matter

Question 1

equation for specific heat capacity (c)? (E, m, θ)

Answer 1

ΔE = mcΔθ

where E = energy, m = mass and θ = change in temperature (IN KELVINS)

Question 2

equation for change in momentum molecules experience when they hit side of container? (F, m, v, u, t)

Answer 2

F = (mv - mu)/Δt

Question 3

equation for pressure (P)? (F, A)

Answer 3

P = F/A

where F = force and A = cross-sectional area

Question 4

‘equation’ for distance (d) moved by particles in random walk (due to brownian motion)? (N)

Answer 4

d ∝ √N

where N = number of steps taken by particle

Question 5

‘equation’ for distance (d) moved by particles in random walk (due to brownian motion)? (t)

Answer 5

d ∝ √t

t = time taken for particle to be displaced

Question 6

equation for average KE of a particle? (m, <c^2>)

Answer 6

KE = 0.5m<c^2>

where m = mass and <c^2> = mean square speed (alternate symbol below)

Question 7

average energy (E) of a particle? (T)

Answer 7

E = 1.5kT

where k = boltzmann’s constant and T = temperature in Kelvins

Question 8

equation for root mean square speed (c rms)? (T, m)

Answer 8

c rms = √[(3kT)/m]

Question 9

equation for total internal energy/KE of ideal gas (so all particles summed together)? (N, m, <c^2>)

Answer 9

E total = 0.5Nm<c^2>

where N = number of particles/molecules [NOT MOLES], m = mass and <c^2> = mean square speed

Question 10

equation for charles’ law?

Answer 10

V ∝ T
OR
V/T = constant
[at constant pressure]

where V = volume and T = temperature

Question 11

equation for pressure law?

Answer 11

p ∝ T
OR
p/T = constant
[at constant volume]

where p = pressure and T = temperature

Question 12

equation for boyle’s law?

Answer 12

p ∝ 1/V
OR
pV = constant
[at constant temperature]

Question 13

‘equation’ (the relationship) for density (ρ) of gas w fixed mass?

Answer 13

ρ ∝ 1/volume
so
ρ ∝ pressure

Question 14

equation of state for gas?

Answer 14

pV/T = constant
OR
p1V1/T1 = p2V2/T2

Question 15

ideal gas equation? (p, V, N, k, T)

Answer 15

pV = NkT

where p = pressure, V = volume, N = number of molecules/particles of gas, k = boltzmann constant

Question 16

ideal gas equation (p, V, n, R, T)

Answer 16

pV = nRT

where p = pressure, V = volume, n = number of moles of gas, R = molar gas constant, T = temperature

Question 17

equation for kinetic theory of gases? (p, V, N, m, <c^2>)

Answer 17

pV = (0.33…)Nm<c^2>

Question 18

equation relating pressure (p), density (ρ) and mean square speed (<c^2>) of particles in gas?

Answer 18

p = (0.33…)ρ<c^2>

Question 19

equation for density (ρ) of a gas? (N, m, V)

Answer 19

ρ = Nm/V

Question 19

equation for APPROXIMATION of average energy (E) of particle? (T)

Answer 19

E ≈ kT

where k = boltzmann constant and T = temperature in Kelvins

Question 20

how to work out if reaction will take place at noticeable rate? (ε, T)

Answer 20

ε/kT = constant

if ratio = 15 to 30, then reaction will take place at noticeable rate (bc some particles will always have above average energy)

(if above 30, reaction will be too slow to be noticeable, and if below 15, reaction will be too fast to be noticeable)

Question 21

equation for how many particles have how many times more energy particle has above/below average particle energy?

Answer 21

n1E = N(f^n2)

where n1 = number of levels (i made up this constant), E = kT (energy gained/lost in each collision), N = total number of particles and n2 = number of successive collisions (i made up this constant)

n1 = n2

Question 22

equation for the boltzmann factor (f) (aka, ratio of number of particles in two different energy states)? (ε, T)

Answer 22

f = e^(-ε/kT)

where ε = activation energy (i.e. energy of particles in higher energy state) and kT = average energy of particle

Question 23

equation for number of particles that can go through with reaction (have higher energy state)? (

Answer 23

N = N0 x f
OR
N = N0[e^-ε/kT]

where N = number of particles that can go through with reaction (made up this constant), N0 = number of particles in whole sample (made up this constant), f = boltzmann constant

Question 24

equation for total pressure (p) exerted by N molecules on side of container? (m, u, V)

Answer 24

p = (Nm<u^2>)/V
or
pV = (0.33…)Nm(c rms^2)

[look familiar?]

where N = number of particles/molecules, m = mass, <u^2> = mean square initial speed and V = volume

Question 25

equation for number of molecules (N) contained in n moles of substance?

Answer 25

N = n x N A

where n = number of moles and N A = avogadro’s constant

Question 26

equation for number of moles in substance of mass Ms of molar mass M?

Answer 26

n = Ms/M