Dry gas problem in junior high school chemistry exam

1, (20 1 1 Suzhou, Jiangsu, 12) The common methods for preparing carbon dioxide gas in the laboratory are as follows

A. Calcining limestone B. Igniting charcoal

C. limestone reacts with dilute hydrochloric acid to decompose carbonic acid.

2.(20 1 1 Suzhou, Jiangsu, question 22) The following gas generating device about "solid-liquid reaction without heating" is reasonable.

Asian Development Bank.

3. (Shandong Linyi 20 1 1 year, 8 questions) Using the device on the right, the following experiments can be carried out.

A. preparing and collecting hydrogen from zinc and dilute sulfuric acid

B. prepare and collect oxygen with KClO3 and MnO2.

C, preparing and collecting oxygen with potassium permanganate.

D, preparing and collecting oxygen with hydrogen peroxide solution and manganese dioxide.

4, (20 1 1 year, Wuhan, Hubei, 6 questions) The following gas preparation device or experimental operation is wrong ().

A. a generator for generating oxygen B. collecting oxygen

C, check whether carbon dioxide is completely collected; D, verify that the carbon dioxide aqueous solution is acidic.

Fill in the blanks and answer the short questions.

1, (20 1 1 Quzhou, Zhejiang, question 23) is shown as the experimental device diagram of the reaction between hydrogen and copper oxide. Please analyze and answer:

(1) At the beginning of the experiment, the reasonable operation sequence is (choose "A" or "B");

A. heat first, and then introduce hydrogen. B, introducing hydrogen first, and then heating.

(2) The phenomenon seen in the experiment is that the black copper oxide turns into a red substance, and water drops appear at the mouth of the test tube, indicating that hydrogen is sexual.

(1)B(2) reduction

2.(20 1 1 Meishan, Sichuan, 20 questions) After one year of chemistry study, you have mastered some laws of gas production in the laboratory. The following are some experimental devices provided by the teacher. Please use the following pictures to answer the questions:

(1) Write the chemical equation for preparing carbon dioxide in the laboratory.

(2) Select the combination of devices for preparing and collecting oxygen (fill in the letter number).

(3) As we all know, ammonia is a gas with lower density than air and is easily soluble in water. Invert the cylinder filled with ammonia into the water dripping with colorless phenolphthalein, and the observed phenomenon is as follows.

(4) heating the solid mixture of ammonium chloride and sodium hydroxide to generate ammonia gas, and the selected reaction generating device is.

(1) CaCO3+2hcl = CaCl2+CO2 =+H2O (2) BC (or BD…)(3) The liquid turns red and the liquid level in the container rises (4) a.

3.(20 1 1, Longyan, Fujian, 16) An interest group used the following equipment to study the laboratory preparation methods and related properties of O2 and CO2.

(1) Write the names of the following numbered instruments: ① ②.

(2) A student reacted with dilute hydrochloric acid and marble in device B, and purple litmus test solution was observed in a beaker.

(Filling phenomenon)

(3) If student B wants to prepare O2 from KMnO4 solid, he should choose the one in the above figure (fill in the number). The chemical equation of the reaction is: A student also tested the collected gas, please write down the operation and phenomenon.

(1)① beaker ② conical flask (2) turns red (3)A2KMnO4 K2MnO4+MnO2+O2↑ Put the wooden strips with Mars into a gas container and observe the re-ignition of the wooden strips.

4.(20 1 1 Jiangxi, question 25) The following picture shows the common equipment in the laboratory. Please answer according to the picture:

(1) Write the name of the instrument ①. Only one device can be used to collect a certain gas, so it can be inferred that the nature of this gas is

(2) The combination of devices for making oxygen with potassium permanganate is (fill in the serial number), and the chemical equation of the reaction is:

(3) CO2 gas produced in the laboratory often contains HCl and water vapor. In order to prepare pure and dry CO2 gas, the connecting sequence of the ducts of the impurity removal device according to the airflow direction is (fill in the serial number).

A.abcdB.bacdC.cdabD.dcba

(1) Long-necked funnel is soluble in water and its density is lower than that of air (2)BC (or BD)2KMnO4 heating K2mno4+MnO2+O2 = 3 C.

5. (Taizhou, Jiangsu, 20 1 1 Question 24) Fill in the relevant blanks according to the following device drawing:

A B C D

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(1) The name of instrument ① in equipment A is▲; The name of instrument ② in equipment D is▲.

(2) The above-mentioned ▲ or ▲ (fill in serial number) device can be selected as the generator of hydrogen production from dilute sulfuric acid and zinc particles; Hydrogen can be collected by ▲ or ▲ (insert serial number) devices.

(3) The experimental steps of removing insoluble impurities in the raw salt are ▲ filtration and evaporation crystallization, and the evaporation device used is ▲. (Fill in the serial number), and you must also use ▲ (fill in the serial number) in the following glass instrument combination to complete the experiment.

① Funnel, beaker, glass rod ② dropper, measuring cylinder, test tube ③ container, watch mirror and jar.

(4) To prepare 5% sodium chloride solution with sodium chloride solid and water, you need to use ▲ (fill in the serial number) in the device shown in the above figure.

If 5g of sodium chloride and 95mL of water are added into a beaker with a small amount of water during the preparation process, and other operations are standardized, the mass fraction of sodium chloride in the obtained solution is ▲ (fill in ">" or ".

(1) alcohol lamp separating funnel

(2)C D； G H

(3) dissolve B 1

(4) me