In an experiment, a student collects 107 mL of H2 over water at a pressure of 104.8 kPa and a temperature of 30°C. How many grams of H2 are present?
A) 0.024 g
B) 4.00 g
C) 0.04 g
D) 0 049 g
And why

Answers

Answer 1

Answer:

The answer options provided are incorrect. The correct answer is 0.009g

Explanation:

Using PV = nRT

Where;

P = pressure (atm)

V = volume (L)

R = gas constant (0.0821 Latm/Kmol)

T = temperature (K)

n = number of moles

Based in the information provided;

V = 107mL = 107/1000 = 0.107L

P = 104.8kPa = 104800 Pa = 1.03atm

T = 30°C + 273.15 = 303.15K

PV = nRT

1.03 × 0.107 = n × 0.0821 × 303.15

0.1102 = 24.89n

n = 0.1102/24.89

n = 0.0044 mol

mole = mass/molar mass

Molar mass of H2 = 2g/mol

mass = molar mass × mole

mass = 2 × 0.0044

mass = 0.0088

mass = 0.009g


Related Questions

How do intermolecular forces of methane and water explain the different boiling points of the two substances?

Answers

Explanation:

In methane the intermolecular forces are the weak London dispersion forces. Water molecules are held together by hydrogen bonding.

London dispersion forces are weak forces of attraction between molecules. It is a predominant in compounds that have very weak polarity.Hydrogen bonding is the electrostatic attraction between the hydrogen of one molecule and the electronegative atom(O or N or F) of a neighboring molecule.

Hydrogen bonds holds water molecules together. Since it is a stronger bond, it confers a higher boiling point

how many kilograms are in 125 pounds

Answers

Answer:

125 pounds = 56.6990463 kilograms

Explanation:

Which answer best describes what is happening in the following reaction?

2C8H18 + 25O2 Right arrow. 16CO2 + 18H2O
This is not a redox reaction. It is an example of combustion.
This is a redox reaction in which octane (C8H18) is oxidized.
This is a redox reaction in which carbon dioxide (CO2) burns due to ignition.
This is not a redox reaction, because a solution of carbon dioxide and water results.

Answers

Answer:

b. This is a redox reaction in which octane (C8H18) is the reducing agent.

Explanation:

edge 2021 i just did it

The statement which best describes the reaction is:

This is not a redox reaction. It is an example of combustion.

What is redox reaction?

This is a reaction which is accompanied by a change in the oxidation number of the reacting elements

What is combustion reaction?

This is a reaction in which a substance burns in air (oxygen) to produce carbon dioxide, CO₂ and water, H₂O

Considering the equation given

2C₈H₁₈ + 25O₂ —> 16CO₂ +18H₂O

we can see that C₈H₁₈ burns in air (oxygen) to produce carbon dioxide, CO₂ and water, H₂O

Thus, we can conclude that the reaction is not redox but an example of combustion reaction

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Describe the movement of the asthenosphere

I am giving 62 points to first person to answer

Answers

Heat from deep within Earth is thought to keep the asthenosphere malleable, lubricating the undersides of Earth's tectonic plates and allowing them to move.

Answer:

Explanation:

Convection currents generated within the asthenosphere push magma upward through volcanic vents and spreading centres to create new crust.

Element ______ has 2 valence electrons and is in period 4.

Answers

Answer:

Calcium

2.8.8.2

last energy she'll got 2 electrons

as 2 valency

2. Which of the following element has no neutron partied particle?
A. Hydrogen B. Helium
C. Lithium
D Sodium​

Answers

Answer:

A.hydrogen

Explanation:

A normal hydrogen (H) atom does not have any neutrons in its tiny nucleus

Why do you think the size of a white dwarf affects its visual luminosity?

Reward
_________
Brainliest
Thanks
Points
_________

Thank you so much!

Answers

There size may affect how they view things, such as how tall someone or something may be could be over sized to them.

Answer:

the bigger the size the more easier to see from a distance and the smaller the harder to see.

Explanation:

HELP ME AGAIN FOR BRAINLIEST

Answers

Answer:

1: C

2: a

3: B

4: D

hope this helps

URGENT!

A series of experiments are conducted with five different cups, each filled with the same amount of water. One cup is kept at room temperature (25 °C), while the other four cups are heated to four different temperatures. Sugar is added to each cup until no more will dissolve. The amount of sugar added to each cup is recorded. Which answer correctly identifies the control group, independent variable, dependent variable, and controlled variable in the experiment?

Control Group: temperature of the water Independent Variable: cup of water at room temperature Dependent Variable: amount of sugar dissolved Controlled Variable: amount of water in each cup

Control Group: temperature of the water Independent Variable: cup of water at room temperature Dependent Variable: amount of water in each cup Controlled Variable: amount of sugar dissolved

Control Group: cup of water at room temperature Independent Variable: temperature of the water Dependent Variable: amount of sugar dissolved Controlled Variable: amount of water in each cup

Control Group: temperature of the water Independent Variable: amount of sugar dissolved Dependent Variable: amount of water in each cup Controlled Variable: cup of water at room temperature

Answers

Answer:

Either the first one or the third one.

Explanation:

Using process of elimination: knowing that the controlled variable is something the conductor is able to control and stays the same throughout; the amount of water is the same, but it also states that temperature is not the same throughout. This cancels out B because the amount of sugar dissolved varies and doesn’t stay the same. D fits the same criteria as well.

so now we are left with A and C.

An independent variable is something that can be by itself and doesn’t depend on anything else. Sugar is NOT independent, as it dissolves DEPENDING on the amount of liquid. So we can already rule out that sugar is a dependent variable. Both A and C have those choices though, so now we are with the control group and the independent variable.

Think about it, which is the independent variable? Water amount doesn’t depend on anything, while the temperature depends on the room. So the answer is most likely A.

Hope this helps, don’t stress about homework. Happy Holidays!

Which symbol represents a salt?
O CaCl2
O C6H12O6
O C2H2
O 02

Answers

A) CaCl2

Calcium chloride is an inorganic compound, a salt with the chemical formula CaCl2. It is a colorless crystalline solid at room temperature, highly soluble in water.

what phase change requires a substance to absorb energy?

Answers

Note that melting and vaporization are endothermic processes in that they absorb or require energy, while freezing and condensation are exothermic process as they release energy.
Solid because in order for ice to melt heat has to be near

What is the volume of a gas balloon filled with 4.0 moles of tha gas, when the barometer reads pressure of 780 Torr and temperature is 30°C.​

Answers

Answer:

V = 96.61 L

Explanation:

Given data:

Number of moles = 4.0 mol

Pressure = 780 torr (780/760 = 1.03 atm)

Temperature = 30°C

Volume of gas = ?

Solution:

The given problem will be solve by using general gas equation,

PV = nRT

P= Pressure

V = volume

n = number of moles

R = general gas constant = 0.0821 atm.L/ mol.K  

T = temperature in kelvin

Now we will convert the temperature.

30+273 = 303 K

1.03 atm × V = 4.0 mol × 0.0821 atm.L/ mol.K  × 303 K

V = 99.505 atm.L / 1.03 atm

V = 96.61 L

The net force on a car accelerating
at a rate of 2.5 m/s2 is 2,000
newtons. Calculate the mass of the
car.

Answers

Answer:

800 kg

Explanation:

The mass of the car can be found by using the formula

[tex]m = \frac{f}{a} \\ [/tex]

f is the force

a is the acceleration

From the question we have

[tex]m = \frac{2000}{2.5} \\ [/tex]

We have the final answer as

800 kg

Hope this helps you

Which of the following of elements would have all four valence electrons
B, Si, As, Te
C, Si, Ge,Sn
O, S, Se, Te
Ga, Ge, As, Se

Answers

Answer:

D

they are used for manufacturing Of diodes

Answer:

is the answer D

Explanation:

hsjskajdidbxksbsvzjwvshhz7duw

Difference between absolute atomic mass and relative atomic mass with example

Answers

“Atomic mass” is relative to the isotope carbon-12 weighing exactly 12 atomic mass units. Therefore “atomic mass” is precisely the same as “relative atomic mass.”

Two further points:

First, atomic mass as stated on the periodic table is a average of the masses of an element’s naturally-occurring isotopes, weighted by their abundance. This is because atomic mass as normally used is a bulk property: we weigh out many trillions of atoms at a time, because we usually deal in macroscopic quantities. And that means that an average mass is more useful to us.

Second, all masses are relative masses (until the new, physical-constant-based kilogram comes online; and arguably even then). We mass something by comparing it to some standard of reference: until later this year, that something is a chunk of alloy in Paris, France. When the new standard comes into use, we will be comparing the kilogram’s gravitational mass to the strength of the electromagnetic force.

But that’s kind of trivial; it just stems from the fact that any and every measurement is a comparison to something else.

Edit: IUPAC, the world’s premier organization for the imposition of picky definitions that most people never need to use, has the following:

Atomic mass is the mass of a single atom; the unit is the Dalton or unified atomic mass unit. (I would use “isotopic mass” to specify the mass of a particular atom, but that’s not sanctioned by IUPAC.)

Relative atomic mass is the measured average mass of all atoms of a particular element in a particular sample. To make it unitless, it’s divided by the value of the unified atomic mass unit.

Standard atomic weight is the value you read off of the periodic table; it’s an Earth-based average over many samples, of experimental values of the relative atomic mass. Values are promulgated by the IUPAC Commission on Atomic Weights and Isotopic Abundances, and are revised every two years.

Most chemists refer to standard atomic weight as “atomic mass” or “atomic weight” and get on with their lives.

The unified atomic mass unit is 1/12 of the mass of an atom of carbon-12. It is sometimes called the Dalton.

Definitions taken from the IUPAC Gold Book.

As far as I can tell, relative atomic masses and standard atomic weights are made unitless so that they can be used with any convenient macroscopic mass unit to determine correct proportions for a desired chemical reaction.

relative atomic mass of sulphuric acid

Answers

I believe it’s 98.07848 g mol

Which sentence would be inappropriate in an informational piece of writing with a formal tone?

A: People find Shakespeare's Pericles, Prince of Tyre boring and annoying because it's possible that he didn't even write the entire play.
B: Thirty-nine plays, a combination of comedies, histories, and tragedies, are attributed to William Shakespeare.
C: William Shakespeare, a poet, and playwright have generally deemed the greatest writer in the history of the English language.
D: Scholars speculate that Hamlet may have been informed by the relationship between Shakespeare and his son Hamnet, who died at eleven years of age.

Answers

Answer:

Its a

Explanation:

i took the quiz

The sentence that is inappropriate in an informational piece of writing with a formal tone is "People find Shakespeare's Pericles, Prince of Tyre boring and annoying because it's possible that he didn't even write the entire play." The correct option is A.

What is a formal tone?

In academic or professional settings, a formal writing tone is common. This tone emphasizes thoroughness and directness while remaining respectful.

It emphasizes facts and grammatical correctness and uses full words rather than contractions.

The use of standard English, more complex sentence structures, the infrequent use of personal pronouns, and the absence of colloquial or slang terms characterize formal language.

In informal language, nonstandard English forms, colloquial vocabulary, and typically shorter sentence structures are permitted.

"People find Shakespeare's Pericles, Prince of Tyre boring and annoying because it's possible that he didn't even write the entire play," is an inappropriate sentence in a formal informational piece of writing.

Thus, the correct option is A.

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Old photographic flashbulbs burn magnesium metal in a reaction that causes a flash of brilliant white light. A photographer would need to take care not to suffer burned fingers when trying to replace the hot bulb. What best identifies the energy transformation that occurs in the flashbulb? chemical energy to electromagnetic energy and thermal energy electromagnetic energy to chemical energy and thermal energy chemical energy to electromagnetic energy thermal energy to chemical energy

Answers

Answer:

A

Explanation:

Answer:

A

Explanation:

Not D or B

What is the variable for the equilibrium constant?

Answers

Answer:

The constant can be calculated using the ratio of products to reactants when the equation has reached equilibrium. The equilibrium constant is often represented by the variable Keq, which is defined by the equilibrium constant expression

THE CONSTANT OF A VARIABLE FOR THE EQUALIRBIN CONSTANT

what is the number of sigma and pi bond in butanol?

Answers

Answer:

Sigma Bonds = 14

Pi bonds = 0

Explanation:

Butanol:

[tex]\sf CH_{3} -CH_{2}-CH_{2}-CH_{2}-OH[/tex]

There is no pi bond in this compound (since there is no double or triply bond)

So,

Pi bond = 0

Now, Coming towards sigma bonds

Sigma bonds = 3 (First carbon with hydrogen) + 2 (Second C with H) + 2 (Third C with H) + 2 (Fourth C with H) + 1 (Bond of O and H) + 4 (Bonds between C and C and C and O)

Sigma Bonds = 14

[tex]\rule[225]{225}{2}[/tex]

Hope this helped!

~AnonymousHelper1807

What is the approximate temperature of 1.4 moles of a gas with a pressure of 3.25 atmospheres in a 4.738-liter container

Answers

Answer:

134K

Explanation:

Using the ideal gas law equation;

PV = nRT

Where;

P = pressure (atm)

V = volume (Litres)

n = number of moles (mol)

R = gas constant (0.0821 Latm/Kmol)

T = temperature (K)

Based on the information provided, n = 1.4moles, P = 3.25atm, V = 4.738L, T = ?

3.25 × 4.738 = 1.4 × 0.0821 × T

15.3985 = 0.11494T

T = 15.3985/0.11494

T = 133.969

Approximately;

T = 134K

Supongo que quiere preparar una solución al 10% de sulfato de magnesio en peso. El frasco del producto químico que se tiene indica que el sulfato de magnesio heptahidratado Cuántos gramos de hidratado serán necesarios para preparar 120 gramos de esta solución .Cuántos gramos de agua?

Answers

Answer:

Se requerirán 14.57 gramos de MgSO₄·7H₂O, que se disolverían en 105.43 gramos de agua.

Explanation:

Si tenemos 120 gramos de una solución al 10% de sulfato de magnesio en peso, habrán en la solución (120*10/100) 12 gramos de sulfato de magnesio (MgSO₄).

Sin embargo, el reactivo que está disponible es heptahidratado (MgSO₄·7H₂O), por lo que hay que calcular cuántos gramos de sulfato de magnesio heptahidratado contendrán 12 gramos de MgSO₄.

Calculamos las moles de 12 gramos de MgSO₄, usando su masa molecular:

12 g MgSO₄ ÷ 120.305 g/mol = 0.0997 mol MgSO₄.

Después calculamos la masa de MgSO₄·7H₂O que contendrá 0.0997 mol MgSO₄, usando la masa molecular de MgSO₄·7H₂O:

0.0997 mol * 246.305 g/mol = 14.57 g MgSO₄·7H₂O

Para saber la cantidad de agua en la que se disolverá el reactivo, restamos la masa de soluto de la masa total de la solución:

120 g - 14.57 g = 105.43 g

Which of the following represents a molecule

A Ca
B Co
C CO
D Cu

Answers

Answer:

C. CO

Explanation:

A molecule is a substance that is a combination of two or more atoms through a chemical bond while an element is a substance containing only one type of atom. However, some elements are also considered molecules because of having diatoms such as: Hydrogen, Oxygen, Chlorine, Bromine, Fluorine, Nitrogen and Iodine.

Among the choices above, it is only choice C (Carbon monoxide) that is a molecule. All the other options (Calcium, Cobalt and Copper) are elements. Carbon monoxide is a combination of one atom of carbon and another atom of oxygen.

The option that represents a molecule would be CO. That is option C.

What is a molecule?

A molecule is defined as the substance that is made up of two or more elements that are chemically combined together.

From the options give above, CO which is carbon monoxide is diatomic. This shows that it contains two elements making it a molecule.

Learn more about molecules here;

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68 POINTS WILL GIVE BRAINliest!!!


The table below shows the age of fossils found in four separate layers of an undisturbed rock:


Fossils In Rock Layers
Layer Fossil in Layer Age of Fossil (million years)
A W 550
B X 240
C Y 680
D Z 450


Which is the topmost layer of the rock?
Layer A
Layer B
Layer C
Layer D

Answers

Answer:

D

C

Explanation:

A folded rock formation with the label A at the top of one of the folds. A geologist sees this folded rock when studying in the field. He is drawn to the sample that is labeled A. He determines this formation was caused by compression. What type of landform did he find at label A? anticline syncline plateau fault-block mountain

Answers

Answer:

Anticline

Other than that Just A C:

Explanation:

Answer:

A

Explanation:

1. Lithium, water, edible salt, chalk, Carbon, Lime, Nitrogen, Potassium, Oxygen,
Iodides, Iron, Chlorine, etc are some matters.

(a) Expressing the matters of the stem by symbol and formula separate the elements
and compounds. ---3 marks

Answers

Answer:

Explanation:

An atom is the smallest unit of an element that can take part in a chemical reaction. Atoms (and there corresponding symbols) mentioned in the question are

Lithium ⇒ Li

Carbon ⇒ C

Nitrogen ⇒ N

Potassium ⇒ K

Oxygen ⇒ O

Iron ⇒ Fe

Chlorine ⇒ Cl

A compound is substance that contains two or more atoms that are chemically combined and can be represented with a chemical formula. The compounds (and there corresponding formula) mentioned in the question are

Water ⇒ H₂O

Edible salt (sodium chloride) ⇒ NaCl

Chalk (calcium carbonate) ⇒ CaCO₃

Lime (calcium oxide) ⇒ CaO

Iodides (such as sodium iodide and potassium iodide) ⇒ NaI and KI respectively

Why is a reaction between Sodium and Potassium impossible?

Answers

Answer:

it is because a number of factors, including sample surface cleanliness and temperature, can prevent chunks of alkali metals from exploding on contact with water. The team eliminated those variables and others by using a sodium-potassium alloy that remains liquid at room temperature and a droplet delivery system featuring a calibrated syringe.

Answer: Potassium has a chloride mixture which makes it so sodium interacts easily with it to form the bond

What would happen to the air pressure on Earth's surface if the density of Earth's atmosphere were to suddenly double?A. The air pressure would decrease by half. B. The air pressure would increase 2X. C. The air pressure would stay the same. D. The air pressure would increase 4X.

Answers

Answer:

B. The air pressure would increase 2X

Explanation:

Pressure = density × acceleration due to gravity × height

p = ρ × g × h

Pressure is force per unit area

p = F/a

Density is mass per unit volume

Pressure is directly proportional to density hence, any change in the density of a body directly affects the change in pressure of the body and vice versa.

Which of the following situation Is the best example of long-term movement? A- Take a quick trip to the store B- Go to school each day C- Move to a new state D- Visit the library after school?

Answers

Answer:

The Answer Is C

A student measures the sides of a piece of paper to determine the area of the paper. His measurements are: 5.70 cm length and 10.22 cm width. What is the area of the paper (recorded to the correct number of significant figures)?

Answers

Answer:

58.3 cm

Explanation:

took the quiz.

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