Notes, abstracts, papers, exams and problems of Chemistry

pure substance: is a phase of uniform composition and unchanging can not be decomposed into other substances of different classes by physical methods.

elements: they are pure substances that can not be decomposed into simpler ones through normal chemical processes.

compounds: they are pure substances made up of two or more elements, which can be decomposed by chemical methods on the elements of which are constituted. A compound always has the same elements and the same proportions regardless of the process followed.

Blended is an aggregation of different substances without causing any chemical reaction between them and therefore may be separated by physical methods.

ponderal laws: they refer to the quantity of matter of different substances... Continue reading "Laws ponderal" »

5. Describe what is electrodeposition, describe the different Experimental methods. Give examples. Advantages and disadvantages. It is the process of production a coating, usually Metallic, on a surface by the action of an electric current._Experimental Methods::-Electroplating: It is a plating process in which metal ions in a Solution are moved by an electric field to coat an electrode. Metallic cations From a solution are reduced on a conductive object (to form a thin layer).-Electrophoretic Deposition:Colloidal particles suspended in a liquid migrate under the Influence of an electric field (electrophoresis) and are deposited onto an Electrode._Advantages: uniform coating thicknen,easy control,high speed of Coating and high pucity._Disadvantages:

Anhydrides:

Non metal + O2 = Systematic Nomenclature / IUPAC (Anhydride)

Acids / Oxoacids:

Acids + H2O = IUPAC (Acid)

Basic Oxoacids:

Metal + O2 = Stock Nomenclature (nº) / IUPAC (Oxide)

Hydroxides:

Basic Oxide + H2O = IUPAC (Hydroxide)

Salts:

Hydroxide + Acid (ic - ate / ous - ite) Fe(OH)2 + HClO = Fe(ClO)2 - Ferrous Hyperchlorite

• Hypo - ous
• - ous
• - ic
• Hyper - ic

Stoichiometry:

Law of Conservation of Mass

Mole:

Amount of Substance that Contains as Many Particles (g)

Molar Mass:

1 mol of --- / g of ----

The environment plays an important role in our lives and people wouldn't be able to live without it. However, we are polluting it every day and it needs to stop. As individuals, we can do lots of things to solve this issue, and this essay will focus on two of them - recycling and the efficient use of energy.

According to recycling, it is the easiest way to see an immediate change and everybody can do it. First, recycling bins are a great method of dividing our waste into paper, plastic, glass, etc., and they can be easily found in every city. Another idea is to reuse the things we have at home and make them new. For example, turning …. 

When it comes to the use of energy, there are many things we can do, especially at home. When we talk about... Continue reading "I choose to live" »

Q#6.3: Define (i) Crystal lattice (ii) Unit Cell.

Ans.(i) Crystal Lattice.

A particular three-dimensional arrangement of particles (atoms, ions, molecules) in a crystal is called a crystal lattice.

In a crystal lattice, particles are located at definite positions in space. These positions are represented by points in a crystal and are called lattice points or lattice sites. This arrangement is called a crystal lattice or space lattice. A crystal lattice actually shows the shape of a crystal.

(ii) Unit Cell.

The smallest geometrical portion of the crystal which is used to build up the whole crystal. OR

If is the smallest portion of a crystal lattice which includes all the positions of each type of particle in the crystal. For example, a cubic crystal... Continue reading "Crystal Lattice and Unit Cell" »

H-hydrogen  2 BE-beryllium    3  B-boron     4 ca-carbon       5n-nytrogen

LI-lithium      MG-magnesium  Ai-aluminium si-silicon         p-phosphorus

na-sodium     CA-calcium        ga-gallium    ge-germanium as-arsenic

CS-cesium      bA-barium        in-indium      se-tin               sb-antimony

FR-francium   RA-radium        ti-thallium      pb-lead            bi-bismuth

6o-oxygen    7 f-fluorine     8 he-hellium        maass(m)   current intensity(iv)

s-sulfur         ci-chlorine        ne-neon          length(l)      surface area(s)

se-selenium  br-bromine      ar-argon         ... Continue reading "What is the time of the pet" »

An ion is an atom which has more or less electrons than protons

Ozone (O3 ) is a made with three oxygen atoms; it is very unstable and has a short lifetime. At room Temperature and pressure has acrid odour and no colour, although at high concentration levels can turn Into blue. At high concentrations can be toxic and can cause death. It s not emitted directly into the air, but is created by chemical reactions between oxides of nitrogen (NOx) and volatile organic compounds (VOC) in the presence of sunlight. VOC + NOx + sunlight tropospheric O3Particulate Matter (PM) "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small Particles and liquid droplets. Particle pollution is made up of a number of components, including acids (such as nitrates and sulfates), organic... Continue reading "Divergence in the upper air results, near the surface in: atpl" »

Three major characteristics of life

The cell theory

Three major domains of life