Chemistry equations Flashcards

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1
Q

Formula used to find fingerprint of gaseous elements

A

f= frequency lambda=wavelength c= speed of light h= plank’s constant (6.63 x 10-34 J•s)

**Can only predict E of atoms or ions with one electron (Bohr atom)

Change in E predicts wavelength of photons emitted when electron fall to lower E level (emission) or jump to higher E level (absorption)

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2
Q

Name the type of radioactive decaythat can be stopped by skin or paper

A

Alpha Decay

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3
Q

Type of radioactive decay that emits 2 protons and 2 neutrons

A

Alpha Decay

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4
Q

21084PO ►20682PO

A

Alpha Decay

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5
Q

Too many neutrons, so neutron is converted to proton + electron

A

Beta Neg. decay

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6
Q

Atomic Number + 1

A

Beta Neg Decay

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7
Q

146C►147C

A

Beta Neg Decay

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8
Q

Too few neutrons, proton ocnverted to neutron and poistron

A

Beta Pos. Decay

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9
Q

Atomic # = -1

A

Beta Pos. Decay or Electron Capture

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10
Q

189C►188C

A

Beta Pos Decay

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11
Q
A
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12
Q

What is the difference b/w Electron Capture and Beta Pos. Decay?

A

both have too few neutrons, but electron capture captures electron from closest shell to convert proton into neutron. Beta pos. decay converts proton into neutron without capturing electron.

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13
Q

What type of radioactive decay needs concrete or Lead to stop?

A

Gamma Decay

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14
Q

Atomic # and mass stay the same in what radioactive decay?

A

Gamma

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15
Q

What does Gamma Decay emmit?

A

gamma photons

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16
Q

Nuclear Binding Energy

A

c=3x108m/s

1ev= 1.6x10-19J

1amu= 1.66x10-27kg

EBin ev for equation

m in amu

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17
Q

The greater the binding energy, the more ______ the nucleus

A

stable

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18
Q

Formal Charge Equation

A

FC=V-1/2B-L

FC= formal charge

V=#valence electrons

B=#bonding electrons

L=#lone-paired electrons

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19
Q

Amount of E required to complete transition ___

A

heat of transition (Delta H)

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20
Q

what is formula for calculating energy required to complete phase transition/change

A

q=nXΔH

q=heat

n= #of moles

H=change of phase change

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21
Q

q=nXΔH

q and H are +, heat is _____

A

absorbed

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22
Q

q=nXΔH

q and H are -, heat is _______________

A

released

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23
Q

To calculate temperature change in a reaction

A

q=mcΔT

q=heat added or released

m=mass of sample

c=specific heat of substance

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24
Q

What is specific heat?

A

How resistant a substance is to change in temperature. The greater the specific heat, the less there will be a change in temperature

25
Q

Define calorie

A

Amount of heat required to raise 1 gram of water by 1degree C

26
Q

1cal= ?J

A

4.2

27
Q

1atm=?torr=?mmHg

(pressure)

A

760, 760

28
Q

1cm3=?cc=?mL

(volume)

A

1cc, 1mL

29
Q

1m3=?L

(volume)

A

1000

30
Q

1atm=?kPa=?Pa

(P)

A

101.3kPa

1x105Pa

31
Q

The ideal gas law

A

PV=nRT

R=universal gas constant (.0821L-atm/kmol)

T in kelvins

32
Q

combined gas law

A

P1V1/T1=P2V2/T2

33
Q

At constant P, how does V relate to T?

A

V1/T1=V2/T2

34
Q

At constant T, how does P relate to V?

A

P1V1=P2V2

35
Q

At constant V, how does P relate to T?

A

P1/T1=P2/T2

36
Q

Boiling Point elevation equation?

A

ΔTb=kbim

kb= solven’s boilng point elevation constant

i is van’t hoff factor (basically how many ions are in it?)

m= molal concentration of the solution (molal=#mol/kg)

37
Q

Freezing point depression equation?

A

ΔTf=kfim

38
Q

van’t hoff equation? aka osmotic P

A

Π=MiRT

Π=osmotic P in atm

M-molarity

i=van’t hoff factor (how many ions?)

R=Planks constnat .0821 L•atm/k•mole

T = T in K

39
Q

If keq < 1 →

If keq = 1 →

If keq > 1 →

A

rxn favor reactants

rxn balances reactants and products

rxn favors products

40
Q

keq stands for, which is constant IF ___________

A

equilibrium constant, constant if T is constant

41
Q

Q stands for ____

if Q < Keq ______

if Q > Keq _________

A

reaction quotient when rxn is not at equilibrium

Rxn proceeds forward

Rxn proceeds backwards

42
Q

ksp stands for

A

solubility product constant - how easily a salt dissolves in water

43
Q

In a problem with solubility constant (ksp) what is left out of equation?

A

solids

44
Q
A
45
Q

What does Ka stand for?

A

acid ionization - tells if products or reactants are favored.

46
Q

The larger the Ka value the _____________ the acid

A

stronger (Ka>1 is a strong acid)

47
Q

What does kw stand for?

A

autoionization of water aka the ion product constant of water

48
Q

What is the kw of water at 25ºc?

A

1 x 10-14

49
Q

What is the formula for PH in its relation to acids? Bases?

A

PH = -log [H+]

[H+]=10-PH

pOH=-log[OH-]

[OH-]=10-pOH

50
Q

What is the neutralization formula?

A

a x [A] x VA= b x [B] x VB

a = # of acidic hydrogens per formula unit,

b = how many H+ ions the base can accept

VA is volume of acid, same for Vb, A is concentration of acid

51
Q

Henderson-Hasselbach equation

A

pH=pka + log( [CB]/ [weak acid] )

52
Q

First law of thermodynamics equation

A

ΔE=q+w

Change in E = heat + work

53
Q

Gibb’s free energy equation

A

ΔG = ΔH - TΔS

H - enthalpy

S - entropy

54
Q

What does ΔG tell you about chemical rxn?

A

Whether it’s spontaneous or not.

55
Q

If…

ΔG < 0

ΔG = 0

ΔG > 0

A

spontaneous, forward directoin

equilibrium

nonspontaneous

56
Q

What is the equation for Gibbs free Energy at equilibrium?

A

ΔGº = -RT lnKeq

57
Q

What equation relates Gibbs free energy to redox rxns?

A

ΔGº = -nFEº

n = # of moles of E transferred

F is constant = 96500 coulombs

Eº = reduction potential

58
Q

At STP 1 mole of an ideal gas occupies ?L

A

22.4L