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Temperature Unit Kelvin (K) Kelvin = °C + 273
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Temperature Unit Kelvin (K) Kelvin = °C + 273 Temperature Convert 45°C to Kelvin 45°C + 273 = 318 K.

Jan 12, 2016

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Myra Marsh
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Page 1: Temperature Unit Kelvin (K) Kelvin = °C + 273 Temperature Convert 45°C to Kelvin 45°C + 273 = 318 K.

Temperature

Unit Kelvin (K)

Kelvin = °C + 273

Page 2: Temperature Unit Kelvin (K) Kelvin = °C + 273 Temperature Convert 45°C to Kelvin 45°C + 273 = 318 K.

Temperature

Convert 45°C to Kelvin

45°C + 273= 318 K

Page 3: Temperature Unit Kelvin (K) Kelvin = °C + 273 Temperature Convert 45°C to Kelvin 45°C + 273 = 318 K.

Temperature

Absolute zero – 0 K Molecules stop moving

Question: what is absolute zero temperature in Celsius?

-273°C

Page 4: Temperature Unit Kelvin (K) Kelvin = °C + 273 Temperature Convert 45°C to Kelvin 45°C + 273 = 318 K.

Volume

Units: mL L

Page 5: Temperature Unit Kelvin (K) Kelvin = °C + 273 Temperature Convert 45°C to Kelvin 45°C + 273 = 318 K.

Amount

Units grams moles

Page 6: Temperature Unit Kelvin (K) Kelvin = °C + 273 Temperature Convert 45°C to Kelvin 45°C + 273 = 318 K.

Gas Laws

Each gas law relates the 4 variables: Pressure Temperature Volume Amount

For the next 4 gas laws, amount is not a factor

We will only pay attention to P, T, & V

Page 7: Temperature Unit Kelvin (K) Kelvin = °C + 273 Temperature Convert 45°C to Kelvin 45°C + 273 = 318 K.

Boyles’ Law: P/V relationship

Defn – at constant T, volume of a fixed amount of gas varies inversely with pressure inversely – as one variable increases,

other variable decreases

P

V

Page 8: Temperature Unit Kelvin (K) Kelvin = °C + 273 Temperature Convert 45°C to Kelvin 45°C + 273 = 318 K.

Boyle’s Law

FormulaP1V1 = P2V2

P1 & V1 are initial conditions

P2 & V2 are final conditions

Page 9: Temperature Unit Kelvin (K) Kelvin = °C + 273 Temperature Convert 45°C to Kelvin 45°C + 273 = 318 K.

Boyle’s Law

A balloon filled with helium gas has a volume of 500 mL at 1.00 atm. When it rises to a higher altitude, the pressure is reduced to 0.50 atm. If the temperature is constant, what is the volume of the balloon?

1000 mL

Page 10: Temperature Unit Kelvin (K) Kelvin = °C + 273 Temperature Convert 45°C to Kelvin 45°C + 273 = 318 K.

Charles’ Law: V/T relationship

Defn – at constant P, volume of fixed amt of gas varies directly with Kelvin temp Directly – as one variable increase,

the other increases

V

T

Page 11: Temperature Unit Kelvin (K) Kelvin = °C + 273 Temperature Convert 45°C to Kelvin 45°C + 273 = 318 K.

Charles’ Law Formula

V1 & T1 are initial conditions V2 & T2 are final conditions

2

2

1

1

T

V

T

V

Page 12: Temperature Unit Kelvin (K) Kelvin = °C + 273 Temperature Convert 45°C to Kelvin 45°C + 273 = 318 K.

Charles’ Law

A helium balloon has a volume of 2.75 L at 20°C. On a cold day, the balloon is placed outside where it shrinks to 2.46 L. What is the temperature outside?

262 K

Page 13: Temperature Unit Kelvin (K) Kelvin = °C + 273 Temperature Convert 45°C to Kelvin 45°C + 273 = 318 K.

Gay-Lussac’s Law: P/T relationship

Defn – at constant V, pressure of fixed amt of gas varies directly with Kelvin temp Directly – as one variable increase,

the other increases

P

T

Page 14: Temperature Unit Kelvin (K) Kelvin = °C + 273 Temperature Convert 45°C to Kelvin 45°C + 273 = 318 K.

Gay-Lussac’s Law Formula

P1 & T1 are initial conditions P2 & T2 are final conditions

2

2

1

1

T

P

T

P

Page 15: Temperature Unit Kelvin (K) Kelvin = °C + 273 Temperature Convert 45°C to Kelvin 45°C + 273 = 318 K.

Gay-Lussac’s Law

Before a trip from Sugar Land to South Padre, the pressure in an automobile tire reads 2.1 atm at 27°C. Upon arriving in Padre, the gauge reads 2.3 atm. What is the temperature in South Padre?

329 K

Page 16: Temperature Unit Kelvin (K) Kelvin = °C + 273 Temperature Convert 45°C to Kelvin 45°C + 273 = 318 K.

Combined Gas Law: P/T/V Defn – relationship between P,V, & T

of fixed amount of gas Formula

2

22

1

11

T

VP

T

VP

Page 17: Temperature Unit Kelvin (K) Kelvin = °C + 273 Temperature Convert 45°C to Kelvin 45°C + 273 = 318 K.

Combined Gas Law

The volume of a gas is 27.5 mL at 22.0°C and 740 mm Hg. What will be its volume at 15°C and 755 mm Hg?

26 mL

Page 18: Temperature Unit Kelvin (K) Kelvin = °C + 273 Temperature Convert 45°C to Kelvin 45°C + 273 = 318 K.

Avogadro’s Principle

Defn – equal volumes of gases at same temp and pressure contain equal number of molecules- the size of the molecule does not influence the volume a gas occupies

- for example, 1000 relatively large Kr gas molecules occupies the same volume as 1000 smaller He gas molecules

Page 19: Temperature Unit Kelvin (K) Kelvin = °C + 273 Temperature Convert 45°C to Kelvin 45°C + 273 = 318 K.

Molar Volume of a Gas

Molar Volume – volume that one mole of a gas occupies at STP (0°C, 1 atm)

1 mole = 22.4 L

Page 20: Temperature Unit Kelvin (K) Kelvin = °C + 273 Temperature Convert 45°C to Kelvin 45°C + 273 = 318 K.

Molar Volume of a Gas

Ex prob #1: calculate the volume 0.881 mol H2 will occupy at STP.

0.881 mol H2

0.881 mol H2 x 22.4 L H2

1 mol H2

= 19.7 L H2

Page 21: Temperature Unit Kelvin (K) Kelvin = °C + 273 Temperature Convert 45°C to Kelvin 45°C + 273 = 318 K.

Molar Volume of a Gas

What is the mass of 0.0752 L of oxygen gas at STP? 0.0752 L O2

0.0752 L O2 x 1 mol O2

22.4 L O2

0.0752 L O2 x 1 mol O2 x 32 g O2

22.4 L O2 1 mol O2

= 0.107 g O2

Page 22: Temperature Unit Kelvin (K) Kelvin = °C + 273 Temperature Convert 45°C to Kelvin 45°C + 273 = 318 K.

Ideal Gas Law

Defn – relationship between P,V,T and # of moles, n

FormulaPV = nRT

Page 23: Temperature Unit Kelvin (K) Kelvin = °C + 273 Temperature Convert 45°C to Kelvin 45°C + 273 = 318 K.

Ideal Gas Law

Defn – relationship between P,V,T and # of moles, n

FormulaPV = nRT

ideal gas constant

Page 24: Temperature Unit Kelvin (K) Kelvin = °C + 273 Temperature Convert 45°C to Kelvin 45°C + 273 = 318 K.

Ideal Gas Constant 3 different R

constants

R = 0.0821 L·atm mol·K

= 62.4 L· mm Hg mol·K

= 8.314 L·kPa mol·K

pay attention to what unit of pressure is given in problem to use the appropriate R

Page 25: Temperature Unit Kelvin (K) Kelvin = °C + 273 Temperature Convert 45°C to Kelvin 45°C + 273 = 318 K.

Ideal Gas Law

Ex prob 1: what is the volume of 0.250 moles of oxygen gas at 20°C and 740 mm Hg?

which R do we use?

6.18 L O2

Page 26: Temperature Unit Kelvin (K) Kelvin = °C + 273 Temperature Convert 45°C to Kelvin 45°C + 273 = 318 K.

Ideal Gas Law

Ex prob 2: calculate the pressure, in atm, of 4.75 L NO2 containing 0.86 mol at 27°C.

4.46 atm

Page 27: Temperature Unit Kelvin (K) Kelvin = °C + 273 Temperature Convert 45°C to Kelvin 45°C + 273 = 318 K.

Ideal Gas Law

Ex prob 3: calculate the grams of N2 present in a 0.600 L sample kept at 1.0 atm and 22°C.first determine # of moles

0.025 mol N2

convert to grams0.70 g N2