EXAM QUESTIONS Flashcards
Why is the percentage yield of ammonia less than expected?
Because the reaction is reversible
What ion makes something alkaline?
Hydroxide (OH-)
Why wouldn’t the electrolysis of a solid potassium salt work?
Because it needs to be molten or dissolved to make the ions move
What gas would be produced at the negative electrode for the electrolysis for potassium
Hydrogen because the ions are positive and potassium is more reactive
Why are alloys harder than pure metals?
Because they have different sized atoms,
This would distort the layers and they wouldn’t be able to slide
Describe the structure and bonding of a diamond
Giant lattice,
Strong bonds,
Covalent,
Each carbon atom has 4 bonds
Describe the structure and bonding in a thermos often if polymer and explain why they melt when heated
They are chains with weak intermolecular forces that are easily broken when heated
Why in terms of structure is carbon dioxide a gas even at low temperatures
Small molecules
Weak intermolecular forces,
Only a little energy is needed to overcome the bonds
What’s the purpose of gas chromatography
To separate
What information does the molecular ion peaks from the mass spectrometer give about the substances?
Their relative mass
What’s an isotope
They have the same amount of proton and electrons
Different number of neutrons
What ion makes something acidic?
Hydrogen H+
Why do different substances separate in a gas chromatography column?
The different substances travel at different speeds
Describe the structure and bonding of chlorine
Covalent bonds between atoms
Forms simple molecules
Weak attraction between molecules
Low boiling point
Describe the structure and bonding of sodium chloride
Ionic bonds which are strong
Giant lattice formed between oppositely charged ions
High energy needed to break bonds
High melting point
