In a past paper this is the question:
In a different experiment 50.0 cm3 of 0.500 mol dm–3 aqueous hydrochloric acid are
reacted with 50.0 cm3 of 0.500 mol dm–3 aqueous sodium hydroxide.
NaOH(aq) + HCl(aq) → NaCl(aq) + H2O(l) ΔH = –57.1 kJ mol–1
The initial temperature of each solution is 18.5 °C
Calculate the maximum final temperature of the reaction mixture.
Assume that the specific heat capacity of the reaction mixture, c = 4.18 J K–1 g–1
Assume that the density of the reaction mixture = 1.00 g cm–3
The markscheme has this as the answer:
n(HCl) or n(NaOH) = 50 x 0.500 / 1000 = 0.025 moles
q = –ΔH x n = 57.1 x 0.025 = 1.4275 kJ
ΔT = q/mc
ΔT = (1.4275 x 1000) / (100 x 4.18) = 3.4(2) °C
Final Temperature = 18.5 + 3.4 = 21.9 °C
Which I get up until
ΔT = (1.4275 x 1000) / (100 x 4.18) = 3.4(2) °C
... why do they times by 1000? Does the volume need to be in dm^3 or something?