Introduction

In chemistry, we divide compounds into two kinds, one is called ionic compounds and the other one is called molecular compounds (covalent compounds). Specifically, an ionic compound is a compound that ions are held together in a lattice structure by ionic bonds; a molecule compound is a compound that two or more atoms held together by covalent bonds. Due to the different form of bonds, different compounds have different properties. For example, ionic compounds are often hard; have high melting and boiling point; good at conducting heat and electricity. However, molecular compounds are often soft; have low melting and boiling point; not good at conducting both heat and electricity.
Owing to the reason that ionic compounds and molecular compounds have diversity in the conduct of electricity, therefore we can measure their conductivity by dissolves them in distilled water (ionic compounds will produce ions and enable the solution to conduct the electricity) and then classify them into three kinds of electrolyte: nonelectrolytes (not dissociate, have very low conductivity), strong electrolytes (totally dissociate, have very high conductivity), and weak electrolytes (dissolve a little, have not very low but not very high conductivity). In this way, in the first chemistry lab experiment, I measured the conductivity of diverse of compounds and the same solution at the different concentration to see their conductivity and compute whether it is an ionic compound or molecular compound. Here is what I got.

Data and calculation

A – Classes of compounds

Solution

Conductivity (μS/cm)

Distilled Water

19

0.05M CH3OH

22

0.05M C2H6O2

22

0.05M NH3

334

0.05M CH3COOH

290

0.05M KBr

6132

0.05M HCl

9089

Tap Water(control)

535

In Part A, I measured the same concentration but different kinds of 8 compounds, from the data table above, it is clearly shows that distilled water has the lowest value of conductivity, and 0.05M of HCl has the highest value of conductivity.
If place them from low to high, it will looks like this:
Distilled water < CH3OH = C2H6O2 < CH3COOH < NH3 < Tap Water < KBr < HCl

Classifying them to nonelectrolytes, strong electrolytes, and weak electrolytes, I can get that:
Nonelectrolytes
Distilled water
CH3OH
C2H6O2 strong electrolytes
KBr
HCl

weak electrolytes
NH3
CH3COOH

B – Effect of concentration

Conductivity(μS/cm)
Volume(Drops)
AlCl3
NaCl
CaCl2
CH3OH
0
11
9
7
11
1
254
131
152
7
2
393
214
328
7
3
513
271
442
7
4
680
344
608
7
5
846
414
757
6
6
989
476
906
7
7
1091
501
1025
7
8
1289
609
1178
7

In Part B, I measure the conductivity of the same solution in the different concentration.
Slope (AlCl3) = 159.75
Slope (NaCl) = 75
Slope (CaCl2) = 146.375
Slope (CH3OH) = -0.5
Therefore, the conductivity of 1.0M of AlCl3, NaCl, and CaCl2 increase as the concentration of the solution increase; however, the conductivity of CH3OH is decrease when the concentrations increase.
Over all, to