Observations Of Chemical Changes: Aqueous Solutions Of Ionic Compounds

Experiment 1: Observations of Chemical Changes
Lab Partners: None
Date of Experiment: February 25, 2015
Location: My House

Abstract: The experiment intended to provide observations of chemical changes as the primary objective. The experiment was divided into two parts, first, mixing two aqueous solutions of ionic compounds. The second part involved the observance of heating and combustion reactions, using the supplied solid elements and compounds.
Experiment and Observations: The first part of this experiment involved mixing the compounds, provided by Hands-On Lab, in a 24-well plate. Aqueous solutions of ionic compounds were mixed in eight separate wells. A few drops of each solution were mixed in a well and any reaction was immediately
Metal elements and compounds provided by Hands-On Lab were first heated in a test tube over an open flame. Next, each solid substance was placed over the open flame using either tweezers or a metal spatula. A table was made noting the initial observation, including when the substance was being heated, and when the solid element or compound was ignited by a direct flame.
Mixing Aqueous Solutions of Ionic Compounds
Ionic Compounds Mixed
Description of Reaction
Chemical Reaction
HCl + NaHCO3
Colorless, effervescing
Yes
(1) NaOCl + KI
No reaction
No
(2) NaOCl + KI + Starch
No reaction
No
KI + Pb(NO3)2
Bright yellow, cloudy, precipitate
Yes
NaOH + C20H14O4
Purple, pink, opaque
Yes
HCl + C20H14O4
No reaction
No
NaOH + AgNO3
Clear pink, brown precipitate
Yes
AgNO3 + NH4OH
Milky white, cloudy precipitate
Yes
AgNO3 + NH4OH +
Chemical e. Chemical change f. Physical change g. Physical h. Chemical

Part 2
A. Sodium bicarbonate effervesced, produced bubbles of gas when mixed with Hydrochloric Acid (HCl).
C. Well A1, HCl + NaHCO3, was colorless with effervescing gas bubbles.
D. When Phenolphthalein was mixed with HCl, the solution remained colorless. Pink color would indicate the solution was a base, not vinegar (an acid).
F. When lead nitrate and potassium iodine are mixed, a yellow precipitate can be observed from the reaction.
H. A physical reaction. The CO2 bubbles being released from the can do not change the chemical composition of the beverage’s solution.
I. Photon rays caused a chemical change. The photons caused the solution to turn from colorless to purplish-brown.
J. Supports phenolphthalein as an acid/base indicator. Phenolphthalein in an acid remains colorless, when placed in a basic solution the phenolphthalein turns pink.
1. Sodium Bicarbonate. The results of the observation indicate NaHCO3 would be the unknown chemical. A test could be performed by mixing sodium bicarbonate with the chemicals and observing the reactions.
2. Decomposition of CuCO3(s)CuO(s) + CO2(g)
3. Combustion of 2Mg(s) +