First Law: Key Equations and Data

Question 1

What is the perfect gas law and the two values of R?

Answer 1

pV=nRT

R=8.314JK^-1mol^-1

R=0.08206dm³atmK^-1mol^-1

Question 2

What is the temperature and pressure of SATP?

Answer 2

T=298.15K p=1.00x10⁵Pa=1 bar

Question 3

What is the temperature and pressure of STP?

Answer 3

T=0.00°C=273.15K p=1.00atm

Question 4

What is the equation for root mean square(rms) speed?

Answer 4

((s₁²+s₂²+s₃²+…s_N²)/N)^½

Question 5

What is the equation for root mean square(rms) speed from temperature and molar mass?

Answer 5

Where u_rms=c

Question 6

How is rate of effusion related to molar mass?

Answer 6

rate of effusion∝(1/M)^½

Question 7

What is the rms speed in terms of collison frequency and mean free path?

Answer 7

c=λz

Question 8

What is the equation for mean free path in terms of temperature, diameter of the atom and pressure?

Answer 8

Question 9

What is the equation for collision cross section?

Answer 9

σ=πd²

Question 10

What is the van der Waals equation of state?

Answer 10

Question 11

What equation relates K_p and K_c?

Answer 11

K_p=K_c(RT)^Δn

Question 12

What is the equation for work in terms of the perfect gas equation?

Answer 12

w=-p_exΔV=-ΔnRT

Question 13

What is the equation for internal energy changes?

Answer 13

ΔU=w+q

Question 14

What is the equation for enthalpy in terms of internal energy?

Answer 14

ΔH=ΔU+ΔnRT

Question 15

What is the equation for change of enthalpy with temperature using Kirchhoff’s law?

Answer 15

Δ_rH_T2=Δ_rH_T1+Δ_rC_pΔT

Where Δ_rC_p=ΣνC_p(products)-ΣνC_p(reactants)