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: