Question

A student is trying to determine the identity of some pieces of an unknown
substance by finding their density. He finds the mass of a weighing boat to
be 2.69 g and the mass of the unknown pieces, including the weighing
boat, to be 18.01 g. To find the volume of the pieces, he measured out 25.7
mL of water in a graduated cylinder and then added the pieces to find a
new volume of 32.3 ml. What is the identity of the substance?
Density
2.16
Mineral
Halite
2.32
Gypsum
Quartz
2.65
2.72
Calcite
3.18
Fluorite
O halite
O quartz
O
O gypsum
fluorite
juju

Answer 1

Answer : The identity of the substance is gypsum.

Explanation : Given,

Mass of weighing boat = 2.69 g

Mass of unknown pieces including weighing boat = 18.01 g

Initial volume = 25.7 mL

Final volume = 32.3 mL

First we have to calculate the mass of unknown pieces.

Mass of unknown pieces = Mass of unknown pieces including weighing boat - Mass of weighing boat

Mass of unknown pieces = 18.01 g - 2.69 g

Mass of unknown pieces = 15.32 g

Now we have to calculate the volume of unknown pieces.

Volume of unknown pieces = Final volume - Initial volume

Volume of unknown pieces = 32.3 mL - 25.7 mL

Volume of unknown pieces = 6.6 mL

Now we have to calculate the density of unknown pieces.

$\text{Density of unknown pieces}=\frac{\text{Mass of unknown pieces}}{\text{Volume of unknown pieces}}$

Now putting all the given values in this formula, we get:

$\text{Density of unknown pieces}=\frac{15.32g}{6.6mL}$

$\text{Density of unknown pieces}=2.32g/mL$

From the given table we conclude that the unknown piece is gypsum whose density is 2.32 g/mL.

Therefore, the identity of the substance is gypsum.

Answer 2

The material with the density equivalent to the unknown piece has been Gypsum. Thus, the unknown piece has been gypsum.

Density can be defined as the mass of the substance per unit volume.

To calculate the density of the unknown piece, the mass has been calculated as:

Mass of unknown piece = Mass of weighing boat with the unknown piece - Mass of weighing boat

Mass of unknown piece = 18.01 g - 2.69 g

Mass of unknown piece = 15.32 grams.

The volume of the unknown piece can be calculated as:

The volume of unknown piece = Final volume - Initial volume

The volume of the unknown piece = 32.3 mL - 25.7 mL

The volume of the unknown piece = 6.6 mL.

The density can be expressed as:

Density = $\rm \dfrac{Mass}{Volume}$

The density of the unknown piece = $\rm \dfrac{15.32\;g}{6.6\;ml}$

The density of the unknown piece = 2.32 g/mL.

From the given set of pieces, the material with the density equivalent to the unknown piece has been Gypsum. Thus, the unknown piece has been gypsum.

For more information about density, refer to the link:

https://brainly.com/question/952755