Calculation involving volumes of gases (1 Viewer)

[Sarah182]

Ah so here I am again, I was wondering how to do this question:

Sodium hydroxide reacts with carbon dioxide to form sodium carbonate and water. What volume of carbon dioxide (measured at 0 degrees and 100 kPa) will 100mL of 1.35 mol/L solution of sodium hydroxide absorb?

Thanks in advance guys

 

[Pwnage101]

Ah so here I am again, I was wondering how to do this question:

Sodium hydroxide reacts with carbon dioxide to form sodium carbonate and water. What volume of carbon dioxide (measured at 0 degrees and 100 kPa) will 100mL of 1.35 mol/L solution of sodium hydroxide absorb?

Thanks in advance guys

n = m/M = v/V =c*v

where n = moles, V = molar volume (NB there are 2 depending on the tmp), M = Molar Mass, c = concentration, m = mass, v=volume

that is the mega equation about moles you should have learnt in year 11

Now

2NaOH _(aq) + CO_{2 (g)} -----> Na₂CO_{3 (s)} + H₂O _(l)

we are given, with regards to the sodium hydroxide, v = 0.1 L and c = 1.35 mol/L, so we can work out n

n=cv = 0.1 * 1.35 = 0.135 moles

now the moles ration of NaOH : CO₂ = 2:1

so there will be 0.5 * 0.135 = 0.0675 moles of CO₂ reacting

molar volume (V) @ 0 degrees and 100kPa = 22.71L

n = v/V

we know V and n, but need v, so rearranging:

v = n*V = 0.0675 *22.71= 1.532925L = 1.53L (3 sig fig)

 

[Sarah182]

Ahhhhh I was getting confused with the concentration and all.
That's so much clearer, thanks