2) A student carries out a titration to determine the concentration of some hydrochloric acid. The student titrates the hydrochloric acid against a standard solution of sodium carbonate,
Na2CO3. The equation is shown below.
Na2CO3(aq) + 2HCl (aq) + 2NaCl (aq) + H2O(l) + CO2(g)
The student prepares 0.150 mol dm-3 Na2CO3 in a 250.0 cm3 volumetric flask.
The hydrochloric acid is added to a 50.0 cm3 burette.
The student pipettes the Na2CO3(aq) using a 25.0 cm3 pipette. en sosial
The student's obtained concordant results and determined the mean volume of HCI used to
be 24.25cm3
Calculate the concentration, in mol dm-3, of the hydrochloric acid.
Give your answer to 3 significant figures.
3 marks.

For questions 1 and 2, consider the following experimental data. hydrogen emission lines were detected at the following wavelengths (in nm): 121.6102.697.395.093.8question 1use the electromagnetic radiation classifications below and figure 1-1 in the introductory information for this lab (in the lab manual) to determine the nf value for the experimental data provided? wavelength, ? (nm) 650 700 550 600 400 450 500 visible spectrum wavelength, ? (m) 11 10 3 10 10 10 8 10 5 10 10 -10 10 9 10 10 10 10 -12 10 microwave radio infrared x-ray ultraviolet gamma 1020 1019 1018 1 1016 015 1014 01 12 109108 frequency, v (hz)a.1b. 2c. 3d. 4e. 5question 2using the data for the emission line with the longest wavelength, the known value of nf (from question 1 in this prelab), and the value of ni (deduced from the ? and nf values) calculate the rydberg constant for hydrogen (rh) in units of m-1.a) 1.097 x 10-11 m-1b) 5.921 x 107 m-1c) 1.097 x 10-2 m-1d) 9.252 x 106 m-1e) 1.097 x 107 m-1