Independent work on chemistry Speed chemical reactions(catalysts) for 9th grade students. Independent work consists of 3 options each with 4 tasks and is intended to test knowledge on the topic general characteristics chemical elements and reactions.
1 option
1.
3Complete the reaction schemes:
a) Zn + HCl (p-p) → …;
b) KOH (solution) + H 2 SO 4 (p-p) → …;
c) N 2 + N 2 → ….
2.
4FeS 2 + 11O 2 = 2Fe 2 O 3 + 8SO 2
Justify your conclusions.
3.
A 10% solution was poured into test tubes with Zn, Fe and Mg granules of hydrochloric acid. In which test tube the reaction rate will be:
a) maximum;
b) minimum?
Explain your answer.
4. What can be observed in the action of hydrogen peroxide on raw and cooked meat? How to explain these phenomena?
Option 2
1.
Complete the reaction schemes:
a) CH 4 + O 2 → …;
b) NaCl
→ … ;
c) CaCO 3 + HCl
→ … .
Indicate which of the reactions you have given are heterogeneous and which are homogeneous.
2.
Suggest ways to increase reaction speed
Fe + H2SO4
FeSO 4 + H 2
Justify your conclusions.
3.
A 10%, 20% and 30% solution of hydrochloric acid was poured into three test tubes containing zinc granules, respectively. In which test tube the reaction rate will be:
a) maximum;
b) minimum?
Explain your answer.
4. If water is added to a mixture of iodine and aluminum, the release of violet vapor is observed almost immediately, and then a flame appears. What role does water play in this process?
Option 3
1.
Complete the reaction schemes:
a) H 2 S + O 2 → …;
b) CuS + O 2 → …;
c) FeS + HCl → … .
Indicate which of the reactions you have given are heterogeneous and which are homogeneous.
2.
Suggest ways to increase reaction speed
2SO2 + O2 = 2SO3
Justify your conclusions.
3.
Mg and Zn granules were placed in two test tubes and a 10% solution of hydrofluoric acid was poured into each test tube. The same Mg and Zn granules were placed in two other test tubes and a 10% solution of hydrochloric acid was added. In which test tube the reaction rate will be:
a) maximum;
b) minimal.
Explain your answer.
4. Why do laundry detergents containing enzymes not remove stains when boiled? What type of catalyst are they most likely?
Answers to independent work in chemistry Rates of chemical reactions
Option 1.
1.
a) Zn + 2HCl = ZnCl 2 + H 2 heterogeneous,
b) 2KOH + H 2 SO 4 = K 2 SO 4 + 2H 2 O - homogeneous,
c) N 2 + 3H 2 = 2NH 3 - homogeneous.
2. Grind FeS 2, increase the concentration of O 2, its pressure, and increase the temperature.
3.
a) with Mg;
b) with Fe.
The speed depends on the nature of the metal and its position in electrochemical series metal stresses.
4. On raw meat, the reaction goes much faster, since there are enzymes - biological catalysts.
Option 2.
1.
a) CH 4 + 2O 2 = CO 2 + 2H 2 O - homogeneous;
b) NaCl + AgNO 3 = AgCl + NaNO 3 - homogeneous;
c) CaCO 3 + 2HCl = CaCl 2 + CO 2 + H 2 O - heterogeneous.
2. The speed will increase if Fe is crushed, the concentration of H 2 SO 4 is increased, and the temperature is increased.
3.
a) with a 30% solution;
b) with a 10% solution.
4. H 2 O - catalyst.
Option 3.
1.
a) 2H 2 S + 3O 2 = 2SO 2 + 2H 2 O - homogeneous,
b) 2CuS + 3O 2 = 2CuO + 2SO 2 - heterogeneous,
c) FeS + 2HCl = FeCl 2 + H 2 S - heterogeneous.
2. Increase pressure, increase temperature, apply catalyst.
3.
a) Mg and HCl;
b) Zn and HF.
The nature of the metal and the strength of the acid influences.
4. Enzymes are biological catalysts; they work only at temperatures up to 40°.
Analysis of Unified State Exam tasks on this topic:"The rate of a chemical reaction."
Tumanova Elena Borisovna , chemistry teacher, GBOU secondary school No. 806,
Moscow
Etcocarried out in the late 90s. XX century condition analysis Russian system education revealed dissatisfaction of the professional community and the public with the current practice of school final examsoin and entrance examinations in institutions of higher and secondary vocational education. Traditional system final control did not provide reliable information about quality general education necessary for making informed decisions in the management systemoeducation.
For Poincreasing the objectivity of the final certification of graduates educational institutions and ensuring equal opportunities to receive secondary and higher vocational education by the Government Russian Federation the task was set to change the existing system of graduation and entrance exams taking into account the results of the experiment on the introduction of the Unified State Exam (USE).
WereoThe goals of introducing the Unified State Exam are defined:
Increasing the accessibility of vocational education, primarily for capable young people from low-income families and places of residence remote from university centers;
Ensuring continuity of general and professional education;
Ensuring national control and management of the quality of education based on an independent assessment of graduates’ training.
Over the years of the experiment on introducing the Unified State Exam, a regulatory framework for conducting the exam in a new form was formed, the technology of conducting the exam, and the procedure for creating control measuring materials (CMM) were developed.
Behind last years there has been a tendency towards stabilization Unified State Exam results. However, it still reveals recurring patterns from year to year. typical mistakes examinees while performing tasks of the same topic. It should be noted that tasks for the rate of chemical reactions in all years conducting the Unified State Exam caused certain difficulties for most graduates. Students formally, without taking into account the specific conditions of the task, use knowledge about the rate of a chemical reaction and the factors influencing its change. In addition, there is a “confusion” between the concepts of “factors influencing changes in the rate of a chemical reaction” and “factors influencing the displacement chemical equilibrium" Apparently, this topic has not received enough attention in school course. In this work, I want to analyze the main mistakes students make when completing USE tasks in block A on the topic “Rate of chemical reaction.”
Example 1.
Forward reaction rate
N 2 + 3 H 2 ↔ 2 N.H. 3 + Q
increases with:
increasing nitrogen concentration
reducing nitrogen concentration
increasing ammonia concentration
decreasing ammonia concentration
Let us remember that, in accordance with the law of mass action of Gulberg and Waage, the rate of a chemical reaction is proportional to the concentration of the reactants. In this regard, answers 3 and 4 immediately fall out of consideration, requiring a change in the concentration not of the reagents, but of the reaction product. Changing (increasing or decreasing) the ammonia concentration will not affect the reaction rate in any way. From
for the other two, we choose the first answer - it is the increase in the concentration of one of the reagents (in this case nitrogen) that will lead to an increase in the rate of the direct reaction. Correct answer 1.
Example 2.
The reaction proceeds at the fastest rate under normal conditions
2 Ba+O 2 = 2BaO
Ba 2+ + CO 3 2- = BaCO 3 ↓
Ba+2H + =Ba 2+ +H 2
Ba + S = BaS
This is a problematic task. We often hear that schoolchildren have never seen barium and do not know how quickly it reacts with oxygen or sulfur. The fact is that when studying chemistry there is no need to get acquainted in detail with the properties of all 118 chemical elements; it is enough to study the properties of the most typical of them. And then - use the power periodic law and studied chemical theories to predict the properties of unknown substances and patterns of reactions.
Let's analyze the proposed answers. First, let's compare answers 1 and 4. Barium is one of the most active metals, which is even stored under a layer of mineral oil or kerosene to prevent oxidation by atmospheric oxygen. The reaction with oxygen proceeds quite quickly; when barium is heated in air, it burns effectively, combining with oxygen, but in any case this is not the fastest reaction. Barium will react with sulfur much more slowly compared to oxygen.
There is no doubt that barium reacts very violently with an acid solution (answer 3). But isn't there an even faster response? It exists - it is a reaction between aqueous solutions barium and carbonic acid. Anyone who has done this or a similar experiment in the laboratory has seen that a precipitate of barium carbonate precipitates instantly. And this is not only a feature of barium salts. It has been established that it is the reactions in electrolyte solutions that occur at the highest rates - neutralization reactions, precipitation and the like.
So the correct answer is 2.
Example 3.
Zn (TV) + 2 H + (sol) → Zn 2+ + H 2 +154 kJ
necessary:
reduce the concentration of zinc ions
increase the concentration of hydrogen ions
reduce temperature
increase the concentration of zinc ions
Remember that the rate of chemical reactions depends on
The nature of the reactants
Temperatures
Concentrations of reactants,
Degree of grinding of solids (based on the contact area in the case of heterogeneous reactions),
Presence of a catalyst (inhibitor).
It's obvious that
changing the concentration of zinc ions (increasing or decreasing it) will not affect the reaction rate in any way, since zinc ions are not reagents, but reaction products;
a decrease in temperature always leads to a decrease in the rate of a chemical reaction.
Therefore, only an increase in the concentration of hydrogen ions (i.e., reactants) will cause the chemical reaction to accelerate. So the correct answer is 2.
Example 4.
To increase the rate of a chemical reaction
Fe (TV) + 2 H + (sol) → Fe 2+ + H 2
necessary:
1) add a few pieces of iron,
2) increase the concentration of iron ions,
3) reduce the temperature,
4) grind the taken iron.
Most of the examinees chose the wrong answer to this question, namely answer 1. Indeed, if not one, but two or three pieces of iron are added to a test tube with acid, the amount of hydrogen released will increase significantly. But will this increase the reaction rate? Of course not! And that's why. The rate of a heterogeneous reaction is equal to the amount of reaction product substance formed per unit surface area of contact of the reactants (for example, per square centimeter). Regardless of how many pieces of metal are taken for the experiment, from a unit surface area of each of them (from 1 cm 2 ) the same constant amount of hydrogen will be released. Since the area of three pieces of metal is greater than the area of one piece, more hydrogen will be released, although the reaction rate will not change from this - it will be constant. The correct answer is 4, since the rate of a heterogeneous reaction depends on the contact area of the reagents (the more crushed the substance is, the larger the contact area).
Example 5.
On the rate of reaction between acetic acid and ethanoldoes not affect :
catalyst
reaction temperature
concentration of starting substances
pressure.
The reasoning is very simple. Acetic acid and ethanol are liquids. Therefore, the rate of reaction between these substances is not affected by changes in pressure. The correct answer is 4.
Example 6.
Reacts with hydrogen at the fastest rate
chlorine
fluorine
sulfur
carbon
To answer the question, let us recall the comparative chemical activity of the nonmetals indicated in the task. Carbon and sulfur are low-active nonmetals. When heated, their activity increases noticeably, but at high temperatures, hydrogen gas will interact with solid sulfur (melting point of sulfur 444 0 C) and solid carbon. And the rate of reactions between gas and solids, as a rule, less than with the participation of only gaseous substances. Chemical activity There are much more halogens than other non-metals (all other things being equal). The most active among the halogens is fluorine. As is known, even stable substances such as water and fiberglass burn in a fluorine atmosphere. Indeed, hydrogen and chlorine interact either when heated or in bright light, and fluorine and hydrogen explode under any conditions (even very low temperatures). Correct answer 2.
Example 7.
To increase reaction speed
2CO + O 2 = 2СО 2 +Q
necessary:
increase CO concentration
reduce O concentration 2
lower blood pressure
lower the temperature
It is known that the rate of a chemical reaction depends on the following factors:
The nature of the reacting substances (other things being equal, more active substances react faster);
Concentrations of reactants (the higher the concentration, the higher the reaction rate);
Temperature (increasing temperature leads to faster reaction);
The presence of a catalyst (a catalyst accelerates the process, an inhibitor slows it down);
Pressure (for reactions involving gases, an increase in pressure is equivalent to an increase in concentration, therefore the rate of reactions increases with increasing pressure);
Degrees of grinding of solids9 the greater the degree of grinding, the larger the contact surface of solid reagents, and the higher the reaction rate).
Taking these factors into account, let us analyze the proposed answers:
1) An increase in the concentration of CO (the starting substance) will indeed lead to an increase in the rate of the chemical reaction.
2) Decrease in O concentration 2 will lead not to an increase, but to a decrease in the reaction rate.
3) A decrease in pressure is essentially the same as a decrease in the concentration of reagents, therefore, the reaction rate will also decrease.
4) A decrease in temperature always leads to a decrease in the rate of a chemical reaction.
So the answer is 1.
Example 8.
To increase the rate of interaction of iron with hydrochloric acid, you should
1) add an inhibitor
2) lower the temperature
3) increase blood pressure
4) increase the concentration of NSL
First of all, let’s write down the equation for the interaction of iron with hydrochloric acid:
Fe (TV) + 2 HCl (rr) = FeCl 2(r-r) + H 2(g)
Analyzing the proposed answer options, we note that the addition of an inhibitor reduces the rate of reactions, and a decrease in temperature has a similar effect. Pressure does not affect the speed of this reaction (since there are no gaseous substances among the reagents). Therefore, to increase the reaction rate, the concentration of one of the reagents should be increased, namelyHCl. Answer 4.
In custody
The experience of conducting the Unified State Exam shows that, in general, graduates cope quite successfully with new form exams. However, to increase the objectivity of the results, it is necessary to carry out special preparation of students for the final certification, for example, to develop the ability to work with various types test tasks. Introduce test forms of assessing educational achievements into teaching practice more widely, along with traditional methods and forms. It is advisable to organize a repetition of the material covered, especially for the basic school course, by allocating for this special time in the educational process. The attention of teachers, textbook authors and developers should be drawn to methodological manuals on the need to improve educational process taking into account the results of the Unified State Exam.
Used Books
Medvedev Yu.N., Kaverina A.A., Koroshchenko A.S. Single State exam 2007. Chemistry. Educational and training materials for preparing students / FIPI - M.: Intellect-Center, 2007
A.A. Kaverina, D.Yu. Dobrotin, A.S. Koroshchenko, Yu.N. Medvedev, M.G. Tackle. We pass the state exam. Chemistry - M.: Bustard, 2008
Kaverina A.A., Koroshchenko A.S., Medvedev Yu.N., Yashukova A.V. Unified State Exam 2009. Chemistry. Universal materials for training students/FIPI. – M.: Intellect-Center, 2009
A.A. Kaverina, Yu.N. Medvedev, D.Yu. Dobrotin. Unified State Exam 2010. Chemistry: collection exam tasks– M.: Eksmo, 2009 (Unified State Examination. Federal bank of examination materials.
Subject: chemistry
Grade: 9
Topic: Rate of chemical reactions
The purpose of the lesson : creating conditions for awareness and comprehension of knowledge on the topic “Rate of chemical reactions. Factors influencing the rate of chemical reactions""
Lesson objectives:
Educational aspect:
form the concept of “rate of chemical reactions”, as a result of observation, analysis, comparison, generalization, lead students to understand the dependence of the rate of chemical reactions on various factors;
skills formation research activities students.
Developmental aspect:
contribute to the formation of general educational skills:
educational and intellectual (analyze facts, establish cause-and-effect relationships, draw conclusions);
educational and informational (work with tests);
educational and organizational (understand the meaning of the task, allocate time for completing test tasks and checking them);
educational and communicative (ability to conduct a dialogue, express one’s point of view);
contribute to the development of students' horizons.
Educational aspect:
promote accuracy, attentiveness, and caution when working with laboratory equipment and reagents.
Equipment:
for laboratory work: set of reagents: HCl solution, Zn in tablets and powder, Fe, Mg; alcohol lamps, matches, holders, test tubes;
on the teacher's desk: HCl (conc.), lithium salt, sugar cube, alcohol lamp, matches, crucible tongs;
Demonstration computer equipment.
Type of training session: lesson of “discovery” of new knowledge with elements of research
Form of organization: frontal, pair work
Usage pedagogical technologies:
problem-based learning technology;
technology of collective interaction;
critical thinking technology
learning based on learning situations
Teaching methods and techniques:
problematic dialogue;
stimulating dialogue;
leading dialogue;
comparative method;
study
During the classes
Teacher activities
Student activities
I. Motivational-target stage.
1. Updating knowledge (3 min.)
Today we have an unusual lesson. Tell me please, do you like juice?
After opening the package, it is recommended to consume the juice immediately. But it happens that it stays for 2-3 days. As a result, the juice begins to ferment and acquires an unpleasant odor.
What does this indicate (from a chemical point of view)? What signs of chemical reactions are observed in this case?
This means that even in everyday life we constantly deal with chemical reactions. And today we will talk about reactions.
2. Goal setting (3 min.)
What has changed in the spoiled juice from a chemical point of view?
But it happens that the juice can stand unchanged, and there are no signs of spoilage.
Does this mean that chemical reactions do not occur?
This means that chemical reactions occur at different rates. And today we have to get acquainted with the concept of “chemical reaction rate” and identify on what factors it depends. Chemical reactions – processes as a result of which old ones are destroyed chemical bonds and new ones arise.
Write down the topic of the lesson.
II. Procedural stage. Joint discovery of new knowledge.
1. The concept of the rate of a chemical reaction. (10 min.) - change in reactants per unit time.
2. Physical education minute (2 minutes.)
We have a physical education session again
Let's bend over, come on, come on!
Straightened up, stretched,
And now they’ve bent over backwards.
My head is tired too
So let's help her
Right-left, one and two
Think, think, head.
Even though the charge is short,
We rested a little.
3. Factors influencing the rate of chemical reactions (20 minutes.)
Let's go back to our example.
What can we do to keep the juice as long as possible?
Right. So, the first factor:
1) the nature of the reacting substances - the nature of which reagent affects the rate of interaction of the acid with the metal?The essence of reactions of metals with acid is that metal atoms donate electrons (i.e., are oxidized, are reducing agents) to hydrogen protons (i.e., are reduced, are oxidizing agents). But metals have different reducing abilities; this ability is characterized by the standard electrode potential, for zinc it is -0.76 V, for iron -0.037 V, for hydrogen 0.
2) concentration of reacting substances - the higher the concentration, the higher the speed
3) contact area of reacting substances. The larger the surface area of contact, the greater the speed of the chemical reaction.
4) Temperature
The higher the temperature, the faster the rate of chemical reactions; the lower the temperature, the slower the rate of chemical reactions.
So, we have learned what the rate of a chemical reaction is and what it depends on.
III. Self-test. Correction of the obtained results. (3 min.)
I propose to take the test and evaluate the knowledge gained. Choose the correct answer options.
Self-test: answers: 1. B); 2. B); 3. G); 4. B); 5. D).
IV. Reflection. (2 minutes.)
I hope that during our lesson you learned a lot of new and important things that can be useful in life.
Now I will offer you small test. Give pluses for statements.
I learned a lot of new things.
I will need this in life.
There was a lot to think about during the lesson.
I received answers to all the questions I had.
I worked conscientiously in class.
Count the number of pluses. Their number tells you how you did in the lesson.
V. Homework. (Slide 15) (2 minutes.)
1. Solve the problem: Determine the rate of chemical reaction H2 +Br2 = 2HBr, if the initial hydrogen concentration was 1 mol/l, and after 30 s it became 0.8 mol/l. (The task is printed on pieces of paper)
2. Give examples of the influence of various factors on the rate of chemical reactions that you carry out at home, in everyday life.
Answer(usually yes )
Answer:
- A chemical reaction occurs
- Emission of gas, appearance of odor
The rate of a chemical reaction and its dependence on various factors
1. The rate of a homogeneous chemical reaction is proportional to the change
1) concentration of a substance per unit time
2) the amount of substance per unit volume
3) mass of substance per unit volume
4) volume of substance during the reaction
2. Under normal conditions, interaction occurs at the lowest speed between
1) iron and oxygen
2) magnesium and 10% hydrochloric acid solution
3) copper and oxygen
4) zinc and 10% solution
3. To increase the speed of a chemical reaction
2СО+O2=2CO + Q necessary
1) increase the concentration of carbon monoxide (II)
2) reduce oxygen concentration
3) lower the pressure
4) lower the temperature
4. At room temperature, the reaction between
1) Zn and HCl (1% solution)
2) Zn and HCl (30% solution)
3) Zn and HCl (10% solution)
4) ZnCl2 (solution) and AgNO3 (solution)
5. On the rate of chemical reaction between a solution of sulfuric acid and iron Does not provide influence
1) acid concentration
2) iron grinding
3) reaction temperature
4) increase in pressure
6. To increase the speed of a chemical reaction
FeO(solid) + CO(g) ? Fe(s) + CO2 (g) + 17 kJ
Necessary
1) increase the concentration of CO2
2) reduce CO2 concentration
3) reduce the temperature
4) increase the degree of FeO grinding
7. To increase the speed of a chemical reaction
2CuS(s) + 3O2(g) = 2CuO(s) + 2SO2 (g) + 2920 kJ
Necessary
1) increase the concentration of SO2
2) reduce SO2 concentration
3) reduce the temperature
4) increase the degree of grinding of CuS
8. To increase the speed of a chemical reaction
Zn(sol) + 2H+ ? Zn2+ + H2 (g) + 154 kJ
Necessary
1) reduce the concentration of zinc ions
3) reduce the temperature
4) increase the concentration of zinc ions
9. To increase the speed of a chemical reaction
Mg(s) + 2H+ ? Mg2+ + H2(g) + 462 kJ
Necessary
1) reduce the concentration of hydrogen ions
2) increase the concentration of hydrogen ions
3) lower the temperature
4) increase blood pressure
10. To increase the speed of a chemical reaction
Zn(s) + 2HCl(g) = ZnCl2(s) + H2(g) + 231 kJ
Necessary
1) increase the concentration of hydrogen
2) increase the amount of zinc
3) reduce the temperature
4) increase the concentration of hydrogen chloride
11. To increase the rate of interaction of iron with hydrochloric acid, you should
1) add an inhibitor
2) lower the temperature
3) increase blood pressure
4) increase the concentration of hydrochloric acid HCl
12. To increase the rate of carbon dioxide release when hydrochloric acid acts on marble, you need
1) dilute the acid
2) crush marble
3) add an indicator
4) carry out the reaction in an inert gas atmosphere
13. They interact with the highest speed under normal conditions
1) nitrogen and hydrogen
2) magnesium and water
3) sodium hydroxide solution and hydrochloric acid
4) sulfur and iron
14. They interact with the highest speed under normal conditions
1) zinc and hydrochloric acid
2) sodium and water
3) magnesium and water
A. When heated, the rate of some reactions increases, while the rate of others decreases.
B. The reason the reaction rate increases when heated is the increase in the frequency of particle collisions.
1) only A is correct
2) only B is correct
3) both judgments are correct
4) both judgments are incorrect
16. Reacts with hydrogen at the highest speed
A. A catalyst is a substance that increases the rate of a chemical reaction without being consumed.
1) only A is correct
2) only B is correct
3) both judgments are correct
4) both judgments are incorrect
18. To increase the rate of reaction of hydrogen with nitrogen
1) cool the nitrogen-hydrogen mixture
2) reduce the pressure in the system
3) use a catalyst
4) use the circulation of a nitrogen-hydrogen mixture
19. As the pressure increases, the reaction rate increases
1) oxygen with sulfur dioxide
2) zinc with sulfuric acid
3) sulfur with iron
4) sodium hydroxide with copper (II) chloride
20. A catalyst is required to carry out a reaction.
1) chlorination of alkanes
2) neutralization of phosphoric acid
3) methane pyrolysis
4) esterification of acetic acid
21. They interact with the highest speed under normal conditions
1) ammonia and hydrogen chloride
2) nitrogen and hydrogen
3) nitrogen and oxygen
A. When heated, the rate of many reactions decreases.
B. A catalyst is a substance that increases the speed of a chemical reaction, but is not consumed in it itself
1) only A is correct
2) only B is correct
3) both judgments are correct
4) both judgments are incorrect
23. Pressure affects the rate of reaction between
1) zinc hydroxide and nitric acid
2) zinc and sulfuric acid
3) ammonia and oxygen
4) sulfur and aluminum
24. A reaction whose equation is
FeO + 2H+ = Fe2+ + H2O + Q,
You can speed it up if
1) increase blood pressure
2) lower the pressure
3) increase the temperature
4) lower the temperature
25. Reaction speed
Zn + H2SO4 = ZnSO4 + H2 + Q
Will decrease at
1) increasing temperature
2) decrease in pressure
3) increased pressure
4) diluting the acid solution
26. Reaction speed simple substances with hydrochloric acid decreases in the series
|
Na, Ca, Zn, Cr, Cu |
|
|
Mg, Na, Ni, Zn, Cu |
|
|
Na, Ba, Fe, Cu, Zn |
|
|
Ba, Na, Zn, Cu, Fe |
A. A catalyst increases the rate of a reaction, but does not cause a shift in chemical equilibrium.
B. An increase in the pressure of the reacting gases leads to an increase in the reaction rate.
1) only A is correct
2) only B is correct
3) both judgments are correct
4) both judgments are incorrect
28. Reaction speed
N2 + 3H2 = 2NH3 + Q
Will increase with
1) decreasing temperature
2) decreasing NH3 concentration
3) diluting the mixture with argon
4) using a catalyst
29. Which metal reacts with sulfuric acid faster than others?
30. A reaction, the speed of which depends on the surface area of contact of the reacting substances, is
1) neutralization of sulfuric acid with sodium hydroxide solution
2) combustion of hydrogen in oxygen
3) interaction of solutions of copper chloride and potassium hydroxide
4) combustion of aluminum in oxygen
Answer: 1-1, 2-3, 3-1, 4-4, 5-4, 6-4, 7-4, 8-2, 9-2, 10-4, 11-4, 12-2, 13-3, 14-2, 15-2, 16-2, 17-3, 18-3, 19-1, 20-4, 21-1, 22-2, 23-3, 24-3, 25- 4, 26-1, 27-3, 28-4, 29-2, 30-4.
