Chem P2 Flashcards
(15 cards)
Name an element in group 7 that is a liquid at room temperature
Bromine
Name a piece of apparatus to measure exactly 10.00 Cm3 of water
Burette
Suggest why the boiling tube is not directly heated using a bunsen burner when making a saturated solution
Water might spit out and be lost
Suggest how the student can improve the reliability of their results
Repeating 3 times and calculating a mean result
Suggest why the values for solubility may be less accurate at 95 degrees than other temperatures
As some water may be have been evaporated
Give the chemical reaction between potassium oxide and water
k2O + H2O -> 2KOH
Predict the effect of adding a catalyst to the yield of any reaction
-The yield will stay the same
-As adding a catalyst increases the forward reaction and backward reaction by the same amount
Write the half equation for oxygen
4OH- → O2 + 2H2O + 4e-
What is the temperature for catalytic cracking?
600-700 degrees celsius
Ethanol can be oxidised to produce a carboxylic acid
What are the names of the 2 reagents of the reaction?
-Potassium dichromate (VI)
-Dilute sulfuric acid
What is the colour change for a reaction when ethanol gets oxidised?
Orange to green
When oxidising an alcohol why is it better to use a water bath rather than using a bunsen burner flame?
As alcohol are flammable
What is the name of the ester with the structural formula?
CH3CH2COOCH3
Methyl propanoate
Explain how adding a catalyst increases rate of reaction (2)
-As it provides an alternate pathway
-With a lower activation energy
Explain why this reaction is exothermic
(Refer to bond breaking and bond making in your answer)
-Energy needed to break bonds is endothermic
-Energy given out when bonds are formed is exothermic
-Energy given out is greater than energy needed so it is exothermic
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