Practice.
1 The following substances are pure ( ).
a river water b air c oil d nitrogen.
2 In June 2021, China successfully launched the ** "Fengyun-4" satellite, and one of the rocket fuels used for launch is liquid hydrogen (H2), which belongs to ( ).
A elemental B oxide C mixture d organics.
3 The following substances are oxides ( ).
a．h2o b．o2 c．na2so4 d．h2co3
4 The following classifications are correct ( ).
a Amorphous: ice, rosin, bitumen b Insulators: rubber, glass, graphite.
c Noble gases: helium, neon, argon d Pure substances: liquid oxygen, diamond, mineral water.
5 Classification is an important learning method, and the following substances are not acids, bases, and salts ( ).
a．so2 b．na2co3 c．h2so4 d．ba(oh)2
6 The following substances are listed in the order of mixture, alkali and oxide ( ).
a Ice-water mixture, caustic soda, manganese dioxide b Liquefied petroleum gas, hydrated lime, sulphur dioxide.
c Salt water, soda ash, dry ice d Natural gas, potassium hydroxide, marble.
7 Distinguishing substances is a basic requirement for learning chemistry. The following substances are oxides ( ).
a vinegar b ice c earth d silver.
8 The following substances are pure ( ).
a Air B Milk C 84 disinfectant D Distilled water.
9 Among the following substances that are compounds, they are ( ).
a sulphuric acid solution b ice c mercury d oxygen.
10 The classification of substances is an important way to learn chemistry. The following substances are elemental ( ).
a mercury b clean air c carbon dioxide d hydrochloric acid.
11 The common names, chemical formulas, and classifications of the following substances are exactly correct ( ).
A Soda ash, NaHCO3, salt B caustic soda, Naoh, alkali.
C Quicklime, Ca(OH)2, oxide d Mercury, AG, elemental.
12 Reasoning is a common method of learning chemistry, and the following reasoning is correct ( ).
a If the anion is negatively charged, then the negatively charged particle must be the anion.
b If a single element contains only one element, then a substance containing only one element must be elemental.
c The type of element is determined by the number of protons, so an atom with the same number of protons must belong to the same element.
d Carbonate reacts with hydrochloric acid and has gas formation, so the substance that reacts with hydrochloric acid to produce gas must be carbonate.
13 The rock formation of the Danxia landform in Langshan Mountain, Xinning, is red because of the presence of Fe2O3. From the perspective of compositional classification, Fe2O3 belongs to ( ).
a Elemental. b Oxide.
c Alkali. d Salt.
14 Classification is a commonly used method in chemical research. The correct classification of the following substances is ( ).
a Alkali: caustic soda, soda ash, potassium hydroxide.
b Oxides: phosphorus pentoxide, alumina, hydrogen peroxide.
c Mixture: air, petroleum, sodium nitrite.
d Trace elements in the human body: calcium, iron, selenium, iodine.
15 Most of the substances in nature are chemical compounds. The following compounds are acids ( ).
a．kcl b．naoh c．cuo d．hno3
16 When an archaeological team excavated a painting covered with volcanic ash, it used a laser to break up the tiny limestone attached to its surface, and this process released calcium ions, which combined with the fluoride ions around the volcanic ash to form calcium fluoride (CaF2). Calcium fluoride belongs to ( ) in the classification of substances
A acid B base C salt D oxide.
17 Chemical energy guides us to better understand, modify, and apply substances. The following substances are pure ( ).
a fruit juice b medical alcohol.
c Cement mortar d Ice-water mixture.
18 The following substances are mixtures ( ).
A hard water b kmno4 c football ene (c60) d fe2o3
19 Classification of substances is a common method of learning chemistry. The correct classification of the following substances is ( ).
a Elemental: hydrogen, air b Acid: nitric acid, citric acid.
c Alkali: ammonia, ammonium sulfate d Organics: glucose, ammonium bicarbonate.
20 Classification is a way to learn chemistry, and the following substances are pure ( ).
a sugar water b air c brass d dry ice.
21 Classification is one of the common ways of thinking in chemistry. In the material classification relationship shown in the figure below, there is a juxtaposition relationship with , which is included in . If it is pure, it cannot be.
a air b potassium nitrate c helium d nitrogen dioxide.
22 In the following diagrams, " " " represents the atoms of two different elements, where the mixture is denoted .
23 The following statement of the interrelationship between concepts is correct.
a Sugars and starches are juxtaposed.
b Saturated solution and concentrated solution belong to the inclusion relationship.
c Oxygenates and oxides belong to the inclusion relationship.
d The neutralization reaction and the metathesis reaction belong to the cross-relationship.
Answer] D Analysis] A. River water is a mixture of water, soluble substances and other substances, which does not meet the topic;
b. Air is a mixture of oxygen, nitrogen and other substances, which does not meet the topic;
c. A mixture of petroleum and petroleum substances, which does not conform to the topic;
d. Nitrogen is a pure substance composed of nitrogen, which is in line with the topic; Answer: d.
Answer] A Analysis] Liquid hydrogen is liquid hydrogen, which belongs to a pure substance composed of elements and belongs to elemental substances, so it is selected: A.
Answer] A Analysis] A. Water is a compound composed of two elements, hydrogen and oxygen, which is an oxide, which is correct;
b. Oxygen is a pure substance composed of an element, which belongs to elemental matter, not oxide, wrong;
c. Sodium sulfate contains three elements: sodium, sulfur and oxygen, which is wrong;
d. Carbonic acid contains three elements: hydrogen, carbon, and oxygen, which is wrong. So choose A.
Answer] C Analysis] A. Ice belongs to crystals, rosin and asphalt belong to amorphous, which does not meet the meaning of the topic;
b. Rubber and glass belong to insulators, and graphite has conductivity and belongs to conductors, which does not conform to the topic;
c. Helium, neon and argon are rare gases, which are in line with the topic;
d. Liquid oxygen is liquid oxygen, which is composed of the same substance and belongs to pure substances; Diamond is composed of the same substance and belongs to pure substances, while mineral water is made of a mixture of water and minerals, which is a mixture, which does not meet the topic. Therefore, C.
Answer] A analysis] Acid is a compound with ionized cations and all hydrogen ions, alkali is a compound with ionized anions and all hydroxides, and salts are compounds composed of acid ions and metal ions or ammonium ions;
According to the analysis, SO2 does not belong to acid, alkali and salt, Na2CO3 is salt, H2SO4 is acid, and Ba(OH)2 is base; Therefore, choose A;
Answer] B Analysis] A. Ice water mixture, which is pure, A is wrong.
b. Liquefied petroleum gas contains a variety of substances and belongs to the mixture, hydrated lime is calcium hydroxide is alkali, manganese dioxide is composed of two elements and contains oxygen elements, belongs to oxide, B is correct.
c. Soda ash is sodium carbonate, which belongs to salt, and c is wrong.
d. The main component of marble is calcium carbonate, and marble belongs to the mixture, D is wrong. Therefore, b.
Answer] B Analysis
Oxide refers to a substance that contains two elements, one of which is a compound of oxygen;
Analysis] The main component of vinegar is acetic acid, which is an organic compound; Ice is solid water and belongs to oxides; Soil is a mixture of many substances; Silver is an elemental metal; Therefore, choose B.
Answer] D Analysis] Pure substance refers to a substance composed of only one substance, and a mixture refers to a substance formed by mixing two or more substances;
Analysis] According to the analysis, air, milk, and 84 disinfectant are all substances mixed with a variety of substances, which belong to the mixture; Distilled water, on the other hand, contains only one substance, water, which is pure; Therefore, D is chosen.
Answer] B Analysis] A. The sulfuric acid solution is a mixture, which does not meet the topic;
b. Ice is solid water, and water is a pure substance composed of hydrogen and oxygen, which is a chemical compound, which is in line with the topic;
c. Mercury is the common name of mercury, which is a pure substance composed of mercury elements, which is elemental and does not conform to the topic;
d. Oxygen is a pure substance composed of oxygen elements, which is elemental and does not conform to the topic. Therefore, b.
Answer] A Analysis] A. Mercury is the common name of mercury, which is a pure substance composed of mercury elements, which is elemental and in line with the topic;
b. Clean air is a mixture of nitrogen, oxygen, etc., which is a mixture and does not conform to the topic;
c. Carbon dioxide is a pure substance composed of C and O elements, which is a compound and does not conform to the topic;
d. Hydrochloric acid is mixed with water, which is a mixture and does not conform to the topic. So choose A.
Answer] B Analysis].
a. Soda ash is the common name of sodium carbonate, in which the valency of sodium element is +1, the carbonate ion is -2 valence, and the chemical formula is Na2CO3, which belongs to salt, the chemical formula is wrong, and a is wrong;
B. Caustic soda is the common name of sodium hydroxide, the chemical formula is NaOH, which belongs to alkali, and B is correct;
c. Quicklime is the common name of calcium oxide, the chemical formula is CAO, which belongs to oxide, the chemical formula is wrong, C is wrong;
D. Mercury is the common name of mercury metal, the chemical formula is Hg, which belongs to the metal element, the chemical formula is wrong, and D is wrong. Therefore, b.
Answer: C Analysis
a. Anions are negatively charged, but negatively charged particles are not necessarily anions, but may also be electrons, etc., so the option reasoning is wrong;
b. Elemental matter is a pure substance composed of the same element, and there is only one element in the element, but the substance containing one element must be elemental, or it may be a mixture, such as a mixture of oxygen and ozone, a mixture of diamond and graphite, etc., so the choice reasoning is wrong;
c. According to the general term that an element is a class of atoms with the same number of protons (i.e., the number of nuclear charges), and the type of element is determined by the number of protons, then the atoms with the same number of protons must belong to the same kind of element, so the reasoning of the option is correct;
d. Carbonate and hydrochloric acid react with gas generation, and the substance that reacts with hydrochloric acid to produce gas is not necessarily carbonate, but may also be active metal, etc., so the choice reasoning is wrong. Therefore, C.
Answer] B Analysis].
a. A pure substance composed of the same element is called elemental, and iron oxide is not elemental;
b. A pure substance composed of two elements, one element is oxygen called oxide, and iron oxide belongs to oxide;
c. The compound in which all the anions dissociated in the aqueous solution are hydroxide ions is called a base, and iron oxide is not a base;
d. Compounds composed of metal cations or ammonium ions and acid ions are called salts, and iron oxide does not belong to salts; Therefore, b.
Answer] B Analysis].
a. Caustic soda is the common name of sodium hydroxide, sodium hydroxide and potassium hydroxide are all compounds of hydroxide ions produced during ionization, which belong to alkali, and soda ash is the common name of sodium carbonate, which is a compound composed of sodium ions and carbonate ions, which belongs to salt and does not conform to the topic;
b. Phosphorus pentoxide is a compound composed of two elements, P and O, which belongs to oxides; Alumina is a compound composed of two elements, Al and O, which belongs to oxide, and hydrogen peroxide is a compound composed of elements H and O, which belongs to oxide, which is in line with the topic;
c. Air is a mixture of nitrogen, oxygen, etc., which belongs to the mixture; Petroleum is a mixture of gasoline, diesel, etc., and belongs to the mixture; Sodium nitrite is composed of the same substance, which is pure and does not conform to the topic;
d. Calcium is a macro element, and iron, iodine, and selenium are trace elements, which does not meet the topic. Therefore, b.
Answer] D Analysis].
Acid: The cation produced during ionization is all H+, and the compound is acid.
Alkali: The anions produced during ionization are all oh- compounds that are bases.
In chemistry, salts refer to a class of compounds in which metal ions or ammonium ions are combined with acid ions.
Analysis] a, according to the definition of potassium chloride is salt, which does not meet the topic;
b. According to the definition, NAOH is an alkali, which does not conform to the topic;
c. Cuo is a metal oxide, which does not meet the topic;
d. According to the definition, Hno3 is an acid, which is in line with the topic; Therefore, choose D.
Answer: C Analysis
CaF2 is a compound composed of metal cations (calcium ions) and acid anions (fluoride ions), which belong to the salt group. Therefore, C.
Answer] D Analysis].
a. The juice contains water and some nutrients, which belongs to the mixture, and A is wrong.
b. Medical alcohol contains alcohol and water, which is a mixture, and B is wrong.
c. Cement mortar contains a variety of substances such as cement sand, which belongs to the mixture, and c is wrong.
d. The ice-water mixture only contains one substance, water, which is a pure substance, and D is correct. Therefore, choose D.
Answer] A Analysis].
a. Hard water contains soluble calcium and magnesium minerals, which belong to the mixture, and a is correct.
b. KMNO4 is composed of a substance, which is pure, and B is wrong.
C. Soccer olefin (C60) is composed of a substance, which is pure, and C is wrong.
D, Fe2O3 is composed of a substance, belongs to the pure substance, D is wrong. So choose A.
Answer] B Analysis].
a. Elemental matter is a pure substance composed of the same element, and the air contains a variety of substances, which belongs to a mixture, so A is wrong;
b. Acid refers to a compound in which the cations produced when ionized in an aqueous solution are all hydrogen ions, nitric acid and citric acid are all acids, so B is correct;
c. Alkali refers to the compound that the anions produced when ionized in aqueous solution are hydroxide ions, and ammonium sulfate belongs to salt, not alkali, so C is wrong;
d. Organic matter is a general term for carbon-containing compounds (except carbon monoxide, carbon dioxide, carbonic acid, carbonate, bicarbonate, metal carbide, cyanide, thiocyanide, etc.) or hydrocarbons and their derivatives. Therefore, b.
Answer] D Analysis].
a. Sugar water is a mixture of sugar and water, which is a mixture and does not conform to the topic;
b. The air is a mixture of nitrogen, oxygen, etc., which is a mixture and does not conform to the topic;
c. Brass is made of copper, zinc, etc., which is a mixture and does not conform to the topic;
d. Dry ice is solid carbon dioxide, which is composed of the same substance, which is a pure substance, which is in line with the topic.
Therefore, choose D. 