August 2007 Chemistry Regents #31-40
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31 What is the net charge on an ion that has
9 protons, 11 neutrons, and 10 electrons?
(1) 1+ (3) 1–
(2) 2+ (4) 2–
|3||more electrons means it is negative|
|32 Which two particles make up most of the mass
of a hydrogen-2 atom?
(1) electron and neutron
(2) electron and proton
(3) proton and neutron
(4) proton and positron
|3||H-2 has a proton and a neutron|
|33 Which statement explains why sulfur is classified
as a Group 16 element?
(1) A sulfur atom has 6 valence electrons.
(2) A sulfur atom has 16 neutrons.
(3) Sulfur is a yellow solid at STP.
(4) Sulfur reacts with most metals.
|1||group 16, 6 valence electrons|
|34 How do the atomic radius and metallic properties
of sodium compare to the atomic radius and
metallic properties of phosphorus?
(1) Sodium has a larger atomic radius and is more metallic.
(2) Sodium has a larger atomic radius and is less metallic.
(3) Sodium has a smaller atomic radius and is more metallic.
(4) Sodium has a smaller atomic radius and is less metallic.
|1||table S for radius
more metallic bottom left of the PT
|35 A compound has a molar mass of 90. grams per
mole and the empirical formula CH2O. What is
the molecular formula of this compound?
(1) CH2O (3) C3H6O3
(2) C2H4O2 (4) C4H8O4
90/30; so 3 times this
|36 At standard pressure, a certain compound has a
low boiling point and is insoluble in water. At
STP, this compound most likely exists as
(1) ionic crystals
(2) metallic crystals
(3) nonpolar molecules
(4) polar molecules
|3||water is polar and like dissolves
like, so nonpolar
low BP covalent
|38 Which group on the Periodic Table of the
Elements contains elements that react with
oxygen to form compounds with the general
(1) Group 1 (3) Group 14
(2) Group 2 (4) Group 18
|1||X has a charge of +1
so group 1
|39 An unsaturated solution is formed when
80. grams of a salt is dissolved in 100. grams of
water at 40.°C. This salt could be
(1) KCl (3) NaCl
(2) KNO3 (4) NaNO3
|4||Below the line on TABLE G at 40C|
|40 Which kelvin temperature is equal to 56°C?
(1) –329 K (3) 217 K
(2) –217 K (4) 329 K
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