Question
(c) A scientint sot up two test-fubes as shown below. In test-tube B the zing strip was slowly covered with a grey deposit. Nothing happened in the other test-tube. (i)What was the grey deposit in test-tube B? __ (ii)Why was this grey deposit formed in test-tube B? __ (iii) Explain why no reaction took place in test-tube A. __ Q7. For 200 million years the proportions of the different gases in the atmosphere hav much the same as today. Over the past 150 years the amount of carbon dioxide in atmosphere has increased from 0.03% to 0.04% (a) Describe how carbon dioxide is released into the atmosphere by human an industrial activity; __
Answer
4.1
(315 Votes)
Max
Veteran · Tutor for 9 years
Answer
i. The grey deposit in test-tube B is perhaps zinc oxide.ii. This grey deposit was formed due to the reaction of zinc with oxygen.iii. No reaction took place in test-tube
because the conditions harder facilitate a chemical reaction. Q7.a. Carbon dioxide is released into the atmosphere by human and industrial activity primarily through the combustion of fossil fuels and deforestation.
Explanation
(i) The question describes a scenario in which a zinc strip in test-fube B is slowly covered with a gray deposit. This phenomenon typically occurs when there happens a chemical reaction. The grey deposit appears to be a byproduct of such reaction. In the context given, it is likely zinc oxide (ZnO).(ii) This grey deposit “zinc oxide" forms when zinc metal reacts with oxygen in the environment.(iii) For test tube A, without any further information, we can regard that the condition of the test-tube is not conducive to any reactions between zinc strip and components present in or absent from tube A.Q7:(a) The question refers to an increase in atmospheric CO2 concentration, and requests for a description of how human and industrial activities contribute to it. This typically happens as a result of burning fossil fuels and deforestation.