7 Written questions
6 Multiple choice questions
- density is usually between that of the component metals; alloy remains malleable and ductile
- Metallic mixtures
- Alloy formation sometimes alters the chemistry such as the formation of a chemically inert oxide layer in stainless steel.
- Poor: ionic lattices are rigid and once broken tend to cleave along an entire plane.
- Good: alloys usually retain a sea of mobile electrons (delocalized covalent bonds) and so remain conducting (for both HEAT and ELECTRICITY)
- interstitial atoms do not appreciably expand the lattice and so density is often substantially increased; interstitial atoms make the lattice more rigid reducing ductility and malleability
6 True/False questions
Water solubility of an ionic solid → Insoluble: ionic compounds tend not to dissolve in nonpolar solvents because the attractions between ions are much more favorable than the attractions among the separated ions and nonpolar solvent molecules.
Interstitial Alloy (definition) → formed between atoms of different radius, where the smaller atoms fill the interstitial spaces between the larger atoms
Brittleness of an ionic solid → Hard: ionic lattice is strong and rigid
Malleability and ductility of a metallic solid → Poor: ionic lattices are rigid and once broken tend to cleave along an entire plane.
Identification of an ionic solid → Non-conductive (insulators): ions are pinned by the rigid lattice.
Conductivity of an ionic solid → Good: electrons are delocalized and relatively free to move