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/cm3 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/cm3 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/cm3 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.
Data Collected:
Part 1
Aqueous
substances
Observations after reacting with 0.02 M Na2CO3
Mg(NO3)2
Ca(NO3)2
Ba(NO3)2
Part 2
Aqueous
substances
Observations after reacting with 0.10 M AgNO3
NaCl
NaBr
NaI
Part 3
Metallic
substances
Observations during and after reaction with atmospheric O2
Mg
Al
Si
Part 4
Metallic
substances
Observations during and after reaction with aqueous HCl
Mg
Al
Si
Discussion:
Conclusion:
Date Completed & Signature: