Question

check for understanding
use your understanding of density to complete the activities.
what is it? an unknown fluid substance has a mass of 5 grams and a volume of 7 milliliters. which of the following items is a possible identity of the substance?
a. lamp oil, 0.2 g/ml
b. vegetable oil, 0.71 g/ml
c. honey, 1.3 g/ml
d. dish soap, 1.7 g/ml
identifying substances by density the densities of three metals are shown:

• iron, 7.8 g/ml
• tin, 7.3 g/ml
• titanium, 4.5 g/ml

determine the identities of the unknown samples based on their densities.
iron tin titanium

1. sample a: 225 grams, 50 milliliters __________
2. sample b: 365 grams, 50 milliliters __________
3. sample c: 780 grams, 100 milliliters __________

Explanation:

Part 1: "What Is It?" Question

Step1: Recall density formula

Density formula is $
ho = \frac{m}{V}$, where $m$ is mass and $V$ is volume.

Step2: Calculate density of unknown substance

Given $m = 5$ g, $V = 7$ mL. So $
ho=\frac{5}{7}\approx0.71$ g/mL.

Step3: Compare with options

Check which option has density close to 0.71 g/mL. Option B (vegetable oil) has 0.71 g/mL.

Step1: Apply density formula

$
ho=\frac{m}{V}=\frac{225}{50}=4.5$ g/mL.

Step2: Match with metal densities

Titanium has density 4.5 g/mL.

Step1: Apply density formula

$
ho=\frac{m}{V}=\frac{365}{50}=7.3$ g/mL.

Step2: Match with metal densities

Tin has density 7.3 g/mL.

Answer:

B. vegetable oil, 0.71 g/mL

Part 2: Identifying Substances by Density (Sample A, B, C)

Sample A: 225 grams, 50 milliliters