Among the following common substances, oxides are A NaClB Al2O3C CH4D KMnO

First of all, you should choose A for this question. It should be noted that your answer d is not written incorrectly, it should be kmno4.

This question should be a question in the third year of junior high school or the first year of high school, but in fact, this question is not difficult. As long as you go back and turn down the chemistry book to see the concept of oxides, it should be quite easy to do, rather than looking for the answer on the Internet for the first time! Since you don't want to turn the book, then I'll tell you about it here.

Definition of oxide: Oxide refers to a binary compound composed of oxygen and another chemical element, such as carbon dioxide (CO), calcium oxide (CAO), etc.

Mechanism characteristics of oxides: Oxides belong to chemical compounds. It contains only two elements, one of which must be oxygen, and if the other is a metal element, it is called a metal oxide; If the other element is not a metallic element, it is called a non-metallic oxide.

After reading the definition and characteristics of oxides, it should be clear how to do this question. Answer a is sodium chloride, which has no oxygen and can be excluded; Answer B is aluminium oxide, which is a binary compound containing the element oxygen, so answer B is correct; Answer c is methane, which has no oxygen and can be ruled out; The answer d is potassium permanganate, an aerobic element, but it is made of three elements, which does not conform to the concept of binary compounds, so it is excluded. In the end, the answer is only A.

a. Sodium chloride is a compound composed of sodium and chlorine, but there is no oxygen in it, and it does not belong to oxides, so it is wrong;

b. Alumina is a compound composed of oxygen and aluminum, which belongs to oxide, so it is correct;

c. Methane is a compound composed of carbon and hydrogen, but there is no oxygen in it, and it does not belong to oxides, so it is wrong;

d. Potassium permanganate is a compound composed of potassium, manganese and oxygen, because there are three elements, so it does not belong to oxides, so it is wrong

Therefore, b

a、kmno4

If it is composed of three elements, K, Mn, and O, it does not belong to oxides, so a is wrong;

B, NO2 is composed of two elements, N and O, and contains.

Oxygen. then it belongs to oxides, so b is correct;

c、c6h12o6

It is composed of three elements, C, H and O, and does not belong to oxides, so C is wrong;

d、fecl2

It is composed of Fe and Cl, but does not contain oxygen, so it does not belong to oxides, so D is wrong;

Therefore, b

a. Cao is a substance containing two elements, Ca and O, and aerobic elements, which belongs to oxides, so it is correct;

b. Oxygen is a substance composed only of oxygen elements, which is elemental, so it is wrong;

c. KMNO4 contains three elements, which are compounds, but not oxides, so it is wrong;

d. Sulfuric acid contains three elements: S, H and O, which are compounds, but not oxides, so they are wrong;

So choose A

Oxide refers to a compound composed of two elements and one of the elements is oxygen a, ferric tetroxide is a compound composed of iron and oxygen, which belongs to oxide Therefore, it is correct;

b. Oxygen is a pure substance composed of oxygen elements, which belongs to elemental substances and does not belong to oxides, so it is wrong;

c. Potassium permanganate contains potassium, manganese and oxygen, which are not oxides, so they are wrong;

d. Alcohol contains carbon, hydrogen and oxygen, which are not oxides

a. Sodium chloride is a compound composed of sodium and chlorine, but there is no oxygen in it, and it does not belong to oxides, so it is wrong;

b. Alumina is a compound composed of oxygen and aluminum, which belongs to oxide, so it is correct;

c. Methane is a compound composed of carbon and hydrogen, but there is no oxygen in it, and it does not belong to oxides, so it is wrong;

d. Copper hydroxide is a compound composed of copper, hydrogen and oxygen, because there are three elements, so it does not belong to oxides, so it is wrong

Therefore, b

a. KMNO4 contains three elements, which are compounds, but not oxides, so it is wrong;

b. H2O is a substance containing two elements, H and O, and aerobic elements, which belongs to oxides, so it is correct;

c. NaCl is a compound formed by metal sodium ions and chloride ions, which belongs to salts and does not belong to oxides, so it is wrong;

D, O2 is a substance composed of only oxygen, then it belongs to the element, so it is wrong to choose B

a. Sodium chloride is a compound composed of sodium and chlorine, but there is no oxygen in it, and it does not belong to oxides, so it is wrong;

b. Alumina is a compound composed of oxygen and aluminum, which belongs to oxide, so it is correct;

c. Methane is a compound composed of carbon and hydrogen, but there is no oxygen in it, and it does not belong to oxides, so it is wrong;

D, Fe3O4, SO2, and H2O are all compounds composed of two elements, and one element is oxygen

Therefore, bfe3o4．

a、kmno4

It contains potassium, manganese, and oxygen, so error B, NO2 refers to a compound composed of two elements, nitrogen and oxygen, and one of them is oxygen, so it is correct

c、c6h12

O6 contains three elements: carbon, hydrogen, and oxygen, so there is no oxygen element in the error, so error D, FeCl3

It does not contain oxygen, so it is wrong

Therefore, b