Question 23. Test results on two white crystalline solids are shown in the table below
II. PART 2 (3.0 points) Question 1. The reaction between aqueous barium chloride and dilute sulfuric acid
BaCl2(aq) + H2SO4(aq) 2HCl (aq) + BaSO4(s) a) State the colour of this precipitate. ...
b) A series of experiments are done to find the mass of precipitate formed when different volumes of dilute sulfuric acid are added to a fixed volume of aqueous barium chloride.
The precipitate formed is filtered, dried and transferred to a container.
- Solution V is 1.20 mol / dm3 barium chloride.
- Solution W is sulfuric acid of unknown concentration.
- The table below shows the results of these experiments. Complete the final column by calculating the mass of precipitate formed in each experiment
c) Use the data on your table to deduce
- the volume of W that would produce 1.20 g of precipitate, ... cm3 - the maximum mass of precipitate that is produced, ...g - the minimum volume of W that reacts completely to produce the maximum mass of precipitate ... cm3
d) Using your answer to (d) and the equation for the reaction, calculate the concentration of the sulfuric acid, W, used in the experiment. ...mol.L- Question 2. Dendritic crystals of silver are formed when copper metal is added to a solution of silver nitrate (AgNO3). The copper metal forms Cu2+ ions and displaces silver from solution.
Write two balanced ionic half-equations and a redox equation for the reaction between copper metal and a silver nitrate solution.
Question 3. M is compound which contains two ions. Complete the table by adding the observation in test (a), the conclusions in tests (b) and (c) and both the test and
observation for test (d). Guess the formula of the compound M
Test Observation Conclusions
(a) M is dissolved in water and the resulting solution is divided into three parts for tests (b), (c) and (d)
M is not a compound of a tranition metal (b)
(i) To the first part, aqueous sodium hydroxide is added until a change is seen.
(ii) An excess of aqueous sodium hydroxide is added to the mixture from (i)
A white precipitate forms
The precipitate dissolves (c)
(i) To the second part, aqueous ammonia is added until a change is seen.
(ii) An excess of aqueous
ammonia is added to the mixture from (i)
A white precipitate forms
The precipitate is insoluble
(d) (iii) If adding AgNO3 solution to solution
A white precipitate forms
ĐÁP ÁN ĐỀ ÔN TẬP SỐ 8 I. PART 1 (7.0 points)
II. PART 2 (3.0 points)
Question 1. The reaction between aqueous barium chloride and dilute sulfuric acid produces a precipitate of barium sulfate.
BaCl2(aq) + H2SO4(aq) 2HCl (aq) + BaSO4(s) a) State the colour of this precipitate is white
b) A series of experiments are done to find the mass of precipitate formed when different volumes of dilute sulfuric acid are added to a fixed volume of aqueous barium chloride.
The precipitate formed is filtered, dried and transferred to a container.
- Solution V is 1.20 mol / dm3 barium chloride.
- Solution W is sulfuric acid of unknown concentration.
- The table below shows the results of these experiments. Complete the final column by calculating the mass of precipitate formed in each experiment
Volume of V/ cm3
Volume of W/
cm3
Mass of empty container/g
Mass of container + precipitate /g
Mass of precipitate/g
10.0 2.0 2.70 3.35 0.65
10.0 4.0 2.70 4.00 1,30
10.0 6.0 2.70 4.65 1,95
10.0 8.0 2.70 5.30 2,60
10.0 10.0 2.70 5.50 2,80
10.0 12.0 2.70 5.50 2,80
c) Use the data on your table to deduce
- the volume of W that would produce 1.20 g of precipitate is 3,69cm3 - the maximum mass of precipitate that is produced is 2,80g
d) Using your answer (at a,c) and the equation for the reaction
Câu Đ/án Câu Đ/án Câu Đ/án Câu Đ/án
1 A 11 A 21 A 31 A
2 D 12 A 22 A 32 C
3 A/C 13 B 23 D 33 D
4 D 14 B 24 A 34 A
5 B 15 B 25 B 35 B
6 A 16 C 26 A
7 B 17 A 27 C
8 B 18 A 28 A
9 B 19 D 29 D
10 B 20 D 30 A
- Calculate the concentration of the sulfuric acid, W, used in the experiment: 0.14 mol.L- - The minimum volume of W that reacts completely to produce the maximum mass of precipitate: 8.6cm3
Question 2.
- Oxidation reaction: Cu → Cu2+ + 2e - Rection reaction: Ag+ + 1e → Ag
- Redox equation: Cu + 2Ag+ → 2Ag + Cu2+
Question 3.
Test Observation Conclusions
(a) M is dissolved in water and the resulting solution is divided into three parts for tests (b), (c) and (d)
M is not a compound of a tranition metal (b)
(i) To the first part, aqueous sodium hydroxide is added until a change is seen.
(ii) An excess of aqueous sodium hydroxide is added to the mixture from (i)
A white precipitate forms
The precipitate dissolves
The hydroxide of M is amphoteric
(c)
(i) To the second part, aqueous ammonia is added until a change is seen.
(ii) An excess of aqueous ammonia is added to the mixture from (i)
A white precipitate forms
The precipitate is insoluble
Metal ion does not form complexes with NH3
(d) (iii) If adding AgNO3 solution to solution
A white precipitate forms
M contains Cl- ions
The formula of the compound M is AlCl3
ĐỀ ÔN TẬP SỐ 9 I. PART 1 (7.0 points)
Question 1. Someone has accidentally spilled battery acid on his or her skin. The first aid treatment for this is to apply plenty of:
A. Salt B. Water C. Vinegar D. Baking soda Question 2.Which one of the following substances, when dissolved in water, gives a solution with the lowest pH?
A. Li2O B. HI C. KO2 D. H2S Question 3.What is the oxidation state of vanadium in the compound NH4VO3
(commonly known as ammonium metavanadate)?
A. –1 B. +1 C. +3 D. +5 Question 4. A technician dissolves 62.425 g of CuSO4ã5H2O (Mf = 249.7) in water and dilutes the solution to 250.00 mL in a standard flask. He then measures out a 25.00 mL aliquot of the solution. What amount (in moles) of CuSO4 does this aliquot contain?
A. 0.00100 B. 0.01600 C. 0.02500 D. 0.2500 Question 5.The following reaction is used as the basis of the contact process (a step in the production of sulfuric acid).
2SO2(g) + O2(g) 2 SO3(g); H = –197 kJãmol–1
Which one of the changes listed below could be used to increase the rate of production of SO3 but would actually reduce the amount of SO3 in the system if it were allowed to reach equilibrium?
A. Heat the mixture. B. Increase the amount of oxygen fed into the reactor.
C. Use V2O5 as a catalyst. D. Increase the pressure of the mixture.
Question 6.Which of the following substances will conduct electricity in the liquid state but not in the solid state, and will not dissolve in water?
A. Ca B. Cu C. CuI D. C6H12O6
Question 7.Some students have been measuring the rate of reaction between 5.0 g of zinc granules and 100 mL of 1.0 M hydrochloric acid at room temperature. The equation for the reaction is:
Zn(s) + 2 HCl(g) ZnCl2(aq) + H2(g)
Which of the following changes to the procedure would probably NOT increase the rate of reaction?
A. Warming the HCl before adding the zinc. B. Using 50 mL of 2.0 M HCl.
C. Using zinc powder instead of zinc granules. D. Using 200 mL of 1.0 M HCl.
Question 8.Consider the following reaction, which is allowed to attain equilibrium in an enclosed system:
CaCO3(s) CaO(s) + CO2(g); H = +178.3 kJãmol–1
In addition to the temperature, the equilibrium constant for this reaction depends on:
A. The initial amount of CO2(g) B. The initial amount of CaCO3(s) C. The equilibrium amount of CO2(g) D. The equilibrium amount of CaCO3(s) Question 9.Which one of the following molecules has the largest bond angle?
A. CH4 B. NH3 C. H2O D. CO2
Question 10.When 0.1 M aqueous solutions of the following pairs of reagents are mixed at room temperature, which pair will NOT give a precipitate?
A. HCl + AgNO3 B. NaOH + CuSO4 C. CaCl2 + Na2CO3 D. NH4NO3 + K2SO4
Question 11. Concern plaster of Paris, which is used for setting broken limbs. Its formula is CaSO4ã0.5H2O (Mf = 145.1). When water is added it sets to give gypsum,
CaSO4ã2H2O (Mf = 172.2) What is the minimum mass of water needed to set 0.500 kg of plaster of Paris?
A. 62.0 g B. 93.1 g C. 0.124 kg D. 2.90 kg Question 12. A cylinder of gas particles is shown below
The cylinder is fitted with a moveable piston that can be raised and lowered. Which of the following would result in an increase in the pressure of the gas below the piston?
A. increasing the volume of the cylinder
B. removing some of the gas from the cylinder C. decreasing the volume of the cylinder
D. decreasing the pressure outside the cylinder
Question 13. The correct name for an aqueous solution of HCl is A. chloric acid. B. chlorous acid.
C. hydrochloric acid. D. hydrogen chloride.
Question 14. The diagram below shows part of the Periodic Table.
Using only the symbols of the elements shown above, write down the symbol for an element which:
is a pale green coloured toxic gas
is stored under oil
has five electrons in its
outer electron energy shell
is the most reactive Group II
element
is the most reactive halogen
is the only liquid shown
A Cl2 Li P Ca Cl2 Br2
B He Be Si Be Br2 Ar
C O2 Ca P Zn Cl2 Br2
D Cl2 B Br2 Ca Br2 Ga
Question 15. A catalyst is? ( select the best answer) A. A substance that heats up a reaction
B. A substance that is consumed to speed up a reaction C. A substance that slows down a reaction
D. A substance that is not consumed but speeds up the reaction
Question 16. A substance that dissolves in water and conducts electricity when present in an aqueous solution is
A. Metallic B. ionic C. molecular D. network covalent Question 17. We have reaction
3Cl-(aq) + 4CrO42-
(aq) + 23H+(aq) → 3HClO2(aq) + 4Cr3+(aq) +10H2O(l)
In the reaction shown above, Cl-(aq) behaves as
A. an acid B. a base C. a reducing agent D. an oxidizing agent Question 18. A solid mixture contains an ionic salt, X, and a covalent organic
compound, Y.Two students suggested methods of separating the mixture as shown.
Which methods of separation are likely to work?
A. Either (1) or (2) B. Neither (1) nor (2) C. only (1) D. Only (2) Question 19. What do the nuclei in hydrogen molecules contain?
A. electrons and neutrons B. electrons and protons C. neutrons only D. protons only
Question 20. The diagram shows part of the Periodic Table.
Which element is correctly matched with its electronic structure?
element Electronic structure
A W 2,8,1
B X 2,4
C Y 2,8,2
D Z 2,8
Question 21. Which particle is an ion?