Anonymous
Anonymous asked in Science & MathematicsChemistry · 5 months ago

# What is the density (in g/cm^3) of a piece of copper that has a mass of 1.12 oz and occupies a volume of 3.54 mL?

I did d=m/v but still got the answer wrong

Relevance

Density ....

Convert ounces to grams. Everyone knows that 1 milliliter is equivalent to 1 cubic centimeter.

D = m / V

D = (1.12 oz x 28.3495 g / 1 oz) / 3.54 cm³ = 8.97 g/cm³

The answer can only be expressed to three significant digits.

• Anonymous
5 months ago

31.75147 grams/3.54 cm³ = 8.97 g/cm³

• Did you pay any attention to the units?

• Assumption 1: "Mass" 1.12 oz is Avp (Avoirdupois) weight and not troy of precious and semi-precious metals. (The teacher or book could have an error in this)

Assumption 2: The "volume" means displacement of water at standard conditions.

Without these assumptions, the numbers change.

1 AVP ounce = 28.3495231 grams

3.54 mL water = 3.54 cm³.

1.12 * 28.3495231 grams = 31.75147 grams

31.75147 grams/3.54 cm³ = 8.97 g/cm³

• Convert ounces to grams

1 pound = 453.59237 grams, exactly

1 ounce = 1/16 pounds = 453.59237/16 grams

1.12 ounces =>

1.12 * 453.59237 / 16 grams =>

0.07 * 16 * 453.59237 / 16 grams =>

0.07 * 453.59237 grams =>

7 * 4.5359237 grams =>

31.7514659 grams

1 ml occupies 1 cubic cm of space

31.7514659 / 3.54 grams/cm^3 =>

8.9693406497175141242937853107345... grams/cm^3

8.97 g/cm^3, taken to 3 sf

EDIT: Google confirms that we're at least on the right track