Chemistry and Biology assignment
woshinibaba
Chem-Finaltest.docGeneral Chemistry
Term: 2019 Summer
Final-term Exam
Name: ______________________ Time: _______________ Total: _________(100)
I. Choose the right answer: (3points each,18 points)
1. The environment performs 15kJ of work on the system, and the system loses 5kJ of heat to the environment, the internal energy of the system changes to ( )
(A) -15kJ (B) 10kJ (C) -10kJ (D) 15kJ
2. In the following molecules, the dipole moment is not zero is ( )
(A) BBr3 (B) SiCl4 (C) PCl5 (D) H2Se
3. Which of the following reagents should we choose to remove a small quantity of CuSO4 from ZnSO 4 solution ( )
(A) NH3·H2O (B) NaOH (C) Zn (D) H2S
4. Which of the following Compound that have ionic bonds, covalent bonds and coordination bonds together: ( )
(A)H3PO4 (B) Ba(NO3)2 (C) NH4Cl (D) NaOH
5. Which of the following cations will NOT precipitate while treated with HCl(l). ( )
(A)Ag+ (B) Hg22+ (C) Pb2+ (D) Cd2+
6. In F － Cl — Br －I order, the incorrect regularity of halogen is ( )
(A) X- ionic radius: F- < Cl- < Br - < I-
(B) electronegativity: F > Cl > Br > I
(C) Acid: HF > HCl > HBr > HI
(D) ionic polarizability: F- < Cl- < Br - < I-
II. True of False(3points each,12 points)
1. O3 is a nonpolar molecule. ( )
2. H3BO3 is a weak ternary acid. ( )
3. (Go is a constant for a particular reaction at a given temperature. ( )
4. The sign of (Go tells us not only the relative amounts of products and reactants when equilibrium is reached, but also the direction of the net reaction. ( )
III. Name these compounds: (3points each,15 points)
(a) K2HPO4
(b) K2Cr2O7 ,
(c) Al(OH)3,
(d) Na2CO3·10H2O,
(e) LiNO3,
IV. Classify each of these molecules as alcohol, aldehyde, ketone, carboxylic acid, amine, or ether: (3points each,15 points)
(a)
H
3
COCH
2
CH
3
(b)
H
2
NCH
2
CH
3
(c)
CH
3
CH
2
C
O
H
(d)
H
3
CCCH
2
CH
3
O
(f)CH
2
CHCH
2
COOH
NH
2
V. Sodium bicarbonate (NaHCO3) is called baking soda because when heated, it releases carbon dioxide gas, which is responsible for the rising of cookies, doughnuts, and bread. HCO3- , its conjugate base is , its conjugate acid is .
(5 points)
VI Nitrous oxide (N2O) is also called “laughing gas.” Itcan be prepared by the thermal decomposition of ammonium nitrate (NH4NO3). The other product is H2O. (a) Write a balanced equation for this reaction.(b) How many grams of N2O are formed if 0.46 mole of NH4NO3 is used in the reaction? (15 points)
VII. HCl gas can be prepared by concentrated H2SO4 and NaCl, while HI gas can not be prepared by concentrated H2SO4 and KI. Why？ (5points)
VIII. At the start of a reaction, there are 0.249 mol N2, 3.21×10-2mol H2, and 6.42×10-4 mol NH3 in a 3.50-L reaction vessel at 750C. If the equilibrium constant (Kc) for the reaction is 1.2 at this temperature, decide whether the system is at equilibrium. If it is not, predict which way the net reaction will proceed. (15 points)
