Unit 12/13/14

Question 0

Fast diffusion

Answer 0

High to low concentration

Question 1

Low density of liquid or solid

Answer 1

Liquid 1g/1000 cc

Solid 1g/cc

Question 2

1 atm

Answer 2

760mm Hg or 760 torr

Question 3

1 Pa

Answer 3

.0000009869 atm (6 zeros)

.00750 torr or mm Hg

Question 4

Sea level=1 atm

Answer 4

760 torr=760 mm Hg=101.325 kPa=14.696 psi

Question 5

Stp T

Answer 5

0 C or 273 K

Question 6

Standard pressure 1 atm

Answer 6

760 torr or mm Hg=101.325 kPa

Question 7

Standard molar volume

Answer 7

1 mole of any gas 22.4 L

Question 8

Dalton’s partial pressure law

Answer 8

Total pressure is equal to sum of each gases partial pressure
Pt=Pa+Pb+Pc….+Pn

Question 9

*Charles law V1/T2=

Answer 9

V2/T1

Question 10

Boyles law P1V1=

Answer 10

P2V2

Question 11

Combined gas laws

P1V1/T1=

Answer 11

P2V2/T2

Question 12

PV=nRT

Answer 12

P=pressure in atm
V=volume in liters
n=number of moles
R=gas constant .0821L(atm)/mol(K)
T=temp in K

Question 13

Molecular weight and density

D=MP/RT

Answer 13

M=molar mass 
D=density mass/volume
R=.0821
T=temp in K
P=pressure in atm
M=DRT/P
Remember HOFBRINCL

Question 14

Graham’s law (effusion)

Answer 14

Rate a/rate b=sqrt(molar mass b/molar mass a)

Question 15

Convert pressure to atmospheres

Answer 15

645 mm to atm

645 x 1 atm/760 mm = .85 atm

Question 16

Density in?

Answer 16

g/L

Question 17

Find mass using density formula

Answer 17

m=MPV/RT

Question 18

What type of equation?

An 800 mL sample of gas, measured at 44 C and 900 mm pressure. How many moles?

Answer 18

PV=nRT or n=PV/RT

Question 19

What type of equation?
Total pressure is 1.8 atm. Container contains 255 mm pressure due to N2, 518 mm pressure due to CO2 and in unknown pressure of CL2. What is the pressure due to the chlorine gas?

Answer 19

Pt=Pa+….Pc

Pt=760(1.8)-518-255=595 mm

Question 20

What type of equation?

What is the molecular weight of a gas that effuses 0.629 times as fast as O2.

Answer 20

Rate of a/rate of b=sqrt(Mb)/sqrt(Ma)

.629=sqrt(32g/mol)/x

Question 21

What type of equation?

What is the molecular weight of 3.47 g of a gas at 87 C with a volume of 3 L at a pressure of 1.4 atm?

Answer 21

D=PM/RT or M=DRT/P

Question 22

What type of equation?

What is the mass in grams of 1 L of methane (CH4) at STP?

Answer 22

m=MPV/RT

Question 23

What type of equation?

Convert to standard conditions: 1520 mL of gas at -33 C and 720 mm pressure.

Answer 23

V1P1T2=V2P2T1 or V1P1/T1=V2P2/T2

Question 24

What type of equation?

A sample of gas occupies 50 L at 27 C. What will be the volume of the gas in L at ST?

Answer 24

V1T2=V2T1

Question 25

What type of equation?

A gas has a volume of 240 mL at 70 cm pressure. What pressure, in cm is needed to reduce the volume to 60 mL.

Answer 25

V1P1=V2P2

Question 26

Mole-mole

How many moles of ammonia are produced when 6 moles of hydrogen gas react with an excess of nitrogen gas?

Answer 26

3H2+N2—>2NH3

6molH2 x 2mol NH3/3molH2= 4 mol NH3

Question 27

Mercury (ii) oxide

Answer 27

HgO

Question 28

Write the combustion reaction for pentane

Answer 28

C5H12—>5CO2+6H2O

Question 29

Limiting reactant

Answer 29

That amount of reactant that controls the amount produced. Completely consumed in the reaction.

Question 30

Excess reactant

Answer 30

Left over. Not completely consumed.

Question 31

Rules for finding limiting reactant

Answer 31

Solve both equations

-the one that produces the least is the limiting-correct amount

Question 32

Percent yield formula

Answer 32

Percent yield=actual/theoretical x 100

Question 33

Butane

Answer 33

C4H10

Question 34

Pentane

Answer 34

C5H12

Question 35

Stoichiometry and density in liquid and gas

Answer 35

Liquid g/mL

Gas g/L

Question 36

Stoichiometry molarity

Answer 36

Used when determining volume of aqueous solution. M=moles/Liter

Question 37

H is always terminal atom

Answer 37

Can only hold 2 electrons

Question 38

Central atom usually has lower

Answer 38

Electronegativity