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nd silver nd xenon
(3) tin and silver (4) tin and xenon
38
June 2011 #37
Part B–1
Answer all questions in this part.
1–50): For each statement or question, write in your answer booklet the number of the word
t, of those given, best completes the statement or answers the question. Some questions may
f the Reference Tables for Physical Setting/Chemistry. o the atoms of nonmetals in Period 3,
f metals in Period 3 have
alence electrons lence electrons
lectron shells ectron shells
ments are malleable and good of electricity?
Sample Regents Questions
in the ground state requires the nt of energy to remove its valence
compound:
Formula A Formula B
CH3 C2H6
Which statement describes these formulas?
Given two formulas representing the same
atom
m atom
(3) rubidium atom (4) sodium atom
Choice #2
Answer
he chemical formula of iron(III)
(1) Formulas A and B are both empirical.
(2) Formulas A and B are both molecular.
(3) Formula A is empirical, and formula B is
molecular.
(4) Formula A is molecular, and formula B is
Explanation:
1. We are given 2H2 + O2
2H2O.
(3) FeSO
3 Let’s fill in the mass now based on the question.
(4) Fe2(SO3)3
empirical.
• “What is the mass of H2O produced?”:
39 Given the balanced equation representing a
2H2 + O2 ? grams 2H2O
e percent composition by mass of reaction:
• “When 10 grams of H2 react completely with 80 grams of O ”: e compound MgSO (gram-formula 2
4 10 grams 2H + 80 grams O ? grams 2H O
2 Zn(s) + H2 2SO4(aq) → 2ZnSO4(aq) + H2(g)
. grams per mole)?
(3) 46% 2. Now let’s find the missing mass based on this equation:
Which type of reaction is represented by this
The left side = 90 grams, which means that the right side = 90 grams, too.
(4) 53%
(1) decomposition (3) single replacement pound becomes less soluble in water (2) double replacement (4) synthesis
erature of the solution is increased? (3) NaCl
40 In a laboratory where the air temperature is
Therefore, there are 90 grams of H2O.
37 Given the balanced equation representing a reaction:
2H2 + O2 → 2H2O
What is the mass of H2O produced when 10.0 grams of H2 reacts completely with 80.0 grams of O2?
(1) 70.0 g (3) 180. g (2) 90.0 g (4) 800. g
equation?
3 a o
t o
a l
e
a a
m
u
h h
m p
UNIT 6: MATH IN CHEMISTRY © 220