TEST
CHEMCOM CHAPTER 2A/B

1) The experiment in which pennies were put into solutions of hot NaOH and zinc proved
a) copper atoms will change to zinc atoms
b) copper atoms will change to brass atoms
c) both a and b
d) coatings of zinc and brass change copper's properties
e) resources like copper can be lost by chemical changes

2) " In chemical reactions matter is neither destroyed or made" is a statement of
a) the law of molar masses
b) law of conservation of matter
c) law of conservation of energy
d) law of mass action
e) law of action and reaction

3) According to this law the number of atoms after a reaction takes place is
_________________the number of atoms present before a reaction takes place
a) the same as b) greater than c) less than

3) The total number of atoms in the entire chemical formula:
4 Ca(OH)₂ is
a) 2 b) 3 c) 4 d) 12 e) 20

5) The average person creates 4 pounds of garbage per
a) day b) week c) month d) year e) lifetime

6) A sanitary landfill requires a) garbage be burned daily
b) garbage be covered daily c) recyclable materials be removed before
garbage is disposed d) waste be tested for safety before disposal
e) all of these

7) Changing natural resources into manufactured items usually involves
a) producing waste b) a chemical reaction c) generating pollution
d) reducing available resources e) all of these


8-9) When methane or natural gas is burned the following reaction takes place:
CH₄ + 2 O₂ ---> CO₂ + 2 H₂O + heat

8) What happens to the atoms in methane
a) they are destroyed and changed into energy
b) they are made into fire c) they help form water
d) they help form carbon dioxide e) both c and d

9) AS methane is burned how does this effect the supply of this resource?
a) it doesn't because it can be recycled
b) its renewable and will be rapidly replaced
c) it doesn't because it can be reused
d) it can't be recovered and its nonrenewable, so the supply is lessened
e) a,b,c

10) Nonrenewable resources are produced by the earth
a) at a relatively fast rate b) at a relatively slow rate
c) as quickly as they are needed d) in large quantities
e) in small quantities

11) -12) The following "chemical equation" describes the use of all resources in a general way

Resource A + Resource B + Resource C ---> Manufactured Item + Garbage
+ Pollution

11) The atoms of the resources are rearranged but not lost in this process a) true b) false

12) The weight of the reactants would equal the weight of the products
a) true b) false

13) Chlorine is a yellow gas(1) which is more dense(2) than air. It forms hydrochloric acid when breathed into the lungs(3) and kills bacteria(4) when
dissolved in water(5) How many of these 5 properties are physical?
a) 0 b) 1 c) 2 d) 3 e) 4

14) Density, boiling point, melting point and activity all follow predictable patterns on the periodic chart. Why does this occur?
a) the elements were arranged this way
b) the electron structure of atoms follows a pattern
c) the size of atoms follows a pattern on the chart
d) the reason is not understood

15) During the labs done in class many chemical changes have been observed.
What observation will tell you a chemical change has happened?
a) a gas is produced b) a temperature change takes place
c) a color change takes place d) a solid is formed(a precipitate)
e) all of these

16) Which of these are not a property of metals
a) they react with acids
b) they are malleable
c) they conduct electricity
d) they form negative ions
e) they react with nonmetals

17) The elements in the modern periodic chart that we use is arranged by increasing
a) density b) size c) melting point d) atomic number e) activity

18) The density of calcium is 1.55g/cc. The density of barium(Ba) is 3.50g/cc. What is the density of magnesium(Mg)
a) less than 1.55g/cc b) 2.52g/cc c) 5.05 g/cc d) cant be determined

19) Fact 1: Iron is brown.
Fact 2: Iron becomes red after it is exposed to oxygen.
The first fact describes a _____________
The second fact describes a ____________
a) physical change; physical property b) chemical change; chemical property
c) physical property; chemical change d) physical property; physical property
e) physical property; physical change

20)The Russian chemist who proposed the first periodic chart based on physical and chemical properties was a) B.F Stroganof b) D. Mendeleev c) J.Llennodo d) K.Serasira e) none of these

21)In a metal family the most active elements are found_____________________
a) at the bottom b) at the top c) in the middle d) on the right edge
e) on the left edge

22) Which of these elements has chemical properties like most Argon(Ar)
a) Cesium(Cs) b) Lanthanum(La) c) Strontium(Sr) d) Iodine(I)
e) none

23) The value of gold was based upon its unique physical properties
According to the periodic chart which one of these properties would be true about gold
a) it is very active b) it has a relatively low density
c) it does not react with other elements easily d) it has a low melting point e) it has a low boiling point

24) Which of these factors is not necessary in the process of galvanic corrosion
a) two nonmetals must be present
b) two metals must be present
c) an electrolyte must be present
d) substances must have different activities

25) Element in the same family have similar chemical properties because
a) they have the same activity b) they have the same number of e- in their last shells c) they are the same size of atoms d) they all atomic number e) none of these

Essays 10 POINTS EACH Name ___________________________________

1) Examine these equations.Balance the equation

a) __ CaI₂ + __Ba(NO₃)₂ ---> __Ca(NO₃)₂ + __BaI₂

WRITE the above equation in words_________________________________________
__________________________________________________________________________


b) The next reaction shows the burning of propane

__ C₃H₈ + __ O₂ -----> __ CO₂ + __ H₂O + energy

WRITE the above equation in words_________________________________________
__________________________________________________________________________

Sulfuric acid is neutralized by a base in the following reaction:
c) __H₂SO₄ + __NaOH ------> __ H₂O + Na₂SO₄

Write out in words ______________________________________________________

ALL BLANKS WILL NOT BE FILLED IN ON THE CHART

Element Properties

D Metalloid which forms the compound DCl4

J Nonmetal; relatively high density
high melting point, and large size

L Metal; forms a +2 ion; very dense;
has nearly 200 x heavier than "M"

M Nonmetal; forms the compound M2O; very low
melting point and density

Q Metal ; forms the compound QCl2 low
density metal; modertely active; low
melting point

a) List the metals from the most active to the least active______ _____ _____ _____

b) Based upon the periodic chart which above solution(s) would Magnesium react with

_______________________________________________________________________________

4) Analyze the following data and classify each substance as a metal, nonmetal or metalloid

Element	Malleable or brittle/color	Shiny or dull	Conductor?	Reacts with acid?	Metal, Nonmetal or metalloid?
A	brittle/yellow	dull	yes	no	.
B	malleable/silver	shiny	yes	yes	.
C	brittle/grey	dull	no	no	.
D	brittle/black	dull	yes	no	.
E	malleable/grey	shiny	yes	yes	.

Substance B and C react with each other and form the compound BC₂ Clue: check charges
What family does B belong to ________________
What family does C belong to ________________ ("C" is not carbon)

5) In water treatment "floc" is formed in a chemical reaction to remove clay from drinking water. The forming of "floc" is described below

To the water is added sodium hydroxide and alum or aluminum sulfate. They dissolve, react, and form a solid floc. A second product is also formed which dissolved in the water. From the substances below write the equation described above. Leave out the water.

a) What happens to the atoms of sodium hydroxide in this reaction
_________________________________________________________________________________
b) Floc must be insoluble in water to remove clay. What clue is given in your chemical equation that this substance doesn't' dissolve?
_________________________________________________________________________________