Flashcards
C3
Flashcards do conjunto (82)
- 1Why are elements arranged in columns/groups?Because they have similar properties
- 2Why is it called a periodic table?Because similar properties occur at regular intervals
- 3How was the early periodic table first arranged in?According to their proton number
- 4How is the modern periodic table arranged?In order of their electronic structure. The number of electrons in the highest energy level
- 5The elements in Group 1 are...(4)- Low density
- Reacts with non metals to form +1 ions
- Reacts with water to form hydrogen gas
-Forms hydroxide which dissolve to form alkaline solutions - 6What colour are the ionic compounds and what happens when they react in water?The compounds are white and dissolves to form colourless solutions
- 7What is the trend in Group 1 as you go down? (2)-The more you go down, the more reactive they are
-Have lower melting and boiling points - 8Why are Group 1 elements more reactive when you go down?As the number of shells increase, the outer most electron gets further away
This means there is more shielding between the electron and nucleus
This means the electron can be easier to lose because there is less attraction holding it. - 9What is the trend in Group 7?-As you go down, the less reactive the elements become
-Higher melting and boiling point - 10What are Group 7 metals and what do they do? (3)- The halogens are non metals with coloured vapours
-They form ionic bonds with metals e.g. F- because it absorbs 1 electron
- More reactive halogens displace less reactive ones in reactions e.g. Chlorine displaces Iodine - 11What are trends of transition metals compared to Group 1 (3)COMPARED TO GROUP 1
- Higher melting points and higher densities
- Stronger and harder
- Less reactive so do not react violently with water, oxygen etc - 12What are features of transition metals? (3)-Have more than 1 ion
- Make colourful compounds
- They make good catalysts e.g. Iron in Haber Process - 13Soft water and soap produces?Lather
- 14Hard water and soap produces?Scum
- 15What is scum?A white solid that forms from the reaction of hard water and soap
- 16How can you make scum become lather?Add more soap
- 17How does water become hard?When dissolved compounds such as calcium and magnesium when water comes into contact with rocks
- 18What is permanent hard water and what is it caused by?Water that remains hard after boiling.
It is caused by dissolved calcium sulphate - 19What is temporary hard water and what is it caused by?Water that is softened by boiling.
It is caused by the hydrogencarbonate ion - 20When the temporary hard water is heated what happens and what is produced, WHY IS WHAT PRODUCED A PROBLEM?The hydrogencarbonate ion decomposes to form calcium carbonate which is insoluble.
This calcium carbonate is the limescale found in kettles and REDUCES THE EFFICIENCY OF HEATING SYSTEMS AND KETTLES - 21Why does heating not work for permanent hard water?Heating a sulfate ion does not do anything
- 22How can both types of hardness be removed?- Adding sodium carbonate
- Putting the water through an ion exchange column - 23Why does hard water increase costs?Because more soap is required to make it into a lather
- 24What benefits does hard water have? (2)The calcium compounds are good for teeth and bones
Reduces heart disease - 25How does adding sodium carbonate soften hard water?The carbonate ions react with the calcium and magnesium ions to form an insoluble precipitate of calcium carbonate and magnesium carbonate
- 26How does running hard water through an ion exchange column soften the water?Ion exchange columns containing sodium or hydrogen ions, replace the calcium and magnesium ions in water.
- 27What is the titration method? (8)1. Fill burette with 50cm3 of soap solution
2. Add 50cm3 of water into flask
3. Add 1cm3 of soap solution to flask
4. Shake until a good lasting lather is formed for 30 seconds
5. Repeat steps 3 and 4 until a lasting lather is made
6. Record the amount of soap needed to lather from burette scale
7. Repeat all steps with other water samples
8. Boil each new sample for 10 minutes before starting - 28What do some water filters contain and what is their effect?Some water filters contain carbon (REMOVES CHLORINE TASTE), silver (KILLS BUGS) and ion exchange resins to remove some dissolved substances to improve the quality of water
- 29What is the process of water purification? (4)1. Water is passed through a mesh screen to remove big bits like twigs and sticks
2. Chemicals are added to make solids and microbes stick together and fall to the bottom
3. This water is filtered through a GRAVEL BED to rid of any solids
4. The water is chlorinated to kill harmful microbes left - 30Why is distilling totally pure water a problem?It is too expensive and lots of energy is used
- 31What is fluorine and chlorine added to water?Fluorine helps reduce tooth decay
Chlorine prevents disease - 32What are some advantages of adding fluorine and chlorine to water? (3)-Chlorine can react with other substances to produce toxic by products which some think could cause cancer
-In high doses, fluoride can cause cancer and bone problems
-People should be allowed to choose to what they have in their drink - 33When temperature is raised or reduced in a reaction what happens in the endo and exo thermic-When temp raised the endo reaction will increase to use the extra heat
-When temp reduced the exo reaction will increase to release more heat - 34When pressure is raised or reduced in a reaction what happens in the reaction-When pressure raised, reaction produces less volume
When pressure reduced, reaction produces more volume
MANY REACTIONS HAVE A GREATER VOLUME ON ONE SIDE OF THE REACTION - 35What is meant by equilibrium?When the amount of reactants and products reach a certain balance and stay there.
- 36What are the reactants for making ammonia?Nitrogen and Hydrogen
- 37Where does nitrogen and hydrogen come from?Nitrogen- from the atmosphere
Hydrogen - natural gas or crude oil etc - 38What are the conditions for the making of ammonia? Pressure, temp and catalystPressure - 200 atmospheres
Temp - 450oC
Catalyst - Iron - 39Why does pressure increase the production of ammonia?Greater pressure favours the direction of the reaction which produces the least number of molecules
N2 + 3H2 -> 2NH3 - 40In making ammonia which direction is endothermic and exothermic?Producing ammonia is exothermic
Going back to reactants is endothermic - 41Which reaction does higher temperature affect in making ammonia?The endothermic reaction (going back to reactants)
- 42Should the temperature in making ammonia be lower or higher?Lower because it favours the exothermic reaction which produces ammonia
- 43What effect does a high and lower temp have on yield and rate of reaction?Higher temperature means lower yield but greater rate of reaction
Lower temp means higher yield but smaller rate of reaction - 44What effect does high and lower pressure have on yield and rate of reaction?High pressure - higher yield and higher rate of reaction
Low pressure - lower yield and lower rate of reaction - 45Explain the Haber Process (4)1. Hydrogen and Nitrogen mixed in a 3:1 ratio
2. It is placed in a reaction vessel and reacts surrouned by iron catalysts
3. The ammonia is formed as a gas and becomes condensed as in cools in the condenser to become a liquid and flow out
4. Unused nitrogen and hydrogen is recycled - 46What is the functional group of Alcohols?-OH
- 47What is the symbol for Methanol?Think of it as order of alkanes e.g. Methane, Ethane, Propane, Butane.
WRITE IT AS CH3OH instead of CH4O - 48What are the first three member of the homologous series of alcohols?Methanol, Ethanol and Propanol
- 49What are 4 things methanol, ethanol and propanol can do?-Dissolves in water to form a neutral solution
-Reacts with sodium to produce hydrogen
-Burns in air
-Used as fuels and solvents - 50Ethanol is a solvent used for what type of products (2)Perfumes and aftershave lotions
- 51Why is ethanol used as a fuel?It can be made from fermenting sugar and can be used in cars and produces less pollution
- 52What is the functional group of Carboxylic Acids?-COOH
- 53What is the symbol for methanoic acid?HCOOH
- 54Carboxylic acids can..? (5)1. Dissolves in water to form acidic solutions
2. Reacts with carbonates to produce carbon dioxide
3. Reacts with alcohols to produce esters
4. Are weak acids cause they don't ionise fully
5. Solutions of weak acids have a stronger pH than solutions of strong acids with same concentration - 55What can carboxylic acids be used to make?Carboxylic acids with long chains of carbon atoms make Soaps and Esters
- 56What is the functional group of Esters and how do you make it and what else is produced?-COO
Alcohol + carboxylic acid -> ester + water - 57Diagram of ethyl ethanoateETHyl ETHANoate acid
ETH is the alcohol
ETHAN is the carboxylic acid
- 58What can esters be used for and why? (3)Perfumes because they have pleasant smells and are volatile
Flammable so their volatility makes them dangerous
Can be used for solvents (nail varnish dissolves in esters not water) - 59Problems with esters? (3)1. When inhaled in fumes, irritates mucous membranes
2. Fumes are heavier than air and very flammable
3. Some are toxic - 60What type of reaction occurs when there is bond breaking and why?Endothermic reaction occurs because energy is supplied to break the existing bonds
- 61What type of reaction occurs when there is bond making and why?Exothermic reaction occurs because energy is released during the making of the bonds
- 62During an exothermic reaction, do the reactants or products have higher energy?The products are at a lower energy than the reactants
- 63Energy level diagram of exothermic reactionRISING line to show activation energy
Line under to show energy given out
- 64During an endothermic reaction, do the reactants or products have higher energy?The products are at a higher energy than reactants
- 65Diagram for endothermic reaction
- 66What lowers the activation energy?A catalyst
- 67What does a catalyst do for a reaction?Provides an alternative pathway for the reaction that has a lower activation energyi
- 68Advantage of using hydrogen gas as a fuelOnly produces water which is not harmful
- 69Disadvantages of using hydrogen gas as a fuel (3)1. Special, expensive engine needed
2. Energy needed from another source to make it
3. Hydrogen gas is hard to store safely - 70What is a fuel cell?An electrical cell thats supplied with a fuel and oxygen and uses energy from the reaction between them to generate electricity
- 713 advantages of fuel cells1. Doesn't need recharging and doesn't run down
2. No pollutants produced
3. Reduces need for crude oils - 723 disadvantages of fuel cells1. Hydrogen is a gas so takes up lots of space to store
2. Very explosive
3. Hydrogen fuel is often made from fossil fuels - 73What colours from flame tests are given out from lithium, sodium, potassium, calcium and barium?Lithium - Crimson flame
Sodium - Yellow flame
Potassium - Lilac flame
Calcium - Red flame
Barium - Green flame - 74What is the process of testing for positive ions? (4)1. First dip the inoculating loop in hydrochloric acid
2. Rinse this with water
3. Dip the loop into the compound
4. Place loop into blue part of flame (where it is hottest) - 75What is the other method of testing for positive ions and what is the process IF THE PRODUCT FORMS A WHITE PRECIPITATE? 41. First add sodium hydroxide to an unknown solution
2. When white precipitate is formed, add excess sodium hydroxide
3. If the white precipitate dissolves in the sodium hydroxide, then it shows aluminium ions are present
4. If it does not dissolve then a flame test will have to be conducted
CALCIUM PRODUCES RED FLAME, MAGNESIUM PRODUCES NO COLOURED FLAME - 76What if a coloured precipitate is formed when adding sodium hydroxide and what are the names and colours of it? 3Fe3+ = Brown (Iron man 3 makes me shit brown)
Fe2+ = Green (Iron man 2 makes me vomit green)
Cu2+ = Blue - 77How do you test for negative ions for carbonates? 31. First you add some dilute acid (hydrochloric or sulphuric or nitric)
2. The reaction will produce CO2 gas
3. This gas can be collected and passed through limewater to confirm it is CO2
ACID + CARBONATE -> SALT + WATER + CO2 - 78How do you test for negative ions for halides (chloride, bromide, iodide ions)?You add dilute nitric acid and silver nitrate solution
- 79What shows the presence of a chloride?A white precipitate of silver chloride
- 80What shows the presence of a bromide?A cream precipitate of silver bromide
- 81What shows the presence of a iodide?A yellow precipitate of silver iodide
- 82How can you show the presence of a sulphate ion amd what is produced?Add dilute hydrochloric acid and barium chloride solution.
A white precipitate of barium sulphate is produced showing the original compound was a sulfate.
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- Descrição
- GCSE Chemistry FlashCards sobre C3, criado por Dale George em 13-06-2016.
- Criado por
- Dale George · jun 2016
- Atualizado
- 7 abr 2018
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