Answer: An exothermic reaction is a "reaction for which the overall standard enthalpy change ΔH⚬ is negative." Exothermic reactions usually release heat and entail the replacement of weak bonds with stronger ones.
Exothermic reactions are important to forensic sciences and particularly to fire and explosion investigation. When a chemical reaction requires heat (rather than producing it) and results in cooling down the surroundings, it is conversely called endothermic.
Example-
Respiration is a series of exothermic reactions that occur in the mitochondria of living cells in order to release energy from food molecules. This energy can then be used to produce heat, for movement, growth, reproduction and active uptake.
Hope it helps
How many moles are in 79.6 grams of Fe2O3?
Answer:
0.49847139613321184
Explanation:
Fe2O3 in 1 mol is 159.6882.
Divide 76.9 by 159.6882.
PLEASE SOMEONE HELP ME WITH THIIS QUESTION
The labels have fallen off three bottles. Bottle A contains a gas, bottle B contains a liquid and bottle C contains a solid. The labels indicate that the compounds have the same number of carbon atoms, one being and alkane, one an alcohol, and the other a carboxylic acid. Suggest the identity of the contents of each bottle, and give reasons for your answer.
Answer:
The correct answer is - 5 carbon compounds due to low to high intermolecular forces between their molecules.
Explanation:
Bottle C has gas in it and we know that alkane has carbon and hydrogen only which means they have a single sigma bond between them and very low intermolecular forces in between molecules and are present mostly at gaseous state. Thus, bottle C has alkane.
Alcohols have -OH group that can form rarely two pi bonds which means they have intermediate intermolecular force whereas acids have -cooH group with a high molecular force so bottle B with liquid is alcohol and A has acid.
2. Sulfur dioxide gas (SO2) reacts with excess oxygen gas (O2) and excess liquid water (H2O) to form liquid sulfuric acid (H2SO4). In the laboratory, a chemist carries out this reaction with 67.2 L of sulfur dioxide and gets 250 g of sulfuric acid.
• Write a balanced equation for the reaction.
• Calculate the theoretical yield of sulfuric acid.
• Calculate the percent yield of the reaction.
(One mole of any gas occupies 22.4 L under certain conditions of temperature and pressure. Assume those conditions for this question.)
Answer:
See explanation
Explanation:
The balanced equation for the formation of sulphuric acid is;
2SO2 + O2 + 2H2O → 2H2SO4
If 1 mole of SO2 occupies 22.4 L
x moles occupy 67.2 L
x = 1 × 67.2/22.4
x= 3 moles
From the reaction equation;
2 moles of SO2 yields 2 moles of H2SO4
Hence 3 moles of SO2 also yields 3 moles of H2SO4
Theoretical yield of H2SO4 = 3 moles × 98 g/mol = 294 g
Percent yield = actual yield/theoretical yield × 100
Percent yield = 250g/294g × 100
Percent yield = 85%
Characteristics of a mixture?
Answer:
the substance mixture can be sperate by filtration, distillation, and freezing.
(c) Describe and explain how fractional distillation can be used to separate a mixture of neon,
argon, krypton and xenon.
Answer:
in fractional distillation we look at different boiling point of the mixture
Explanation:
argon will be separated from the mixture first because it has the lowest boiling point
The mixture of elements of gases of neon,argon, krypton and xenon can be separated using fractional distillation as the have difference in their boiling points.
What is an element?
An element is defined as a substance which cannot be broken down further into any other substance. Each element is made up of its own type of atom. Due to this reason all elements are different from one another.
Elements can be classified as metals and non-metals. Metals are shiny and conduct electricity and are all solids at room temperature except mercury. Non-metals do not conduct electricity and are mostly gases at room temperature except carbon and sulfur.
The number of protons in the nucleus is the defining property of an element and is related to the atomic number.All atoms with same atomic number are atoms of same element.
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Isotopes (such as hydrogen-1, hydrogen-2, and hydrogen-3) are the atoms of
the same element that differ in:
Answer:
The number of neutrons in nucleus
3. 79.0 grams of water was produced with a percent yield of 75.0%. How many grams of
oxygen did he start with?
4. 2.00 moles of oxygen gas at STP will produce how many grams of water, if the percent
yield is 82.0%?
Answer:
Explanation:
3 )
18 grams of water contains 16 grams of oxygen .
Let the grams of oxygen needed be m .
yield is 75%
Only 75 % of m will make water .
.75 m will form water .
water formed by .75 m of oxygen = 18 / 16 x .75 m
Given that
18 / 16 x .75 m = 79
m = (16 x 79) / ( 18 x .75 )
= 93.63 grams .
So oxygen required is 93.63 grams .
4 )
One mole of water contains 0.5 moles of oxygen.
2 moles of oxygen will make 2 /,5 = 4 moles of water .
percent yield is 82 % ,
so water produced = .82 x 4 = 3.28 moles of water.
Why boiling point is less at hilly station?
if shoto todoroki has a half hot half cold quirk and he eats a ice cube does one half melt and one half freeze
Answer:
in a way yes and no
Explanation:
shoto can control the temperature of both of his quirks so one can over power the other
he can melt the ice with the fire
and freeze the fire over the ice
hope it helps
Why slaked lime is used for white wash?
[tex]here \: is \: your \: answer[/tex]
Solution used to white wash the walls is Quick lime(CaO) and when it is mixed with slaked lime [Ca(OH)2]. When this paste is used for white washing it combines with atmospheric CO2 to form calcium carbonate (CaCO3) which gives it a shiny texture.
Which statement describes the "Law of Conservation of Mass" for the following reaction?
4 Fe + 302 -
2 Fe₂O₃
Select one:
tion
a.
grams of Fe + grams of Fe2O3 = grams of O2
O b. grams of O2 + grams of Fe2O3 = grams of Fe
O c. grams of Fe +grams of O2 = grams of Fe203
O d. None of these.
Name this ionic compound.
Answer:
c
Explanation:
Por favor, necesito ayuda, es urgente!!!
Answer:
what type of language this is ??
Identifica las formas de energía mecánica
(cinética y potencial) que tienen lugar en diferentes puntos del movimiento en
un sistema mecánico (caída libre, montaña rusa, péndulo).
2 Tipos de Energía Mecánica
2.1 1. Energía hidráulica
2.2 2. Energía eólica
2.3 3. Energía Mareomotriz
3 Ejemplos de Energía Mecánica
3.1 1. Planta hidroeléctrica
3.2 2. Máquinas de Vapor
3.3 3. Motor de Combustión interna
3.4 4. Molinos de Viento
3.5 5. Un Juego de Billar
3.6 6. Motor eléctrico
3.7 7. Locomotora
3.8 8. Bala
3.9 9. Una pistola de Dardos
3.10 10. Pelota sobre una mesa
https://www.aura-energia.com/ejemplos-de-energia-mecanica/
Which of these provides the most creative explanation for how rocks are made at present?
Law of Superposition
O Law of Unconformities
Principle of Uniformitarianism
O Principle of Original Horizontality
Answer:
Principle of Original Horizontality
Using salt and ice to make ice cream is an example of:
Answer:
An exothermic reaction
Explanation:
Which of the following is true for the equilibrium constant of a reaction?
It is a ratio of the concentrations in a reaction.
It remains the same at different temperatures.
It is represented by the symbol H.
Its value is always close to 1.
Answer:
The correct answer is It is a ratio of the concentrations in a reaction.
Explanation:
⇒ It is a ratio of the concentrations in a reaction.
This sentence is true because the equilibrium constant is calculated from the product of the concentration of the reaction products divided into the product of the concentrations of the reactants, each concentration raised by the stoichiometric coefficient. For example, for the following reaction:
aA + bB → cC + dD
The equilibrium constant is expressed as:
[tex]K = \frac{[C]^{c}[D]^{d} }{[A]^{a} [B]^{b} }[/tex]
⇒ It remains the same at different temperatures.
The sentence is false because the equilibrium constant changes with the temperature. In general, an endothermic reaction is favored by the increment of temperature (the equilibrium shifts to the right side) and disfavored with the decrease in temperature (shifts to the left).
⇒ It is represented by the symbol H.
This sentence is false because the equilibrium constant is represented with the letter K.
⇒ Its value is always close to 1.
It is not true because the equilibrium constant can be a number below or above 1.
K < 1 ⇒ there is more concentration of reactants at equilibrium
K > 1 ⇒ there is more concentration of products at equilibrium
An unknown compound has the following chemical formula: NxO
where x stands for a whole number.
Measurements also show that a certain sample of the unknown compound contains 5.2 mol of nitrogen and 2.65 mol of oxygen
Write the complete chemical formula for the unknown compound.
Taking into account the definition of empirical formula, the complete chemical formula for the unknown compound is N₂O.
The empirical formula of a chemical compound shows the ratio between the atoms of the compound. That is, it indicates which elements are present and the minimum ratio in whole numbers between their atoms. The empirical formula is the simplest chemical formula for a chemical compound, which is why it is also called the minimum formula.
The empirical formula must be expressed using integer relationships, then to obtain this formula, divide the numbers of moles by the smallest result of them. In this case:
Nitrogen: [tex]\frac{5.2 moles}{2.65 moles}[/tex]= 1.96 moles ≅ 2 moles
Oxygen [tex]\frac{2.65 moles}{2.65 moles}[/tex]= 1 mole
Being the chemical formula of hte compound NxO, where x stands for a whole number, this indicates that the elements N and O are in the compound in a whole number ratio of x: 1. Then, as in the empirical formula, the numbers of moles must be expressed in whole numbers, as previously calculated, the value of x must be 2.
In summary, the complete chemical formula for the unknown compound is N₂O.
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A hot metal plate at 150°C has been placed in air at room temperature. Which event would most likely take place over the next few minutes?
Molecules in both the metal and the surrounding air will start moving at lower speeds.
Molecules in both the metal and the surrounding air will start moving at higher speeds.
The air molecules that are surrounding the metal will slow down, and the molecules in the metal will speed up.
The air molecules that are surrounding the metal will speed up, and the molecules in the metal will slow down.
Answer:
d. The air molecules that are surrounding the metal will speed up, and the molecules in the metal will slow down.
Explanation:
hopes this helps
sorry if it doesn't
:)
Please answer both questions Thankyou
Answer:
The limiting reactant is oxygen gas and the reaction would produce 3.932 x 10 ^ 7 moles of water
Explanation:
Step 1: Convert everything into moles
nH2(l) = 1.06 x 10^8 g / 2.016 g/mol = 5.26 x 10^7 mols
nO2(l) = 6.29 x 10^8 g / 32.00 g/ mol = 1.966 x 10^7 mols
Step 2: Find the limiting reagent
The limiting reagent would be oxygen gas from
the balanced equation because we have less moles of oxygen gas needed to fully combust with the hydrant gas
Step 3: Stoichiometry time
The mole ratio from oxygen gas to water is 1:2
This means that for every mole of oxygen gas two moles of water is produced
We need to multiply the moles of oxygen gas by two to find out how many moles of water has been produced
nH2O = nO2 x 2
nH2O = 1.966x10^7 x 2
nH2O = 3.932x10^7
Step 4: Therefore statement
Therefore the limiting reactant is oxygen gas and the reaction would produce 3.932 x 10 ^ 7 moles of water
método científico problema: María, se encontraba observando a su madre mientras cocinaba una sopa, cuando de pronto, la estufa se apagó. ¿Qué sucedió?
Answer:
1) Hacer una pregunta con respecto al fenómeno observado: ¿Por qué se apagó la estufa mientras se cocinaba la sopa?
2) Investigar sobre el tema: Los alimentos necesitan una fuente constante de calor para cocinarse. La estufa es la fuente de calor utilizada para la cocción de alimentos, existen dos modelos de estufas: (i) combustión de gas natural, (ii) inducción eléctrica.
Las estufas por combustión de gas natural requieren de un suministro de gas y una unidad de ignición, generalmente mantienen la llama una vez garantizado el suministro de gas natural. Son los modelos más económicos y comunes, aunque son las de menor eficiencia energética.
Las estufas por inducción eléctrica utilizan la energía eléctrica como suministro, la cual es transformada en calor por medio de inductores. Son más costosas que las estufas por combustión de gas natural, pero tienen mayor eficiencia energética.
Se debe determinar que tipo de estufa posee la madre de María. No obstante, una posible causa sea la interrupción del suministro, otra por daños en algún componente (gas natural o electricidad).
3) Elaborar una hipótesis: La estufa se apagó por una interrupción en el suministro o por daños en el sistema.
4) Se realiza un experimento:
(i) Estufa por combustión de gas natural - Se abre el suministro de gas en otra hornilla, no sale gas.
(ii) Estufa por inducción eléctrica - Se enciende otra hornilla y no se activan los inductores.
5) Análisis de datos y obtención de conclusiones - Se analiza los datos y se encuentra que no existe suministro de gas/electricidad.
6) Compartir resultados - María concluye que la estufa se apagó por interrupción en el suministro.
Explanation:
El método científico consiste en el cumplimiento de los siguientes pasos:
1) Hacer una pregunta con respecto al fenómeno observado.
2) Investigar sobre el tema.
3) Elaborar una hipótesis.
4) Se prueba una hipótesis haciendo un experimento.
5) Analizar los datos y sacar una conclusión.
6) Compartir resultados.
A continuación, representamos cada paso:
1) Hacer una pregunta con respecto al fenómeno observado: ¿Por qué se apagó la estufa mientras se cocinaba la sopa?
2) Investigar sobre el tema: Los alimentos necesitan una fuente constante de calor para cocinarse. La estufa es la fuente de calor utilizada para la cocción de alimentos, existen dos modelos de estufas: (i) combustión de gas natural, (ii) inducción eléctrica.
Las estufas por combustión de gas natural requieren de un suministro de gas y una unidad de ignición, generalmente mantienen la llama una vez garantizado el suministro de gas natural. Son los modelos más económicos y comunes, aunque son las de menor eficiencia energética.
Las estufas por inducción eléctrica utilizan la energía eléctrica como suministro, la cual es transformada en calor por medio de inductores. Son más costosas que las estufas por combustión de gas natural, pero tienen mayor eficiencia energética.
Se debe determinar que tipo de estufa posee la madre de María. No obstante, una posible causa sea la interrupción del suministro, otra por daños en algún componente (gas natural o electricidad).
3) Elaborar una hipótesis: La estufa se apagó por una interrupción en el suministro o por daños en el sistema.
4) Se realiza un experimento:
(i) Estufa por combustión de gas natural - Se abre el suministro de gas en otra hornilla, no sale gas.
(ii) Estufa por inducción eléctrica - Se enciende otra hornilla y no se activan los inductores.
5) Análisis de datos y obtención de conclusiones - Se analiza los datos y se encuentra que no existe suministro de gas/electricidad.
6) Compartir resultados - María concluye que la estufa se apagó por interrupción en el suministro.
How does the arrangement of particles determine the physical properties of different states of matter?
Answer:
See explanation
Explanation:
Matter may exist in three phases; solid, liquid and gas. The state in which matter exists depends on the extent of intermolecular forces operating in the substance.
In solid particles, the molecules that compose the solid are close together because the molecules of a solid do not move from place to place but they continue to vibrate about their fixed position.
For liquids, the molecules that compose a liquid are in random motion but are less energetic than molecules of a gas.
In gases, the molecules are not held together at all. The molecules of a gas have the highest degree of freedom. They move from one point another at a high velocity.
Hence, the order of increasing degree of movement of the particles in different states of matter = solids<liquids< gases.
Solids have well arranged particles, the molecules of a liquid are a little more disorderly than liquid particles while gas particles are the most disorderly of all the states of matter.
If 0.735J of heat is added to 0.9916g of water, how much will the temperature increase?
0.238 oC
0.177 oC
0.310 oC
1.78 oC
Answer:
1.78 oC i think -_-
Explanation:
Have a great day-...
Which of the following are properties of metalloids?
A. Semi-conductors
B. All of these
C. React like metals sometimes
D. React like non-metals sometimes
Answer:
all of these are properties of metalloids
Answer:
The answer is B. All of these
Explanation:
Can you mark me the brainliest?
Two solids of identical mass, A and B, are analyzed using identical calorimeters. Each calorimeter contains the same amount of water and is at room temperature. When the solids are heated to the same initial temperature and placed in their calorimeters, the final temperature of solid A's calorimeter is higher than that of B. What can we infer from this
Answer:
Specific heat of solid A is greater than specific heat of solid B.
Explanation:
In the calorimeter, as the temperature is increasing, the vibrational kinetic energy will increase and this means that additional amount of energy will be needed to increase the temperature by the same value. Therefore, we can conclude that specific heat increases as temperature increases.
Now, we are told that the final temperature of solid A's calorimeter is higher than that of B.
This means from our definition earlier, Solid A will have a higher specific heat that solid B.
The intermediate product formed during the production of urea is,
Answer:
Arginine is intermediate product formed during the production of urea
The key combination is ornithine, on which the urea molecule is 'created'; intermediates in the procedure contain citrulline and arginine.
What is the Production of Urea?
The urea cycle is a procedure of conversion of toxic ammonia to negligibly toxic urea. Consequences of the urea cycle are 1 molecule of urea, 2 molecules of ADP, and 1 molecule of both AMP and fumaric acid.
When Ammonia and carbon dioxide recovery During urea decomposition a mixture of gaseous carbon dioxide and also ammonia is accumulated and also immersed into a dilute aqueous urea resolution.
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chemical formula of magnesium nitrate
Hello.
Magnesium nitrate is a chemical compound with the formula Mg (NO₃) ₂. Magnesium nitrate is an inorganic salt very soluble in water and alcohol and has the appearance of fine white crystals.
Magnesium Nitrate is commonly used as a fertilizer due to its high nutritional value, since it provides Magnesium and Nitrogen, these are important nutrients in the growth of crops. It is a water soluble fertilizer. Contains 10.5% N - 15.6% MgO. Provides nitrogen in the form of nitrate.
A chemist wait out 87.1 g of sodium. Calculate the number of moles of sodium she weighed out. Round your answer to three significant digits
here's the answer to your question
Name the following compound NiBr2?
Answer:
the Name of NiBr2 is
Nickel(II) bromide
TIME REMAINI
166:31:2
Which statement best describes why computer models are useful in science?
O
They can store and process data to make accurate weather predictions.
O They are used to create more complex representations of large systems.
O They cannot be revised after they are developed, tested, and shared with others.
They can be used to accurately make predigtions without scientific evidence.
Answer:
A. They can store and process data to make accurate weather predictions.
Explanation:
Evidentially its very accurate and useful in Science like making accurate Weather predictions.
hope i helped,
What is the name of a hydrocarbon that has the formula CH3(CH2)4CCH?
6-heptyne
1-heptene
1-heptyne
6-heptene
The name of the hydrocarbon with formula CH₃(CH₂)₄CCH has been 1-heptyne. Therefore, option C is correct.
What are hydrocarbons ?The hydrocarbon has been given as the organic compound with the carbon and hydrogen chain. The molecules are bonded by the covalent bonds.
The hydrocarbon has been named established on the number of carbon in the structure and the bond. The hydrocarbon with single bond has -ane suffix, the double bond hydrocarbon has -ene suffix, and the triple bond hydrocarbon has -yne suffix.
The given hydrocarbon has seven carbon atoms,So the name has been hept. In the presence of a triple bond in the structure, the suffix -yne has been added to it.
Thus, option C is correct.
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Answer:
C. 1-heptyne
Explanation:
