- Created by: Gina Hayley Phillips
- Created on: 04-01-12 16:24
Ores are not homogenous, what does this mean?
Homogenous means not the same composition all the way through.
A scientist wants an easy method to find the densi
To find the volume of an irregular shaped piece of apatite you can put it into a measuring cylinder containing a known volume of water, the displaced volume can be calculated to work out the volume of the piece.
What is the chemical formula for iron oxide?
What is ilmenite composed of and where are the maj
Ilmenite: A weakly magnetic titanium-iron oxide mineral which is iron black or stell gray.
Worlds largest ilmenite mine is in the Tellnes mine located in Sokndal and Norway. One of the richest magnetite ilmenite ore bodies in Australia.
What is rutile mainly composed of and what else it
Rutile is a mineral composed primarily of titanium dioxide. It also contains natural iron and significant amounts of niobium and tantalum.
What is the chemical equation for the formation of
2 FeTiO3 + 7 C12 + 6 C à 2 TiC14 + 2 FeC13 + 6 CO
What impurities are then removed from the titanium
This material is derived from ilmenite by the removal of iron, either by using carbon reduction or extraction with sulfuric acid. Crude contains a variety of volatile halides which must be separated.
What is vacuum distillation?
Vacuum distillation: Distillation of a liquid under reduced pressure, enabling it to boil at a lower temperature than normal.
90% of the titanium tetrachloride is used to make
96,000 x 10 = 960, 000 tonnes of titanium tetrachloride originally. To find the tonnage of titanium dioxide, 960000 - 96000 = 864000 tonnes.
Find a diagram to summarise the Kroll process.
A process for the production of metallic titanium by the reduction of titanium tetrachloride with an active metal such as magnesium.
Titanium dioxide from rutile.
Step 1: The crude ore is reduced with carbon.
Step 2: Carbothermal chlorination then occurs (oxidised with chlorine to give titanium tetrachloride.)
Step 3: Distillation then occurs and the titanium tetrachloride is re-oxidised in a pure oxygen flame at 1500-2000K to give titanium dioxide.
Step 4: This gives pure titanium dioxide and regenerates the chlorine.
The previous question considers the chloride proce
Utilizes ilmenite as the titanium dioxide source, which is digested in sulfuric acid. The sulfate is crystallixed and filterd off to yield only the titanium salt in the digestion solution.
When titanium dioxide is used as pigment, what are
When used as a pigment it is called titanium white, pigment 6 or CI77891.
When used in food colouring it has the name E number E171
Why is titanium dioxide used in sunscreens?
- Physical blocker because of its high refractive index, it's strong UV light absorbing capabilities and it's resistance to discolouration under ultraviolet light.
Advantages: Enhances its stability and ability to protect skin from ultraviolet light.
Sunscreens designed for infants or people with sensitve skin are often based on titanium dioxide and/or zinc oxide mineral blockers are believed to cause less skin irritation than other UV absorbing chemicals.
Disadvantages: Radicals are carcinogenic and could damage the skin.
A sunscreen contained particles that had a diamete
60nm is 0.000006cm
What does titanium dioxide cause the UV rays to do
Used in organic sunscreens is to reflect or scaattering the harmful rays ofthe sun it is also resistant to discoloration under ultraviolet light.
What does spectrophotometer do?
Quantitve measurement of the reflection or transmission properties of a material as a function of wavelength. It is more specific than the general term electromagnetic spectroscopy.
Are nanoparticles in sunscreen safe?
There is the debate as to whether tiny particles can be absorbed into the skin and penetrate a cell leading to cell damage.
This can causes DNA damage after exposing to sunlight,
Many studies show that nanoparticles are not small enough to penetrate the skin.
What does transmission mean? What wavelength does
Transmission is the amount of radiation that is able to get through the sunscreen. At 27% it is a wavelength of 329nm and is a UVA.
What is the difference between UVA and UVB radiati
UVA rays are constantly present, no matter the season or the weather.
- They are so powerful they can penetrate some clothing and glass.
- Considered safe however used used in tanning beds (dangerous before age of 30 and can increase the risk of skin cancer by 75%)
- Responsible for the signs of ageing as can penetrate surface damaging cells underneath)
UVA - think sun spots, leathery skin and wrinkles
UVB rays can be blamed for sunburn.
- Not strong all around the year - more in summer months.
- Responsible for slow cancer
UVB- think sunburn and cancer.
Why do sunscreens need to be tested on an in vitro
To make sure that there are no effects on human cells before they test on animals.
What is a quantitative test?
The determination of the absolute or relative abundance (Often expressed as a concentration) of one, several or all particular substances present in a sample.
What is gravimetric analysis?
Gravimetric analysis is a set of methods for the quantitative determination of an analyte based on the mass of a solid.
Gravimetric analysis usually consists of the follo
A: What is meant by precipitation?
A precipitation is the formation of a suspension of an insoluble compound.
B: What may be the problem when trying to form the precipitate of the target analyte?
The problem why trying to get the precipitate may be the other precipitates may form.
C: What may be the problem with using filter paper?
The problem with filter paper is that some chemicals will corrode the paper.
What is a colorimeter?
A colorimeter is a piece of equipment used for colourimetry.
It measures the absorbance or light or transmission of light.
(Curved graph) The following standard curve was ob
The unknown sample of titanium used gave a reading of 0.8OD, what was the concentration of the sample?
The concentration should be between 2.6-2.9
Describe how a serial dilution is made to produce
(A table can be used to demonstrate what you mean)
Use distilled water to dilute the stock solution, a table to show to mix the water and the solution together.
Find some other uses of titanium and titanium diox
Aerospace industry - for example aircraft engines and air frames.
For replacement hip joints.
For pipes when corrosion is likely to occur.
For organic make-up and vitamins and minerals.