2.4 Properties and what not

Question 1

MP and BP of metallic structures?

Answer 1

Varies

Question 2

Volatility of Metallic structures

Answer 2

Low

Question 3

Solubility of metallic structures?

Answer 3

Low

Question 4

Thermal&Electrical conductivity of metallic structures?

Answer 4

High

Question 5

Are metallic structures brittle?

Answer 5

No their malleable

Question 6

Are metallic structures susceptible to corrosion?

Answer 6

Yes

Question 7

Ionic Structure properties

Answer 7

MP/BP: High
Volatility: low
Water Soluble: Varies
Electrical/Thermal conductor: only when molten/dissolved, No
Briitle?: yes
Susceptible to Corrosion: varies

Question 8

Why are ionic crystals brittle?

Answer 8

The ions within them cannot easily slide past each other.

Question 9

Elastic

Answer 9

Will change in shape when subjected to a force, and return to their original shape after the force is removed.

Question 10

Plasticity

Answer 10

A property of a material that retains it’s deformed shape even after the force Is removed.

Question 11

Corrosion

Answer 11

The oxidation of a metal in the presence of O2 or H2O

Question 12

Silicon is between the metallic and covalent regions, outline it’s properties?

Answer 12

• Metalloid
• Shiny/lustrous like a metal
• Forms covalent bonds, brittle and forms weakly acidic oxide.
• Semiconductor, poor electrical conductors, yet it increases when heated, illuminated, or in the presence of certain impurities.

Question 13

Magnesium Iodide has a 50/50 percentage of ionic and covalent character, what are it’s properties?

Answer 13

High lattice enthalpy

Question 14

AlCl3 is ionic but has significant covalent contribution, properties?

Answer 14

• Unusually low boiling point (Bonding triangle not always accurate since magnesium iodide is also in that region).
• Forms ionic lattices when solid,
• melts into Al2Cl6 dimers at high-pressure at 190C, very low for an ionic compound
• Soluble in non-polar solvents such as Cl3CH4

Question 15

Alloys

Answer 15

Mixtures of pure metals and other metallic or non-metallic substances. Components of alloys retain their physical properties.

Question 16

How does alloying make metals stronger?

Answer 16

• Adding ions with different radii to the cations of the pure metal disrupts the regular structure of the lattice by not allowing the layers of cations to slide easily past each other.

Question 17

Nak is a

Answer 17

sodium-pottasium alloy

Question 18

What property of NaK makes it used as a nuclear reactant coolant that is non-volatile and can be pumped as any other liquid?

Answer 18

It has a lower melting point than its constituents, liquid at room temperature.

Question 19

Memory metals

Answer 19

Alloys that return to their original shape upon heating.

Question 20

Properties of pure iron

Answer 20

• can be deformed relatively easily

Question 21

Properties of Steel

Answer 21

• Harder than pure iron
• Rusts in the presence of water and elemental oxegyn, transforms it into hydrated iron(III) oxide, (ionic compound with no valuable properties of metals )

Question 22

What are some examples of rust protection methods?

Answer 22

• Barrier methods (painting or oiling)
• Sacrificial methods (galvanizing by adding zinc)

Question 23

Why does stainless steel have applications in cooking and medical-grade equipment?

Answer 23

• Iron alloy contains at least 11% chromium, which reacts with O2 or H2O to form a chromium oxide layer that prevents rusting.

Question 24

A lil properties of polymers in general 😛🙏

Answer 24

• Low thermal and electrical conductivity
• Low density
• Vary large molecules (large molecules)

Question 25

Repeating unit

Answer 25

A group of atoms that appears repeatedly along a polymer chain.

Question 26

Why are polymers low in electrical and thermal conductivity?

Answer 26

Macromolecular nature, don’t contain moving charged particles.

Question 27

Why are polymers high in melting and boiling points?

Answer 27

-Intermolecular forces along the polymers - Long polymers can wind up and take more energy to disentangle

Question 28

Cellulose

Answer 28

- Polymers of glucose that support fibrous structures in plants. - Can firm H-binds due to -OH groups which makes them strong.

Question 29

Starch

Answer 29

- Glucose polymer that can be broken down and easily digested. - Irregular branched structure, cannot be packed as tightly as cellulose and therefore forms fewer hydrogen bonds

Question 30

Plastics

Answer 30

Synthetic polymers composed mostly of carbon and hydrogen.

Question 31

Some properties of plastics

Answer 31

- often chemically interactive - can catch fire and sustain combustion

Question 32

Polystyrene Properties

Answer 32

- Non-polar hydrocarbon so insoluble in water - LDFs hold chains together, can be overcome by heating for reshaping, reform between molecules so the polymer solidifies again. - Cannot rotate easily due to C6H5, so it’s brittle - Good thermal insultatpr particularly in its expanded form.