Quiz 4
May 27, 2005.
(Due May 31)
Mark the best answer among the given multiple-choices. Then, give your explanation
below.
1.
A Chemist finds that 30.82 g of nitrogen will react with 17.60 g, 35.20 g, 70.40 g,
or 88.00 g of oxygen to form four different compounds. (A) Calculate the mass of
oxygen per gram of nitrogen in each compound. (B) This example obeys which
law?
2
Name the following compounds: (A) Fe(OH)3, (B) Cr2(CO3)3, (C) (NH4)2SO4, (D)
N2O, (E) N2O5, (F) Cu2O
3
Fill in the gaps in the following table assuming each column represents a neutral
atom or an ion:
Symbol
Protons
Neutrons
Electrons
Mass no
Net charge
121
Sb
51
70
51
121
0
Sr
38
50
38
88
0
W
74
108
74
182
0
Se
34
46
36
80
2-
Os
76
116
74
192
2+
I
53
74
54
127
1-
4.
How many hydrogen and oxygen atoms are in each of the following: (A) C2H4OH
(B) Ca(CH3COO)2 (C) (NH4)3PO4
5
Write the chemical formulas for the following compounds. (A) copper(I) oxide,
(B) iron(III) carbonate, (C) Barium chlorate, (D) dinitrogen tetroxide, (E)
tetraphosphorus hexasulfide
Provide your brief explanations here:
1.
A) O / N = 17.60/30.82 = 0.571; 35.2 / 30.82 = 1.14; 70.4 / 30.82 = 2.28; It
obeys the law of multiple proportions.
2.
(A) Iron(III) hydroxide (B) Chromium(III) carbonate (C) Ammonium sulfate
(D) Dinitrogen monoxide (E) Dinitrogen pentoxide (F) Copper(I) oxide
3.
Provided in table above
4.
(A) 5 H atoms and 1 O atom (B) 6 H atoms and 4 O atoms
4 O atoms.
5.
(A) Cu2O
(B) Fe2 (CO3)3
(C) Ba(ClO3)2
(D) N2O4
(C) 12 H atoms and
(E) P4S6