Chemistry College

The mass of an unidentified rock is 15.5 grams. Students determine the volume of the rock by placing the rock in a cylinder with water. What was the density of the rock that the students should have calculated?

Hint: The graduated cylinder measures volume. Read the difference in water level.

The Mass Of An Unidentified Rock Is 15.5 Grams. Students Determine The Volume Of The Rock By Placing

Answers

Answer 1
The concept of water by displacement. D=m/v therefore m=15.5 g and volume=5 mL (final - initial) then calculate the density

Related Questions

The weight loss of an aluminum alloy corroding in a solution of hydrochloric acid was observed to be 0.250 g/cm2 after an 8 h immersion period [13]. What is the corresponding anodic current density in milliamperes per square centimeter, assuming that all the corrosion is due to the following anodic half-cell reaction:

Answers

This question is incomplete, the complete question is;

The weight loss of an aluminum alloy corroding in a solution of hydrochloric acid was observed to be 0.250 g/cm² after an 8 h immersion period [13]. What is the corresponding anodic current density in milliamperes per square centimeter, assuming that all the corrosion is due to the following anodic half-cell reaction:

Al → Al³⁺ + 3e⁻

The atomic weight is 58.7 g/mol

Answer:

Current density in milliamperes per square centimeter is 45.81 mA/cm²

Explanation:

Given the data in the question;

we know that Faradays law of electrolysis states that;

amount of substance produced at each electrode is directly proportional to the quantity of charge flowing through the cell.

so

m = ( Q/F) (M/z)

where m is the mass of substance liberated at an electrode( 0.250 g/cm²)

Q is the total electric charge passed through the substance

F is Faradays constant (96,500 C/mol)

M is the molar mass of the substance( 58.7 g/mol )  and Z is the number of electrons transferred(3)

Also

we know that; Q = It

where I is current and t is time( 8hrs × 60 × 60 = 28800 sec )

we substitute  Q = It  into our equation'

we have;

m = ( It/F) (M/z)

m = ItM / Fz

mFz = ItM

I = mFz / tM

so we substitute

I = [0.250 g/cm² × 96,500 C/mol × 3] / [ 28800 × 58.7 g/mol]

I = 72375 /  1690560

I = 0.04581 A/cm²

we know that; 1 ampere = 1000 milliampere

so

I = 0.04581 × 1000

I = 45.81 mA/cm²

Therefore, current density in milliamperes per square centimeter is 45.81 mA/cm²

atomic radius(size)______ from left to right across a period on the periodic table

Answers

Answer:

Decreases

Explanation:

Do the substances that are reactants in a chemical reaction remain the same after the reaction is complete?

Answers

The first answer is nine you are currently correct

13 Elements within the same main groups (1-8)

Answers

Answer: Valence electrons

PLEASE HELP ASAP I NEED IT HELP PEASEEEEEEEEEEE it’s number 4 (this is science)

Answers

Here you go:
Continent Polar - Cold and Dry
Maritime Polar - Cold and Humid
Arctic - Extremely Cold and Dry
Maritime Tropical- Warm and Humid

Hope this helps:)

What type of charge do ionic compounds have

Answers

Answer:neutral

Explanation:ionic compounds is between a cation and anion so they cancel eachother out

Which factor can help balance Earth’s temperature?

Answers

Answer:

Clouds

Explanation:

Because I just got it right

A student is given a sample of an unknown solid and asked to identify it. The student begins by making a list of questions to investigate about the sample.
BRAINLY QUICK!

Which question would be the least useful in helping the student identify the sample?


A) Is the sample soluble in water?

B) What is the weight of the sample?

C) Is the sample attracted to a magnet?

D) What is the melting point of the sample?

Answers

Answer:

B) What is the weight of the sample?

Explanation:

The least useful question for the student to identify the sample is "What is the weight of the sample?"

To identify a sample, it is important to know its solubility (homogenous or heterogenous), chemical properties such as melting and boiling point, and whether sample is attracted towards the magnet or not to know the nature of the sample.

Weights is the least useful characteristic of a sample that can help to identify the sample.

Hence, the correct answer is "B) What is the weight of the sample?".

A 558 mg of a mixture of fluorene and benzoic acid was weighed out and subjected to an extraction and recrystallization. After this purification was completed the product crystals were dried and analyzed. The purification procedure produced 185 mg of fluorene and 144 mg of benzoic acid. Calculate the percent composition of this mixture.

Answers

Answer:

See explanation

Explanation:

Mass of mixture of  fluorene and benzoic acid = 558 mg

Mass of pure fluorene  after purification = 185 mg of fluorene

Mass of pure  benzoic acid after purification = 144 mg of benzoic acid

Percentage of fluorene int he mixture = 185mg/558mg * 100 = 33.15 %

Percentage of benzoic acid in the mixture = 144mg/558mg * 100 = 25.81 %

Percentage of impurities = 100% - [33.15 + 25.81]

Percentage of impurities = 100 - 58.96

Percentage of impurities = 41.04 %

The blood cells that directly attack germs are: *​

Answers

Answer:

lymphocytes

Explanation:

it consists of the b and the t cells

The white blood cells are the ones that attack germs.
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