Day 3 of Science Eureka Sabbat.

Today we had another lesson on chemistry. Today the lesson was conduted by nicholas and another senior that I had forgotten his name. Today lesson was like yesterday’s 7 experiments but today we had only one break. In this post I am going to tell you the things I learnt in today’s lesson, I am going to present in experiment by experiment format.

Experiment 1: Home-made pH indicator

In the experiment, we made our own pH indicator using red cabbage and ionized water. Here are some things that I learnt:

- Saliva is an acid

- Fluid in our stomach is hydrochloric acid (HCL), an acid

- To find the pH level we use: log[H+]

- Let’s take hydrogen for example:

   if hydrogen is written in H it is an atom

   if hydrogen is written in H2 it is a molecule

   if hydrogen is written in H+ it is an ion

- When using a Universal Indicator to test the pH level of something:

   for acids: 0-3 red, 3-6 yellow/orange

   for neutral: 7 green

   for alkaline: 8-11 blue, 11-14 purple

Experiment 2: Disappearing Ink

In this experiment we get to stain a cloth with a solution then we wait for the solution to dry and “disappear” then we use ammonia to make the solution reappear. Here are some things I learnt in this experiment:

- pH of ethonal: 8-9

  pH of sodium hydroxide: 12-14

  pH of ammonia: 8

Experiment 3: Rainbow Reactions

In this experiment we used sodium hydrochloric acid, hydrochloric acid, sodium carbonate and universal indicator solution to create a rainbow effect. Here are a few things I learnt:

- When acids react with:

 

Metal

Hydrochloric acid + magnesium will become magnesium chloride + hydrogen

Alkali

Hydrochloric acid + sodium hydroxide will become sodium chloride + water

Carbonate

Sulfuric acid + calcium carbonate will become calcium carbonate + carbon dioxide gas + water

- Reaction of an acid and alkali

   if acid increases, pH<7

   if alkaline is excess, pH>7

Experiment 4: Exothermic and Endothermic Reaction

In this experiment we used several combination of solution to observe the reaction both exothermic and epothermic. What I learnt:

-       When anhydrous copper (II) sulfate + deionise water exothermic reaction will take place

-       When Citric acid + sodium hydrogen endothermic reaction take place

-       When zinc + copper (II) sulfate exothermic reaction takes place

-       Exothermic reaction is when the solution gains heat and endothermic is when the solution lose heat

Experiment 5: Diffusion in Liquids

In this experiment we learnt about diffusion. Here is what I learnt:

-       Diffusion describes the spread of particles through random motion from regions of higher concentration to regions of lower concentration, concept of diffusion is tied to that of mass transfer driven by concentration.

-       Lead (II) nitrate + potassium iodine will become lead (II) iodine + potassium nitrate

-       Copper (II) sulfate + sodium hydroxide will become copper (II) hydroxide + sodium sulfate

-       Iron (II) sulfate + hydroxide will become Iron (II) hydroxide + sodium sulfate

Experiment 6: Cool Inflation

In this experiment we investigate the principle behind exothermic reactions and to gain an understanding of the products that would form in various chemical reactions

Experiment 7: The effects of concentration on a rate of reaction

In this experiment we explored the effects on the effects of concentration on a rate of reaction, we also learn that pressure of gas, temperature, surface area and catalyst also affect the rate of reaction.