Chemistry : Organic Vs Inorganic Acids

The dependent variable in the experiment was the temperature and energy absorbed by the water.

The only dependent variable is the time the ice cubes take to melt. The controlled variables are the size of the ice cube, and the room conditions they melted in. Aim: To see which type of ice cube melts faster (the one with or without sugar).

When combined Sodium Bicarbonate and Hydrochloric Acid, Carbon Dioxide is produced. The two chemicals do not undergo a change in color but a chemical change when CO2 is produced.

Students will place a potato cube into a test tube and add 3 ml of H202 into each tube. Then students will wait one minute and record the height in cm of the bubbles and rate how rapidly the solution bubbles on a scale of 0-5. (0=no reaction, 1=slow,……. 5= very fast.)

1. For this experiment, what were the independent variable and the dependent variable? What were the constants?

How concentration affects the rate of reaction between Hydrochloric Acid and Sodium Thiosulphate Chemistry Coursework How Concentration Affects a Reaction Aim: The aim of this experiment is to find out how concentration affects the rate of reaction between Hydrochloric Acid and Sodium Thiosulphate. Introduction: This experiment will be carried out by drawing a cross on a piece of paper and mixing hydrochloric acid and sodium thiosulphate together to see if the cross disappears. The concentration of hydrochloric acid would change every reaction to show that concentration effects a reaction.

The independent variable for the experiment was the paper towels. The dependent variable was the absorbency and strength. The constants for the experiment were the size of the paper towels that were used, the amount of water, the size of the beaker, the size of the cylinder and the amount of the weight.

Dependent: The dependent variable is the time as it will be the aspect being measured and recorded.

4. The Independent variable is the dissolved oxygen and the dependent variable is the number of fish observed.

Variables: In this experiment, the temperature (in degrees Celsius) of the chemicals is the independent variable. To change the temperature, the materials are placed in a bath of water being heated by a hotplate.

The research question for the Alka Seltzer Lab is, “What is the effect of different surface areas of an Alka Seltzer tablets reaction time?’. Inside of an Alka Seltzer tablet there are two key ingredients; which are citric acid and baking soda. When a tablet is dropped into a liquid, the acid and baking soda show a physical reaction of fizzing and eventually dissolving. Materials needed for this lab was goggles, aprons, beakers, water of the same temperature, mortar pestle, and three alka seltzer tablets. In each beaker there was 150 mL of water. The first tablet was a full tablet, the second was broken into quarters, and the last tablet was crushed in a mortar pestle. The dependent variable of the lab was the rate of reaction, and the independent

Dependent variable- jar volume after the egg is out (ml). Controlled variables- jar, same amount of water and corn syrup, same number of days it stayed there, same grade egg, same process, same surface we put them on. The experimental group are both the eggs because they both got tested on. We didn't have a control group because we didn't have an egg that didn't go through a test. The experimental group is the group you experiment on. The control group which doesn´t get tested

To start off the experiment 25mL of water was placed into a labeled beaker and tested for the pH using pH test strips. Next the antacid tablet was placed in the solution and timed for how long it took to dissolve the tablet. Finally the temperature was measured. This same process was repeated for the acidic solution, and finally for the basic solution. After each experiment the pH, the reaction time, and the temperature of the beaker were recorded into a table. For this experiment the independent variable was the substance used (acid, neutral or base), and the dependent variable was the reaction time of each substance. The constant conditions of this experiment included the amount of substance being used, and the placing of one antacid tablet into each beaker. The experimental group was the acidic and basic solution, and the control group was the neutral

The independent variable is sugar concentration. This will be changed by using solutions with different amounts of sugar (2%, 6%, 10%).

Independent variable: We will change the amount of drops of Hydrochloric acid added to the Amylase. ( 5 drops, 10 drops, 15 drops)