January 2006 Chemistry Regents #21-30

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Questions 1-10 Questions 11-20 Questions 21-30 Questions 31-40 Questions 41-50

Other Regents Exams

Questions	Answer	Explanations
21 What is the oxidation number assigned to manganese in KMnO4? (1) +7     (3) +3 (2) +2     (4) +4	1	K=+1     O=-2 x 4   Mn=+7
22 Which of the following aqueous solutions is the best conductor of electricity? (1) 0.10 M CH3OH     (3) 0.10 M NaOH (2) 1.0 M CH3OH       (4) 1.0 M NaOH	4	not the alcohol, NaOH, base highest concentration
23 One acid-base theory states that an acid is (1) an H– donor         (3) an H+ donor (2) an H– acceptor     (4) an H+ acceptor	3	Acids H+ donor Bases H+ acceptor
24 Positrons are spontaneously emitted from the nuclei of (1) potassium-37     (3) nitrogen-16 (2) radium-226        (4) thorium-232	1	Table N Decay Modes
25 The amount of energy released from a fission reaction is much greater than the energy released from a chemical reaction because in a fission reaction (1) mass is converted into energy (2) energy is converted into mass (3) ionic bonds are broken (4) covalent bonds are broken	1	Nuclear mass is converted to energy
	3	O=C=O  4 dots on each oxygen   KNOW IT
27 Types of nuclear reactions include fission, fusion, and (1) single replacement (2) neutralization (3) oxidation-reduction (4) transmutation	4	transmutation- creating one element from another
	2	5 carbon chain with -OH on #3 and CH3 on carbon number 2
29 When an atom becomes a positive ion, the radius of the atom (1) decreases (2) increases (3) remains the same	1	positive loses an electron, gets smaller
30 Compared to the freezing point of 1.0 M KCl(aq) at standard pressure, the freezing point of 1.0 M CaCl2(aq) at standard pressure is (1) lower (2) higher (3) the same	1	lower CaCl2 breaks up into 3 ions while KCl breaks up into 2