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The student measures the hydrogensulfite concentration by titrating samples against a standard iodine solution, with starch as the indicator. Every three days, 25.00 of cordial is withdrawn from each flask, diluted to 250.0
The following burette readings are recorded in one of the titrations. Final burette reading = 26.15 ± 0.05 Initial burette reading = 1.15 ± 0.05 Calculate the percentage uncertainty in the titre volume.
The student's results are plotted below. (i) Calculate the average rate at which the hydrogensulfite concentration in the 24 h flask decreased over the 12 days. Include units in your answer. (ii) Before starting, the student wrote this hypothesis: "The longer…
Suggest one way of extending the investigation so that it could lead to additional advice on storing cordial.
α-particles are the nuclei of helium-4 atoms. In an experiment based on the work of Geiger and Marsden, a beam of α-particles is directed at a very thin platinum foil and the angle of deflection, θ, of each particle is recorded by a detector that can be moved…
The presence of hydrogen in stars is deduced from lines in their spectra. (i) Outline what the emission spectrum of hydrogen looks like. Emission spectra of species that contain a single electron can be explained by a model in which the electron is held by the…
Outline why scientists have replaced earlier models of the atom with new ones.
An unknown element E has the six successive ionization energies given below. Ionization number 1st 2nd 3rd 4th 5th 6th Ionization energy / 562.3 1091.8 4265.4 5637.9 7052.1 8893.6 Which is the formula of the chloride of E? A. …
By drawing a suitable line on the graph, determine the rate at which carbon dioxide is released at the start of Experiment 1. Give your answer in .
Estimate how long after the start of the experiment the piston would first move if a total mass of 750 g were loaded on it.