Chemistry Flashcards
equations and other things :)
What is the equation for gas volumes?
Moles = Volume / 24
Conversion: 1cm^3 to 1dm^3
/1000
Which direction do the electrons flow in a fuel cell?
Anode to cathode
Concentration, mass and volume?
Concentration = Mass / Volume
Explain, in terms of particles and forces, how a solid turns into a liquid. (6)
- In solids, strong attractive forces hold particles in place
- So they can only vibrate in fixed positions
- When heated, particles gain kinetic energy
- Which causes the particles to vibrate faster and faster
- Eventually, particles overcome forces and melts
Why do alkali metals become more reactive going down the group?
- Going down the group, atomic radius increases
- This means there is more shielding, and therefore weaker electrostatic attraction between the nucleus and outer electron.
- This means less energy is required to lose the outer electron, and for a reaction to occur.
What’s the most accurate way to measure rate of reaction?
Change in mass, because scales are the most accurate measure.
How can you calculate rate of reaction?
- Use a balance to monitor how the mass changes over time
- Take measurements at regular intervals
- Plot results on a graph w/ tangent and find the gradient
What happens if you increase the concentration of the reactants? (Le Chatelier’s principle)
The equilibrium will shift to the right, reducing the reactants concentrations and restore equilibrium.
What are four properties of graphene?
Strong, conducts electricity, light, and high boiling point
Are noble gases diatomic?
No, they’re monoatomic. Idiot…
What indicator is used in titrations?
Methyl orange
Describe the structure and bonding of graphite. (or draw it)
- Giant covalent lattice
- Each carbon atom is bonded to 3 others
- Between atoms are covalent bonds
- Separate sheets held together by intermolecular forces
- Delocalised electrons
Describe the structure and bonding of metals.
- Giant structure
- Delocalised electrons
- Metal ions are arranged in a regular lattice structure
- Strong metallic bonds between positive metal ions and negative del. electrons
(What’s the equation) for atom economy?
Mr of desired products / Mr of reactants
How do you test for hydrogen?
It burns rapidly with a ‘pop’ when you apply a lighted splint
How do you test for oxygen?
It relights a glowing splint
How do you test for carbon dioxide?
When bubbled through limewater, it turns the solution cloudy
How do you test for chlorine?
It bleaches damp blue litmus paper white
How do you calculate retention factor?
Distance moved by substance / Distance moved by solvent
