Pre-lab 4
Title: Periodic Trends
Date: 9/12/18
Unknown: N/A
Purpose: The purpose is to observe chemical properties of elements in periods (rows) and in
groups/families (columns).
Balanced Equations:
Part 1: Chemical Properties of the Alkaline Earth Metal Nitrates
Mg(NO3)2(aq) + Na2CO3(aq) MgCO3(s) + 2NaNO3(aq)
Ca(NO3)2(aq) + Na2CO3(aq) CaCO3(s) + 2NaNO3(aq)
Ba(NO3)2(aq) + Na2CO3(aq) BaCO3(s) + 2NaNO3(aq)
Part 2: Chemical Properties of the Halides
NaCl(aq) + AgNO3(aq) AgCl(s) + NaNO3(aq)
NaBr(aq) + AgNO3(aq) AgBr(s) + NaNO3(aq)
NaI(aq) + AgNO3(aq) AgI(s) + NaNO3(aq)
Part 3: Reactivity of Third Period Elements with Oxygen
2 Mg(s) + O2(g) 2 MgO(s)
4 Al(s) + 3 O2(g) 2 Al2O3(s)
Si(s) + O2(g) SiO2(s)
Part 4: Reactivity of Third Period Elements with Hydrochloric Acid
Mg(s) + 2 HCl(aq) MgCl2(aq) + H2(g)
2 Al(s) + 6 HCl(aq) 2 AlCl3(aq) + 3 H2(g)
Si(s) + 4 HCl(aq) SiCl4(aq) + 2 H2(g)
Table of Chemical and Physical Properties:
Chemical Name Molecular
Weight
Boiling Point Density Safety
Barium nitrate
Ba(NO3)2
261.34
529 C 3.24 g/cm
3 Poisonous. Do
not mix with
flammable
materials.
Silver nitrate
AgNO3
169.87 440 C 4.35 g/cm 3 Corrosive and
toxic. Avoid
skin contact.
Sodium Chloride
NaCl
58.44 801 C (melting
point)
2.16 g/cm3 Nonhazardous
Magnesium
Mg
24.31 650 C (melting
point)
1.738 g/cm3 Flammable. Do
not stare are
flame during
reaction with
magnesium and
oxygen
Calcium
Ca
40.08 842 C (melting
point)
1.54 g/cm3 Flammable
gases produced
with in contact
with water
Aluminum
Al
26.98 2460 C 2.7 g/cm 3 Flammable
Silicon
Si
28.09 2355 C 2.33 g/ml Nonhazardous
Oxygen
O
15.999 u 90.188 K 1.429 g/L Flammable gas
Hydrochloric
acid
HCl
36.46 110 C 1.18 g/cm 3 Toxic and
corrosive. Can
cause irritation
or burns to skin.
Procedure Observation
Part 1
1. Add 1ml of each solution to each labeled test tubes
2. Add about three drops of solution from tube 4 into tubes 1-3 and record
observations.
Part 2
3. Repeat steps 1&2 for part 2 with different solutions
Part 3
4. On a watch glass, add small pieces of magnesium, aluminum and silicon and
observe physical appearances.
5. Take turns placing each substance over an open flame and record
observations.
Part 4
6. Place a small piece of magnesium, aluminum, and silicon in separate test
tubes and label appropriately.
7. Place 1ml of HCl into each test tube and record observations.
All observations are documented in the data
tables below
Data Collected:
Part 1
Aqueous
substances
Observations after reacting with 0.02 M Na2CO3
Mg(NO3)2 No physical change observed
Ca(NO3)2 Semi-solid, cloudy substance formed and sunk to the bottom of the test tube
Ba(NO3)2 Solution became milky and slowly sunk to the bottom
Part 2
Aqueous
substances
Observations after reacting with 0.10 M AgNO3
NaCl Slow reaction. Started a bluish color and became milkier
NaBr Top layer of solution turned a milky color and slowly spread throughout
NaI Slow reaction. Went from a translucent yellow to a bluish color
Part 3
Metallic
substances
Observations during and after reaction with atmospheric O2
Mg Produced a bright white flame and sparks
Al The aluminum turned bight orange and produced an orange flame
Si No reaction observed
Part 4
Metallic
substances
Observations during and after reaction with aqueous HCl
Mg Immediately bubbled. Condensation and steam produced. Test tube was warm
Al Slow reaction. Solution bubbled and aluminum piece dissolved in solution
Si No reaction observed
Discussion:
In this lab we observed physical and chemical properties. For example, we observed a
chemical reaction when magnesium was introduced to oxygen. It produced a bright white flame.
Changes in color are physical changes like when AgNO3 was introduced to NaI.
Conclusion:
Some chemicals are more reactive than other. We can observe physical and some
chemical changes when we mixing chemicals together.
Date Completed & Signature:
——
4th pre-lab
Periodic Trends is a title that has been given to a group of people who
9th of September, 2018
N/A: N/A: N/A: N/A: N/A
The goal is to observe chemical properties of elements in periods (rows) and in combinations.
families/groups (columns).
Equations that are balanced:
Part 1: Alkaline Earth Metal Nitrate Chemical Properties
MgCO3(s) + 2NaNO3 + Mg(NO3)2(aq) + Na2CO3(aq) (aq)
CaCO3(s) + 2NaNO3 + Ca(NO3)2(aq) + Na2CO3(aq) (aq)
Ba(NO3)2(aq) + Na2CO3(aq) BaCO3(s) + 2NaNO3(aq)
Part 2: Chemical Properties of the Halides
NaCl(aq) + AgNO3(aq) AgCl(s) + NaNO3(aq)
NaBr(aq) + AgNO3(aq) AgBr(s) + NaNO3(aq)
NaI(aq) + AgNO3(aq) AgI(s) + NaNO3(aq)
Part 3: Reactivity of Third Period Elements with Oxygen
2 Mg(s) + O2(g) 2 MgO(s)
4 Al(s) + 3 O2(g) 2 Al2O3(s)
Si(s) + O2(g) SiO2(s)
Part 4: Reactivity of Third Period Elements with Hydrochloric Acid
Mg(s) + 2 HCl(aq) MgCl2(aq) + H2(g)
2 Al(s) + 6 HCl(aq) 2 AlCl3(aq) + 3 H2(g)
Si(s) + 4 HCl(aq) SiCl4(aq) + 2 H2(g)
Table of Chemical and
