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AS and A Level: Inorganic Chemistry
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Top tips for writing reactions
- 1 Remember to balance the charges on any ionic compounds. The common ions are NO3-, SO42-, OH- and CO32-.
- 2 Do not forget to put state symbols on all of your balanced reactions.
- 3 Each side of the reaction must have the same number of atoms on it. Think about a balanced seesaw.
- 4 Your three main acids that you will use have the formulae HNO3 (nitric acid), H2SO4 (sulphuric acid) and HCl (hydrochloric acid).
- 5 Remember that all metal hydroxides and metal oxides are bases. This will help you when using word equations to figure out your products.
Five common mistakes students make when studying inorganic chemistry
- 1 When observing a gas being produced, you would not write “I saw a gas” as most gases are invisible. Instead you should write “I saw bubbling / fizzing / effervescence”.
- 2 When asked to write a word equation, students often write a symbol equation and vice versa. This will get you no marks in the exam.
- 3 - When asked for “standard conditions” people often say “room temperature”. This is not sufficient. You must say 25 degrees celsius (298K). Other standard conditions you must know are 1 atmosphere of pressure and concentrations of 1 mol dm-.
- 4 If you are asked to state a colour change you must state the initial and final colour.
- 5 Students often give group 2 metals a 1+ charge. Remember that all group two metals (Be, Mg, Ca, St, Ba, Ra) have a 2+ charge.
Five word equations that you must know
- 1 Acid + base / alkali = salt + water (eg HCl + NaOH becomes NaCl + H2O)
- 2 Metal carbonate = metal oxide + carbon dioxide (eg CaCO3 becomes CaO + CO2)
- 3 Metal + oxygen = metal oxide (2Mg + O2 becomes 2MgO)
- 4 Metal + water = metal hydroxide + hydrogen (eg 2Na + 2H2O becomes 2NaOH + H2)
- 5 Metal oxide + water = metal hydroxide (eg CaO + H2O becomes Ca(OH)2)
- Word count: 3996
CHANGE = -53.90 kJ mol�� Enthalpy change of HNO3: Q = M x C x change in T = (25 + 21) x 4.2 x 7.2 = 46 x 4.2 x 7.2 = 1391.04 J No of moles = C x V = 1 x 25/1000 = 0.025 1/0.025 = 40 40 x 1391.04 = 55641.6 55641.6/1000=55.64kJ ENTHALPY CHANGE = -55.64 kJ mol�� Enthalpy change of H2SO4: Q = M x C x change in T = (25 + 24)
- Word count: 908
To overcome this problem, chlorine and sodium hydroxide in a mercury cathode cell are produced in two different containers. Titanium anodes, coated with an oxide are in the top of the container where chlorine ions are discharged and Cl2 is formed. 2Cl- (aq) Cl2 (g) + 2e- A layer of mercury flowing along the base of the container is the cathode.The bottom of this container is called the decomposer. There, sodium ions are reduced to sodium and sodium and the sodium dissolves in the mercury.
- Word count: 1467
You will also notice that Endothermic reactions have a much greater Activation energy than Exothermic reactions and this is because the energy taken to form new bonds is greater than the energy taken to break them. The rate of a reaction is the time taken for the particles to reach the activation energy and for the reaction to 'go'. The fewer the number of particles with the activation energy, the slower the rate of reaction, and vice-versa. Not every particle in a substance can have the minimum energy requirement for the reaction and this is when outside factors can affect the rate of the reaction.
- Word count: 6099
In the collection of gas, I expect to collect double the volume of gas when metal reacts with H2SO4 than that of produced in the reaction with HCl. Apparatus: Titration Equipment: Quantity: Reason for choosing: Sulphuric acid (H2SO4) 200 cm3 As a source of hydrogen ions/ to accept a pair of electrons Hydrochloric acid (HCl) 200 cm3 Same as above Pipette (25cm3) X1 To measure out an accurate volume of NaOH Pipette Filler X1 To assist in filling pipette White tile X1 To distinguish the colour change of the solution Clamp X1 To secure burette Conical flask (250cm3)
- Word count: 1429
Single bonds are relatively easy to break as opposed to double or triple bonds. Endothermic and Exothermic Reactions: Exothermic reactions are those that give energy into their surroundings in the form of heat, heating the surroundings. This allows us to heat up the water directly above the spirit burner. An endothermic reaction is totally opposite to an exothermic reaction as endothermic reactions take in energy from the surroundings and cool the surroundings. Here are some bond energy diagrams for exothermic and endothermic reactions: This shows the negative enthalpy change as energy is given to the surroundings.
- Word count: 3433
Procedure [Hazard Warning: 1.0M sodium hydroxide and 0.05M sulphuric(VI)acid are irritant] 1.Three aspirin tablets (totally no more than 1.5 g) were weighted accurately into a 250cm3 conical flask. 2.The hydrolysis of the aspirin was initiated. 25.0cm3 of 1.0M sodium hydroxide was added from a pipette into a beaker. The same volume of deionized water was added and diluted. The flask was warmed gently for ten minutes to complete the hydrolysis. 3.After the mixture was cooled, it was transferred with washings quantitatively to a 250cm3 volumetric flask.
- Word count: 1352
Measuring cylinder had been used to measure out 100cm3 of approximately 1M hydrochloric acid and place it in a vacuum flask. 3. The temperature of the acid had been determined and recorded. 4. Then the weighted portion of calcium was added and the solution had been stirred thoroughly with a stirrer until all the metal had been reacted. 5. The maximum temperature attained by the solution had been record. Data: Mass of Ca used /g 1.03g Final temperature /?
- Word count: 960
Gloves may be worn to protect skin when handling the acid. Limewater is an irritant and should be handled carefully. List of equipment: * Burette: To titrate the hydrochloric acid into the limewater. * Clamp stand with clamp: To hold the burette securely upright while titration takes place. * 25ml pipette: To measure out the hydrochloric acid for dilution. * White tile: To place under the limewater solution while titrating to see clearly the colour change. * 250ml volumetric flask: To dilute the hydrochloric acid. * Conical flask: To hold the calcium hydroxide in while titration takes place.
- Word count: 847
There's 100cm� of LiOH, so it will be: 0.003485 � 4 = 0.01394 Moles present in 100cm� of LiOH 0.0139 moles Relative atomic mass of Lithium R.A.M mass / moles 0.12 / 0.0139 8.633093525 R.A.M of Li 8.633 HAZARD OF CHEMICALS IN THIS EXPERIMENT Care must be taking when handling chemicals in this experiment. Safety goggles and lab coat must be worn at all times. Ensure room is well ventilated. Li: Flammable, burns in air, react violently with water and oxygen.
- Word count: 1283
After all this work he finally decided that he wanted to take up a scientific career and went to work with Ludwig Knorr at Hena for one and a half years to publish with him a joint paper on diacetosuccinic ester yet orthodox methods at the institute under Jena gave Haber little satisfaction. Still uncertain whether to devote himself to chemistry or physics he was offered a job in 1894 at the age of 25 as an assistantship at the Technische Hochschule of Karlsruhe by the Professor of Chemical Technology there who was Hans Bunte.
- Word count: 925
by H2 and Fe3+. This allows soluble products to dissolve. FeAsS(s) -> Fe2+ (aq) + As3+ (aq) + S6+ (aq) This Process occurs at the cell membrane of the bacteria. The electrons pass into the cells and are used in biochemical processes to produce energy for the bacteria in order to reduce the oxygen in water. Stage 2 the bacteria then oxidise the Fe2+ to Fe3+ Fe2+ -> Fe3+ The bacteria then oxidises the metal to a higher oxidation state.
- Word count: 1117
It can measure to 0.05cm3. Conical flask- For solutions to react in. Pipette- For measuring limewater solution. This is also very accurate. Pipette controller- To control amount of solution going in and out of pipette. Clamp stand- To hold burette. Clamps- To make sure equipments are secure. Funnel- So chemicals can be poured safely without spilling. White tile- To see clearly when reaction takes place. Distilled water- To clean equipments with and to use in the experiment. Beaker- To contain chemicals, solutions and distilled water Chemicals Limewater containing calcium hydroxide Hydrochloric acid will be used in titration and dilution.
- Word count: 930
: 2 0.0003375 : 0.000675 if the concentration of HCl is 2 mol dm-3 then 0.000675 = 0.0003375 dm3 = 0.3375 cm3 2 This is a very small volume so the measurement errors will be large: (the error margin for a 50cm3 burette is � 0.1) 0.1 � 100 = 29.6 % 0.3375 As I plan to use a 50cm3 burette, an ideal volume of HCl to be measured out would be between 20-30cm3; so if I want to use about 25cm3 of HCl then the concentration will need to be about: 0.000746 = 0.02984 mol dm-3 25/1000 To make dilution process easier (and more accurate)
- Word count: 1778
First I needed to find the moles of calcium hydroxide, I did this by dividing its mass by its relative molecular formula, 1/74.1 = 0.0135 Then I needed to work how many moles there where in a 25cm( 0.0135 x 0.025 = 0.000338 Because the ratios of Calcium hydroxide to hydrochloric acid are 2:1 we need to have twice as many moles .000378 x 2 = 0.000676 To get volume of hydrochloric acid needed to neutralise the calcium hydroxide we divide the moles by concentration 0.000676/2 =0.000338 dm-( or 0.338cm-( This is too small of a volume to measure accurately so I will need to dilute the acid to get a more suitable volume.
- Word count: 673
All chemicals have different rates of reaction. The rate of a chemical reaction can be changed if (2): - The pressure of the gas is changed Increase in pressure means that the molecules (mainly in gases) have less space to move around in so have a greater chance to collide with other molecules and react. - The temperature of the reactants is increased Increasing the temperature of the system will increase the chances of successful collision because the molecules will have more kinetic energy and will collide with other molecules with more power increasing the chance of a reaction.
- Word count: 3551
In this experiment I will not use the halogen fluorine because of the strong bond it forms with carbon. According to bond enthalpy the C-F bond is the less reactive of the halogenoalkanes because of how strong the bond energy is between them. The bond energy in the C-F bond is 467 kJ mol-1. So the C-F bond will be too strong to be affect by nucleophiles. Equations for nucleophilic substitution reactions are: C4H9Br + OH � C4H9OH + Br� C4H9Cl + OH � C4H9OH + Cl� C4H9I + OH � C4H9OH + I� Prediction My prediction for which bond will react most vigorously with the nucleophile will be the C-I halogenoalkane.
- Word count: 1054
---------------------> CuO (s) + CO2 (g) '1 mole of copper carbonate will decompose to 1 mole of CuO and 1 mole of CO2' '1 mole of gas occupies 24360 cm� at 20�C, 100kPa'. I aim at 30 cm� volume of gas, so I can ensure all gas is measured. Thus, if 1 mole of copper carbonate produces 24360 cm� of CO2, to produce 30 cm� we need: * number of moles = volume cm�/24360 cm� = 30 cm� /24360 cm� = 0.0012315271 moles of gas * Mr of CuCO3 = 63.5+12+(3*16)= 123.5 * Mass= moles* Mr = 0.0012315271 moles* 123.5 =0.1520935969 g =0.15 g ( 2 d.p.)
- Word count: 1228
In the nineteenth century the first recognizable Periodic Table was pieced together by comparing properties of different elements. At least 47 elements were discovered, and scientists began to see patterns in the characteristics. In 1828 Jakob Berzelius published a table of atomic weights and introduced letter-based symbols for elements. Johann Wolfgang proposed his `law of triads` in 1829, stating that: ` Nature contains triads of elements where the middle element has properties that are on average of the other two members of the triad when ordered by the atomic weight.' Wolfgang discovered that strontium had similar chemical properties to calcium and barium and that its atomic weight fell midway between the two.
- Word count: 1687
n = m therefore Ar = m = 0.08 = 7.34 (3 s.f.) Ar n 0.0109 2. a) LiOH(aq) + HCl(aq) LiCl(aq) + H2O(l) b) Finding the number of moles of HCl: To find the number of moles of HCl used in the titration, we use the values we have collected, and place them into the following equation: C = n therefore n = CV V C = 0.1M V = 25.6 + 25.4 + 25.4 = 25.47cm3 (2 d.p) = 0.02547dm3 3 n = ? n = CV = 0.1 x 0.2547 = 0.002547 mol c)
- Word count: 1258
Visible light wavelengths vary from around 400 nm (blue) to 700 nm (red). Colorimetry is relevant to our investigation as Fe(II) will go from pale green (almost colourless) to form a violet complex ion with the bidentate ligand ferrozine (see fig.3). The formula of this complex ion is [Fe(ferrozine)3]2+. A solution containing ferrozine would appear coloured to us because white light enters and violet light is not absorbed (otherwise there would be no violet to see). It is the other colours that are absorbed.
- Word count: 886
This assumption is made because the equation is "stoichiometric" (3) meaning 1 mole of CuCO? decomposes to exactly 1 mole of CuO and 1 mole of carbon dioxide. However, 24000cm� would be too much gas to produce in a school lab, as that size of apparatus is not available. Gas syringe will be used but has a maximum of 100cm�, so it would not be sensible to produce 100cm� of gas because if equation 1 turns out to be correct (which would mean oxygen will also be produced), and there would consequently be more gas.
- Word count: 821
Both organic and inorganic fertilisers are called manures, derived from the French expression for manual tillage, but this term is now mostly restricted to organic manure. Inorganic or artificial fertilisers are formulated in appropriate concentrations and combinations for various crops and growing conditions. The most popular inorganic fertilisers include: anhydrous ammonia, a gas that is 82% nitrogen; urea, a solid compound containing 46% nitrogen and diammonium phosphate, containing 18% nitrogen and 46% phosphate. Ammonia is most commonly used as a fertiliser and applied directly to the soil from tanks containing the liquefied gas.
- Word count: 779
Using the + 0.1g balance, weighing approximately between 1.2g and and 1.4g of sodium carbonate into the small beaker. (Do not record the mass) 2. using the + 0.1 balance, weighing the small beaker and its contents accurately, then recording the mass. 3. then transfer the content to the small beaker in to the large beaker. Weigh the small beaker again using the + 0.1 balance so I get a accurate result. 4. Next I add de-ionised water cautiouly down the side of the large beaker. Use about 150cm3 of water, and swirl the beaker to mix the contents. 5.
- Word count: 2058
The stationary phase is usually a piece of high quality filter paper. The mobile phase is a developing solution that travels up the stationary phase, carrying the samples with it. Components of the sample will separate on the stationary phase according to how strongly they adsorb to the stationary phase versus and how much they dissolve in the mobile phase. The purpose of this experiment is to observe how chromatography can be used to separate mixtures of chemical substances, in this case separate felt tip pen. Chromatography serves mainly as a tool for the examination and separation of mixtures of chemical substances.
- Word count: 2870