How to identify the experiment of copper oxide and toner

The easiest way to tell them apart is:

1.Put them into the water separately, sink copper oxide powder, and float on the surface of the water is carbon powder;

2.Take a small amount and burn it on the fire, what can burn is toner, and what does not change is copper oxide powder.

If other methods require complex operations or need more difficult reagents to distinguish, it should not be regarded as the easiest method, I wonder if the landlord agrees with me?

Good luck with your studies!

Method 1: Sampling and adding dilute hydrochloric acid 1, if the black powder disappears completely, and the solution changes from colorless to blue, the black powder is copper oxide; 2. If there is no obvious change in the solution, the black powder is toner; 3. If the black powder partially disappears and the solution changes from colorless to blue, the black powder is copper oxide and carbon powder;

Method 2: Heat with hydrogen or carbon monoxide and powder together, observe the color of the black powder, if it turns reddish-brown, it is copper oxide, and unchanged is carbon.

Dilute hydrochloric acid was added to the sample.

1.If the black powder disappears completely, and the solution changes from colorless to blue, then this black powder is copper oxide 2If there is no significant change, the black powder is toner.

3.If the black powder partially disappears and the solution changes from colorless to blue, the black powder is copper oxide and toner.

1.Heat it with hydrogen or with carbon monoxide and powder to observe the color of the black powder. If it turns reddish-brown, it is copper oxide, and if it does not change, it is carbon.

2.Add acids, such as HCl, H2SO4

Chemical Equation:

2HCl + CuO = CuCl2 + H2OCuO+H2SO4===CuSO4+H2O, whereas carbon does not react with acid.

Method 1: Sampling and adding dilute hydrochloric acid 1, if the black powder disappears completely, and the solution changes from colorless to blue, then the black powder is copper oxide; 2. If there is no obvious change in the solution, the black powder is toner; 3. If the black powder partially disappears and the solution changes from colorless to blue, the black powder is oxygen and copper and carbon powder;

Method 2: Heat with hydrogen or carbon monoxide and powder together, observe the color of the black powder, if it turns reddish-brown, it is copper oxide, and if it does not change, it is shed carbon.

The answer should be C, not DBecause copper oxide reacts with hydrochloric acid to become a blue solution, carbon does not react with hydrochloric acid and does not change.

cuo+2hcl=cucl2+h2o

D Error, copper oxide and charcoal powder do not react with copper sulfate, and a error cannot be identified because charcoal powder and copper oxide are both black.

b False, because neither charcoal powder nor copper oxide are soluble in water.

Answer: Ccuo+2HCl=CuCl2+H2O CUO reacts to dissolve, while charcoal powder does not.

a.The colors are all black.

b. It is not soluble in water.

Neither D nor cuso4 reacts.

1.Take a small amount of samples and put them in the test tube, and add dilute sulfuric acid dropwise. If the phenomenon is that the solid is completely dissolved and the solution changes from colorless to blue, it is copper oxide. If there is no significant change in the amount of solids, the conclusion is toner.

2.When burned in the air, it will burn charcoal powder, copper oxide does not burn.

3.A small amount of samples were taken and placed in a test tube, and hydrogen was introduced and heated. If the phenomenon is that the solid turns red, it is copper oxide. If there is no significant change in the color of the solid, it is toner.

A relatively simple method to check whether copper powder contains carbon powder is thermal analysis, and the specific operation steps are as follows:

1.A small amount of copper powder sample was removed, a small amount of pickling was added, and 2-3 drops of dilute hydrochloric acid were added and then washed with distilled water.

2.Place the cleaned sample in a thermal balancer and heat the sample to about 1000. If a change in the color of the sample is observed, such as brown or gray, during the heating process, the sample may contain toner.

3.If the sample turns white or silver during heating, the sample may not contain toner.

4.X-ray fluorescence spectroscopy, scanning electron microscopy analysis and other methods can also be used to detect the elemental components in copper powder, and further obtain the status of carbon content.

It should be noted that the above methods are only common methods for testing samples, and the specific results need to be comprehensively judged according to factors such as the operation and conditions of the experiment. When performing experimental operations, it is necessary to strictly control the experimental conditions and handle the experimental results correctly.

Method 1: Burning.

A small amount of copper powder is placed on a porcelain plate and heated with an alcohol or kerosene lamp. If the surface of the copper powder turns black after heating, it means that the copper powder contains carbon powder.

Method 2: Hydrolysis.

Put the mountain bench macro copper powder into nitric acid to heat and dissolve, and then add a sufficient amount of sodium hydroxide solution to produce copper hydroxide precipitation, filter it with filter paper and wash it, and burn the precipitate to red, if there is a black or dark gray precipitate, the coarse macro means that the copper powder contains carbon powder.

Method 3: Nitrogen blowing method.

The copper powder is added to the nitrogen blower, dried with nitrogen, and then the carbon content in the remaining sample is detected by the method of determining the copper powder content, and if the test results show that the copper powder contains carbon powder, it can be determined that the copper powder contains carbon powder.

The FeCl3 solution does not distinguish between copper oxide and nuclear cover carbon powder.

Caustic soda solution cannot distinguish between iron powder and carbon powder.

Concentrated hydrochloric acid reacts with copper oxide to form a blue solution.

Reaction with iron powder has gas production and base change.

It does not react with toner.

It reacts with manganese dioxide and frontal land heat to form chlorine gas.

1.Take a small amount of sample, add dilute sulfuric acid to dissolve the blue copper oxide.

cuo+h2so4===cuso4+h2o2.Heating, reducing is toner, will not be less than the judgment of the ox carrying rush sensitized manganese.

c+O2==ignition===CO2

The gas produced is passed into sufficient amount of clarified lime water, and the precipitation can be obtained by isolating the mixture of carbon powder, copper oxide and calcium carbonate from the air to strengthen the mass of carbon dioxide generated by heat is, assuming that carbon dioxide is all carbon powder and copper oxide reaction to obtain Huaiwu, the mass of copper oxide is 2 times that of carbon powder, for, so the mass of copper oxide at this time is 80, and the carbon dioxide actually generated by Laming infiltration is also obtained by calcium carbonate decomposition, so the amount of carbon dioxide that should be generated by carbon powder and copper oxide reverse wheel ridge is less than, The mass of copper oxide in the mixture is less, so a is selected

There may be a certain amount of water left in carbon or copper oxide, and when heated, the condensate formed will flow backwards and burst the test tube, and the mouth of the test tube should be tilted downward; It is necessary to control the mixing ratio of copper oxide and carbon so that the two are exactly completely reacted, otherwise the test effect of the products produced after the reaction will be affected; The outer flame temperature of the alcohol lamp is the highest, so it is necessary to preheat the test tube when heating it, and other precautions for using the alcohol lamp for heating

Therefore, the answer is: the nozzle should be slightly inclined downward; control the mass ratio of toner and copper oxide; Toner and copper oxide should be mixed evenly; Pay attention to the correct heating method, etc