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After the end of World War II on October 24, 1946 and a good
while before the Sputnik satellite opened the space age, a group of soldiers
and scientists in the New Mexico desert saw something new and wonderful—the
first pictures of Earth as seen from space.
The White Sands rocket (official name V-2 No. 13) was the
first man-made object to take a photograph of the Earth from outer space. Launched from the White Sands Missile Range
in White Sands, New Mexico, the rocket reached a maximum altitude of 107.5
miles (173 km), well above the commonly accepted boundary of space at 100
The famous photograph was taken from an altitude of 65 miles
(104 km) with an attached 35 mm black-and-white camera.
Snapping a new frame every second and a half, the
rocket-borne camera climbed straight up, then fell back to Earth minutes later,
slamming into the ground at 500 feet per second. The camera itself was smashed,
but the film, protected in a steel cassette, was unharmed.
It was one of many firsts for the V-2 research program of
the late 1940s, during which the Army fired dozens of captured German missiles
brought to White Sands in 300 railroad cars at the end of the war. While the
missileers used the V-2s to refine their own rocket designs, scientists were
invited to pack instruments inside the nosecone to study temperatures,
pressures, magnetic fields and other physical characteristics of the unexplored
A pH indicator is a colour changing (or halochromic)
chemical compound that is added in small amounts to a solution so that the pH
(acidity or basicity) of the solution can be determined visually.
A pH indicator is a chemical detector for hydronium ions
(H3O+) or hydrogen ions (H+). Normally, the indicator causes the colour of the solution to change depending on the pH.
(potential of hydrogen) is a scale of acidity from 0 to 14. It tells how acidic
or alkaline a substance is. More acidic solutions have lower pH. More alkaline
solutions have higher pH. Substances which are not acidic or alkaline (neutral)
usually have a pH of 7. Acids have a pH less than 7. Alkalis have a pH greater
than 7. pH indicator solutions are themselves weak acids or bases. As one chemical is added it changes the arrangement of the electrons in the molecule causing it to absorb different wavelengths of light and therefore appear different in colour. Different chemicals can be used for different pH ranges as shown in the diagram below.
pH indicators are frequently employed in titrations in
analytical chemistry and biology to determine the extent of a chemical
reaction. Because of the subjective choice (determination) of colour, pH
indicators are susceptible to imprecise readings. For applications requiring
precise measurement of pH, a pH meter is frequently used.
Many plants or plant parts contain chemicals from the
naturally-coloured anthocyanin family of compounds. They are red in acidic
solutions and blue in basic. Anthocyanins can be extracted with water or other
solvents from a multitude of coloured plants or plant parts, including from
leaves (red cabbage); flowers (geranium, poppy, or rose petals); berries
(blueberries, blackcurrant); and stems (rhubarb). Extracting anthocyanins from
household plants, especially red cabbage, to form a crude pH indicator is a
popular introductory chemistry demonstration.
On the 10th
October 1897 German chemist Felix Hoffmann discovered an improved way of
synthesizing acetylsalicylic acid or 'aspirin'.
Around c400 BC Hippocrates in Greece gives women willow leaf tea to
relieve the pain of childbirth. In 1763 Reverend Edward Stone of Chipping Norton near Oxford
gives dried willow bark to 50 parishioners suffering rheumatic fever and describes his findings in a letter to the Royal Society of
London. In 1823 the active ingredient is extracted from willow
and named salicin. Salicylic acid is made from salicin by French scientists in 1853 butis found to irritate the gut. In 1893 German scientists find that adding an acetyl group to
salicylic acid reduces its irritant properties and in 1897 in Germany, Bayer's Felix Hoffmann develops and patents
a process for synthesising acetyl salicylic acid or aspirin. First clinical
Aspirin is often used as an analgesic to relieve minor aches and pains,
as an antipyretic to reduce fever, and as an anti-inflammatory medication.
Aspirin is now accepted as an important weapon in the prevention of heart disease. A single dose of 300 mg is now recommended for patients in the acute stages of a heart attack followed by a daily dose of 75-100 mg. A similar low dose treatment regime is recommended for patients with angina, a history of heart problems or who have undergone coronary by pass surgery.
Aspirin is also used in other medical situations:-
Strokes - to reduce the risk
Complications - Pre-eclampsia and foetal growth retardation, both caused by blockages of the
blood vessels of the placenta, are two of the commonest complications of
pregnancy - aspirin helps to reduce this risk.
cancer - In a long term study of 90,000 US nurses between 1976 and 1995, those who took
4-6 tablets of aspirin a week had a reduced incidence of colorectal cancer. The
benefits were greatest in those who had taken the drugs the longest.
Diabetes-Blindness, coronary artery disease, stroke and kidney failure are all common
complications of diabetes resulting from impaired blood circulation. The
benefits of taking one aspirin a day are now so widely accepted that it is considered
unethical to perform placebo controlled trials to prove the case.
(including Alzheimer's disease)-There is some
evidence that aspirin may help prevent both the condition resulting from
impaired blood flow and the most serious form of dementia, Alzheimer's disease.
The most common use is as a painkiller for headaches or fevers.
Zinc is a metallic chemical element; it has the symbol Zn
and atomic number 30. It is the first element of group 12 of the periodic
table. It’s the 24th most abundant element in the Earth's crust and has five
stable isotopes. The most common zinc ore is sphalerite (zinc blende), a zinc
sulfide mineral. The largest mineable amounts are found in Australia, Asia, and
the United States.
Brass, which is an alloy of copper and zinc, has been used since at least the 10th century BC.
Zinc is an essential mineral of "exceptional biologic and
public health importance". Zinc
deficiency affects about two billion people in the developing world and is associated
with many diseases. In children it
causes growth retardation, delayed sexual maturation, infection susceptibility,
and diarrhoea, contributing to the death of about 800,000 children worldwide
The metal is most commonly used as an anti-corrosion agent. Galvanization, which is the coating of iron or
steel to protect the metals against corrosion, is the most familiar form of
using zinc in this way. Zinc is more
reactive than iron or steel and thus will attract almost all local oxidation
until it completely corrodes away. A
protective surface layer of oxide and carbonate forms as the zinc corrodes. This protection lasts even after the zinc
layer is scratched but degrades through time as the zinc corrodes away. The zinc is applied electrochemically or as
molten zinc by hot-dip galvanizing or spraying. Galvanization is used on
chain-link fencing, guard rails, suspension bridges, light posts, metal roofs,
heat exchangers, and car bodies.
Zinc Oxide used in paint pigments
Zinc is useful for the human body and helps speed up the healing process after an
injury. It is also suspected of being
beneficial to the body's immune system. Indeed, zinc deficiency may have
effects on virtually all parts of the human immune system.
Our blog is normally reserved for science news & facts and other interesting things! However we thought we'd share this video featuring the new range of Ohaus Adventurer balances. With dual USB ports, one at the front and one at the back connectivity is easy. With colour touchscreen, fast stabilisation and accuracy these balances are worth a look. Visit our website news page on the link below to download a brochure.
Back in your school days there was probably an experiment where you placed a small amount of a compound into a flame and observed it's colour. This is the flame test and depending on the colour observed it can tell you what elements are present.
Scientifically put, A flame test is an analytic procedure used in chemistry to detect the presence of certain elements, primarily metal ions, based on each element's characteristic emission spectrum. The colour of flames in general also depends on temperature.
The test involves introducing a sample of the element or compound to a hot, non-luminous flame, and observing the colour of the flame that results. The idea of the test is that sample atoms evaporate and since they are hot, they emit light when being in flame.
The flame test is relatively quick and simple to perform, and can be carried out with the basic equipment found in most chemistry laboratories. However, the range of elements positively detectable under these conditions is small, as the test relies on the subjective experience of the experimenter rather than any objective measurements. The test has difficulty detecting small concentrations of some elements, while too strong a result may be produced for certain others, which tends to cause fainter colours to not appear.
The table above from www.compoundchem.com shows the range of colours chemicals produce. These tests work better for some metal ions than other; in particular, those ions shown on the bottom row of the infographic are generally quite faint and hard to distinguish. Sodium’s flame colour is also very strong, and can easily mask the colours of other metal ions.
Sodium hypochlorite is a chemical compound with the formula
NaClO. It is composed of a sodium cation (Na+) and a hypochlorite anion (ClO−);
it may also be viewed as the sodium salt of hypochlorous acid. When dissolved
in water it is commonly known as bleach or liquid bleach, and is frequently
used as a disinfectant or a bleaching agent.
Potassium hypochlorite was first produced in 1789 by Claude
Louis Berthollet in his laboratory on the quay Javel in Paris, France, by
passing chlorine gas through a solution of potash lye. The resulting liquid,
known as "Eau de Javel" ("Javel water"), was a weak
solution of potassium hypochlorite. Antoine Labarraque replaced potash lye by
the cheaper soda lye, thus obtaining sodium hypochlorite (Eau de Labarraque).
Various methods have been used since to produce this but the modern method, the Hooker process, is the only one producing this in any bulk capacity.
Sodium Hypochlorite has many uses as can be seen above:-
In bleach cleaning products and to remove stains. In Swimming pools as a disinfectant. In Antibacterial sprays To neutralise nerve agents To reduce skin damage - using very low concentrations.
Sodium Hypochlorite although used in household bleach is not the only component. There is often Sodium Hydroxide and Calcium Hypochlorite amongst others. it must be remembered not to mix household cleaning products as some may contain hydrochloric acid. If these are mixed with bleach, it can react with sodium hypochlorite, and form toxic chlorine gas