4. States of Matter
Download
1 / 14

Learning Outcomes Candidates should be able to: - PowerPoint PPT Presentation


  • 57 Views
  • Uploaded on

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Learning Outcomes Candidates should be able to:' - wes


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Learning outcomes candidates should be able to

4. States of MatterI The gaseous state:(i) Ideal gas behaviour and deviations from it(II) pV = nRT and its use in determining a value for MrII The liquid stateThe kinetic concept of the liquid state and simple kinetic-molecular descriptions of changes of stateIII The solid stateLattice structures


Learning outcomes candidates should be able to

  • Learning Outcomes

  • Candidates should be able to:

  • state the basic assumptions of the kinetic theory as applied to an ideal gas

  • (b) explain qualitatively in terms of intermolecular forces and molecular size:

  • (i) the conditions necessary for a gas to approach ideal behaviour

  • (ii) the limitations of ideality at very high pressures and very low temperatures

  • (c) state and use the general gas equation pV = nRT in calculations, including

  • the determination of Mr

  • (d) *describe, using a kinetic-molecular model, the liquid state; melting;

  • vaporisation and vapour pressure

  • (e) *describe, in simple terms, the lattice structure of a crystalline solid which is:

  • (i) ionic, as in sodium chloride, magnesium oxide

  • (ii) simple molecular, as in iodine

  • (iii) giant molecular, as in graphite; diamond; silicon(IV) oxide

  • (iv) hydrogen-bonded, as in ice

  • (v) metallic, as in copper

  • [the concept of the ‘unit cell’ is not required]


Learning outcomes candidates should be able to

  • (f) explain the strength, high melting point and electrical insulating properties of

  • ceramics in terms of their giant molecular structure

  • (g) relate the uses of ceramics, based on magnesium oxide, aluminium oxide

  • and silicon(IV) oxide, to their properties (suitable examples include furnace

  • linings; electrical insulators; glass; crockery)

  • (h) describe and interpret the uses of the metals aluminium, including its alloys,

  • and copper, including brass, in terms of their physical properties

  • understand that materials are a finite resource and the importance of

  • recycling processes

  • (j) outline the importance of hydrogen bonding to the physical properties

  • of substances, including ice and water

  • (k) suggest from quoted physical data the type of structure and bonding

  • present in a substance


Learning outcomes candidates should be able to

  • Avogadro’s law: insulating properties of

    Equal volumes of any gas measured at the same temperature and pressure contain the same numbers of particles (atoms and molecules

    In order for volumes of gases to be comparable, they must be measured under the same conditions of temperature and pressure. Alternatively the volumes at the required temperature can be worked out using the Ideal Gas Equation.


Learning outcomes candidates should be able to


Learning outcomes candidates should be able to

  • PV = constant (for a fixed mass of gas) insulating properties of

    T

    If we take 1 mole of gas the constant is given the symbol R and is called the gas constant, and for n moles of gas we have

    PV = nRT

    R is a constant, 8.314 KJ-1mol-1

P, pressure must be in Pascals, Pa; V, volume must be in m3 (1m3 = 106 cm3 = 103 dm3), T, temperature must be in Kelvin, K


Learning outcomes candidates should be able to

Kinetic theory insulating properties of is an attempt to explain the observed properties of gases

  • The particles are moving randomly

  • We can neglect the volume of the particles themselves in comparison

  • to the total volume of the gas

- The particles do not attract one another

- The average kinetic energy of the particles is proportional to the

temperature of the gas

- No energy is lost in collisions between particles

  • Bombardment of the walls of the container explains pressure and

  • increasing temperature makes them hit walls harder, so pressure

  • increases


Learning outcomes candidates should be able to

  • Deviations from Ideal Gas Behaviour insulating properties of

    When gases are put under high pressure or cooled down the gas molecules get closer together (or move slower at lower temperatures) and they become attracted to each other using intermolecular forces and start to form a liquid. So there are no gases at 0 K!


Learning outcomes candidates should be able to

What volume is needed to store 0.050 moles of helium gas at 202.6kPa and 400K?

What pressure will be exerted by 20.16g hydrogen gas in a 7.5L cylinder at 20oC?

A 50L cylinder is filled with argon gas to a pressure of 10130.0kPa at 30oC. How many moles of argon gas are in the cylinder?

To what temperature does a 250mL cylinder containing 0.40g helium gas need to be cooled in order for the pressure to be 253.25kPa?


Learning outcomes candidates should be able to

What volume is needed to store 0.050 moles of helium gas 202.6kPa and 400K?

at 202.6kPa and 400K?

PV = nRT

P = 202.6 kPa

n = 0.050 mol

T = 400K

V = ? L

R = 8.314 J K-1 mol-1

202.6V=0.050x8.314x400

202.6 V = 166.28

V = 166.28 ÷ 202.6

V = 0.821 L (821mL)


Learning outcomes candidates should be able to

What pressure will be exerted by 20.16g hydrogen gas 202.6kPa and 400K?

in a 7.5L cylinder at 20oC?

PV = nRT

P = ? kPaV = 7.5Ln = mass ÷ MM  mass=20.16g  MM(H2)=2x1.008=2.016g/mol

n=20.16 ÷ 2.016=10molT=20o=20+273=293KR = 8.314 J K-1 mol-1

Px7.5=10x8.314x293Px7.5 = 24360.02P = 24360.02 ÷ 7.5 = 3248kPa


Learning outcomes candidates should be able to

A 50L cylinder is filled with argon gas to a pressure of 10130.0kPa

at 30oC. How many moles of argon gas are in the cylinder?

PV = nRT

P = 10130.0kPaV = 50Ln = ? molR = 8.314 J K-1 mol-1T=30oC=30+273=303K

10130.0x50=nx8.314x303506500=nx2519.142n=506500 ÷ 2519.142=201.1mol


Learning outcomes candidates should be able to

To what temperature does a 250mL cylinder containing 0.40g helium

gas need to be cooled in order for the pressure to be 253.25kPa? PV = nRT

P = 253.25kPaV=250mL=250 ÷ 1000=0.250Ln=mass ÷ MM  mass=0.40g  MM(He)=4.003g/moln=0.40 ÷ 4.003=0.10molR = 8.314 J K mol-1T = ? K

253.25x0.250=0.10x8.314xT63.3125 = 0.8314xTT=63.3125 ÷ 0.8314=76.15K


Learning outcomes candidates should be able to