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When potassium thiocyanate solution is added to a pale yellow solution containing iron(III) ions, the following equilibrium is established. [Fe(H2O)6]3+(aq) + SCN−(aq) ⇌ [Fe(SCN)(H2O)5]2+(aq) + H2O(l) [Fe(H2O)6]3+(aq) is pale yellow and…
Which property is the same for ammonia molecules containing deuterium, ND3, and ordinary ammonia molecules, NH3? A. Molar mass B. Molecular geometry C. Density of the gas at STP D. Rate of diffusion
(i) State the independent variable and the dependent variable of the investigation. (ii) Apart from the mass of leaves and the volume of water, suggest two other conditions that should be kept constant for the comparison between boiling times to be valid.
(i) State what the graph shows about the relationship between the boiling time and the amount of oxalate ions extracted. (ii) Comment on the range of boiling times and on the number of measurements made in the investigation.
The hypothesis being tested was that a longer boiling time would extract more oxalate ions from the leaves. (i) Evaluate the hypothesis in the light of the results, giving a reason. (ii) Suggest one way in which the investigation could be changed so that it…
Naturally occurring gallium consists of two isotopes: 60 % of the atoms contain 38 neutrons and the remaining 40 % contain 40 neutrons. (i) Use section 7 of the data booklet to deduce the nuclear symbol of the heavier isotope. (ii) Calculate the relative…
Gallium forms a sulfate of formula Ga2(SO4)3. (i) Both ionic and covalent bonding are present in this compound. State which particles are held together by each type of bond. (ii) Contrast covalent and ionic bonds in terms of what happens to the valence…
Which of the following could be the empirical formula of a compound with Mr = 70? I. CH2 II. C4H6O III. C5H10 A. I and II only B. I and III only C. II and III only D. I, II and III
Describe how a standard aqueous solution of potassium manganate(VII) can be prepared from the solid.
Describe the steps by which this standard solution is turned into a calibration curve for the colorimeter.