concept of mole chemistry question



Answers

Answer 1

Answer:

How many molecules of water are there in 54 g of H2O H 2 O ? Solution. Molar Mass of H2O H 2 O = 2 + 16 = 18 g/moles. So ,number of moles of H2O H 2 O = Mass/Molar Mass = 54/18 =3 moles. Now 1 moles = 6.022×1023 6.022 × 10 23 molecule.


Related Questions

what is the difference between polar and non-polar

Answers

Answer:

Polar molecules occur when there is an electronegativity difference between the bonded atoms. Nonpolar molecules occur when electrons are shared equal between atoms of a diatomic molecule or when polar bonds in a larger molecule cancel each other out.

Explanation:

Polar molecules occur when there is an electronegativity difference between the bonded atoms. Nonpolar molecules occur when electrons are shared equal between atoms of a diatomic molecule or when polar bonds in a larger molecule cancel each other out.

How do you calculate the percent composition of an element in a compound

Answers

Answer:

Percent composition is calculated from a molecular formula by dividing the mass of a single element in one mole of a compound by the mass of one mole of the entire compound. This value is presented as a percentage.

Explanation:

Atoms have been traditionally viewed as being composed of three different types of particles: protons, neutrons, and electrons. However, research done by Louis de Broglie and expanded upon by Erwin Schrödinger changed how scientists viewed electrons. How has our increased understanding of the electron led to current atomic models?

Answers

Answer:

See explanation

Explanation:

Before the advent of the wave-particle duality theory proposed by Louis de Broglie, there was a sharp distinction between mater and waves.

However, Louis de Broglie introduced the idea that mater could display wave-like properties.  Erwin Schrödinger developed this idea into what is now known as the wave mechanical model of the atom.

In this model, electrons are regarded as waves. We can only determine the probability of finding the electron within certain high probability regions within the atom called orbitals.

This idea has been the longest surviving atomic model and has greatly increased our understanding of atoms.

Which section of the ocean floor is near the coastline of all continents

Answers

Inter tidal zone, is the correct answer.

All changes saved
A gas is at 275 K, and its temperature is raised to 400 K. The volume is measured at 5.82 L after the gas is heated. What is
the volume of the gas before it is heated?
8.25 L
12.0L
2.00 L
4.00 L

Answers

Answer:

4.00L

Explanation:

Using Charle's law, which have the following equation:

V1/T1 = V2/T2

Where;

V1 = initial volume (litres)

T1 = initial temperature (Kelvin)

V2 = final volume (litres)

T2 = final temperature (Kelvin)

According to the information provided, T1 = 275K, T2 = 400K, V1 = ?, V2 = 5.82L

Hence, using the formula;

V1/275 = 5.82/400

400 × V1 = 275 × 5.82

400V1 = 1600.5

V1 = 1600.5 ÷ 400

V1 = 4.001

Therefore, volume of the gas before it is heated is 4.00L

The magnifying power of a telescope is computed by dividing the focal length of its objective by _______.

Answers

Answer:

by focal length of the eyepiece.

Explanation:

hope it helps!!plz mark as brainleist.

Carbon dioxide is used by plants for ___?​

Answers

Answer:

photosynthesis

Explanation:

that's the way plants feed themselves

Answer:

photosynthesis

Explanation:

I hope i helped

What is the percent composition of nitrogen in N 2 O

Answers

Answer:

63.6%

Explanation:

The given compound is:

     N₂O;

The problem here is to find the percent composition of nitrogen in the compound.

First find the molar mass of the compound:

 Molar mass of N₂O = 2(14) + 16  = 44g/mol

So;

 Percentage composition of Nitrogen  = [tex]\frac{2 x 14}{44}[/tex]  x 100  = 63.6%

How many moles of sand (SiO2) are in 30 g of sand?

Answers

Answer:

0.50 mol SiO₂

General Formulas and Concepts:

Math

Pre-Algebra

Order of Operations: BPEMDAS

Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to Right

Chemistry

Atomic Structure

Reading a Periodic TableUsing Dimensional AnalysisExplanation:

Step 1: Define

30 g SiO₂ (sand)

Step 2: Identify Conversions

Molar Mass of Si - 28.09 g/mol

Molar Mass of O - 16.00 g/mol

Molar Mass of SiO₂ - 28.09 + 2(16.00) = 60.09 g/mol

Step 3: Convert

Set up:                                [tex]\displaystyle 30 \ g \ SiO_2(\frac{1 \ mol \ SiO_2}{60.09 \ g \ SiO_2})[/tex]Multiply/Divide:                  [tex]\displaystyle 0.499251 \ mol \ SiO_2[/tex]

Step 4: Check

Follow sig figs and round. We are given 2 sig figs.

0.499251 mol SiO₂ ≈ 0.50 mol SiO₂

Answer:

[tex]\boxed {\boxed {\sf About \ 0.5 \ moles \ of \ SiO_2}}[/tex]

Explanation:

To convert from grams to moles, we must use the molar mass.

1. Molar Mass

Use the Periodic Table to find the masses of the individual elements (silicon and oxygen) in sand.

Silicon (Si): 28.085 g/mol Oxygen (O): 15.999 g/mol

Examine the formula for sand: SiO₂. There is a subscript of 2 after oxygen, so there must be 2 oxygen atoms. Multiply oxygen's mass by 2 and add silicon's mass to find the molar mass of sand.

SiO₂: 2(15.999 g/mol) + 28.085 g/mol= g/mol

2. Calculate Moles

Use the molar mass as ratio.

[tex]\frac{60.083 \ g \ SiO_2}{1 \ mol \ SiO_2}[/tex]

Multiply by the given number of grams (30)

[tex]30 \ g \ SiO_2 * \frac{60.083 \ g \ SiO_2}{1 \ mol \ SiO_2}[/tex]

Flip the fraction so the grams of sand will cancel.

[tex]30 \ g \ SiO_2 *\frac{1 \ mol \ SiO_2}{60.083 \ g \ SiO_2}[/tex]

[tex]30 *\frac{1 \ mol \ SiO_2}{60.083 }[/tex]

[tex]\frac{30 \ mol \ SiO_2}{60.083 }[/tex]

[tex]0.499309289 \ mol \ SiO_2[/tex]

3. Round

The original measurement of grams has 1 signfiicant figure. We must round our answer to 1 sig fig.

For the answer we found, that is the tenth place. The 9 in the hundredth tells us to round the 4 to a 5.

[tex]\approx 0.5 \ mol \ SiO_2[/tex]

There are about 0.5 moles of SiO₂ in 30 grams.

Laura has three beakers. Each contains 200 cm3 of a colourless liquid. Suggest how Laura could nd out which beakers contain pure water, and which contain solutions.

Answers

Answer:

See explanation

Explanation:

A pure liquid has a sharp boiling point. Now we know that the boiling point of water is 100°C.

If Laura begins to heat each liquid with a thermometer inserted into each liquid, the liquid that boils at exactly 100°C is pure water while the rest are solutions.

What are redox half-reactions?

Answers

Answer:

C. Equations that separate the oxidation and reduction parts of the reaction.

Explanation:

Redox half-reactions are actually used when balancing redox reactions. It gives the oxidation or reduction reaction components/parts of a redox reaction.  The change in oxidation and reduction states in the substances that are involved in a redox reaction is used to obtain a redox half-reaction.

This redox half-reaction can also be used to explain what takes place in an electrochemical cell; how the anode is undergoing oxidation and how the cathode is undergoing reduction.

Below is an example of a redox half-reaction:

2 Fe³⁺(aq) + 6e⁻ → 2 Fe(s) (Reduction)

3 Mg(s) → 3 Mg²⁺(aq) + 6e⁻ (Oxidation)

How many hydrogen atoms are there in 2 molecules of C3H6?​

Answers

Answer:

there are 12 hydrogen atoms in 2 molecules of C3H6

Explanation:

Explain how to use the ATOMIC NUMBER and ATOMIC MASS, of any element to calculate the amount of neutrons located in the nucleus of a atom

Answers

Explanation:

Atomic Number :

It only explain number of protons and electrons in nuclous

Atomic Mass :

Atomic mass tell how much neutrons are present in atom.

Answer:

[tex]\underline{ \boxed{atomic \: number = atomic \: mass - neutron \: number}} \\ \underline{ \boxed{atomic \: mass = proton \: number + neutron \: number}} \\ \underline{ \boxed{neutron \: number = atomic \: mass - proton \: number}}[/tex]

Explanation:

[tex] \underline{ \boxed{1}} \\ ATOMIC \: NUMBER = (atomic \: mass \: number\: - neutron \: number \: )\\ (which \: is \: same \: as ) = \: \underline{ \boxed{proton \: number}}\\ \\ \underline{ \boxed{2}} \\ ATOMIC \: MASS = (proton \: number \: + neutron \:number) \\ (is \: same \: as ) = \: \underline{ \boxed{sum \: of \:atomic \: nuclear \: content}} \\ \\ \underline{ \boxed{3}} \\ neutrons = (atomic \: mass \: number - proton \: number) \\ [/tex]

An ____,or an element located in group 7A, will form a salt when reacted with a metal atom.

A. Alkali metal
B. Halogen
C. Noble gas
D. Transition metal

Answers

Answer:

B. Halogen

Explanation:

Halogens are the family of chemical elements found in the group VIIA of the periodic table which means they possess seven (7) outer electrons. Some examples of halogens are Fluorine (F), Iodine (I), Bromine (Br), and Chlorine (Cl).

A halogen, or an element located in group 7A, will form a salt when reacted with a metal atom.

For example, when Chlorine reacts with Sodium it would form a salt known as Sodium Chloride.

Na + Cl ----> NaCl

Which of the following is a polar molecule?
A. A linear Carbon dioxide molecule (C02)
B. A carbon monoxide molecule (CO)
C. A calcium oxide molecule (CaO)
D. An oxygen molecule (02)

Answers

Answer:

B. A carbon monoxide molecule(CO)

Explanation:

CO is polar because oxygen is more electronegative than carbon, so it gives oxygen a partial negative charge and carbon and partial positive charge. This causes a net dipole moment. CO2 is linear with no net dipole moment because each C-O bond is equal and opposite to each other, so they equal 0, which makes them non polar.

The answer will be (B) hope this helps!

pls answer i need it now!! I will give brainliest to the best answer!!

Answers

Answer:

sample 2

Explanation:

hope this helps

the answer is B i think

how is a waves amplitude related to the amount of energy the wave carries?

Answers

Answer:

The energy transported by a wave is directly proportional to the square of the amplitude. So whatever change occurs in the amplitude, the square of that effect impacts the energy. This means that a doubling of the amplitude results in a quadrupling of the energy.

what demonstrated Kinetic Energy

Answers

Kinetic Energy Statement

Kinetic energy is energy that a body possess as a result of its motion. Kinetic energy as it is mathematically written is the "classic statement" of: Kinetic energy is equal to half the mass of an object times its velocity squared.

There are five types of kinetic energy: radiant, thermal, sound, electrical and mechanical. Let us look at some of the kinetic energy examples and learn more about the different types of kinetic energy.

Hope this helped!

❤️

Can you help plzzz thank you

Answers

Answer:

It would be Container 3

Explanation:

Each of the containers has the same amount of salt.  Salinity refers to salt level.  Since the question is asking for the container with the greatest salinity, you are looking for the container with the least water (because it will be the saltiest out of all of them).  Container 3 has the least water.

Hope this helps :)

3 has less water so its saltier

why water is not used as a thermometric substance​

Answers

Answer:

Water can be used as the thermometric liquid. It expands and contracts with temperature so it can be used. It's just not a very good choice because: It's thermal expansion is not very large compared to other liquids like mercury.

Explanation:

Hope this help

Which feature is one of the defining features of a hurricane?
O funnel cloud
O high pressure
O low pressure
O rapid snowfall

Answers

Low pressure is one of the defining features of a hurricane. Therefore, the correct option is option C.

Hurricanes are intense tropical storms with spiralling winds, copious amounts of rain, and storm surges. These storms can pose a variety of issues when they hit land because they often occur over warm ocean waters close to the equator. Hurricanes leave a path of destruction in their wake, wrecking everything in their path from homes and infrastructure to creating severe flooding and landslides. The unpredictable nature of hurricanes is among their most worrisome features. Although modern technology and meteorological techniques have given us improved storm tracking and prediction systems, it is still challenging to correctly anticipate a hurricane's exact route and intensity.

To know more about hurricane, here:

https://brainly.com/question/33034641

#SPJ6

Differentiate between worldwide conservation and national conservation policy.​

Answers

Conservation is generally associated with the protection of natural resources, while preservation is associated with the protection of buildings, objects, and landscapes. Put simply conservation seeks the proper use of nature, while preservation seeks protection of nature from use.

why do minerals only form in certain areas?

Answers

Answer:

Often, chemical changes in the water might result in the release of different minerals such as salt or calcium carbonate. Pressure and heat in the process of creating metamorphic rock can also result in the formation or transformation of minerals.  Minerals in igneous rocks often form where magma has cooled over time.

Explanation:

Minerals only form in certain areas due to presence of specific environment.

Minerals only form in certain areas because of the presence of suitable environmental condition for it. Every mineral needs specific environment for its formation. Without that specific temperature, pressure and some other factors, the mineral can't formed.

Every mineral needs specific environment for its formation which is different from one another so we can conclude that mineral formation needs particular environmental conditions.

Learn more: https://brainly.com/question/21076968

help plzzzzzzzzzzzzz

Answers

Answer:

A: element B

B: element A

C: element B

D: element A

Explanation:

decrease in size leads increase in electronegativity because the smaller the size, the closer the shell is to the nucleus. Also, atomic radius decreases to the right and up on the periodic table. Atomic radius increases to the left and down a period. I hope this helps!

Which section of the ocean floor is near the coastline of all continents?

Answers

Answer shallow ocean

Explanation:

i think

"30 mph north" is an example of:
O velocity
speed
distance
O displacement

Answers

Answer:

distance velocity displacement, all three

Explanation:

Explain, in your own words, what volumic mass is

plss helpp

Answers

Answer:

I think that volumic mass is like weight of an object, or like the space it takes up??

Explanation:

Have A Wonderful Day !!

What type of system is impacting weather in Houston?
A) High pressure
B) Low pressure
C) Warm pressure
D) Cold pressure

Answers

Answer:

a) high pressure

that is the answer i got, but wait for a few more answers before you write the answer

High pressure since the atmosphere is humid and in the south. The weather is somewhat tropical

First to help me with these 4 gets brainless HURRYTTT UPPPPP

Answers

Answer: It's A

Explanation:

Answer:

A

Explanation:

What is the concentration of H+ ions at a pH = 2?
mol/L
What is the concentration of OH– ions at a pH = 2?
mol/L
What is the ratio of H+ ions to OH– ions at a pH = 2?
: 1

Answers

Answer:

0.01M = [H⁺]; 1x10⁻¹²M = [OH⁻]; Ratio is: 1x10¹⁰

Explanation:

pH is defined as -log [H⁺]

For a pH of 2 we can solve [H⁺] as follows:

pH = -log [H⁺]

2 = -log [H⁺]

10^-2 = [H⁺]

0.01M = [H⁺]

Using Keq of water:

Keq = 1x10⁻¹⁴ = [H⁺] [OH⁻]

1x10⁻¹⁴ / 0.01M = [OH⁻]

1x10⁻¹²M = [OH⁻]

The ratio is:

[H⁺] / [OH⁻] = 0.01 / 1x10⁻¹² =

1x10¹⁰

Answer:

1. 0.01 mol/L

2. 0.000000000001 mol/L

3. 10000000000:1

Explanation:

Other Questions
Help pls ill mark u brainliest Which expression is equivalent to 13 - (-21)?Choose 1 answers13 +21B-21 - 13-13 +21D-21 +13HURRY I WILL GIVE BRAINLIEST!!!Choose whether the bolded part of the sentence is the subject or the predicate.Traditional Belgian waffles ARE DOTTED WITH PEARLS OF SUGAR.Choose 1 answer:(Choice A)Asubject(Choice B)Bpredicate 2 box plots. The number line goes from 175 to 450. For resort A, the whiskers range from 175 to 375, and the box ranges from 250 to 300. A line divides the box at 375. For Resort B, the whiskers range from 200 to 400, and the box ranges from 300 to 375. A line divides the box at 325.Compare the two box plots and use the drop-down menus to determine where Kevin should plan to go for vacation.What is the interquartile range for ski Resort A? What is the interquartile range for ski Resort B? Which of the following groups of resources helps generate electricity and does not cause a lot of pollution?possible answer: 1. Phosphate, oil, and water2. Phosphate, oil, and silica3. Wind, solar, and silica4. Wind, solar, and water Will mark brainliest Why are acoustic panels are used in concert halls In a sentence, write what you want to do and the three top reasons you should be allowed to do it. 50+2x=20+5x what does the variable x represent in the equation below what does it mean to unpack your thinking? In the lesson entitled "Online Text: Interactive Art," you explored an art activity website. What goal could you set for yourself before exploring this website? List a few questions that could help you determine that goal or reach that goal. It was on the NGA kids art app website. Calculate the mass of beryllium (Be) needed to completely react with 18.9 g nitrogen gas (N2) to produce Bez N2, which is the only product of the reaction.A. 6.19B. 12.29C. 18.29D. 36.69 which two characteristics describe the kingdom of Mali Alzheimer's disease has some lifestyle factors because A. everyone can contract it in their lifetime B. it can be influenced by nutritional choicesC. up until now there is no known cure for itD. it can be contracted through germs How many 4 decilitre jugs areneeded to fill 8.4 litre container?A 21B. 2 100C. 210D. 33.6 How did slavery influence Texas to enter the Civil War?Select one:Most Texans believed that slavery was vital (important) to the Texas economy.Most Texans wanted to end the slave trade.Most Texans thought slavery was morally wrong and wanted to end it.Most of the political leaders of Texas wished to support the North's efforts to end slavery. Stanzas containing five lines are called:A. quintainsB. sestetsC. tercetsD. couplets I WILL GIVE BRAINLIST Why would the artist George Catlins paintings from the 1800s be considered a form of artistic documentation?READ FROM THISGeorge Catlin was a lawyer, author, and artist, born in New York in 1796. As a child, he was interested in the stories his mother told about American Indians. His interest was further sparked at the age of nine, when he met an Oneida Indian while out exploring the woods.Catlin, an attorney, liked to draw. He had a habit of sketching participants in the courtroom and eventually decided to become a full-time artist. In the 1830s, he traveled from New York to several areas of the West and Midwest in order to study and paint a number of American Indian tribes. He wanted to record what they looked like, their customs, and their culture. Catlin is widely regarded as the first artist to depict Plains Indians in their own territories.Catlin spent between six and eight years traveling between tribes in the West and his home in New York. During this time, he created more than 500 paintings of tribal life. He combined his paintings into a collection that he called his Indian Gallery, and he traveled with the exhibit through Europe and many East Coast cities in the United States. He also wrote a two-volume book describing his travels in Europe.After Catlins death in 1872, his widow donated his available work to the Smithsonian Museum. The Indian Gallery has been on display as a special exhibit at the museum and is a highly valued collection. According to museum curator George Gurney, His collection is the largest of pre-photographic material of American Indians. Its an incredible record. Whitman uses rhyming couplets, but he intentionally breaks the flow and pattern of the couplets in the last four lines of each stanza. Notice, too, that rhymes are sometimes perfect (ex: "done" and "won"), but other times the rhymes are slant or near (ex: "bells" and "trills"). Why, do you suppose, Whitman decided to subtly break the traditional pattern? If poetry comes out of the deepest places in the human soul and experience, shouldn't it be as important to learn about one another's poetry, country to country, as one another's weather or gross national products? The diction used in this sentence helps to create a tone that is An object is subject to a 84 Nm torque about a point when a21 N of force is applied to a second point along the object'slength. How far apart are the two points