Grade 10 Exam Review #1- Chemistry Solutions

Grade 10 Exam Review #1- Chemistry Solutions

1.What is the definition of chemistry?
The study of the composition of matter and its properties and the ways in which matter interacts combines, and changes

2.What are subatomic particles?
A particle smaller than an atom (protons, neutrons, electrons)

3.Where do you find the atomic number and mass?
Atomic number is upper left and atomic mass is upper right for our periodic table we use.

4.How can you determine what the number of protons, neutrons and electrons are in each element?
# Neutrons = rounded atomic mass –atomic number

# Protons = atomic number

# Electrons = # protons for a neutral ion.

5.Copy and fill out the following table:

6.What are the names of all the families we have learned about.
a)Alkali Metals b) Alkaline Earth Metals c) Chalcogens d) Halogens e) Noble Gases

7.Where are all the families located on the periodic table.
a) column 1 –alkali metals b) column alkaline earth metals 2 c) column 6 –chalcogens d) column 7 –halogens e) Column 8–noble gases

8.What are the rows called on a periodic table?
Periods

9.What are the columns called?
Groups or families

10.What is a valence shell?
The most outer shell of an element.

11.How many electrons are found in the valence shells of the following elements:

a.Oxygen - 6.

b.Beryllium - 2.

c.Sodium - 1.

d.Krypton - 18.

12.What are metals and where are they found on the periodic table?
Metals are solids at room temperature that are dense and shiny materials. They are found to the left and beneath the ‘step’on the periodic table.

13.What are metalloids and where are they found on the periodic table?
Metalloids share characteristics of both metals and non-metals and are also called semimetals. They are found on the border or ‘step’between metals and nonmetals.

14.What are non-metals and where are they found on the periodic table?
Non-metals are gases that are found on top and to the right of the ‘step’.

15.What does it mean for an element to be reactive?
An element reactivity depends on the exchange of electrons, to fill its valence shell, becoming more stable than it originally was.

16.What family is the most reactive and why?
The Alkali Metals because they only need to lose one electron.

17.What are stable octets?
A stable octet is when an element has a full valence shell that gained, lost or shared electrons.

18.What family is considered to be the most stable and why?
The Noble gases because they already have a full shell.

19.What is matter? What are the three states of matter?
Matter is all forms of a substance. Solids, Liquids and Gases.

20.What is the difference between elements and compounds?
Elements are single atoms where as compounds are comprised of two or more elements that bond together (e.g., NaCl, Sodium Chloride).

21.Name 3 different compounds
a) NaCl, Salt b) CH4, Methane c) H2O, Water

22.What information does a Bohr model show?
The Bohr model shows # of protons, neutrons and electrons

23.Draw a Bohr model for the following elements:

a.Aluminum

b.Potassium

c.Magnesium

d.Fluorine

24.What is an ion?
An Ion is a charged atom, positive or negative.

25.What is a cation?
A Cation is a positively charged Ion.

26.What is an anion?
An Anion is a negatively charged Ion.

27.What does the term combining capacity mean?
Combining capacity is the number of electrons it needs to gain or lose to obtain a full shell.

28.What is the combining capacity of the following elements:

a.Boron - 3+

b.Calcium - 2+

c.Helium - 0

d.Chlorine - 1-

29.Atoms that lose electrons will have what: a
positive or negative charge?
Positive charge.

30. What is an ionic compound?
An Ionic Compound is when positive and
negative ions bond together.

31.Why do non-metals need to bond with metals?
Non-metals give away their electrons to Metals who need them.

32.What is an ionic bond?
An Ionic Compound is when positive and negative ions bond together.

33.Use a Bohr model to show the ionic bond between Lithium and Fluorine.

34.What is the ionic compound formula for the following elements (cross-over method):

a.Calcium and Iodine –CaI2

b.Aluminum and Chlorine –AlCl3

c.Magnesium and Phosphorus –Mg3P2

d.Mg + F –MgF2

e.Li + S –Li2F

35.Draw the ion Bohr diagram for the following ions:

a.Na+ (put Na+ in center of diagram)

b.S2- (2e first shell, 8e second shell)

c.Mg2+(put Mg2+ in center of diagram)

36. Name the following ionic compounds

a.SrS - strontium sulfide

b.AlCl3 - aluminum chloride

c.NaF - sodium flouride

37.Put the following ionic compounds in their chemical formulas

a.Lithium Sulfide –Li2S

b.Magnesium Oxide - MgO

c.Calcium Fluoride –CaF2

38.What is the Stock Naming System?
Using Roman Numerals to represent the ion charge on a multivalent metal.

39. How do you find the charge of the cation when dealing with multivalent metals?
The anion will always have a definite charge. Since the overall charge is neutral, you can determine the positive charge by finding the total negative side charge then balancing it with the same positive side charge dividing that charge between the number of ions

40.Name the following ionic compounds using the stock system (this means they have multivalent metals in them and you must use roman numerals):

a.PbS2 –lead(II) sulfide

b.TiCl3 –titanium(III) chloride

c.HgI–mercury(I) iodide

41.Given the name of the ionic compound, determine its chemical formula:

a.iron (III) chloride –FeCl3

b.copper (I) bromide - CuBr

c.lead (IV) sulfide –PbS2

42.What is a multivalent metal?
A metal that can have more than one valence state: ie Fe2+ or Fe3+

43. What is a covalent/molecular bond?
A chemical bond that involves the sharing of electrons.

44.What does the term diatomic mean and what are the 7 diatomic elements?
Elements that consist of two atoms. hydrogen, nitrogen, oxygen, fluorine, chlorine, iodine, bromine.

45. Name the following covalent/molecular compounds (remember to use prefixes!)

a.CO2 - carbon dioxide

b.N2O -dinitrogen oxide

c.CF4 - carbon tetrafluoride

d.BCl3 - boron trichloride

46.Write out the formulas of the following molecular compounds

a.nitrogentriiodide–NI3

b.sulfurtetrabromide–SBr4

c.carbon tetrachloride –CCl4

d.dinitrogenpentoxide - N2O5

47. What are polyatomic ions?
Polyatomic ions are electrically charged collections of two or more atoms. (e.g., ammonium ion, NH4+)

48. Using the table, write out the correct formulas for the following polyatomic compounds.

a.aluminum hydroxide - Al(OH)3

b.beryllium nitrate - Be(NO3)2

c.lead (IV) carbonate - Pb(CO3)2

d.scandium phosphate - Sc(PO4)3

49.What is the law of conservation of mass.
The law states that matter can be changed from one form into another.

50.When balancing chemical equations, we use certain terms. What do the following terms mean:

a.Word equation –a chemical reaction described in words

b.Skeletal equation–a chemical reaction described with symbols that is not yet balanced

51. For the following equation, identify the reactant, product and coefficients.

a.2 Ca + O2 ▶ 2 CaO - Ca + O2 = reactants, CaO= product, 2 = coefficient

52. Balance the following skeletal equations:

a.CH4 + 4Cl2 ▶ CCl4 + 4HCl

b.3Mg + N2 ▶ Mg3N2

c.C3H8 + 5O2 ▶3CO2 + 4H2O

d.Pb(NO3)2 + 2KI ▶ PbI2 + 2KNO3

53.Write out the formulas for the following compounds (you should know these my memorization):

a.Ammonia –NH3

b.Water –H2O

c.Methane –CH4

d.Carbon dioxide –CO2

e.Hydrogen peroxide –H2O2

54.Translate these formulas into word equations (remember to watch for multivalent metals, diatomic elements and molecular compounds!):

a.Fe2O3 + H2 Fe + H2O –iron (III) oxide + dihydrogen (hydrogen gas) react to form iron + water

b.N2 + O2 N2O–dinitrogen and oxygen gas react to form dinitrogen monoxide

c.CH4 + O2CO2 + H2O–methane and oxygen gas react to form carbon dioxide and water

d.C + H2O CO + H2 - carbon and water react to form carbon monoxide and dihydrogen

55.Translate the following word equations into formulas.

a.Dinitrogenmonosulfide breaks down to yield hydrogen gas and sulfur –N2S -> H2 + S

b.Bromide gas and calcium iodide react to form iodine gas and calcium bromide. - Br +CaI2 -> I2 + CaBr2

c.Iron (III) sulfate and potassium hydroxide combine to form potassium sulfate. –Fe2(SO4)3 + KOH -> K2SO4

d.Sulfur and oxygen gas combine to form sulfur dioxide. - S + O2 -> SO2

56. What are the 5 major reaction types.
a) double replacement/displacement b) single replacement c) combustion d) synthesis e)decomposition

57. Identify the following formulas with their correct reaction type.

a.H2 + O2H2O - Synthesis

b.HgOHg + O2 - Decomposition

c.C3H8 + O2 CO2 + H2O - Combustion

d.Fe2 (SO4)3 + KOH K2SO4 + Fe (OH)3 - Double Replacement

e.H2S + Cl2  S8 + HCl - Single Replacement

58.What is the definition of an acid?
A liquid that isn’t water or a base with a pH lower than 7

59.What is the definition of a base?
A liquid that isn’t water or an acid with a pH higher than 7

60.What are indicators?
A material that can determine if a liquid is an acid or a base. (e.g., litmus paper, Phenolphthalein)

61.Is our stomach acidic or basic?
Acidic.

62.How does an alkaselzer work in our stomachs?
Alka-Seltzer works by neutralizing your acid when your stomach gets to acidic.

63. What does pH stand for?
Power of Hydrogen.

64.What numbers on the pH scale would indicate a chemically neutral object? An acidic material? A basic material?
a)Neutral= 7 b)Acids= 1-6 c) Bases= 8-13

65.Describe the reactivity of acids and bases with metals.
Acids cause bubbles at the source, while bases do nothing.

66.Describe the conductivity of acids and bases.
The conductivity depends on the electrolytes. Strong acids and bases will break into ions easily

67.What are the two products formed in a neutralizing reaction between an acid and a base?
H2O and salt (any ionic solid!)

68.Write a balanced formula for the following neutralizing reactions.

a.Hydrochloric acid and sodium hydroxide - HCl + NaOH -> NaCl + H2O

b.Sulfuric acid and potassium hydroxide –H2SO4 + 2KOH -> K2SO4 + 2H2O