Water of Crystallization in Washing Soda

To make the results of the experiment valid four variables to take into account are if the freezer is the same temperature for both tests, the water is the same water just different temperatures, the ice cube trays are the same size, and finally both trays are in the freezer for the same amount of time.

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).

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

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.

I took the graduated cylinder and started filling it up with water until the bottom of the meniscus was to the the 100.0 mL mark with the assistance of a dropper pipet. I then took the 13 x 100 mm test tube and slowly poured the water from the graduated cylinder into the test tube until it was full to the top. I then poured the water in the test tube out into the sink and put the graduated cylinder on the counter so I can get an accurate measurement of the lower meniscus to record on my data table. I once again followed the same procedure again filling a second test tube with water from the graduated cylinder then setting it on a straight surface to get an accurate measure of the volume to

Independent: The independent variable in the following experiment is the temperature as it is what is being changed and will impact the overall outcome of the experiment.

The mass percent of water was determined using the mass of water and dividing it by the total mass of the hydrate and then multiplying that answer by 100%. The number of moles of water in a hydrate was determined by taking the mass of the water released and dividing it by the molar mass of water. The number of moles of water and the number of moles of the hydrate was used to calculate the ratio of moles of water to moles of the sample. This ratio was then used to write the new and balanced equation of the dehydration process. The sample was then rehydrated to the original state and the percent of the hydrate recovered was calculated by using the mass of the rehydrated sample by

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.

equilibration period, immerse all six respirometers into the water completely. Water will enter the pipette for

The independent variable of my experience meant is what I’m going to be changing which is the substance, coffee. The dependent variable of my experiment is the Daphnia’s heartbeat per minute, which will also increase immensely. The units I will be using to collect the data is one minute per trial.

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

The dependent variable in the experiment was the percent change in mass and the independent variable was the solution. This is a quantitative experiment because it was measuring the percent change in the mass of the potatoes.

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

Remove the tubes and add 2-3 drops of Iodine – potassium – iodide solution to each tube.

A standard acid solution like HCl can be used as titrant for the analysis of both soda ash and a carbonate-bicarbonate mixture. In the analysis of soda ash, the volume needed to neutralize the soda ash is used to compute for its alkalinity, in this experiment we obtained a 17.6 % alkalinity with an error of 15.14% In the analysis of a carbonate-bicarbonate mixture two indicators (phenolphthalein and methyl orange) were used. The first endpoint determines the half-neutralization of the carbonate and the second determines that of the