中国大学Inorganic chemistry experiment课后答案(mooc2023课后作业答案)

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Chapter 2. Purification of Sodium Chloride

Quiz-Chapter 2. Purification of Sodium Chloride

1、中国作业In the experiment of purification of sodium chloride,大学答案答案 in which step can potassium ion be removed？
A、Dissolution and filtration
B、课后课后Adding barium chloride solution
C、中国作业Adding sodium carbonate solution
D、大学答案答案Evaporation and crystallization

2、课后课后In the experiment of purification of sodium chloride,中国作业 the filtrate is transferred to an evaporating dish and evaporated until the solution is in what state?
A、Boiling starts
B、大学答案答案Crystal film appears
C、课后课后Be a thin paste
D、中国作业Evaporate to dryness

3、大学答案答案What color is 课后课后the precipitate produced in the identification reaction of magnesium ion?
A、Blue
B、中国作业Green
C、大学答案答案Brown
D、课后课后Pink

4、In what medium should the identification of calcium ion be carried out？
A、Hydrochloric acid
B、Sodium hydroxide
C、Acetic acid
D、Deionized water

5、In which medium should the identification of magnesium ion be carried out?
A、Alkaline
B、Acidic
C、Neutral
D、All above

6、In the experiment of purification of sodium chloride, the filtrate was evaporated, concentrated and evaporated to dryness, and then the purified sodium chloride was obtained.

7、When using the tray balance to weigh the reagents, the objects should be placed on the left and the weights should be placed on the right.

8、In the experiment of purification of sodium chloride, 2 mol/L hydrochloric acid was used to adjust the pH of the solution to 6-7 before evaporation.

9、In the experiment of purification of sodium chloride, when barium chloride is added into the solution, white precipitate is formed, which indicates the existence of sulfate ion in the solution.

10、In the experiment of purification of sodium chloride, sulfate ions can be removed by non-toxic calcium chloride solution instead of barium chloride solution.

Chapter 3. Purification of Copper Sulfate

Quiz-Chapter 3. Purification of Copper Sulfate

1、When adding 6 mol/L ammonia to copper sulfate solution, the green precipitate appears first, then the precipitate dissolves and turns into blue solution. What is the green precipitate?
A、Copper hydroxide
B、Copper dihydroxosulphate
C、Tetraammine copper (II) ion
D、Hexaammine copper (II) ion

2、In the experiment of purification of copper sulfate, what pH value should be adjusted before the filtrate is evaporated and concentrated?
A、7
B、1-2
C、4
D、14

3、In the experiment of purification of copper sulfate, in order to remove iron and not reduce the yield of the product, what should be the pH value of the solution?
A、7
B、1-2
C、4
D、14

4、In the experiment of purification of copper sulfate, what solution should be used to adjust the pH of the solution？
A、Sodium hydroxide
B、Potassium hydroxide
C、Copper hydroxide
D、Copper dihydroxosulphate

5、In the copper sulfate purification experiment, if the solution in the evaporating dish turns green during evaporation, what is the reason?
A、Copper ion hydrolyzes.
B、The temperature is too high.
C、The impurities are not removed completely.
D、The evaporation is too dry and the crystal water is lost.

6、In the experiment of purification of copper sulfate, the filtrate was evaporated, concentrated and evaporated to dryness to get the purified copper sulfate

7、In the experiment of purification of copper sulfate, the pH should be adjusted above 4 to remove iron ion.

8、Chemical reagents are usually divided into four grades according to the purity.

9、Crude copper sulfate usually contains soluble impurities such as ferrous sulfate and ferric sulfate, which can be removed by hydrolysis and filtration after adjusting pH.

10、In the experiment of purification of copper sulfate, except for ferrous ion and iron ion, other trace soluble impurities are removed by remaining in the mother liquor.

Chapter 4. Acid-Base Reaction and Buffer Solution

Quiz-Chapter 4. Acid-Base Reaction and Buffer Solution

1、What can be prepared as a buffer solution?
A、HCl and NaOH (excess)
B、HCl and NH3·H2O (excess)
C、HAc (excess) and HCl
D、NaOH and NH3·H2O (excess)

2、In general, what is the buffer solution?
A、Solution of weak acid and weak base salt
B、Solution of weak acid or weak base and its salt
C、Solution with constant pH value
D、Solution with constant ionization degree

3、What is the most important buffer pair in human plasma?
A、-
B、-
C、-
D、-

4、What is wrong with the following description of buffer solution?
A、When the temperature is constant, pKa and buffer ratio are the most important factors affecting the pH value of buffer solution.
B、After the buffer solution was diluted with water, the pH value and buffer capacity remained unchanged.
C、The effective buffer range of buffer solution is pKa±1.
D、hen the buffer ratio is constant, the larger the total concentration is, the larger the buffer capacity is.

5、What pH of the standard solutions should be used for calibration when measuring acid solution with acidity meter?
A、6.86 and 4.00
B、6.86 and 9.18
C、4.00 and 9.18
D、All above.

6、After diluting the buffer solution in a certain range, the pH and buffer capacity of the buffer solution remain unchanged because the ratio of [conjugated base] to [conjugated acid] remains unchanged.

7、The buffer solution can be prepared by adding a small amount of NaOH into a weak acid HB.

8、Acidity meter should be calibrated with standard solution before use.

9、Before each measurement, the electrode of the acidity meter should wash with deionized water.

10、After the measurement, the electrode of the acidity meter should be immersed in deionized water.

Chapter 5. Complexes and Precipitation-Dissolution Equilibrium

Quiz-Chapter 5. Complexes and Precipitation-Dissolution Equilibrium

1、In which of the following solutions, silver bromide precipitate is soluble?
A、Sulfuric acid
B、Silver nitrate
C、Sodium hydroxide
D、Sodium thiosulfate

2、There are four characteristics in the formation of complexes. Which of the following is wrong?
A、Color change of solution
B、Unchanged acidity and basicity
C、Solubility change of insoluble electrolyte
D、Redox change of central ion

3、What color of substance will be produced by adding a small amount of sodium thiosulfate solution to the excess silver nitrate solution?
A、White
B、Yellow
C、Black
D、Colorless

4、5 ml of deionized water was added into the lead iodide precipitation and the precipitation was dissolved. What is the reason?
A、J < KSP
B、Salt dissolution
C、Coordination dissolution
D、Common ion effect

5、Take a drop of sodium sulfide solution (0.1 mol/L) and a drop of lead nitrate solution (0.1 mol/L) into the test tube, shake the test tube, precipitate, and then add 6 mol/L nitric acid solution, shake the test tube, precipitate dissolves. What is the reason?
A、Salt effect
B、Common ion effect
C、Redox reaction
D、Coordination dissolution

6、Adding sodium chloride solution to the silver chromate precipitate, the precipitate turns white.

7、The common ion effect reduces the ionization equilibrium constant of weak electrolyte.

8、Salt effect reduces the solubility of insoluble electrolyte.

9、The silver iodide precipitation disappeared after adding a certain concentration of ammonia

10、For different types of insoluble electrolytes, it is necessary to calculate the concentration of reagent needed to judge the order of precipitation, and the one with higher concentration of reagent precipitates first.

Chapter 6. Oxidation-reduction Reactions

Quiz-Chapter 6. Oxidation-reduction Reactions

1、What is the effect of concentration on redox reaction rate?
A、The higher the concentration, the faster the reaction rate.
B、The higher the concentration, the slower the reaction rate.
C、The lower the concentration, the faster the reaction rate.
D、The concentration had no effect on the reaction rate.

2、In the /Cu half-cell of copper zinc primary cell, after adding excessive 2mol·L-1 ammonia to produce dark blue transparent solution, the electromotive force was measured. Compared with the standard electromotive force, which of the following conclusions are correct?
A、The electromotive force increases.
B、The electromotive force decreases.
C、The electromotive force does not change
D、It can not be determined.

3、What is the relationship between the redox capacity and the corresponding counter electrode potential?
A、The higher the electrode potential, the stronger the oxidizability of the oxidation form.
B、The lower the electrode potential, the stronger the oxidizability of the reduced form.
C、The lower the electrode potential, the stronger the oxidizability of the oxidation form.
D、The higher the electrode potential, the stronger the oxidizability of the reduced form.

4、There is no reaction when 3% hydrogen peroxide is added to 0.1 mol/L cobalt chloride solution, but the reaction occurs when 1 mol/L ammonium chloride is added, then 6 mol/L ammonia water is added, and then 3% hydrogen peroxide is added. Why?
A、When the complex is formed, the reducibility of the central atom is enhanced.
B、When ammonium chloride is added, the oxidation of hydrogen peroxide is enhanced.
C、When the complex is formed, the oxidation of the central atom is enhanced.
D、When ammonium chloride is added, the oxidation of hydrogen peroxide is weakened.

5、What is the role of hydrogen peroxide in potassium permanganate solution acidified by sulfuric acid?
A、Oxidizing sulfuric acid
B、Reducing sulfuric acid
C、Reducing potassium permanganate
D、Decomposing to produce oxygen and hydrogen

6、The electrode potential of saturated calomel electrode is equal to that of standard calomel electrode.

7、The electrode potential of saturated calomel electrode is 0.2415 V.

8、Hydrogen peroxide can be used as both oxidant and reductant. When the pH becomes lower, the reducibility of hydrogen peroxide increases.

9、The electrolyte in the salt bridge does not participate in the battery reaction.

10、After mixing 10 drops of potassium bromide solution (0.1mol/L) and 2 drops of ferric chloride solution (0.1mol/L) in the test tube, 20 drops of carbon tetrachloride were added and the layer of carbon tetrachloride changed from colorless to orange red.

Chapter 7. Properties of p-Block Elements

Quiz-Chapter 7. Properties of p-Block Elements

1、In acidic medium, ammonium molybdate reagent can be used to identify phosphate with the formation of the yellow precipitate.

2、AgNO3 solution acts as a catalyst in the oxidation test of persulfate.

3、Boric acid is a ternary acid.

4、The sodium bismuthate is khaki solid and soluble in water, and has strong oxidizing property.

5、In the experiment of the oxidizability of persulfate, the test tube can be heated directly on a gas lamp.

6、The reaction between Lewis acid and glycerin can produce hydrion.

7、The lead dichloride precipitate is insoluble in cold water but soluble in hot water.

Chapter 8. Preparation of d-Block Elements

Quiz-Chapter 8. Preparation of d-Block Elements

1、The diacetyldioxime reagent can be used to identify Ni2+ ions under alkaline conditions.

2、In the silver mirror experiment, it is better that the more ammonia water is added.

3、Zn2+ is identified by adding CCl4 solution containing diphenylthiazone to the solution, and the reaction phenomenon is that the pink chelate is formed in the CCl4

4、Ag2O cannot dissolve in 2 mol/L NH3·H2O.

5、CuI is brown yellow precipitate.

6、When NaOH solution is added to AgNO3 solution, the final precipitate is Ag2O.

7、The characteristics reaction of the identification of Cu2+ should be performed in a dilute acetic acid medium.

Chapter 9. Preparation of Zinc-Containing Drugs

Quiz-Chapter 9. Preparation of Zinc-Containing Drugs

1、ZnSO4 was prepared from industrial ZnO. Fe2 + impurity in ZnSO4 solution can be removed directly by hydrolysis.

2、After the filtrate of ZnSO4 was evaporated, concentrated and evaporated to dryness, the purified ZnSO4 · 7H2O was obtained.

3、ZnSO4 was prepared from industrial ZnO. The impurities of Cd2 + and Ni2 + in ZnSO4 solution could be removed by Zn powder replacement method.

4、It can be concluded that the basic zinc carbonate has been completely decomposed into zinc oxide after calcined until there is no bubble in sulfuric acid test.

5、The method of testing nickel ion is to add dimethylglyoxime solution into acid solution to see if bright red precipitate is formed.

6、When calcining basic zinc carbonate to prepare zinc oxide, the oxidation flame of gas lamp should be used for heating

Chapter 10. Preparation of Potassium Trioxalatoferrate (III)

Quiz-Chapter 10. Preparation of Potassium Trioxalatoferrate (III)

1、Ferrous oxalate reacts with saturated K2C2O4 solution to form potassium ferrioxalate (III) solution and ferric hydroxide precipitation.

2、Two drops of KSCN solution were added to the potassium ferrioxalate (III) solution, and the solution turned yellow.

Chapter 11. Preparation of Ferrous Citrate

Quiz-Chapter 11. Preparation of Ferrous Citrate

1、When synthesizing ferrous carbonate, the pH of the solution should be controlled at 5-6 to prevent the hydrolysis of ferrous ion.

2、In the experiment of preparing ferrous citrate, iron nails should be added in every step to prevent the oxidation of Fe2 +.

Chapter 12. Preparation of potassium nitrosodisulphonate

Quiz-Chapter 12. Preparation of potassium nitrosodisulphonate

1、Potassium nitrosodisulfonate is orange yellow or yellow brown crystal, and its aqueous solution is purple.

2、Sodium bisulfite solution for the preparation of potassium nitrosodisulfonate needs to be prepared immediately before use to avoid its oxidation by air.

3、The crystal of potassium nitrosodisulfonate decomposes slowly in neutral solution.

Chapter 13. Preparation of Zinc Gluconate

Quiz-Chapter 13. Preparation of Zinc Gluconate

1、Gluconic acid can be prepared by the reaction of calcium gluconate with concentrated sulfuric acid.

2、In order to precipitate zinc gluconate crystal as soon as possible, the filtrate should be heated and concentrated on a bunsen lamp to 1 / 3 of the original volume.

Chapter 14. Preparation of chromium (III) complexes and the determination of splitting energy

Quiz-Chapter 14. Preparation of chromium (III) complexes

1、The splitting energy of the complex can be obtained by measuring its absorption spectrum.

2、The spectrophotometer should be recalibrated every time the measuring wavelength is changed.

3、There are three kinds of D-D transitions in the central chromium (III) ion, but only two obvious absorption peaks can be detected in the splitting energy measurement experiment.

中国大学无机化学实验

无机化学实验一直是大学化学课程的重要组成部分。在中国大学的化学专业中，无机化学实验是一个非常重要的课程。它不仅可以帮助学生深入了解无机化学的基本原理和操作技能，还可以培养学生的科学精神、实验能力和团队合作精神。

实验内容

在中国大学的无机化学实验中，学生将学习一些基本的实验操作技能和理论知识。这些包括：

• 化学平衡和酸碱平衡的基本概念和原理
• 重量法和容量法的基本原理和应用
• 分离和纯化无机化合物的方法
• 无机化合物的合成和性质的研究
• 无机化合物的定性和定量分析

此外，学生还将学习如何使用一些基础实验设备和仪器，例如滴定管、量筒、烧杯、试管、pH计、离心机、旋转蒸发器等。

实验目的

中国大学的无机化学实验的主要目的是培养学生的实验技能和实验思维能力。通过实验，学生能够掌握基本的无机化学知识和实验操作技能，而且还可以培养学生的科学精神、实验能力和团队合作精神。此外，无机化学实验还可以激发学生对化学科学的兴趣和热情，为将来的学习和研究打下坚实的基础。

实验材料

在中国大学的无机化学实验中，学生需要使用一些常用的实验材料和试剂。这些包括：

• 硫酸铜
• 氢氧化钠
• 盐酸
• 氢氧化钾
• 硝酸银
• 硫酸
• 氨水
• 氯化铁
• 氯化钠

此外，还需要一些基础实验设备和仪器，例如热板、搅拌器、热风炉、pH计、天平等。

实验过程

中国大学的无机化学实验通常分为几个部分，每个部分包括不同的实验项目。以下是一个典型的实验过程：

实验一：制备四水合硫酸铜

这个实验的目的是制备硫酸铜的四水合物。

1. 称取一定量的硫酸铜，加入适量的水中，并用热板加热。
2. 逐滴加入氢氧化钠溶液，直到产生蓝色沉淀。
3. 将产生的沉淀过滤，并将滤液收集起来。
4. 将收集的滤液加热至干燥，得到四水合硫酸铜。

实验二：制备氯化铁

这个实验的目的是制备氯化铁。

1. 将氯化铁固体加入适量的盐酸中，转移至热板上加热。
2. 持续加热，直到产生黄色气体。
3. 检查气体是否能够点燃。
4. 持续加热，直到产生黑色固体。
5. 将产生的固体过滤，并用去离子水洗涤。

实验效果

中国大学的无机化学实验可以帮助学生深入了解无机化学的基本原理和操作技能，同时培养学生的科学精神、实验能力和团队合作精神。通过实验，学生能够掌握基本的无机化学知识和实验操作技能，为将来的学习和研究打下坚实的基础。