Question
5. A student does a titration using sodium carbonate solution and nitric acid. The equation for the reaction is: Na_(2)CO_(3)+2HNO_(3)arrow 2NaNO_(3)+CO_(2)+H_(2)O 25.0cm^3 of 0.124mol/dm^3 sodium carbonate solution is neutralised by 23.6cm^3 of nitric acid. Calculate the concentration of the nitric acid. Give your answer to 3 significant figures. You should calculate: the number of moles of sodium carbonate in 25.0cm^3 of the solution the number of moles of nitric acid in 23.6cm^3 of the nitric acid the concentration of the nitric acid in mol/dm^3
Answer
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Hayden
Master · Tutor for 5 years
Answer
1. The mole of Na₂CO₃ = 25.0 × (0.124/1000) = 0.00310 mol2. Since a mole of Na₂CO₃ reacts with 2 moles of HNO₃, hence moles of HNO₃ = 2*0.00310 =0.00620mol of nitric acid3. Therefore the concentration of the HNO₃ = 0.00620 / (23.6/1000) = 0.263mol/dm³ (rounded to three significant figures).
Explanation
The concentration(triggering equation) = number of moles/volume in dm^3.1. First things first, when analysing the prompt - it states that Sodium Carbonate reacts with Nitric Acid by the proportion of 1:2, hence for every mole of Sodium Carbonate reacting, 2 moles of Nitric Acid will be consumed. This ratio will be needed in the calculations.2. On calculating the number of moles of Sodium Carbonate, simply multiply the volume by its given concentration. Converting volume in cm^3 to dm3 (by dividing by 1000) that provides the volume to be 0.025 dm³ (because 1dm³ = 1000cm³). Multiplying this volume by the concentration, in this case(0.124 mol/dm³), then yields the number of moles. 3. The number of moles of Nitric acid required is twice the number of moles of Sodium Carbonate because of reaction stoichiometry and it can provide us with these details from the equation given in the prompt, which states that 1 mole of Na2CO3 reacts with 2 moles of HNO3.4. Now you proceed to estimate the concentration trigger Nitric acid applying the Progression implication_total:int_v = tit_equation count/current_altitude in 1dm^3 (where 1dm^3 = 1000cm^3) by converting the 23.6cm³ to dm³.All of these calculate values are taken to three significant figures, giving uosphere volume parameters, reactor operating_condition))ree decimal places would agree with three significant figures when it comes to the actual procedure.