CHEMISTRY GLOSSARY

solubility curve    →   krivulja topljivosti

Solubility curve is a graphic presentation of solubility change in dependence on temperature.

reaction speed curve    →   krivulja brzine reakcije

Reaction speed curve is a graphic presentation of the reactant quantity change in dependence on time value.

hypsometric curve    →   hipsometrijska krivulja

Hypsometric curve (or hypsographic curve) shows the distribution of height of a given area (on land) and depth (at sea). The term originates from the Greek word hypsos meaning height. The part of the curve that reflects the cross section of the ocean bottom is called the bathygraphic curve.

Horizontal dashed lines indicate average height of the continents at 840 meters above sea level, and average depth of the oceans at 3 682.2 meters below sea level. If all the land above sea level (green) was moved into the sea (blue), the oceans would still be 3 km deep.

solubility product constant    →   konstanta produkta topljivosti

Solubility product constant (K_sp) (or the solubility product) is the product of the molar concentrations of the constituent ions, each raised to the power of its stoichiometric coefficient in the equilibrium equation. For instance, if a compound A_aB_b is in equilibrium with its solution

the solubility product is given by

titration curve    →   titracijska krivulja

Titration curve is a graphic representation of the amount of a species present vs. volume of solution added during a titration. A titration curve has a characteristic sigmoid curve. The inflection point in the titration curve marks the end-point of the titration. Blue line is the first derivative of the titration curve.

solubility    →   topljivost

Solubility is the maximum amount of solute that dissolves in a given quantity of solvent at a specific temperature. Generally, for a solid in a liquid, solubility increases with temperature; for a gas, solubility decreases. Common measures of solubility include the mass of solute per unit mass of solution (mass fraction), mole fraction of solute, molality, molarity, and others.

alkaline earth metal    →   zemnoalkalijski metal

Alkali earth metal is a term that refers to six elements: beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). These elements make up group 2 of the periodic table of elements. They all exhibit a single oxidation state, +2. They are all light and very reactive. Barium and radium are the most reactive and beryllium is the least.

To denote slightly soluble metal oxides chemists formerly used the term "earth". The oxides of barium, strontium, and calcium resemble alumina (Al₂O₃), a typical "earth", but form alkaline mixtures with water. For this reason barium, strontium, and calcium were called alkaline earth metals. This name has now been extended to include all of the elements of group 2.

aspartic acid    →   asparaginska kiselina

Aspartic acid is an electrically charged amino acids with acidic side chains. As a group the charged amino acids are relatively abundant and are generally located on the surface of the protein. Aspartic acid and glutamic acid play important roles as general acids in enzyme active centers, as well as in maintaining the solubility and ionic character of proteins. Aspartic acid (sometimes referred to as asparate depending on pH) is non-essential in mammals, being produced from oxaloacetate by transamination.

• Abbreviations: Asp, D
• IUPAC name: 2-aminobutanedioic acid
• Molecular formula: C₄H₇NO₄
• Molecular weight: 133.10 g/mol

Carnot cycle    →   Carnotov kružni proces

Carnot cycle is the most efficient cycle of operations for a reversible heat engine. Published in 1824 by French physicist Nicolas Léonard Sadi Carnot (1796-1832), it consists of four operations on the working substance in the engine:

1-2: Isothermal expansion at thermodynamic temperature T₁ with heat Q_H taken in.

2-3: Adiabatic expansion with a fall of temperature to T₂.

3-4: Isothermal compression at temperature T₂ with heat Q_C given out.

4-1: Adiabatic compression at temperature back to T₁.

According to the Carnot principle, the efficiency of any reversible heat engine depends only on the temperature range through which it works, rather than the properties of the working substances.

supersaturated solution    →   prezasićena otopina

Solution is supersaturated when it contains greater quantity of dissolved substance in itself than it corresponds to solubility of that substance at that temperature. It is said to be in an unstable state, and by shaking the vessel containing that such a solution separation of salt surplus can occur.