Tanya measured the ability of different substances to dissolve in water by mixing the same amount of water and substance in each test tube and measuring the level of undissolved solute at the bottom. Her results are in the chart below:

\begin{tabular}{|l|l|}
\hline
Substance & Level of Undissolved Solute \\
\hline
W & 0.5 mm \\
\hline
X & 1.0 cm \\
\hline
Y & 0.5 cm \\
\hline
Z & 0.1 mm \\
\hline
\end{tabular}

Which substance has the greatest solubility?

A. Substance W
B. Substance X
C. Substance Y
D. Substance Z



Answer :

To determine which substance has the greatest solubility, we need to analyze the levels of undissolved solute for each substance. The substance with the least amount of undissolved solute will have the greatest solubility, as it means more of the substance has dissolved in the water. Let's start by converting all the measurements to the same unit for easy comparison.

We notice that the measurements given are a mixture of millimeters (mm) and centimeters (cm). Let's convert all the measurements to millimeters (mm):

1. Substance [tex]\(W\)[/tex]: [tex]\(0.5 \, \text{mm}\)[/tex]
2. Substance [tex]\(X\)[/tex]: [tex]\(1.0 \, \text{cm} = 10.0 \, \text{mm}\)[/tex]
3. Substance [tex]\(Y\)[/tex]: [tex]\(0.5 \, \text{cm} = 5.0 \, \text{mm}\)[/tex]
4. Substance [tex]\(Z\)[/tex]: [tex]\(0.1 \, \text{mm}\)[/tex]

Now, we compare the levels of undissolved solute:

- [tex]\(W\)[/tex]: [tex]\(0.5 \, \text{mm}\)[/tex]
- [tex]\(X\)[/tex]: [tex]\(10.0 \, \text{mm}\)[/tex]
- [tex]\(Y\)[/tex]: [tex]\(5.0 \, \text{mm}\)[/tex]
- [tex]\(Z\)[/tex]: [tex]\(0.1 \, \text{mm}\)[/tex]

From this comparison, we see that substance [tex]\(Z\)[/tex] has the lowest level of undissolved solute ([tex]\(0.1 \, \text{mm}\)[/tex]). Therefore, substance [tex]\(Z\)[/tex] has the greatest solubility because it leaves the least amount of solute undissolved.

Hence, the answer is:
Substance [tex]\(Z\)[/tex] has the greatest solubility.