Chemistry question on enthalpy HELP!!!!

Chemistry Question On Enthalpy HELP!!!!

Answers

Answer 1

Answer: The enthalpy change for this reaction is, -803 kJ

Explanation:

The balanced chemical reaction is,

[tex]CH_4(g)+2O_2(g)\rightarrow CO_2(g)+2H_2O(g)[/tex]

The expression for enthalpy change is,

[tex]\Delta H=\sum [n\times \Delta H_f(product)]-\sum [n\times \Delta H_f(reactant)][/tex]

[tex]\Delta H=[(n_{CO_2}\times \Delta H_{CO_2})+(n_{H_2O}\times \Delta H_{H_2O})]-[(n_{O_2}\times \Delta H_{O_2})+(n_{CH_4}\times \Delta H_{CH_4})][/tex]

where,

n = number of moles  

Now put all the given values in this expression, we get

[tex]\Delta H=[(1\times -394)+(2\times -242]-[(2\times 0)+(1\times -75)][/tex]

[tex]\Delta H=-803kJ[/tex]

Therefore, the enthalpy change for combustion of methane is, -803 kJ


Related Questions

What are land plants used for?

Answers

Answer:

Land plants are also known as Embryophytes. Embryophytes are complex multicellular eukaryotes with specialized reproductive organs. The name derives from their innovative characteristic of nurturing the young embryo sporophyte during the early stages of its multicellular development within the tissues of the parent gametophyte.

Explanation:

Answer:

there used for mountains , wait I'm just trynna get points ya feel me

Explanation:


As you climb through the upper stratosphere, the temperature: increases decreases in constant

Answers

Answer:

It increases.

Explanation:

I hope this helps.

Answer:

Increases

Explanation:

Hope this helps :)

How many moles is 118 grams of Argon

Answers

Answer:

[tex]\boxed {\boxed {\sf About \ 2.96 \ moles \ of \ Argon}}[/tex]

Explanation:

To convert from grams to moles we must use the molar mass, which is found on the Periodic Table.

Argon: 39.9 g/mol

Use the molar mass as a ratio.

[tex]\frac{39.9 \ g \ Ar}{1 \ mol \ Ar}[/tex]

Multiply by the given number of grams: 118

[tex]118 \ g \ Ar *\frac{39.9 \ g \ Ar}{1 \ mol \ Ar}[/tex]

Flip the fraction so the grams of argon will cancel each other out.

[tex]118 \ g\ Ar * \frac{1 \ mol \ Ar}{39.9 \ g \ Ar}[/tex]

[tex]118 * \frac{ 1 \ mol \ Ar}{39.9 \ g \ Ar}[/tex]

[tex]\frac {118 \ mol \ Ar }{ 39.9 }[/tex]

[tex]2.95739348 \ mol \ Ar[/tex]

The original measurement of grams had 3 significant figures, so our answer must have 3 sig figs.

For the number we calculated, that is the hundredth place. The 7 in the thousandth place tells us to round the 5 to a 6.

[tex]2.96 \ mol \ Ar[/tex]

There are about 2.96 moles of Argon in 118 grams.

Use the periodic table to determine which of the
following could be an isotope of bromine (Br).
Check all that apply.
Z = 79, A = 196
Z = 35, A = 79
A = 79, N =44
D Z = 44, N = 44
DONE

Answers

A=79, N=44 lmk if I’m wrong ?

ANSWER ASAP THIS IS 6TH GRADE SCIENCE! GIVING BRAINLIEST FIVE STARS ANS A HEART!
Conduction is the transfer of thermal energy through direct contact. Convection is the transfer of thermal energy through the movement of a liquid or gas. Radiation is the transfer of thermal energy through thermal emission.

Answers

Answer:

what are you supposed to answer???

Explanation:

Bubbles are released when nitric acid is added to a potassium carbonate solution.
What is the net ion

Answers


Hi can I have a shout out please thank you for your reply thank you for the wonderful reply thank me love

Which of the following has the smallest atomic radius?
a B
b Al
c F
d N
e Ga

Answers

Answer:

c. F

Explanation:

As you go top to bottom down a column of the periodic table, atomic radius increases.

As you go left to right across a period of the periodic table, atomic radius decreases.

Knowing this trend, that means that the smallest atomic radius would be located in the top right of the periodic table. The closest element to that point is fluorine, or answer C.


What is the formula for nickel || dichromate

Answers

Answer: Cr2NiO7 is the molecular formula for nickel II dichromate.

blance: Mg + HNO2 → Mg(NO2)2 + H2

Answers

Explanation:

Mg + 2HNO2 → Mg(NO2)2 + H2

Answer:

Mg + 2HNO2 → Mg(NO2)2 + H2

Explanation:

the substance that can not be further decomposed by ordinary chemical means is
A.water
B.gold
C.sugar
D.air​

Answers

It’s between c and a

Hold the slides for observation

Answers

What is this

Explanation

AgNO3 ionic or covalent

Answers

Answer:

what i need more details

Explanation:

Answer:

Ionic

Explanation:

AgNO3 is also highly soluble in water. Ionic means that the compound is composed of ions.

describe a difference in our inner planets and outer planets​

Answers

The four inner planets have slower orbits , slower spins,no rings and they are made out of rock and metal. The four outer planets are made out of hydrogen and helium, they are called gas giants

A mixture of metals with properties different than the metals by themselves is called a(n) __________.

Answers

Answer:

Alloy

Explanation:

the law of conversation of mass states that the mass of the reactant is ___ the mass of products

Answers

Answer: equal to

Explanation:


Help out please????

Answers

Answer:

B. X= Elements, Y= Compounds

Explanation:

An element is a substance that is made up of only one type of atom. The atoms of an element can combine together chemically to form a molecule but can still exist as an individual atom e.g. Hydrogen atom; H can form molecule H2. Since only one atom makes up an element, its electrons act independently.

Compounds, on the other hand, are substances that are made up of more than one type of atom chemically combined. A compound can only exist as a molecule because it always contains more than one atom bonded together. However, since more than one atom are involved in the chemical bond that holds them together, electrons are shared with other atoms. Example of a compound is H20 containing atoms of hydrogen and oxygen that are chemically combined.

which one of these is NOT a unit for a reaction rate. 1) g/mL 2) M/min​

Answers

Reaction rate would have to do with time.

G/ml is not a unit of time this the answer

Describe the natural processes which remove carbon dioxide from the atmosphere

Answers

Answer:

Explanation:

The process is photosynthesis as plants need carbon dioxide and humans need oxygen so plants release oxygen which humans breath/take in and plant/trees take in carbon dioxide which humans release.

The natural process which removes  carbon dioxide from the atmosphere is photosynthesis.

What is photosynthesis?

It is defined as a process by which plants and other photosynthetic organisms convert the light energy in to chemical energy  through the process of cellular respiration.

Some of the energy which is converted  is stored in molecules of carbohydrates like sugar and starches  which are made up of from carbon dioxide and water . Photosynthetic organisms which can perform photosynthesis  are algae and cyanobacteria. Photosynthesis is largely responsible for producing and maintaining the content of oxygen in earth's atmosphere.

The process begins with proteins absorbing light energy  which are called reaction centers and contain a green pigment which is called chlorophyll . In plants ,these pigments are present inside organelles called chloroplasts while in bacteria they are present in plasma membrane.

Learn more about photosynthesis,here:

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9.
Which element is most likely to conduct heat and electricity?
A. Na B. Ca C.P D. Ne

Answers

Answer:

A. Na

Explanation:

Sodium is a good conductor of electricity and heat because it has only one electron in its valence shell.

i hope this helps :)

Answer:

C.) P

Explanation:

I believe this is correct, lmk if it's not.

How many elements are in (NH4)3PO4

Answers

Answer:

4

Explanation:

There are 4 different elements in the compound (N, H, P, O) but if you want to count the number of each element then the answer is different.

In NH4, theres 1 N and 4 H, but since there are 3 NH4s then u have 3 N and 12 H. There's 1 P and 4 Os as well.

Added together u have 3 + 12 + 1 + 4 = 20 elements in total.

hope this helps!

it’s four, the answer is four

16. Keesha performed a chemical reaction, and the products looked quite
different from the reactants. She knew the amount of matter had not
changed due to the law of conservation of mass. According to the law of
conservation of mass, what happens in a chemical reaction? *

Answers

Answer:

it's the third one

Explanation:

matter can't change, but mass can differ

An effective treatment for some cancerous tumors involves irradiation with "fast" neutrons. The neutrons from one treatment source have an average velocity of 3.5×107 m/s. If the velocities of individual neutrons are known to within 2.0% of this value, what is the uncertainty in the position of one of them?

Answers

Answer:

4.54 * 10^-14 m

Explanation:

From Heisenberg's uncertainty principle, we can write;

Δp.Δx ≥ h/4π

Given that;

Δp =Δmv

So;

Δmv.Δx ≥h/4π

Δmv =2/100(3.5×10^7 m/s * 1.66 * 10^-27)

Δmv =1.162 * 10^-21 Kgms-1

Δx ≥6.63 * 10^-34 /4 * 3.142 * 1.162 * 10^-21

Δx ≥4.54 * 10^-14 m

Volume of 8.625 g of sulphur di oxide at RTP in cm3

Answers

Answer:

The volume of 8.625 g of sulphur dioxide at RTP is approximately 3,230.84 cm³

Explanation:

The question requires the determination of the volume occupied by the gas based on the molar volume of a gas at STP

The given parameters of the sulphur dioxide, SO₂, gas are;

The mass of the given SO₂ gas = 8.625 g

The molar mass of SO₂ = 64.07 g/mol

The number of moles, 'n', in the given sample of SO₂ gas = Mass of SO₂/(Molar Mass of SO₂)

∴ The number of moles of SO₂ in the gas sample = 8.625 g/(64.07 g/mol) ≈ 0.134618386 moles

The molar volume of a gas at RTP is approximately 24 dm³/mole

24 dm³ = 24,000 cm³

∴ The molar volume of a gas at RTP is approximately 24,000 cm³/mole

The volume occupied by a gas at RTP = (The number of moles of the gas) × (The Molar Volume of a gas at RTP)

∴ The volume occupied by the 8.625 g of SO₂ gas at RTP = 0.134618386 moles × 24,000 cm³/mole ≈ 3,230.84 cm³

The volume occupied by the 8.625 g of SO₂ gas at RTP ≈ 3,230.84 cm³.

The useful energy a light bulb gives out is
(a). kinetic energy (b) chemical energy (c) light energy
science subject

Answers

Answer:

Light bulb gives light energy which is usefull

Answer:

(c) light energy

Explanation:

As bulb is used for giving light and hence the energy that it gives is light energy.

What volume, in liters, does 128 grams of O2 occupy at STP?
89.6 L
22.4 L
67.2 L
44.8 L

Answers

Answer: 89.7 L

Explanation:

89.6 volume, in liters, does 128 grams of O2 occupy at STP. Therefore, option A is correct.

What do you mean by volume ?

A volume is simply the amount of space taken up by any three-dimensional solid. A cube, a cuboid, a cone, a cylinder, or a sphere are examples of solids. Volumes differ depending on the shape.

Every three-dimensional object requires some amount of space. The volume of this space is measured. Volume is defined as the space occupied by an object within the boundaries of three-dimensional space. It is also known as the object's capacity.

1 mole Oxygen has mass 32 grams

Mole of Oxygen in 128 g mass = 128 g / 32 g/mol

= 4.0 mol O2

At Standard temperature and pressure this has volume

= 4.0 mol × 22.4 L/mol

= 89.6 L

Thus, 89.6 volume, in liters, does 128 grams of O2 occupy at STP, option A is correct.

To learn more about the volume, follow the link;

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___________ mL = 2.2 L

Answers

Answer:

2,200 mL I believe it is.

Answer:

2,200 is the answer of your question

The parts of the Earth that contain living organisms ​

Answers

Answer:

Biosphere

The Biosphere --contains all the planet's living things. This sphere includes all of the microorganisms, plants, and animals of Earth. Within the biosphere, living things form ecological communities based on the physical surroundings of an area.

Explanation:

Answer:

Biosphere

Explanation:The Biosphere --contains all the planet's living things. This sphere includes all of the microorganisms, plants, and animals of Earth. Within the biosphere, living things form ecological communities based on the physical surroundings of an area. hope this helps (:

Draw a model to represent the physical property of metals known as ductility, or the ability to be drawn into a wire.

Answers

The model that represents the physical property of metals known as ductility can be seen in the image attached below.

Metals are substances that are good conductors of heat and electricity.

The term ductility is a characteristic of metal and it explains the ability of metals to be drawn into wire. it implies that metal materials can be hammered and beaten into tiny sheets of wires.

The model in the image attached below shows how gold which is metal is drawn into wires.

Learn more about metals here:

https://brainly.com/question/25090336?referrer=searchResults

How does Natural selection lead to the Evolution of bacteria?

Answers

Answer:

Bacteria can evolve quickly because they reproduce at a fast rate.

Explanation:

Bacteria can evolve quickly because they reproduce at a fast rate. Mutations in the DNA of bacteria can produce new characteristics. A random mutation might cause some bacteria to become resistant to certain antibiotics, such as penicillin.

if I have a +2 oxidation number do I give up or accept electrons?​

Answers

Answer:

I will give up the electrons

Explanation:

Consider the following rules:

1. An atom loses electrons if its oxidation number is positive.

2. An atom gains electrons if its oxidation number is negative.

3. An atom neither gains nor loses electrons if its atomic number is zero.

As I have an oxidation number [tex]+2[/tex] that is oxidation number is positive, so, I will give up electrons.

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