3 with NaHCO3; And NaHCO3 with Na2CO3
The way it works can be seen in the buffer containing solution; H2CO3 and HCO3 - which are equilibrium. With the process as follows:
A. On the addition of acid
The addition of acid (H +) will shift the equilibrium to the left. Where the added H + ions will react with HCO3 ions to form H2CO3 molecules.
HCO3- (aq) + H + (aq) → H2CO3 (aq)
B. On the addition of a base
If the added is a base, then the OH-ion of the base will react with the H + ion to form water. This will cause the equilibrium to shift to the right so that the concentration of H + ions can be maintained. Thus, the addition of a base causes a decrease in the acid component (H2CO3), not the H + ion. The added base reacts with H2CO3 acid to form HCO3- and water ions.
H2CO3 (aq) + OH- (aq) → HCO3- (aq) + H2O (l)
2. The base buffer solution
Example: NH4OH with NH4Cl
As for how it works can be seen in a buffer solution containing NH3 and NH4 + that have equilibrium. With the process as follows:
A. On the addition of acid
If an acid is added, the H + ion of the acid binds the OH-ion. This causes the equilibrium to shift to the right, so that the OH-ion concentration can be maintained. Additionally, this addition causes a reduction in the base component (NH3), rather than the OH-ion. The added acid reacts with the NH3 base forming the NH4 + ions.
NH3 (aq) + H + (aq) → NH4 + (aq)
· B. On the addition of a base
If the added is a base, then the equilibrium shifts to the left, so that the OH-ion concentration can be maintained. The added base reacts with the acid component (NH4 +), forming the basic components (NH 3) and water.
NH4 + (aq) + OH- (aq) → NH3 (aq) + H2O (l)
give a sample of base
BalasHapusExample Bases
Hapus1). Ammonia: is present in whitening agents and in the manufacture of fertilizers
2) .Alumunium Hydroxide: present in deodorant, antacid.
3). Calcium Hydroxide: present in medicine to reduce soil acidity
4) Calcium Oxide: contained in the cement material.
5) .Magnesium Hydroxide: present in the ulcer drug.
6). Sodium Hydroxide: present in soap material
Give examples of elements that have covalent bonds?
BalasHapusExamples of compound that have covalent bonds are:
HapusHNO3, NH4Cl, SO3, and H2SO4