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 : 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.

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

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 : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.

you did not give any options thus this is the best answer i can give to you with this little information you have given

> they are both natural and not man made

> they can be tracked and predicted by the right tools

-love shrooms