Chemistry Flashcards
I'm gonna smash this mock - I'm scared.
A teacher extracted copper from copper oxide. box
This is the method used.
1. Mix 1.30 g of zinc and 1.59 g of copper oxide.
2. Heat the mixture strongly.
3. When the mixture starts to glow, stop heating.
4. Let the glow spread through the mixture.
5. Leave the mixture to cool
Which part of the method shows the reaction is exothermic?
Let the glow spread
What type of reaction takes place when zinc reacts with copper oxide?
Displacement
Why is copper used in electrical wiring?
-It is a good electrical conductor
-Can be bent easily
Is Lithium Oxide a compound, element, metal, mixture or polymer?
Compound
Give two factors that can affect reaction time
Age, Alcohol, Distractions, Drugs
How do you measure stopping distance of a car?
Complete the sentence:
The greater the speed, ____________________________________
The greater the braking distance
Give two disadvantages of applying a large braking force.
-Brakes overheat
-Car goes out of control
What is an alloy
A mixture of metals.
Give one reason why alloys are used instead of pure metals
-Alloys are harder
-They are corrosion resistant
Bar magnets are described as __________ magnets
A) Induced 2)Permanent 3) Temporary
Permanent
The magnetic field is strongest at the __________________
poles of the magnet
What do you use to measure the temperature of a solution?
Thermometer
What do use to measure the volume of hydrochloric acid?
Measuring cylinder
Complete the word equation for the reaction:
Hydrochloric acid + sodium hydroxide > ________________ + _______________
Sodium chloride + Water
What is the the typical mean speed for a person cycling?
A) 3.0 m/s B) 4.5 m/s C) 6.0 m/s
6.0 m/s
What does the area under a velocity-time graph represent
Distance travelled
Why is hydrogen chloride not able to conduct electricity but hydrochloric acid is?
-hydrogen chloride molecules do
not have an overall electric
charge
-hydrochloric acid contains ions
-(which) are free to move so
charge can flow
What is direct current?
Current that always passes in the same direction
Why are chloride ions attracted to the positive electrode
Because they are negatively charged
The step-up transformer causes the potential difference to increase and the current to…
a) Decrease b) Increase
Decrease
The use of the step-up causes the energy transferred by heating of the cables to…
a) Decrease b)Increase
Decrease
The step-down transformer causes the potential difference to decrease and the current to…
a)Decrease b) Increase
Increase
What produces acid rain?
Sulfur dioxide
What type of substance is an enzyme?
A protein molecule
What type of substance is manganese dioxide?
Metal compound
What type of substance is zinc sulfate?
a) Acid b) Alkali c)Base d)Salt
d) Salt
Put these metals in order of reactivity:
-Iron
-Magnesium
Nickel
-Zinc
- Magnesium
-Zinc
-Iron
-Nickel
Give two reasons why PVC nano plastic can be harmful to marine life
-They build up in the food chain´
-Marine animals eat them
Give two ways to reduce plastic waste.
-Recycling plastic items
-Charging people for plastic items
What is an exothermic reaction?
When energy is transferred to the sorroundings
What happens during phase 1 in terminal velocity
Acceleration
-Weight > air resistance
What happens during Phase 2 in terminal velocity?
Constant velocity
- Weight = air resistance
What happens during Phase 3 of terminal velocity?
Deceleration
-Air resistance> weight
(Parachute activated)
What happens during Phase 4 in terminal velocity?
Constant velocity
-Air resistance=weight
-(They have reached terminal resistance)
What are group one elements called in the periodic table?
Alkali metals
What are group seven elements called in the periodic table?
Halogens
What’s Newton’s first law?
-if the objects is stationary it remains stationary
What are polymers?
Very large covalent structures
What is the units for current?
Amps (A)
What does it mean when a circuit is in series?
It is connected to one loop
What does it mean when a circuit is connected in parallel
Connected to two or more loops
Acid + Metal Hydroxides > _______ + _________
Salt + Water
Acid + Metal Oxide > ____________ + _____________
Salt + Water
Acid + Metal > ____________ + __________
Salt + hydrogen
Acid + Metal Carbonate > _______________ + _________________ + __________________
Salt + Water + Carbon dioxide
What is an endothermic reaction?
Where energy is taken from the surroundings and the temperature from the surroundings decreases
What is combustion?
It is a chemical reaction when a fuel is burned to release energy
What is an example of rusting?
Iron + Oxygen > Iron oxide
What are signs of chemical reactions occurring?
- Temperature change
- Change in mass
-Colour change
-Effervescence (Gas being formed.)
What is the activation energy?
The minimum amount of energy needed for a collision to be successful
What does the rate of reaction depend on?
Speed and Frequency
What factors affect rate?
- Temperature
- Surface area
- The presence of a catalyst
- Pressure
What happens with a high concentration and how does it affect rate of reaction?
The h_________ the concentration of reactants in a solution the more number of reacting particles per unit volume
How does concentration affect the rate of reaction?
Particles collide more frequently, rate of reaction increases
How does pressure affect the rate of reaction?
Particles collide more frequently, rate of reaction increases.
How does temperature affect rate of reaction?
By the particles gaining more kinetic energy which increases the rate of reaction
What affects the functioning of enzymes
pH and Temperature
Name the ways transferring energy
- Mechanically
- Reheating
- Electrically
- Radiation
What is an irreversible chemical reaction?
When the product cannot go back to form the original reactants
What does the term ‘Reversible’ mean?
When the products can go back to form the original reactants
What are cations?
Positively charged ions
What are anions?
Negatively charged ions
What ions do acids release?
H+ ions
What ions do alkalis release?
OH- ions
Order these in order of reactivity
- Sodium
- Potassium
- Lithium
- Calcium
- Potassium
- Sodium
- Lithium
- Calcium
What is the definition of the term “Electrolysis”
Liquids and solutions that are able to conduct electricity
What happens if a metal is more reactive than hydrogen at the cathode?
Hydrogen forms
What happens if a metal is less reactive than hydrogen?
Then that metal is formed
What forms when a non metal from Group 1-7 such as Bromine is present?
Halogen gas forms.
Covalent bonding is between…
Non-metals and non-metals
Ionic is between…
Metals and non-metals
Metallic bonding is between…
Metals and metals
Metals ________ electrons to become ___________ charged
- lose
- positively
Non metals ______ electrons to become __________ charged
- gain
- negatively
What are hydrocarbons made up of?
Hydrogen and Carbons
What is the formula for Alkanes
Cn H2n + 2
What is the formula for Methane ?
CH4
What is the formula for Propane?
C3H8
What is the formula Ethane?
C2H6
What is the formula for Butane
C4H10
Order these alkanes from biggest to smallest:
-Butane
- Methane
- Propane
- Ethane
- Butane
- Propane
- Ethane
- Methane
Why do giant covalent structures have high melting and boiling points?
Because the atoms are held together by covalent bonds in giant covalent lattice. They also need a lot of energy energy to break so we need to heat them to a high temperature
Why is graphite soft?
Layers easily slide past each other
Why can graphite conduct electricity
Delocalised electrons between layers can move
What are some uses for diamond?
Drill/cutting tools or jewellery
Name the two types of cracking
Thermal and catalytic
What is thermal cracking?
Cracking where alkanes are subject to high temperatures (750 degrees) and high pressure (75)
What is catalytic cracking?
Cracking where alkanes are subject to lower temperatures (500 degrees) and low pressure, they are passed over a catalyst
Which type of cracking is more economical?
Catalytic cracking
Why is catalytic cracking more economical?
it uses lower temperatures and pressures which reduces energy consumption and the use of a catalyst.
Balance this equation:
C₁₆H₃₄ → C₄H₈ + C₈H₁₈
C₁₆H₃₄ → 2C₄H₈ + C₈H₁₈
Practical: Effect of Surface Area
- Why do you need to stopper the flask with the cotton wool?
To trap the gas in and not let it escape
Practical: Effect of Surface Area
- Why does the flask and its contents get lighter during the experiment
Because gas is being made
Practical: Effect of Surface Area
- What observations did you notice in the rates of reaction in the three experiments?
The larger the marble chips, the bigger the mass is
How do you know if there’s Oxygen in a substance?
- Put a glowing splint into a test tube of the gas
- The splint will relight
How do you know if there’s Chlorine in a substance?
- Put damp blue litmus paper into a tube of the gas
- The litmus paper turns red then white
How do you know if there’s Hydrogen in a solution?
- Hold a lit/burnt splint at the end of a test tube of a gas
- You’ll hear a squeaky pop
How do you know if there’s Carbon dioxide in a solution?
- Bubble the gas through limewater
- The lime water will turn milky/cloudy
Alkanes are made up of __________ bonds
Single
What is crude oil?
A mixture of different compounds, it is a finite resource made from ancient biomass
What does the term ‘Finite’ mean?
It is unrenewable, and it is being used more than quickly than it’s replaced
Fill in the gaps: (L)
The ___________ the molecules are, the ____________ the intermolecular force
- Longer
- Stronger
What is fractional distillation?
The process that separates out different compounds from crude oil.
Fill in the gaps:
L_____________ molecules have s__________ intermolecular forces, so require more e___________ to break them and therefore have a _______________ melting and boiling point
- Larger
- Stronger
- Energy
- High
Fill in the gaps:
S___________ molecules have w____________ intermolecular forces, so require ___________ energy to break them down and therefore have a l__________ melting and boiling point
- Smaller
- Weaker
- Less
- Low
Order these from higher to lower temperature:
- Diesel
- Petrol
- Naphta
- Bitumen
- Gas
- Kerosene
- Bitumen
- Diesel
- Kerosene
- Naphtha
- Petrol
- Gas
What do you need to react together to make dry crystals?
Sulfuric acid and magnesium oxide
What do use to take the magnesium oxide?
A spatula
- Firstly you will need to measure the volume of sulfuric acid, what do you use to measure it?
Measuring cylinder
- Until when do you have to keep adding magnesium oxide in the sulfuric acid?
Until it turns black
- You need to filter the magnesium oxide, where do you pour the solution and with the support of what?
- Into a funnel with filter paper
- The solution is collected afterwards, where?
A conical flask.
- What does the filtered solution contain now?
Magnesium and water
- Now we remove the water by heating the solution, what do we use to heat the solution?
A Bunsen burner
Process of fractional distillation:
1. Crude oil is a m_______ which is heated until it v________
- Mixture
- Vaporises
Process of fractional distillation:
2. Where is the crude oil pumped into?
A fractioning column
Process of fractional distillation:
3. V_____ rises through the column. The different h__________ vapour c________ when their temperature falls below b_________ point
- Vapour
- hydrocarbons
- condenses
- boiling
Process of fractional distillation:
4. H__________ with low ____________ points are collected are collected at the _____ of the column, these are _________ chain hydrocarbons with __________ intermolecular forces
- Hydrocarbons
- boiling
- top
- shorter
- weaker
Process of fractional distillation:
4. Hydrocarbons with _________ boiling points are collected at the ________ of the column - these are ________ chain hydrocarbons with _________ intermolecular forces
- high
- bottom
- longer
- stronger
What is petrol used for?
Petrol for cars
What is Naphtha used for?
Manufacture for chemicals
What is Kerosene used for?
Fuel for aircrafts
What is Diesel used for?
Fuel for cars, vans and lorries
What is bitumen used for?
Laying roads
Which hydrocarbon is at the top of the fractioning column?
Gas
Which hydrocarbon is at the bottom of the fractioning column?
Bitumen
A student investigated the rate of the reaction between magnesium and
hydrochloric acid.
The reaction produced a gas
Which gas is produced in the reaction?
Hydrogen
Which symbol represents the state of silicon dioxide at room temperature?
(s) Solid
Explain how worn brakes would increase the stopping distance of the car.
worn brakes:
* less work done by the friction force between the brakes and
wheel
* (so) takes a longer time to slow down
* increasing the braking distance
Explain how being under the influence of alcohol would increase the stopping distance of the car?
Think about reaction time
driver drinking alcohol:
* reaction time increases
* (so) thinking distance increases
How is the stopping distance increased if someone is not under the right state while driving?
stopping distance:
* stopping distance is thinking distance plus braking distance
* (so) if thinking distance increases, stopping distance increases
* (so) if braking distance increases, stopping distance increases.
The ________ the viscosity, the________ the substance flows.
- Lower
- Faster
As the temperature increases, the viscosity of the hydrocarbon ____________
Decreases
What type of substance is copper oxide?
A base
What is the potential of the earth wire
0V
What colour is the live wire?
Brown
What colour is the neutral wire?
Blue
What colour is the earth wire?
Green and yellow
What happens to enzymes when the pH is to acidic
- It becomes denatured because active site has changed
Why are paper clips attracted to magnets?
- It is made of magnetic material, that means it becomes an induced magnet
Name one use of graphene
Composites, Lubricant, Steel manifacturing, electrodes
What does the term ‘inert’ mean?
That it does not react
Practical: effect of changing the surface area of the calcium carbonate on the rate of this reaction
-Why was cotton wool put in the top of the conical flask?
To stop acid splashing out of the
conical flask
Explain why poly(ethene) has a higher melting point than ethene
poly(ethene) has larger
molecules
(so poly(ethene)) has stronger
intermolecular forces
(so) more energy is needed to
overcome the intermolecular
forces
Name two scalar quantities
Speed and mass
Name two vector quantities
Velocity and weight
Vehicles should brake over a distance that is at least equal to the braking distance in order to prevent _______________
Skidding
The shortest distance in which a vehicle can safely stop is called the _____________________
Stopping distance
The distance travelled during the time it takes for the driver to react to the hazard and apply the brakes is called the ____________________
Thinking distance
The distance travelled during a braking force is applied is called the ___________________
Braking distance
Stoping distance = _______________ + _________________
Thinking distance + Braking distance
What affects braking distance?
Speed, mass. weather conditions, road conditions, tyres…
Braking distance = _________________-________________
Stopping distance - Thinking distance
Elastic potential energy is the energy stored in…
stored in stretched objects.
What is Elastic Potential Energy
The energy stored in stretched objects.
What is viscosity
the ease of flow of a liquid
What is the frequency of the UK mains electricity supply?
50 Hz
Explain why generating electricity using natural gas causes environmental problems
- Burning gas produces carbon dioxide´
- This causes global warming
Name a disadvantage of using wind turbines
- Noise pollution
- Kills birds
Give a reason why aluminium is produced in Iceland
A lot of supply of cheap electricity
Name a reason why positive electrodes need to be replaced regularly
- Because graphite reacts to produce gas.
What two components do you need to determine resistance?
Ammeter and Volmeter
Why are the circuits switched off between readings?
So the temperature of the resistors would remain constant
What are two advantages of using a datalogger and light gates instead of a stop clock in this investigation?
- no reaction time error
- performs calculations
automatically
What is chromatography used for?
to separate mixtures of substances.
What are the two main components of chromatography?
The stationary phase and the mobile phase.
What is the stationary phase in chromatography?
The stationary phase is the substance that does not move, usually a solid or a viscous liquid.
What does it carry?
What is the mobile phase in chromatography?
The mobile phase is the liquid or gas that moves through the stationary phase, and it also carries the substances to be separated.
What happens to the components in a mixture during chromatography?
The components in a mixture move at different speeds through the stationary phase, allowing them to be separated.
What is a solvent front in chromatography?
The solvent front is the furthest point reached by the mobile phase on the stationary phase.
In paper chromatography, what type of paper is used?
Chromatography paper, which is a special type of paper designed for the process
What can the results of chromatography be used for?
To help identify substances by comparing them or analysing mixture compositions.
What is the term for the distance a substance travels in chromatography
The Rf value (retention factor).
How is the Rf value calculated in chromatography?
Rf = Distance travelled by substance / Distance travelled by solvent front.
What is a key safety precaution in the “Investigating Surface Area and Rate of Reaction” experiment?
Wear goggles and gloves to protect from acid spills or splashes.
How do you investigate the “Electrical Conductivity” of a solution?
By setting up a circuit with a light bulb or ammeter and measuring the current through different solutions.
