Chem Flashcards
Explain how copper atoms are produced at the negative electrode. (3)
- Copper ions are attracted towards negative electrode.
- They reduce gaining electrons.
- Two electrons.
Suggest one reason why Iron and aluminum are recycled. (2)
- Saves limited resources
- Extraction uses a lot of energy
Why do lithium carbonate and the white solid both produce the same colour in a flame test? (1)
- both contain lithium (ions)
Describe the type of bonding in a molecule of chlorine when magnesium reacts with chlorine to form the compound magnesium chloride. (3)
- Chlorine needs one more electron
- They share electrons
- This is covalent bonding
Get two conditions needed for cracking. (2)
- High temperature.
- A catalyst / steam.
State two observations made when alkali metal reacts with water. (2)
- Effervescence
- Metal gets smaller
Name the 3 products of the reaction between copper carbonate and sulfuric acid. (3)
- Carbon dioxide
- Water
- Copper sulfate
Explain why graphite conducts electricity. (3)
- Each carbon forms 3 bonds
- One electron per atom is delocalized
- Electrons move through the structure
Explain why magnesium fluoride has a high melting point. (4)
- giant structure
- strong electrostatic forces of attraction between oppositely charged ions
- in all directions
- a large amount of energy is needed to overcome
Explain why diamond is hard. (3)
- Each carbon atom is connected to 4 other carbon atoms.
- They have a giant covalent structure.
- They have strong bonds.
Describe what happens in a polymerization reaction. (2)
- Many monomers.
- Join together to form large molecules or chains.
Suggest one disadvantage of phytomining compared to the other methods. (1)
- Not continuous as it takes a long time for plans to grow.
Explain why chlorine is more reactive than bromine. (3)
- Outer energy level closer to nucleus.
- Has greater attraction between the nucleus and the outer electrons.
- Chlorine can gain an electron more easily.
Give improvements in the experiment of titration to make it more accurate. (5)
- Mix and swirl.
- Add potassium hydroxide from pipette.
- Use a conical flask.
- Add a few drops of indicator.
- Repeat experiment until the mean concentration is around 0.1 cm3.
Explain endothermic reactions in term of bond making and bond breaking. (3)
- Energy must be needed to break bonds.
- Energy is released when bonds are formed.
- Energy needed to break existing bonds is greater than the energy release forming bonds.
Explain how magnesium conducts heat. (3)
- delocalised electrons
- move through the metal / structure
- transfer energy
Suggest two advantages of phytomining compared to the other methods. (2)
- Less expensive to extract the small amounts of copper.
- Plans would remove carbon dioxide from atmosphere as they grow.
Describe how crude oil is separated into fractions by fractional distillation. (4)
- Crude oil enters
- Heated up
- Evaporates
- High temperature gradient
Give the differences between the pudding atom model and the normal atom model. (4)
- Model A has no nucleus.
- Model A has no neutrons.
- Model a has no protons.
- Model A has no energy level / shells.
Explain what happens in the second stage of copper oxide being reduced using carbon. (2)
- Carbon gains oxygen
- Carbon is more reactive than oxygen
Describe what happens when magnesium atoms react with fluorine atoms to produce magnesium fluoride. Answer in terms of electrons. (4)
- Magnesium atoms lose 2 electrons.
- Fluorine gains one electron.
- One magnesium atom reacts with 2 fluorine atoms.
- To gain full number of electrons in the outer shell.
Explain why economical to use scrap iron to get copper. (1)
- Iron is cheap
Describe a method to determine the amount of energy released by burning 1 gram of biodiesel. (6)
- Glass beaker placed above spirit burner.
- Measure initial mass and temperature of water.
- Heat water for a fixed time.
- Extinguish flame.
- Measure final mass and temperature of water.
- Calculate energy level.
