Experiment: Testing The Ph Level Of Salt

Purpose/Hypothesis: The purpose of this experiment is to use both cabbage juice and pH paper to determine the pH of household items. This way, we can tell which products are basic and which one are acidic. If we use cabbage juice as an universal pH indicator by comparing it to pH paper then pH determined by the cabbage juice will be unstable because by using cabbage juice, it can be different depending on how diluted it is.

There are several parts to the experiment such as both the independent and dependent variables. The independent variable is controlled or changed during the experiment to test the effects on the dependent variable. The dependent variable is tested and measured during the test .A controlled variable is an example for an independent variable would be variable that is held constant throughout the experiment. An example is a theory that could extend a person’s life expectancy. The independent variable is the amount of vitamin given to the subject within the experiment. The dependent variable is the life span

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.

“The pH of a solution is a measure of the molar concentration of hydrogen ions in the solution and as such is a measure of the acidity or basicity (sic) of the solution. The letters pH stand for power of hydrogen and the numerical value defined as the negative base 10 logarithm of the molar concentration of hydrogen ions.” (PH, 2002). The pH scale is from 0 to 14. When the pH is higher, the hydrogen ions are fewer and the substance considered alkaline. This means when a pH unit increases by one, there is a tenfold change in the hydrogen ion. For example, if a substance has a 7 pH, it has 10 times as many as hydrogen ions available as 8 pH. A lake having a water pH between 6.5 and 8.5 is considered to be neutral. Researchers tested Peckham Park lake water monthly from August 2015 to April 2016 for water pH levels. A water quality PH test strip taken from a jar and dipped into the lake. After a few minutes, the strip will turn a color and this color determines the pH. The jar the strips came in has a chart of the colors on the back which compared to the color on the strip. The lake tested monthly using the PH test strips, which show the pH level, hardness, toxic, etc. using color-change

weak bases). After ranking the pH of these solutions, you will then test your predictions in the laboratory.

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

Problem & error: Write a paragraph about the issues you had in performing this lab. What went well, what did not go so well? What could you have done to improve your performance on the lab?

The purpose of this experiment was to find the amount and percent of water in a hydrated salt. Hydrated salt contains water molecules chemically bound to it while anhydrous salt is a substance that fire can readily remove the water molecules. Using the gravimetric analysis method, the sample salt was measured, heated, and was measured again after cooled down to room temperature; this procedure allowed the weight of water lost in the salt to be obtained. After two trials, the water in the salt was determined to have an average percent water of -35.04%. The null hypothesis, the heat will not affect the amount of water lost, was rejected ,however, the alternative hypothesis, the heat will allow for there to be water lost, was not supported.

When using different methods to measure pH levels there are some tools that can be useful. Some more than others but by putting into action the different methods it may determine which tools will work best and give the best results when testing the pH within a solution. The pH, which stands for the proportion of hydrogen ions in a solution, could be acidic (acidosis), neutral or basic (alkaline). The pH scale goes from numbers 1 through 14. A pH of 7 is neutral;

The number of drops a penny can hold is affected by the type of liquid. Will the number of drops on the penny until it overflows change if I change the liquid from water to sodium chloride water and by how much will it change? To investigate this, there needs to be variables that are not changed when experimenting. The penny is the dependent variable because it depends on the number of drops to overflow and the drops of the liquid the independent variable as it does not change or depend. The controlled variables include using the same penny, applying the same amount of pressure on the dropper for each drop, the height of the drop that is falling onto the penny, and using the same dropper. The independent variable is changed from

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

The independent variable is the salt solution concentration. The dependant variable is the mass of the potato. The control variable is the distilled water.

The manipulated variable in our project is sodium chloride, commonly known as salt. Sodium chloride is a cube-shaped mineral that is mined all over the world. It is known scientifically as NaCL, and it is made up of 40% sodium and 60% chlorine. Sodium chloride is essential to most living things on Earth. For example, the intake of sodium chloride is essential for the survival of plants. All plants can absorb sodium chloride, but some are more tolerant of sodium chloride than others, allowing them to withstand higher amounts of the chemical. As for all living things, too much sodium chloride can actually be toxic. An accumulation of sodium can drastically alter the chemical composition and nutritional imbalance of the plant, which can lead to changes in growth. Aside from living things, sodium chloride can also affect non living things, such as the freezing process of water. During the process of freezing, the water molecules fuse together to form ice crystals. However, sodium chloride can slow these water molecules down as they are trying to freeze into ice. Adding more salt to a consistent amount of water will prolong the amount of time needed to freeze.

2. The independent variable is thewater. The dependent variable is the candy. The controlled variable are the other materials used.