- •1. Why do you think this direction is so important for chemistry?
- •2. For what reason is the major part of scientists involved in chemical engineering? Part I chemical engineering
- •Comprehension Aspect
- •Part II research chemists
- •What’s the difference between a chemical engineer and a research chemist?
- •What is so particular about the job of a research chemist?
- •What personal qualities should a person possess in order to become a research chemist?
- •Grammar aspect the participle
- •Absolute participial construction
- •Text b pharmaceutical chemistry
- •1. Why did this direction of chemistry become a separate branch not so long ago compared to other directions?
- •2. What are the future perspectives of pharmaceutical chemistry: will it be beneficial to humanity or not?
- •Comprehension Aspect
- •Test c ecological chemistry
- •1. What in your opinion caused the emergence of a totally new and separate speciality as environmental chemistry?
- •2. Do you think we possess enough theoretical knowledge and a sufficient instrumental basis for the effective functioning of this branch of chemistry?
- •Comprehension Aspect
- •Text d teaching chemistry
- •1. Do you remember your first teacher? What memories do you have of your chemistry teacher/s?
- •2. What is necessary to become a teacher?
- •Comprehension Aspect
- •Unit II pharmaceutical chemistry text a
- •Drug discovery
- •Comprehension Aspect
- •Grammar Aspect the infinitive (revision)
- •I am glad to visit you я рад посетить вас
- •1) Purpose
- •2) Result or consequence
- •Oral and Written Speech Aspect text b pharmaceutical impurities
- •Impurities Associated with apIs.
- •Inorganic Impurities
- •Impurities Related to Formulation
- •Text c aspirin
- •Unit III colloid chemistry text a
- •In what field of chemistry are colloid chemical problems encountered?
- •Solution
- •Comprehension Aspect
- •Grammar aspect complex subject (The Subjective Infinitive Construction)
- •Complex object
- •Oral and Written Speech Aspect text b electrolyte solutions
- •Unit IV nanotechnology
- •What is nanotechnology?
- •Comprehension Aspect
- •Grammar aspect the gerund
- •Tense and Voice Forms of the Gerund
- •Gerundial constructions
- •Verbs Used Only with the Gerund
- •Oral and Written Speech Aspect text b catalysis
- •Green Chemistry
- •Comprehension Aspect
- •Grammar aspect conditional sentences
- •1. Unreal conditionals can be also expressed in the following way:
- •2. Adverbial clauses of condition containing had, were, could, should are introduced without any conjunction to make the sentences more emphatic. In these cases we find inversion:
- •Mixed Conditionals
- •Oral and Written Speech Aspect text b
- •Text c changing the course of chemistry
- •Comprehension Aspeсt
- •Grammar aspect
- •Incineration
- •Part II
- •Text c environmental questions
- •Part II Writing Skills
- •I . Definitions
- •II. Qualities of a Good Abstract
- •III. Two types of abstracts are typically used:
- •Descriptive Abstracts
- •Informative Abstracts
- •IV. Structure of a Typical Abstract
- •V. Things to Avoid
- •VI. Sample Abstracts
- •Part III supplementary reading Chemists of the future
- •History of pharmacy
- •Internet pharmacy
- •Pharmacology
- •Placebo
- •Placebo in history
- •Solubility
- •Solution
- •A review of how nanotechnology relates to
- •Various disciplines
- •Inorganic Chemistry
- •Paved with titanium
- •Coming to a window near you
- •Carbon nanotubes and general electro-op
- •Abstract writing
- •The structure of a technical report
- •Quiz time “At the Chemist’s”
Solution
In chemistry, a solution is a homogeneous mixture composed of only one phase, In such a mixture, a solute is a substance dissolved in another substance, known as a solvent. The solvent does the dissolving. The solution more or less takes on the characteristics of the solvent including its phase, and the solvent is commonly the major fraction of the mixture. The concentration of a solute in a solution is a measure of how much of that solute is dissolved in the solvent.
Types of solutions
Homogeneous means that the components of the mixture form a single phase. The properties of the mixture (such as concentration, temperature, and density) can be uniformly distributed through the volume but only in absence of diffusion phenomena or after their completion. Usually the substance present in the greatest amount is considered the solvent. Solvents can be gases, liquids, or solids. One or more components present in the solution other than the solvent are called solutes: The solution has the same physical state as the solvent.
Gas
If the solvent is a gas, only gases are dissolved under a given set of conditions. An example of a gaseous solution is air (oxygen and other gases dissolved in nitrogen). Since interactions between molecules play almost no role, dilute gases form rather trivial solutions. In part of the literature, they are not even classified as solutions, but addressed as mixtures.
Liquid
If the solvent is a liquid, then gases, liquids, and solids can be dissolved. Here are some examples:
Gas in liquid:
Oxygen in water.
Carbon dioxide in water is a less simple example, because the solution is accompanied by a chemical reaction (formation of ions). Note also that the visible bubbles in carbonated water are not the dissolved gas, but only an effervescence of carbon dioxide that has come out of solution; the dissolved gas itself is not visible since it is dissolved on a molecular level.
Liquid in liquid:
The mixing of two or more substances of the same chemistry but different concentrations to form a constant.(Homogenization of solutions)
Alcoholic beverages are basically solutions of ethanol in water.
Solid in liquid:
Sucrose (table sugar) in water
Sodium chloride or any other salt in water forms an electrolyte: when dissolving, salt dissociates into ions.
Counter examples are provided by liquid mixtures that are not homogeneous: colloids, suspensions, emulsions are not considered solutions.
Body fluids are examples for complex liquid solutions, containing many different solutes. They are electrolytes since they contain solute ions such as potassium. Furthermore, they contain solute molecules like sugar and urea. Oxygen and carbon dioxide are also essential components of blood chemistry, where significant changes in their concentrations may be a sign of illness or injury.
Solid
If the solvent is a solid, then gases, liquids, and solids can be dissolved.
Gas in solid:
Hydrogen dissolves rather well in metals, especially in palladium; this is studied as means of hydrogen storage.
Liquid in solid:
mercury in gold, forming an amalgam
hexane in paraffin wax
Solid in solid:
steel, basically a solution of carbon atoms in a crystalline matrix of iron atoms.
alloys like bronze and many others.
polymers containing plasticizers.
Properties
The physical properties of compounds such as melting point and boiling point change when other compounds are added. Together they are called colligative properties. There are several ways to quantify the amount of one compound dissolved in the other compounds collectively called concentration. Examples include molarity, mole fraction, and parts per million (PPM).
The properties of ideal solutions can be calculated by the linear combination of the properties of its components. If both solute and solvent exist in equal quantities (such as in a 50% ethanol, 50% water solution), the concepts of "solute" and "solvent" become less relevant, but the substance that is more often used as a solvent is normally designated as the solvent (in this example, water).