January 2003 Regents #11-20

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

 

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Questions

Answer Explanations
11 Which type or types of change, if any, can reach equilibrium?

(1) a chemical change, only
(2) a physical change, only
(3) both a chemical and a physical change
(4) neither a chemical nor a physical change

 
3 both
12 An increase in the average kinetic energy of a sample of copper atoms
occurs with an increase in

(1) concentration     (3) pressure
(2) temperature       (4) volume

 
2 definition temperature- average kinetic energy
13 The empirical formula of a compound is CH2 . Which molecular formula
is correctly paired with a structural formula for this compound?

 
2 carbon must have 4 bonds

formula is a multiple of CH2  

This equation represents the formation of a

(1) fluoride ion, which is smaller in radius than a fluorine atom
(2) fluoride ion, which is larger in radius than a fluorine atom
(3) fluorine atom, which is smaller in radius than a fluoride ion
(4) fluorine atom, which is larger is radius than a fluoride ion

 
2 gaining an electron will make the new ion bigger than that of the original atom
15 The high electrical conductivity of metals is primarily due to

(1) high ionization energies
(2) filled energy levels
(3) mobile electrons
(4) high electronegativities

 
3 metal- a lattice of positive nuclei immersed in a  sea of mobile electrons
16 One similarity between all mixtures and compounds is that both

(1) are heterogeneous
(2) are homogeneous
(3) combine in a definite ratio
(4) consist of two or more substances

 
4 mixtures- homo or heterogeneous

compounds-homogenous only (pure)

17 Which phase change results in the release of energy?

 
4
S L G
1------------->
2----------------------->

3                ------------->

4<-----------------------
4 there must be 4 carbons to have isomers (butane)
19 What occurs when NaCl(s) is added to water?

(1) The boiling point of the solution increases, and the freezing point
of the solution decreases.
(2) The boiling point of the solution increases, and the freezing point
of the solution increases.
(3) The boiling point of the solution decreases, and the freezing point
of the solution decreases.
(4) The boiling point of the solution decreases, and the freezing point
of the solution increases.

 
1 When a solute is added to water the boiling point increases and the freexing point decreases. This is proportional to the amount of particles in the solution (remember ionic subs. break up)
20 Which radioisotope is a beta emitter?

(1) 90Sr       (3) 37K
(2) 220Fr      (4) 238U

 
1 Use Table N- Decay Mode

 

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

 
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