High School 2 Chemistry Question 22?

The key to the correct solution of this problem is not to understand the reaction of this organic matter as complete combustion. How can this be decided? This should start with the question and give conditions.

There are three unknowns (cxhyoz) in this question, but four data are given, which can be judged based on the "over-given" data. From the condition given by the question, it can be seen that the products contain H2O(g), and their average molecular weight = 1 3 44 + 2 3 18≠27. This indicates that the gaseous product contains other gases in addition to CO2 and H2O(g), and it is clear that the amount contained in them can be obtained from the average molecular weight.

If the above correct judgment is made, it is easier to find the molecular formula.

Answer] Let the amount of the substance that produces CO2 after the combustion of the organic matter be n(CO2) and the amount of the substance that produces water is n(H2O), then:

n(co2)=10/100=

n(h2o)=( =

Since 1 3 44 + 2 3 18≠27, the product also contains co, and the amount of the substance is x, then there is:

8+28x)/( =27

Solution: x=

From this, it can be seen that organic matter contains:

n(c)=n(co2)+n(co)=

n(h)=2n(h2o)=

n(o)=2n(co2)+n(co)+n(h2o)-2n(o2)2×

So the molecular formula of this organic substance is C4H8O2

There is nothing wrong with your narrative.

D's narrative is correct, it's just incomplete. But the narrative of D in itself is correct.

The full narrative should be,The solution solute at point B is sodium acetate and sodium hydroxide or sodium acetate

The solution indicated by point B can be sodium acetate or a mixture of sodium acetate and sodium hydroxide. As long as the solution is alkaline, it is fine.

So,The solution solutes at point B are sodium acetate and sodium hydroxideThat's right.

The solution solute at point B is sodium acetateThat's right.

Point B is alkaline. The point corresponding to m is exactly neutralized, and m is less than 20. The point before the curve turns and straightens is m=20, and the pH rises in a straight line at point B, at this time, NaOH is excessive, and the solutes are sodium hydroxide and sodium acetate.

At point B, NaOH is already in excess (M20), at which point the solutes are sodium acetate and sodium hydroxide.

Ammonium bicarbonate decomposition: NH4HCO3(S) = NH3 (G) +CO2 (G) +H2O (G).

Carbon dioxide and water vapor are absorbed when the gas mixture passes through sodium peroxide, oxygen is generated at the same time, ammonia is absorbed when it passes through concentrated hydrochloric acid, and water spring paikai vapor is absorbed when it passes through concentrated sulfuric acid. In the end, you get pure, dry and dry oxygen.

and 31For 2, the oxygen collection needs to be used to exhaust the air downward, 4. The water on the outer wall must be wiped dry otherwise it may cause the test tube to burst, 5. Hydrochloric acid cannot be used because of the formation of slightly soluble calcium chloride to wrap the marble to prevent the reaction, 6. Rubber stoppers should be used but glass plugs.

2.Benzene is less dense than water, so it is not feasible to float on water, sodium carbonate and sulfuric acid reaction is not possible, zinc and copper sulfate will have a displacement reaction, the same is not possible, the introduction of nitrate to generate nitric acid, then in the reaction with zinc, the formation is not hydrogen, but nitrogen dioxide or nitric oxide.

A false, nitrogen-containing phosphorus compounds can be used as fertilizers to eutrophicate water bodies.

B False Green food is planted in a pollution-free ecological environment and the whole process of standardized production or processing of agricultural products, strictly control the content of toxic and harmful substances, so that it meets the national health and safety food standards, and by the special agencies to identify, licensed to use the green food logo of food. There are chemicals.

Error is the absorption of N2 through the root and not the foliage.

d correct.

c Who contains a large amount of monophosphorus compounds will cause eutrophication of water bodies.

There must be chemicals in the business, such as proteins...

Silica is the predominant component in optical fibers.

cBiological nitrogen fixation refers to the process by which nitrogen-fixing microorganisms reduce nitrogen in the atmosphere into ammonia.