Physical Chemistry.

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Difference between soluble and insoluble and examples?
soluble=dissolves. insoluble=won't dissolve. Sodium, potassium, ammonium, nitrates, most chlorides and sulfates = soluble. Most carbonates = insoluble.
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How to make soluble salts using acids and insoluble bases?
pick right acid and insoluble base. add metal oxide, carbonate or hydroxide to the acid, the solid will dissolve in acid as it reacts. when excess solid sinks to bottom and stays the acid has been neutralised, filter, evaporate to get crystals.
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how to make soluble salts using alkali?
add exactly right amount of alkali, to neutralise acid. use indicator to see when reactions finished, then repeat using exact same volumes without indicator so salt isn't contaminated.
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How to do precipitation reactions?
mix two solutions containing ions.
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titrations are used to find out concentration. Describe how to do this.
use pipette and pipette filler, add some alkali (25cm2) to conical flask with 2/3 drops of indicator. fill burette with acid (below eye level), using burette add acid to alkali a bit at a time whilst swirling conical flask.
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last two steps of titrations?
indicator changes colour when alkali neutralised, record volume of acid used to neutralise alkali, record for more reliable results.
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how to work out concentration per moles dm3?
molesper dm3 = concentration x (volume/1000). work out how many moles of 'known substance' you have. write down balanced equation and work out how many moles of 'unknown' stuff you must have, work out concentration of unknown stuff.
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What can the speed of reaction be measured by?
how quickly the reactants are used up and how quickly the products are formed.
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how to measure rate of reaction.
rate of reaction = amount of reactant used or amount of product formed divided by time.
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What are the three different ways reaction can be measured?
1.) Precipitation(solution becomes cloudy, use marker to see how long it takes to disapere, the quciker it goes the quicker the reaction.). 2) change in mass 3.) volume of gas given off
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What are the 4 things rate of reaction depends on?
temp, concentration, catalyst and size of particles.
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Acid + metal oxide =?
salt + water
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acid + metal carbonate =?
salt + water + CO2
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Strongest acid pH? Strongest alkali pH? neutral?
acid=0 alkali = 14 neutral = 7
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what does universal indicator turn in acid and alkali?
green in neutral, purple/blue in alkali, yellow/red in acid.
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what does litmus paper turn in acid and alkali?
red in acid, purple in neutral, blue in alkali.
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what does phenolphthalein turn in acid and alkali?
colourless in acidic, bright pink in alkali.
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what does methyl orange turn in acidic and alkali?
red in acidic, yellow in alkali,
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Difference between acids base and alkalis?
acid is a source of hydrogen ions, base is a substance that neutralises acids, alkalis are soluble bases and a source of hydroxide ions.
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Say neutralisation equation ( reaction between acid and base). and in terms of hydrogen ions.
acid + base -> salt+ water. H+ + OH- ----> H20
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Describe the reaction of marble chips with HCl.
measure volume of gas and take readings at regular intervals, repeat with same volume of acid and same mass of marble chips but with more scrunched up, repeat with same mass of powdered marble instead of marble chips.
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describe decomposition of hydrogen peroxide.
2H202 ----> 2H20+02, slow, Mg0 catalyst speeds it up, O gas given off, providing a way to measure speed of reaction.
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What does the collision theory say?
The rate of a reaction depends on how often and how hard the reacting particles collide with each other, the particles have to collide hard enough (with enough energy).
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Why must energy be supplied to break bonds?
during chemical reaction, old bonds are broken and new bonds are formed. energy must be supplied to break existing bonds, making it endothermic. energy is released when new bonds are formed making it exothermic.
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Difference between exothermic and endothermic?
exo gives out energy - shown by rise in temp. endo takes in energy shown by fall in temp.
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Whats the change in energy called?
enthalpy change. if exo triangleH -. if endo triangleH +.
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On a energy level diagram how is exo and endo shown?
exo goes down, endo goes up.
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what is the activation energy?
represents minimum energy needed by reacting particles for the reaction to occur.
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What is the catalyst shown by on the graph?
lower curve on diagram shows that less initial energy is needed for the reaction to begin.
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describe calorimetry - dissolving, displacement and neutralisation reactions.
to measure amount of energy transferred, take temp of regents, mis and measure temp of solution at end. mix in polystyrene cup, put cup in beaker of cotton wool to give more insulation and put lid on to reduce energy lost via evaporation.
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describe calorimetry combustion. 1
to measure amount of fuel produced when fuel is burnt, burn fuel, heat water, use copper container, use screen to act as draught excluder, put 50g of water in copper can and record it's temp. weight spirit burner and lid.
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describe calorimetry combustion. 2
put spirit burner under can and light wick, heat water stirring constantly, until temp reaches 50C, put out flame using lid and measure final temp of water, weight spirit burner and lid again.
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How to calculate heat energy transferred?
measure temp change and how much fuel burned and work out how much energy supplied by each gram of fuel. specific heat capacity of water id 4.2j/g/c
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what is a reversible reaction?
a reaction where the products of the reaction an themselves react to produce the original reactants.
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What is dynamic equilibrium?
it means the reactants are still taking place in both directions, but the overall effect is nil because the forward and reverse reactions cancel eachother out. They're taking place at exactly the same rate in both directions.
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What does the temp do to the position of the equilibrium?
if temp is raised the endo reaction will increase to use up extra heat
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Other cards in this set

Card 2

Front

How to make soluble salts using acids and insoluble bases?

Back

pick right acid and insoluble base. add metal oxide, carbonate or hydroxide to the acid, the solid will dissolve in acid as it reacts. when excess solid sinks to bottom and stays the acid has been neutralised, filter, evaporate to get crystals.

Card 3

Front

how to make soluble salts using alkali?

Back

Preview of the front of card 3

Card 4

Front

How to do precipitation reactions?

Back

Preview of the front of card 4

Card 5

Front

titrations are used to find out concentration. Describe how to do this.

Back

Preview of the front of card 5
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