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c Mass Abundance Which molecular formula and empirical formula .
.
tu s
2
2 9
(
ho hX u
u u
u)
02 02
up can be of lithium?
(0.925)(7.0
(0.075)(7.0 2.5)(7.02 u) 7.5)(7.02 u)
chlorine t e formula
ic Table co
(3) Gro (4) Gro
(%)
7.5 92.5
sed to deter-
u) u)
form an ionic Cl2. To which ld element X
p 13 p 15
37
38
represent this compound?
(1) C2HNO2 and CHNO
(2) C2HNO2 and C2HNO2
(3) C H N O and CHNO
4 2 S2am4ple Regents Questions
(4) C4H2N2O4 and C2HNO2
What is the gram-formula mass of (NH4)3PO4?
(1) 112 g/mol (3) 149 g/mol (2) 121 g/mol (4) 242 g/mol
Inthegroundstate,whichatomhasacompletely filled valence electron shell?
(1) C (2) V
(3) Ne
June 2012 #37
(4) Sb
Choice #3
Explanation:
[5]
[OVER]
Answer
Element
Number of Atoms (Coefficient × subscript)
Mass of Each Atom
Total Mass of Element (Number of Atoms × mass)
N
3
14
42
H
12
1
12
P
1
31
31
O
4
16
64
Total Mass of All Elements
149 g/mol
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