College

Name: Maycrlus Jompleth Charon
Period:

**Chemistry Semester-1 Final Written Exam (Graphing and Density)**

1. Potassium nitrate [tex]\(\left( \text{KNO}_3 \right)\)[/tex] is a chemical compound with many uses, including as a food preservative and fertilizer. It is an ionic compound and dissolves in water. The amount of [tex]\(\text{KNO}_3\)[/tex] that dissolves depends on the temperature of the water.

**Task**: Graph the data below, which shows the solubility of potassium nitrate at varying temperatures of water. Ensure that the independent variable (the variable that causes the change) corresponds to the [tex]\(X\)[/tex] axis, and the dependent variable (the variable that depends and responds to what's being directly manipulated or tested) corresponds to the [tex]\(Y\)[/tex] axis. Make sure to appropriately scale and label your axes.

[tex]
\[
\begin{array}{|c|c|c|c|c|c|c|c|c|c|c|c|}
\hline
\text{Temp (°C)} & 0 & 10 & 20 & 30 & 40 & 50 & 60 & 70 & 80 & 90 & 100 \\
\hline
\begin{array}{c}
\text{Solubility} \\
(g/100 \, \text{mL})
\end{array} & 13 & 21 & 32 & 46 & 64 & 86 & 110 & 138 & 169 & 202 & 246 \\
\hline
\end{array}
\]
[/tex]

Answer :

To solve this problem, you'll need to create a graph that represents the solubility of potassium nitrate ([tex]\( KNO_3 \)[/tex]) at different temperatures. Here's a step-by-step guide on how to draw the graph:

### Step 1: Understand the Variables
- Independent Variable (X-axis): Temperature in degrees Celsius ([tex]\( °C \)[/tex]). This is the variable that you control or that changes naturally, and it affects the solubility.
- Dependent Variable (Y-axis): Solubility of potassium nitrate in grams per 100 milliliters ([tex]\( g/100 \, mL \)[/tex]). This is the variable that depends on the temperature.

### Step 2: Set Up Your Axes
- X-axis (Temperature):
- You will label this axis as "Temperature ([tex]\( °C \)[/tex])".
- Choose a scale that fits the range from 0 to 100. You might use increments of 10, as the data is given in ten-degree intervals.

- Y-axis (Solubility):
- Label this axis as "Solubility ([tex]\( g/100 \, mL \)[/tex])".
- Choose a scale that includes the smallest and largest values of solubility from your table. Since the values range from 13 to 246, you might choose increments of 20 or 50 to cover the whole range.

### Step 3: Plot the Data Points
Take each pair of temperature and solubility values and mark a point on your graph:
- (0, 13)
- (10, 21)
- (20, 32)
- (30, 46)
- (40, 64)
- (50, 86)
- (60, 110)
- (70, 138)
- (80, 169)
- (90, 202)
- (100, 246)

### Step 4: Draw the Graph
- After plotting all the points, connect them with a smooth line. This will typically be a curve that increases as the temperature increases, showing the relationship between temperature and solubility.

### Step 5: Add Details
- Title: Give your graph a title, such as "Solubility of Potassium Nitrate at Varying Temperatures".
- Grid (optional): Adding a grid can make it easier to read the graph.

By following these steps, you’ll be able to create a clear visual representation of how the solubility of potassium nitrate changes with temperature. If you have any graphing tools, like graph paper or digital software, you can use them to draw this more accurately.