Students as a chemical reaction that absorbs thermal energy for the design of cold packs for the treatment of injuries can combine manganese oxide (MnO2) with hydrogen peroxide (H2O2)
By controlling the amounts of the reactants they can control the temperature, keeping it between 0 °C and 4 °C for 20 minutes or more.
This type of chemical reaction is called endothermic, because energy is absorbed in the form of light or heat, causing the resulting products to have higher energy than the reactants.
Chemical reaction that absorbs thermal energy fpr cold compresses for the treatment of injuriesThe most widely used endothermic chemical reaction in the treatment of injuries is the melting of ice, at least in warm environments, which occurs according to the following reaction:
H2O (s) + Energy ----- H2O (l)
Decomposition of manganese oxide absorbs thermal energyThe effect of an endothermic reaction is absorbs heat energy and in the case of manganese oxide the following decomposition occurs:
MnO2 (s) → MnO (s) + ½ O2 (g); ∆HR = 134kJ
Students can design cold packs for treating injuries with manganese dioxide bcause it breaks down into two products, manganese oxide and oxygen, making the enthalpy greater than zero (∆HR > 0).
MnO2 is a solid between gray and black in color and is present in minerals such as pyrolusite and nsutite, when combined with hydrogen peroxide it acts as a catalyst so that it accelerates chemical reaction
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Classify the reaction in each of the following equations.
a. FeCl2 (aq) + Mg → MgCl2 (s) + Fe(s)
b. NH3 (g) → N2 (g) + H2 (g)
Answer
a. Single displacement
b. Decomposition
When classifying chemical reactions, consider how reactants change to form the products.
An equation for a chemical reaction has a left side and a right side. The arrow separates the left and right sides.
The left side is called the reactants. The right side is called the products.Each product or reactant can be one or more elements.
Some Types of ReactionsWe can use letters* to represent products and reactants in a reaction.
SynthesisTwo reactants become one product.
A + B → ABDecompositionOne reactant becomes two products.
AB → A + BIn equation (b), this is like how NH₃ separated into two products, N₂ and H₂.Single DisplacementStart with two reactants, a compound and an element. To form the products, the element replaces one of the elements that was in the compound.
AB + C → AC + BIn equation (a), this is like how Mg replaced Fe. Fe was part of a compound at first. Now, Mg is part of a compound instead.Double DisplacementStart with two reactants that are compounds. To form the products, an element from each compound replaces each other.
AB + CD → AC + BDTherefore, equation (a) is a single displacement reaction and equation (b) is a decomposition reaction.
*Each letter represents an element. Two elements make a compound. A letter can also represent a compound if compound stays together during the reaction.
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Why do halogens get less reactive?
The halogens gets less reactive as we move down the group because the atomic mass will increases and the number of the electrons are increases.
The halogens get less reactive as we move top to bottom in the group in the periodic table as the atomic mass of the group 17 elements that is halogens will increases and as we move from from top to bottom in the periodic table the electrons are added and the number of electrons are increases.
This is reason , that the reactivity of the group 17 elements that is halogens will decreases as we move from top to bottom.
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What is the molarity of a LiOH solution if 15. 5 mL of a 0. 112 M H2SO4 solution is
required to neutralize a 25. 0-ml sample of the LiOH solution?
2LiOH + H2SO4 --> Li + 2H20
Molarity is a measure of the amount of solute that is dissolved in a given amount of solution.
What exactly is Molarity?
Molarity is a measure of the concentration of a solution, defined as the number of moles of a solute per liter of solution. It is typically expressed as moles per liter, or M. Molarity is an important concept in many chemistry and biology applications, as it can be used to determine the amount of a certain element or compound that is present in a solution.
Moles of H2SO4 required to neutralize LiOH = (15.5 mL x 0.112 M H2SO4) / 1000 mL = 0.01728 moles
Moles of LiOH used = 0.01728 moles
Moles of LiOH in 25.0 mL sample = (25.0 mL x Molarity of LiOH) / 1000 mL
Molarity of LiOH = (0.01728 moles x 1000 mL) / 25.0 mL = 0.6912 M LiOH
Hence, the molarity of a LiOH solution is 0.6912 M.
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The molar mass of CCl4 is 153. 81 g/mol How many grams of CCl4 are needed to have 5. 000 mol?
The molar mass of CCl4 is 153. 81 g/mol. '769.0 g' of CCl4 are needed to have 5.000 mol.
What is molar mass?
Molar mass is the mass of one mole of a substance. It is usually expressed in grams per mole (g/mol). The molar mass of a substance is calculated by taking the sum of the atomic weights of all of the atoms in the molecule multiplied by the Avogadro constant (6.022x10^23).
To find the number of grams of CCl4 needed to have 5.000 mol, use the formula:
Mass (grams) = Molar mass (g/mol) x Number of moles
Mass (grams) = 153.81 g/mol x 5.000 mol
Mass (grams) = 769.0 g.
'769.0 g' of CCl4 are needed to have 5.000 mol.
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Convert: 9.94 × 10²² molecules NH3 = ___ mol NH3
5.99 x 10⁴⁶
none of these
2.81
6.06
0.165
Answer:
correct answer is 0.165 moles by calculation
What are the chances of the offspring being heterozygous for tall plant?
There are 50% chances of the offspring being heterozygous for tall plant.
Crossing homozygous short tt plants with heterozygous tall Tt plants yields short to tall plants in a 1:1 ratio. So the seed has a 50% chance of growing into a large plant.
Under such conditions, the dominant allele is always expressed and the recessive allele is masked. In this example, the size allele is dominant, so the plant grows.
About 80% of an individual's height is determined by differences in their inherited DNA sequences.
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Help me please I have been stuck for some time
Answer:275.4 g Al2O3
Explanation: The mass of Al2O3 formed is 2.7 mol * 102 g/mol = 275.4 g. This is because the molar mass of Al2O3 is 102 g/mol. This means that when 1 mol of Al2O3 is formed, it has a mass of 102 g. Therefore, when 2.7 mol of Al2O3 is formed, it has a mass of 2.7 mol * 102 g/mol = 275.4 g.
Nitric acid has the formula HNO3. If there are 3. 55x10^23 atoms of O in the sample, how many moles of nitric acid are there?
Nitric acid has the formula HNO₃. If there are 3. 55x10²³ atoms of O in the sample, the number of moles of nitric acid is 0.589moles.
Define mole.How many moles of a substance are present in a reaction is determined by comparing its mass to the mass of one mole. One mole, or Avogadro's number, is equal to the sample mass divided by the molar mass, or 6.023×10²³ moles. You can calculate the total number of atoms or molecules in a sample by dividing the number of moles by the Avogadro constant. The equation is: Number of Molecules=Atoms or Molecules /6.022×10²³.
1 mole oxygen atom contains 6.02×10²³ atoms
how many moles of oxygen contains 3.55x 10²³atoms
Moles of nitric acid = 3.55x 10²³atoms/6.02 ×10²³atoms
Moles of nitric acid = 0.589moles.
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Chemical Reactions - Problems
4 NH, +5 O, → 4 NO+6H_O
Which of the following are the reactants in the reaction above?
NH,
NO
I
H₂O
Submit v
IT
Calculate each of the following quantities:
A. Volume (ml) of 2.25 M potassium hydroxide that contains 15.0 g of solute enter a 3 significant figure number
B. molarity of 250. ml of solution containing 1.25 moles of glucose
C. volume (ml) of 10.00 M copper(II) nitrate that must be diluted with water to prepare 750.0 ml of a 2.500 M solution (enter to 4 significant figures)
D. Are the following instructions for diluting a 10.0 M solution to a 1.00 M solution correct: "Take 100.0 mL of the 10.0 M solution and add 900.0 mL water"? enter either true or false
(A) Vol. of solvent is 119.8 ml, (B) Molarity (M) of sol. is 5.00 M, (C) V1 of copper nitrate solution is 187.5 ml, (D) The instruction given is false.
(A). To calculate the volume (ml) of a 2.25 M potassium hydroxide solution that contains 15.0 g of solute, we can use the formula:
The unit of measurement for molarity (M) is moles of solute per liter of solvent.
Rearranging the formula to solve for liters of solvent:
Molecularity = moles of solute / liters of solvent (M)
We know that the molar mass of potassium hydroxide (KOH) is 56.1 g/mol. To find the moles of solute, we can divide the given mass (15.0 g) by the molar mass of KOH:
15.0 g / 56.1 g/mol = 0.2679 moles
Now we can plug this value into the formula above:
Liters of solvent = 0.2679 moles / 2.25 M
Liters of solvent = 0.1198 L or 119.8 ml (rounded to 3 significant figures)
(B). To calculate the molarity of a solution containing 1.25 moles of glucose in 250. ml of solvent, we can use the formula:
The unit of measurement for molarity (M) is moles of solute per liter of solvent.
Plugging in the given values:
Molarity (M) = 1.25 moles / 0.250 L
Molarity (M) = 5.00 M
(C). To calculate the volume of a 10.00 M copper(II) nitrate solution that must be added to water to prepare 750.0 ml of a 2.500 M solution, we can use the formula:
M1V1 = M2V2
Where M1 and V1 are the concentration and volume of the original solution, and M2 and V2 are the concentration and volume of the final solution.
We know that the final solution has a volume of 750.0 ml and a concentration of 2.500 M, so we can plug in these values for V2 and M2:
M1V1 = 2.500 M x 750.0 ml
Now we can solve for V1 (the original volume) by rearranging the formula:
V1 = M2V2 / M1
V1 = (2.500 M x 750.0 ml) / 10.00 M
V1 = 187.5 ml (rounded to 4 significant figures)
(D). The instructions "Take 100.0 mL of the 10.0 M solution and add 900.0 mL water" are not correct for diluting a 10.0 M solution to a 1.00 M solution.
To achieve this dilution, you would need to take a smaller volume of the 10.0 M solution and add a larger volume of water, because the final volume should be larger than the starting volume.
For example, you could take 10.0 mL of the 10.0 M solution and add 90.0 mL of water, which would give you a final volume of 100.0 mL and a concentration of 1.00 M. The instruction given above is false.
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2 H2 + O2 --> 2 H2O
What mass of water (H2O) will be collected if 20. 0 grams of hydrogen gas (H2) are consumed?
Select one:
179 grams
89. 4 grams
44. 7 grams
358 grams
Answer:
2H2 +O2 - 2H20
4g of H react to give 36g of H20
20g of H gives Xg of H20
cross multiply
4x= 36*20
4x= 720
Xg = 720/4
Xg= 180g approximately
That is A which is 179
Consider a fusion reaction in which a proton fuses with a neutron to form a deuterium nucleus. How much energy is released in this reaction?(The mass of the deuterium nucleus is 2.01355u).
Energy released in the reaction in which a proton fuses with a neutron to form a deuterium nucleus is calculated as 2.234 MeV.
What do you understand by a fusion reaction?In fusion reaction, two light nuclei merge to form single heavier nucleus. The process releases energy because total mass of the resulting single nucleus is less than the mass of two original nuclei. And the leftover mass becomes energy.
form a deuterium nucleus: 1^1H+0^1n⟶1^2H+γ The masses are 1^1H(1.0078u) 0^1n(1.0087u) and 1^2H(2.0141u) the γ -ray photon is massless.
Δm= 1.0078 +1.0087- 2.0141
Energy released = 2.4*10^-3 * 931 MeV
= 2.234 MeV
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Which of the following is a physical property of minerals?
Answer:
Below
Explanation:
You didn't list any choices but stuff life color, density, texture,hardness, luster are PHYSICAL properties
I need help plssss:(
the question is in the photo
An ideal ga (which i i a hypothetical ga that conform to the law governing ga behavior) confined to a container with a male piton at the top. (Figure 2) A male wire i attached to the piton. When an external preure of 2. 00 atm i applied to the wire, the ga compree from 6. 40 to 3. 20 L. When the external preure i increaed to 2. 50 atm , the ga further compree from 3. 20 to 2. 56 L. In a eparate experiment with the ame initial condition, a preure of 2. 50 atm wa applied to the ideal ga, decreaing it volume from 6. 40 to 2. 56 L in one tep. If the final temperature wa the ame for both procee, what i the difference between q for the two-tep proce and q for the one-tep proce in joule?
An ideal gas is a gas composed of a large number of identical molecules that obey the ideal gas law.
What do you mean by Gas?
Gas is a state of matter made of atoms and molecules that are not bound together, allowing them to move freely and take the shape and volume of their container. It is one of the four fundamental states of matter (the others being solid, liquid, and plasma).
The heat exchanged in a two-step process is given by
q = CpΔT + (P1V1 – P2V2)
where Cp is the specific heat capacity of the gas, ΔT is the change in temperature, P1 and V1 are the initial pressure and volume, and P2 and V2 are the final pressure and volume.
For the two-step process,
q = CpΔT + (2.00 atm x 6.40 L – 2.50 atm x 3.20 L)
For the one-step process,
q = CpΔT + (2.50 atm x 6.40 L – 2.50 atm x 2.56 L)
The difference in q for the two-step process and the one-step process is
q2 – q1 = (2.50 atm x 3.20 L – 2.00 atm x 6.40 L)
q2 – q1 = (7.68 L atm – 12.80 L atm)
q2 – q1 = -5.12 L atm
Since 1 L atm = 101.3 J, the difference in q for the two-step process and the one-step process is
q2 – q1 = -5.12 L atm x 101.3 J/L atm
q2 – q1 = -517.4 J.
Hence, the difference is -517.4 J.
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(Question) How many atoms are in 3 grams of Cu?
(20 points)
Answer: 2.85 x 10^22
Explanation:
We can use stoichiometry to convert grams to atoms.
*Important quantities*
Original amount of Copper: 3 grams
Molar mass of Copper: 63.5 grams
Avogadro's number: 6.022x10^23 atoms/formula units/molecules
Process - [tex]\frac{3gramCu}{1}[/tex]×[tex]\frac{1 mole Cu}{63.5 gCu}[/tex]×[tex]\frac{6.022x10x^{23} }{1 moleCu}[/tex] = 2.84503937×10^22
After taking sig figs into account, the answer needs to be rounded to 3 decimal places
Final answer: 2.85 x 10^22
the reaction between strontium hydroxide and chloric acid produces __________.
16% of m is 28
16% x m = 28
0.16 x m = 28
m = ...
Answer:
m=175
Explanation:
100/16 = 6.25
6.25x28 = 175
Answer: To solve this equation for m, you can divide both sides of the equation by 0.16. This will give you:
m = 28 / 0.16
Simplifying the right side of the equation gives:
m = 175
Therefore, m = 175.
Explanation:
Iron has a BCC crystal structure, an atomic radius of 0. 124 nm, and an atomic weight of 55. 85 g/mol. Compute its theoretical density
Iron has a BCC crystal structure, an atomic radius of 0. 124 nm, and an atomic weight of 55. 85 g/mol. its theoretical density is 7.9 g /cm³.
The molar mass of the iron = 55.85 g/mol
The atomic radius = 0.124 nm
the edge length is given as :
a = (4r) / √3
a = ( 4 × 0.124 × 10⁻⁷ cm ) / √3
a = 2.86 × 10⁻⁸ cm
The density is given below :
density = ( Z × M ) / Na × a³
density = ( 2 × 55.85 ) / (6.023 ×10²³) × ( 2.86 × 10⁻⁸ )
density = 7.9 g/cm³
Thus the theoretical density is 7.9 g/cm³.
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What is the molarity of a solution in which 0.23 moles of NaCl are dissolved in enough water to make 395.6 mL of solution
The molarity of NaCl in enough water is 0.582[tex]\frac{mol}{mL}[/tex]
The moles of NaCl is given which is 0.23 and NaCl is dissolved in enough water which makes the solution of 395.6 mL.
The total number of moles of solute present in a given solution per litre is known as its molarity. In contrast to mass, which varies as the system's physical circumstances vary, the volume of a solution changes as a function of changes in the system's physical qualities, such as pressure and temperature. This has an impact on the molality of the solution. The symbol M, sometimes known as a molar, denotes molarity. A solution is considered to be one molar when one gram of the solute dissolves in one litre of the solution.
So, the molarity= [tex]\frac{totalnumber of moles}{total volume }[/tex]
molarity=[tex]\frac{0.23}{0.395}[/tex]
molarity=0.582[tex]\frac{mol}{mL}[/tex]
Hence, the molarity is 0.582.
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Suppose you run this reaction in a solvent that dissolves elemental mercury and elemental oxygen. What is the equilibrium-constant expression in terms of molarities for the reaction, using (solv) to indicate solvation.
At 55 °C, the equilibrium constant for this reaction is 6.68. A pharmaceutical chemist prepares 15.0 L of an initial 0.275 M acetic acid and 3.85 M ethanol solution.
Create an equation that can be solved for x by plugging the equilibrium concentrations (expressed in terms of x) into the formula for the equilibrium constant. (d) The equation from subpart (c) is cubic (it bears the formula ax3 + bx2 + cx + d = 0). In general, it is impossible to solve cubic equations in closed form. Indicate the direction (toward product or toward reactants) in which the mixture must change if it is not at equilibrium. The concentrations of SO 2 Cl 2 and SO 2 are 0.108 M and 0.052 M, respectively, in a mixture of the three gases that has reached equilibrium.
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What do these two changes have in common?
an engine using gasoline to power a car
cellular respiration
Select all that apply.
Both are only physical changes
Both converse mass
Both are chemical changes
Both are caused by heating
Answer: Both are only physical changes
Both converse mass
Explanation: the first two ones r correct
Transpiration is when a plant releases water vapor through its stomata, which are pours in its leaves and stems. What other process in the water cycle is this most similar to? explain your reasoning.
In addition to respiration, a process known as guttation involves the loss of liquid water from a plant's healthy leaf or stem, mostly through water stomata.
What is the transpiration process?The physiological loss of water . water of water vapor, mostly from the stomata of leaves, but also by evaporation first from surfaces of leaf tissue, flowers, and stems, is known as transpiration.
Why is transpiration necessary to plants?Additionally, by providing evaporative cooling, vegetation transpiration makes a major contribution to the energy balance of the leaf. Additionally, transpiration speeds up the movement of nutrients and water from roots to the shoots. Transpiration occurs when water vapor leaves a plant through the stomata.
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6.0 mol Al reacts with 4.0 mol O2 to form Al2O3.
4A1+30₂ → 2Al₂O3
How many moles of Al2O3 form when 4.0 mol Al reacts?
2 moles of Al₂O₃ will be produced when 4 moles of Al reacts in accordance with the above equation.
How to calculate moles using stoichiometry?Stoichiometry refers to the study and calculation of quantitative (measurable) relationships of the reactants and products in chemical reactions (chemical equations).
According to this question, 6.0 moles of Al reacts with 4.0 mol of oxygen gas to form Al₂O₃ as follows:
4Al + 30₂ → 2Al₂O₃
Based on the above equation, 4 moles of Al reacts to form 2 moles of aluminium oxide.
This means that 4 moles of aluminium will produce 4 × ²/4 = 2 moles of aluminium oxide.
Therefore, 2 moles of Al₂O₃ will be produced by 4 moles of aluminium.
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75g of a potato chip are burned in a calorimeter that contains 2L of water initially at 297K. After the combustion, the temperature rises 12oC. How much heat is involved per gram of potato chip burned
The amount of heat involved per gram of potato chip burned is 8388J when a 75g of a potato chip are burned in a calorimeter that contains 2L of water initially at 297K.
Given mass of potato chips burned = 75g
Mass of water (m) = 2L = 2000g
Initial temperature (T1) = 297K - 273 = 24oC.
Final temperature after combustion (T2) = 12oC
We know that q = mC∆T where q is heat and C is specific heat of water = 4.2J/g/oC.
q = 2000 x 4.2 x (24-12)
q = 8388J
Hence the heat evolved per gram of potato chip burned is 8388J
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2 points of the water molecule are the paired ______ and _______ electrons from the oxygen atom and ________ electron from each H atom
The other 2 points of the water molecule are the paired _________ electrons of the oxygen atom.
I get what the question is asking and I know general idea of the answer. I just can't for the life of me figure out what exact wording I am supposed to use that will fit these blanks
To solve this we must be knowing each and every concept related to chemical Compound. Therefore, The other 2 points of the water molecule are the paired two electrons from the oxygen atom and one electron from each H atom.
What is chemical Compound?Chemical Compound is a combination of molecule, Molecule forms by combination of element and element forms by combination of atoms in fixed proportion.
There are two types of chemical compound one is covalent compound and other is ionic compound, covalent compound formed by sharing of electron and ionic compound formed by complete transfer of electron. The other 2 points of the water molecule are the paired two electrons from the oxygen atom and one electron from each H atom.
Therefore, The other 2 points of the water molecule are the paired two electrons from the oxygen atom and one electron from each H atom.
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Identify the 13 c nmr chemical shift for each carbon atom in a molecule of 1-penten-3-one
Carbon 1: δ = 2.09 ppm (The C1 atom is a methyl group, and is in a tertiary environment, which typically corresponds to a chemical shift of around 2.09 ppm).
What is chemical shift?Chemical shift is a term used in NMR spectroscopy to describe the relative difference in the resonance frequency of a nucleus in a molecule compared to a reference frequency.
2. Carbon 2: δ = 11.81 ppm (This is the carbonyl carbon, and is in a sp2 hybridized environment, which typically corresponds to a chemical shift of around 11.81 ppm).
3. Carbon 3: δ = 13.92 ppm (This is the terminal carbon of the pentene chain, and is in a sp3 hybridized environment, which typically corresponds to a chemical shift of around 13.92 ppm).
4. Carbon 4: δ = 16.53 ppm (The C4 atom is a methylene group, and is in a secondary environment, which typically corresponds to a chemical shift of around 16.53 ppm).
5. Carbon 5: δ = 17.86 ppm (The C5 atom is a quaternary carbon, and is in a sp3 hybridized environment, which typically corresponds to a chemical shift of around 17.86 ppm).
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What causes stress in rocks? and What happens when stress is released?
What is the mass of 2.30 x 10^24 particles of water, H₂O?
The mass of 2.30 x 10²⁴ particles of water (H₂O) is 60.84 grams.
What exactly is mass defined as?The amount of matter in a particle or object is represented by its mass, which is denoted by the symbol m. In the International System (SI), the kilograms serves as the default unit of mass (kg).
The formula N = n L describes the relationship between a substance's number of particles and number of moles.
n also defined using the equation n = m/M
N = n L
N = m/M L
Then substitute N and L values,
2.30×10²⁴ = m/M × 6.02×10²³
Molar mass of water = 18
2.30×10²⁴ = m/18 × 6.02×10²³
2.30×10²⁴/6.02×10²³ = m/18
3.38 = m/18
m = 3.38 × 18
m = 60.84grams.
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. The reaction rates of many spontaneous reactions are actually very slow. Which of these statements is the best explanation for this observation? (1) The activation energy of the reaction is large. (2) AG for the reaction is positive. (3) Such reactions are endothermic. (4) The entropy change is negative.
In reality, spontaneous reactions occur relatively slowly because The reaction's activation energy is high.
Hence, Option 1 is correct.
A spontaneous reaction is one that favors the creation of products in the environment in which it is taking place.Given that spontaneous reactions discharge free energy, the sign of G must be negative. There are four distinct conceivable combinations because both H and S can be either positive or negative depending on the features of the specific reaction.An exothermic example of a spontaneous reaction is a raging campfire (there is a decrease in the energy of the system as energy is released to the surroundings as heat).Find more information about Activation energy here:
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