Assignment 1: Quantities in Chemical Reactions
The Periodic Table
It consists of 8 groups:
Group 1: Alkali Metals
Group 2: Alkali Earth Metals
Transition Metals (Between Group 2 & 3)
Group 6: Chalcogens
Group 7: Halogens
Group 8: Noble Gases
Group 1 (Alkali Metals)
Sodium is a silvery white metal.
It has a boiling point of 97.8?C and a melting point of 881.4?C.
It reacts with water very vigorously which is why it is usually stored under substances like Kerosene and Naphtha.
It also reacts with acids to produce hydrogen gas.
Group 2 (Alkali Earth Metals)
Calcium is a very soft metal that when cut shows a shiny silver surface.
It has a melting point of 850?C and a boiling point of 1440?C.
It reacts with oxygen mildly to produce Calcium Oxide.
Calcium reacts with the Halogens (Group 17).
The transition metals consist of elements between group 2 and group 3 on the periodic table.
Copper is a very soft and ductile meaning it can be moulded into various shapes (e.g. Strings).
It has a very high conductivity with heat and electricity.
It has a reddish-brown tint.
It also has a melting point of 1083?C, boiling point of 2595?C and a density of 8.96g/cm3.
Copper reacts with most acids and alkalis.
It reacts with water and carbon dioxide in the air to produce hydrated copper carbonate.
Aluminium is a silver like metal
It has a boiling point of 2327?C – 2450?C and a melting point of 660?C
It is also malleable and ductile meaning it can easily be stretched and formed into different shapes.
Aluminium reacts with oxygen slowly to produce aluminium oxide.
It also reacts really quick with hot water and when in powder form it catches fire when exposed to a flame.
Carbon has many allotropic forms; two main ones are Graphite and Diamond (Crystalline Structures).
Diamond being the hardest natural substance known
It has a melting point of about 3700?C and a boiling point of about 4200?C.
Its density is 3.50g/cm3.
Graphite is a very soft material often used as lead in pencils
It has a density of about 1.5g/cm3 – 1.8g/cm3
Graphite does not melt but however goes through sublimation at about 3650°C.
Unfortunately, Carbon doesn’t react with acids or water, however it does react with oxygen to produce carbon dioxide and carbon monoxide
It also has the ability to form virtually endless strings of atoms.
Nitrogen is a tasteless, odourless and colourless gas.
It changes from a gas to a liquid at -195.79°C and also freezes at -210.01°C, it then turns into a white solid.
It is also soluble in water and has a density of 1.25046g/l.
It is very dormant at room temperature and doesn’t react with oxygen, hydrogen and most other elements.
In the presence of lightning or a spark it will however react with oxygen forming nitric oxide.
Nitric oxide then reacts with oxygen and water in the air to make nitric acid.
Group 6 (Chalcogens)
Oxygen is a tasteless, odourless and colourless gas.
It condenses at -182.96°C it then changes to a bluish colour.
It can then be frozen at -218.4°C. It has a density of 1.429g/l.
Oxygen reacts with metals to form rust, it also helps combustion meaning it helps objects to burn however, it doesn’t catch fire itself.
It is moderately soluble in water at 20?C
Group 7 (Halogens)
Fluorine is a pale-yellow gas with a very pungent odour.
It condenses at -188.13° and freezes at -219.61°C.
It has a density of 1.695g/l which is about 1.3 times denser than air.
It is known as the most reactive element.
It reacts with every other element except from Helium, Neon, Argon.
It reacts with water, it reacts explosively.
Group 8 (Noble Gases)
Argon is a noble gas meaning it has a stable electronic structure
It is also a tasteless, odourless, colourless gas.
It condenses at -185.86°C and freezes at -189.3°C
It has a density of 1.784g/l.
Argon being a noble gas means that is unreactive.
Argon has approximately the same solubility as oxygen.
Bohr’s Theory/ Model of an Atom
This explains the structure of an atom, an atom consists of a nucleus (Protons and Neutrons), electrons. They have an electronic structure where there are fixed electrons on the rings that orbit around the nucleus.
Tetrahedral Structure of Carbon
Methane also known as a hydrocarbon combines hydrogen and carbon together to form the tetrahedral structure show below.
Ionic bonding takes place in some compounds, this is where an ion is transferred from one atom to another atom to achieve stability. A good example of this is in Sodium Chloride, the sodium atom transfers and atom to chlorine to complete its electronic structure and therefore making it stable.
Covalent bonding take place in most compounds, this is where an atom shares an electron with another atom in order to achieve stability.
Chlorine can go through covalent bonding when it shares its extra electron in both atoms.
Acid Base Titration
Trial 1 2 3 4
Burette Readings Final (cm?) 26.10 50.20 (Inaccurate) 23.30 23.50 24.20
Initial (cm?) 0.00 26.00 0.00 0.00 0.00
Volume used titre(cm?) 26.10 24.20 23.30 23.50 24.20
Mean titre (cm?) 23.50+23.302=23.40cm3 Potassium hydrogen phthalate = C8H5O4K
Molar mass of C8H5O4K = 204
You are going to make 250 cm3 of a solution of concentration 0.10 moldm-3
Moles of C8H5O4K = 0.025mol
Number of Moles = V×C1000=250×0.101000=0.025mol
Mass of C8H5O4K = 5.1
Mass = Moles ×Mr(Molar Mass) =5.1g
In my experiment I used 25.0cm3 of acid each time. So, the moles of my acid = 0.0025 and the moles of sodium hydroxide = 0.0025. Using the values of the mean titre and the number of moles the Concentration = n×100023.40 = 0.11mol/dm-3
NaOH(aq) + KHC8H4O4(aq) = KNaC8H4O4(aq) + H2O(l)
Diagram of Apparatus
The balanced equation is NaOH(aq) + KHC8H4O4(aq) = KNaC8H4O4(aq) + H2O(l). The molar ratio is 1:1 meaning the number of moles is the same for each compound.
Ionic Bonding takes place in the Sodium Hydroxide (NaOH), Hydroxide (O-H+), (O-K+), Carbon Dioxide Sodium (CO2-Na+), Carbon Dioxide (CO2-K+). The sodium atom (Na+) transfers 1 ion on its outer shell to the Hydroxide (-OH) This is the when the positive ions are transferred to complete the electronic structure. Covalent bonds are formed between the carbon atoms and the Water (H2O). This is where the atoms all share electrons to complete the electronic structure and make it stable.
If you substitute the Sodium Hydroxide (NaOH) with Magnesium Hydroxide, it will transfer 2 electrons from Magnesium to the Hydroxide (OH), making it Mg (OH)2 this is because it belongs to group 2.
If you substitute the Sodium Hydroxide (NaOH) with Aluminium Hydroxide, it will transfer 3 electrons from Aluminium to the Hydroxide (OH), making it Al (OH)3 this is because it belongs to group 3.
When it comes to industrial titration, there are two types:
Karl Fischer Titrations
Potentiometric involves a potentiometer that records the changes present in the electrode potential of a solution. Whereas the Karl Fischer Titration focuses on using volumetric titration to detect trace amounts of starting solution and water in a sample. It is said that the Karl Fischer procedure is more accurate than the Potentiometric method. When preparing a standard solution in industry they use expensive equipment such as automated robots that record the volumes and put the results straight into an excel table to calculate the correct volumes. They also have machines that zero each burette after each procedure to maintain accuracy of results.
There are plenty of real world (Industrial) applications for titration such as:
Acid Rain – To measure the degree of contamination in rain water or snow.
Wastewater (Waste & Recycling Industry) – It is used to measure the contamination of the water to determine the requirements needed for filtering and cleaning.
Pharmacology (Medical Industry) – It is used to determine exact quantities of certain chemicals and compounds used in medication to maintain quality control. For example, when preparing aspirin, a simple titration experiment will tell you the purity of the desired sample.
Nutrition (Food Industry) – It is used to detect the compounds in the foods we eat and identify quantities that are safe to be manufactured. For example, how much acid is in orange juice can easily be detected through a simple titration experiment.
BTEC Level 3 National Applied Science Student Book
Author: Frances Annets,Shirley Foale,Roy Llewellyn,Ismail Musa,Sue Hocking,Ellen Patrick,Joanna Sorensen,Tony Kelly,Lee Hudson
2018 Advameg, Inc
Topics, Sample Papers & Articles Online for Free. (2015). Titration In Industry. Online. Available at: https://studymoose.com/how-titrations-and-standard-solutions-are-prepared-in-industries-essayAccessed: 30 Nov. 2018