Term
| What can be added to sulphate ions to test for them? What would be observed? |
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Definition
BaCl2
White precipitate formed |
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Term
| What can be used to test for ammonia? What would be observed? |
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Definition
Damp litmus paper
Colour change from red to blue |
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Term
| What precipitate is formed and what is the colour of it when NaOH is added to Iron (II) chloride? |
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Definition
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Term
| How could a test to time the colour change of a solution be improved from looking at the solution in a flask? |
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Definition
-Keep the solution at a constant temp because reaction rate is influenced by temp
-Use a colorimeter to monitor colour change which gives a more accurate time of colour change |
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Term
| How could H2O2 be separated from Ba(NO3)2? |
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Definition
| By fractional distillation |
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Term
| Why would it be better to react sulphuric acid with BaO2 rather than nitric acid? |
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Definition
| BaSO4 is insoluble so easier to separate from H2O2 |
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Term
| Why can't infrared spectroscopy be used to identify H2O in a solution of H2O2? |
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Definition
| They both contain an OH group |
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Term
| Why does hydrogen peroxide decompose more quickly if it is kept in a clear glass bottle rather than a brown one? |
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Definition
| Decomposition is accelerated by light |
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Term
| Even if hydrogen peroxide is corrosive, why does a spillage not have long term effects on the environment? |
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Definition
| Decomposition products are harmless |
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Term
| What arrangement, reflux or distillation, should be used for the formation of ethanal and why? |
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Definition
Distillation
If reflux, further oxidation would occur and ethanoic acid would be formed |
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Term
| How would you ensure a reading from a pH meter is accurate? |
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Definition
| Collaborate with a solution of a known pH and plot a collaboration curve |
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Term
| How could the melting point of asprin be measured? |
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Definition
| Put sample in capillary tube and heat in melting point apparatus |
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Term
| Why should a pH meter be collaborated before use? |
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Definition
| pH meter may get less accurate over time |
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Term
| What substance is most likely to oxidise Iron (II) ions when Iron (II) sulphate is used as a weed killer? |
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Definition
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Term
| Suggest a value for the pH of a 0.100 mol dm-3 solution of Iron (II) sulphate? |
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Definition
| Anything in the range 4.0 - 6.9 |
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Term
| What is a chemical hazard when using H2SO4 and what is a safety precaution? |
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Definition
Acid is corrosive
Use gloves or eye protection |
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Term
| Why is it an advantage to add thiocyanate ions to the iron (III) sulphate solution before measuring percentage absorbance? |
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Definition
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Term
| Why is it necessary to maintain a constant temperature in an experiment to measure the equilibrium constant? |
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Definition
| Temperature affects the equilibrium constant |
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Term
| What is one method for maintaining a constant temperature in an experiment? |
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Definition
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Term
| What is observed when 1-chloropropane and ethanoyl chloride are separately added to an aqueous solution of silver nitrate? |
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Definition
1-chloropropane - no visible change
ethanoyl chloride - white precipitate |
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