Notes, abstracts, papers, exams and problems of Chemistry

Sort by

Laws ponderal

Classified in Chemistry

Written at on English with a size of 1.61 KB.

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" »

Advantages and disadvantages of electrometallurgy

Classified in Chemistry

Written at on English with a size of 4.32 KB.

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:

... Continue reading "Advantages and disadvantages of electrometallurgy" »

Chemical Nomenclature and Stoichiometry: An Overview

Classified in Chemistry

Written at on English with a size of 1 KB.


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

Acids / Oxoacids:

Acids + H2O = IUPAC (Acid)

Basic Oxoacids:

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


Basic Oxide + H2O = IUPAC (Hydroxide)


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

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


Law of Conservation of Mass


Amount of Substance that Contains as Many Particles (g)

Molar Mass:

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

I choose to live

Classified in Chemistry

Written at on English with a size of 1.77 KB.

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" »

Crystal Lattice and Unit Cell

Classified in Chemistry

Written at on English with a size of 1.02 KB.

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" »

What is the time of the pet

Classified in Chemistry

Written at on English with a size of 1.29 KB.

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" »

Coh3 chemical name

Classified in Chemistry

Written at on English with a size of 1.75 KB.

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

All atoms want to have a full shell/empty outer shell
Noble gasses have already a full outer shell
All other elements will give or take electrons=chemical reaction

Covalent bonds are.Stronger than ionic
they make molecules and they are formed between non_metals
These bonds are between atoms fighting ever some electrons bonds where electrons are shared

Different forms of carbon: Carbon(black, it can burn)
Graphite(Grey, used as lubricant)
Diamond(Transparent, cutting hard material)

Differences between covalent and ionic compounds:
Ionic: Volatility: none
Solubility: most are very soluble
Electrical conductivity: only when dissolved in water
-liquid form

Solubility: some
... Continue reading "Coh3 chemical name" »

Divergence in the upper air results, near the surface in: atpl

Classified in Chemistry

Written at on English with a size of 4.78 KB.

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" »

Coh3 chemical name

Classified in Chemistry

Written at on English with a size of 3.17 KB.


An atom is the smallest  stable unit of matter 

An element is a pure substance made of only one type of atom.
There are about 120 elements , so 120 different atoms exist.

In the periodic table the elements are organized in rows.
The vertical columns are called groups
The horizontal rows are called periods. 
Li, Na and k are in the same group 
N , O , F are in the same period. 
If the elements are in the same group they have the same number of electrons in the outer shell.
This elements in their same groups can have similar chemical and physical  properties. 

Some groups have specific names :

Group 1 elements : are named ALKALI 
Group 2 elements : ALKALI EARTH METALS
Group 7 elements : HALOGEN 
Group 0 elements : NOBLE
... Continue reading "Coh3 chemical name" »

Characteristics of Life, Cell Theory, and Atomic Structure

Classified in Chemistry

Written at on English with a size of 3.31 KB.

Three major characteristics of life

1.Energy 2.Cells 3.Information
4.Replication 5.Evolution

The cell theory

All organisms are made of cells and come from pre-existing cells

Three major domains of life

Archaea, Bacteria-Prokaryotic microorganism, single-celled whose cells have no nucleus


A trait that increases the fitness of an individual in a particular environment
Genus-Made up of a closely related group of species
Species-made up of individuals who regularly breed together

Atoms are composed of


Atomic number-atoms with the same atomic number, have the same chemical properties, belong to the same element(Is on bottom and represents the number of protons)

Mass Number-

number of protons
... Continue reading "Characteristics of Life, Cell Theory, and Atomic Structure" »