Questions 1
Concentrated ammonia solution gives off ammonia gas. Concentrated hydrochloric
acid gives of hydrogen chloride gas. Ammonia, NH3, and hydrogen chloride, HCI,
are both colourless gases. Ammonia reacts with hydrogen chloride to make the
white solid ammonium chloride. Ammonia has a molar mass of 17 g/mol and
hydrogen chloride of 36.5 g/mol.
The apparatus is set up as shown.
cotton wool
soaked in concentrated
hydrochloric acid
cotton wool
soaked in concentrated
ammonia solution
А
B C D
glass tube
After ten minutes a white solid forms in the tube where the gases meet.
(a) (i) At which point, A, B, C or D, does the white solid form? Explain why the solid forms
at that point.
The solid forms at
Explanation
... [3]
(ii) Name the process by which the ammonia and hydrogen chloride gases move in the
tube.
... [1]
(iii) The experiment was repeated at a lower temperature.
Predict how the results of the experiment would be different. Explain your answer.​

Chen drew a diagram to compare the ways in which different organisms obtain nitrogen. which label belongs to the area marked z?

Experiment: effect of solution concentration on reaction rate you have learned that as the concentration of reactants increases, there will most likely be a greater number of collisions, and hence increase the rate of a reaction. in this experiment, you will see a demonstration of this, with a twist. there will be three reactions going on in this experiment. objectives determine how solution concentration can affect the rate of a reaction. the first reaction will be a reaction of the iodide ion (i-1) with hydrogen peroxide (h2o2) in an acidic solution. this reaction produces a slightly orange solution. in our experiment, we will add some orange food coloring to make this solution more orange. 2 h+ (aq) + 2 i- (aq) + h2o2 (aq) ⟶ i2 (aq) + 2 h2o (l) the next reaction will be between the iodine and starch i2 + starch ⟶ i2-starch complex (blue-black) so, when starch is added to the iodine solution made from the first reaction, the solution will turn black immediately, so it is difficult to find the rate of reaction. in order to be able to time this reaction, you will slow it down with another reaction. adding ascorbic acid will react with the iodine, reducing the concentration of the iodine available to react with the starch. c6h8o6 (aq) + i2 (aq) ⟶ 2i- (aq) + c6h6o6 (aq) + 2 h+ (aq) when the ascorbic acid is used up, the remaining iodine molecules can react with the starch and form the black color. the more ascorbic acid you add, the slower the reaction to form the iodine-starch complex will be. use your data and observations to complete the assignment. analysis and conclusions submit your data and the answers to these questions in the essay box below. what was your hypothesis? plot your data as drops of ascorbic acid vs. time. as the concentration of ascorbic acid was increased, did the rate of the formation of the iodine-starch complex increase or decrease? explain your answer in terms of the chemical reactions involved. was your hypothesis correct? make a general rule about the effects of concentration of reactants on reaction rates. for practice, the molecular formula for ascorbic acid is c6h8o6, and you used 6 g in this experiment, calculate the molarity of the ascorbic acid. now calculate the concentration in moles per drop (assume 1 ml = 20 drops).

The biosphere of the earth is made up of . a. inorganic b. organic