Expt: G Gas Lab

Question 1

Reaction between sulfamic acid and sodium nitrite, where sulfamic acid is the limiting reagent

Answer 1

NaNO2(aq) + HSO3NH2(aq) —> NaHSO4(aq) + N2(g) + H2O(L)

Gas constant is 0.08206 L atm k^-1 mol^-1

Question 2

Graphical determination: PV = nRT

Plot volume (buret) vs mols (stoichiometry)

What is the slope equivalent to?

What should the y-intercept be equal to?

Answer 2

PV = nRT —> V = RT/P • n —> m = RT/P

1:1 ratio

Pwc equivalent, to height of mercury (no column height, no Pwc term)

PH2O calculates H2O pressure

Y = mx + b

m = RT/P

Question 3

Determination of PN2

What are some major sources of error?

How would that affect the value of R?

Answer 3

Patm = PN2 + PH2O + Pwc

Pwc comer height of water column into equivalent height of mercury (no Column height, then no Pwc term)

PH2O calculates the water vapour pressure

PN2 = Patm - Pwc - PH2O

PV = nRT —> V = (RT/P) • n