In which of these experiments could the metal be copper?
Experiment 1 Experiment 2
A + +
B + -
C - +
D - -
Question 34. Some pollutant gases are present in the atmosphere because of the combustion of fossil fuels. For which gases is this statement correct?
CO NO2 SO2
A + + +
B + + -
C + - +
D - + +
Question 34. Air is a mixture of gases. Which gas is present in the largest amount?
A argon B carbon dioxide C nitrogen D oxygen Question 35. The experiment shown in the diagram was set up. Which tube had the highest water level after one month?
II. PART 2 (3.0 points)
Exercise 1. Sometimes it is necessary to work out the percentage by mass of water of crystallisation as well as the number of moles of water present in a hydrated crystal.
Use the information given to calculate the percentage, by mass, of water of crystallisation in a sample of hydrated magnesium sulfate.
Mass of crucible : 14.20 g Mass of crucible + hydrated MgSO4 : 16.66g Mass after heating : 15.40 g
a) Calculate the number of moles of water of crystallisation driven off during the experiment as well as the number of moles of anhydrous salt remaining.
b) Using the information you have obtained in the table, identify the formula of hydrated magnesium sulfate ( MgSO4.xH2O)
Exercise 2. Consider the following five beakers. All have 100 mL of aqueous 0.1 M solutions
of the following compounds.
Beaker A has HI Beaker B has HNO2 Beaker C has NaOH Beaker D has Ba(OH)2 Beaker E has NH4Cl
Answer the questions below, using LT (for is less than), GT (for is greater than), EQ (for is equal to), or MI (for more information required)
1. The pH of beaker B __________ the pH in beaker A.
2. The pH in beaker C __________ the pH in beaker D.
3. The pH in beaker A __________ the pH in beaker E.
4. The pH in beaker B __________ the pH in beaker E.
5. Percent ionization in beaker A __________ the % ionization in beaker C.
Exercise 3. Several chemists examined a pure, unknown substance and observed and measured its physical roperties. Their results are shown below.
Based on the data recorded in the table, answer the following.
a. What is the physical state of this substance at room temperature? Explain how the information in the table is used to make this classification of the substance‘s state.
b. The substance is unreactive in water. What will happen if 10.0 g of this substance is added
to 200.0 g of water at 20°C and standard pressure? Explain your response.
ĐÁP ÁN ĐỀ ÔN TẬP SỐ 9 I. PART 1 (7.0 points)
Câu Đ/án Câu Đ/án Câu Đ/án Câu Đ/án
1 B 11 B 21 D 31 B
2 B 12 C 22 A 32 B
3 D 13 C 23 B,B 33 C
4 C 14 A 24 D 34 A,C
5 A 15 D 25 C 35 D
6 B 16 B 26 D
7 D 17 C 27 D
8 C 18 A 28 D
9 E 19 D 29 A
10 D 20 D 30 C
II. PART 2 (3.0 points) Exercise 1.
a) mass of water of crystallisation driven off during the experiment
= 16.66 – 15.40 = 1.26 g
moles of water of crystallisation driven off during the experiment =1.26/18 = 0.07 mol Mass of of anhydrous salt remaining = 15.4 – 14.2 = 1.2 g
moles of of anhydrous salt remaining =1.2/( 24 + 96) = 0.01 mole
b) We have ratio of w 0.07 7
of anhydratsalt 0.01 mole ater
mole x =7 fomular of crystallization is MgSO4.7H2O
Exercise 2.
1. The pH of beaker B GT the pH in beaker A.
2. The pH in beaker C LT the pH in beaker D.
3. The pH in beaker A LT the pH in beaker E.
4. The pH in beaker B MI the pH in beaker E.
5. Percent ionization in beaker A EQ the % ionization in beaker C.
Exercise 3.
a) The substance is liquid at room temperature. This is because the melting point of the substance is -22.9o C. The substance becomes a liquid at that point and remains a liquid until 76.4o C, when it would become a gas. At room temperature, 20o C, is in between these two values, making the substance a liquid.
b) If 10.0 g of this substance is added to 200.0 g of water at 20°C and standard pressure,
Mass of unknown substance is dissolved = 0.08 200 0.16
100 x g<<10 So, unknown substance is sunk and dissolve not much
ĐỀ ÔN TẬP SỐ 10 I. PART 1 (7.0 points)
Question 1. Which of the following has a positive charge?
A. proton B. neutron C. anion D. electron Question 2. What is the atomic weight of a hypothetical element consisting of two isotopes, one with mass = 64.23 amu (26.0%), and one with mass = 65.32 amu?
A. 65.3 am B. 64.4 amu C. 64.9 amu D. 65.0 amu Question 3.Two isomeric forms of a saturated hydrocarbon
A. have the same structure.
B. have different compositions of elements.
C. have the same molecular formula.
D. have a different content of the isotopes of hydrogen.
Question 4.Which of the following hydrocarbons does not have isomers?
A. C7H16 B. C6H14 C. C5H10 D. C3H8
Question 5. Which one of the following compounds is an isomer of CH3CH2CH2CH2OH?
A. CH3CH2CH2OH B. CH3CH2CH2CH3
C. CH3CH2CH2CHO D. CH3CH(OH)CH2CH3
Question 6. Which of the following compounds is a functional group isomer of C2H5OH, ethanol (ethyl alcohol)?
A. ethanal, CH3CHO B. acetic acid, CH3COOH C. diethyl ether, (C2H5)2O D. propanol, C3H7OH
Question 7.Which of the compounds below has cis-trans isomers possible?