January 2010 Chemistry Regents #31-40
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Other Regents Exams
31 Which formula represents copper(I) oxide?
(1) CuO (3) Cu2O
(2) CuO2 (4) Cu2O2
|32 At STP, a 7.49-gram sample of an element has a
volume of 1.65 cubic centimeters. The sample
is most likely
(1) Ta (3) Te
(2) Tc (4) Ti
then use Table S to match up the element
|33 Which element, represented by X, reacts with
fluorine to produce the compound XF2?
(1) aluminum (3) magnesium
(2) argon (4) sodium
|3||LinkA||X charge is 2+
|2||Link||same number of protons|
|35 As atomic number increases within Group 15 on
the Periodic Table, atomic radius
(1) decreases, only
(2) increases, only
(3) decreases, then increases
(4) increases, then decreases
|2||Link||use table S, more energy levels|
|36 Given the balanced equation representing a
CaO(s) + CO2(g) ==>CaCO3(s) + heat
What is the total mass of CaO(s) that reacts completely with 88 grams of CO2(g) to produce 200. grams of CaCO3(s)?
(1) 56 g (3) 112 g
(2) 88 g (4) 288 g
conservation of mass
|37 What is the empirical formula of a compound
that has a carbon-to-hydrogen ratio of 2 to 6?
(1) CH3 (3) C3H
(2) C2H6 (4) C6H2
|1||Link||reduce the formula
|38 Given the balanced equation representing a
H2(g) + Cl2(g) ==>2HCl(g) + energy
Which statement describes the energy changes in this reaction?
(1) Energy is absorbed as bonds are formed, only.
(2) Energy is released as bonds are broken, only.
(3) Energy is absorbed as bonds are broken, and energy is released as bonds are formed.
(4) Energy is absorbed as bonds are formed, and energy is released as bonds are broken.
|3||Link||released energy is a product, right
of the arrow
bonds are broken then formed
|39 Which solution has the highest boiling point at
(1) 0.10 M KCl(aq)
(2) 0.10 M K2SO4(aq)
(3) 0.10 M K3PO4(aq)
(4) 0.10 M KNO3(aq)
|3||Link||van't Hoff find the one that breaks
up into the most particles
K3PO4 -4 KNO3 - 2
|40 What is the molarity of 1.5 liters of an aqueous
solution that contains 52 grams of lithium
fluoride, LiF, (gram-formula mass =26 grams/mole)?
(1) 1.3 M (3) 3.0 M
(2) 2.0 M (4) 0.75 M
|1||Link||52g/26g/mol= 2 moles
2 moles/1.5L= 1..3M
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