Zadanie 1
Dark crystals of iodine form on a cold glass surface placed in warm iodine vapour. No liquid is seen at any stage. What is the name of this change of state? A. Deposition B. Sublimation C. Condensation D. Freezing
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Dark crystals of iodine form on a cold glass surface placed in warm iodine vapour. No liquid is seen at any stage. What is the name of this change of state? A. Deposition B. Sublimation C. Condensation D. Freezing
Identify the independent variable and the dependent variable in this investigation.
State two variables that should have been kept constant in the four runs.
Discuss the range of the independent variable and the quantity of data in this investigation.
Suggest why the light intensity rose during the first minutes of each run.
Suggest how the total quantity of light emitted in each run could be obtained from the graph.
Explain how the rate at which the light intensity was falling after 15 minutes in the 44.8 °C run could be determined from the graph.
The graph shows the maximum rate of decrease in light intensity for each run, plotted against temperature. (i) Draw the best-fit curve on the graph. (ii) Suggest two possible conclusions that can be drawn from the investigation.
Suggest two modifications to the procedure that would make the data more reliable.
Hydrochloric acid, HCl(aq), and hydroiodic acid, HI(aq), ionize completely in water, whereas propanoic acid, CH3CH2COOH(aq), ionizes only partly. 25.0 cm3 of 0.200 mol dm−3 HCl(aq) was titrated with sodium…