The enthalpy change for the given reaction is -2ΔH°f.
option C.
What is the enthalpy change?The enthalpy change for the given reaction is calculated as follows;
ΔH° = ΣnΔH°f(products) - ΣnΔH°f(reactants)
where;
ΔH° is the enthalpy change of the reactionThe balanced chemical equation is given as;
2H₂O (l) → 2H₂ (g) + O₂ (g)
The sum of the standard enthalpies of formation of the products is:
ΣnΔH°f(products) = 2(0 kJ·mol⁻¹) + 0 kJ·mol⁻¹ = 0 kJ·mol⁻¹
The sum of the standard enthalpies of formation of the reactants is:
ΣnΔH°f(reactants) = 2(-285.8 kJ·mol⁻¹) = -571.6 kJ·mol⁻¹
ΔH° = ΣnΔH°f(products) - ΣnΔH°f(reactants)
ΔH° = 0 kJ·mol⁻¹ - (-571.6 kJ·mol⁻¹)
ΔH° = +571.6 kJ·mol⁻¹
+571.6 kJ·mol⁻¹ = -2ΔH°f
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Hi please help with these questions :)
Answer:
c
Explanation:
because electricity has a good conduct tha is mental
Which of the following is the correct definition of partial pressure *
A) The total pressure exerted by all gases in the mixture
B) The contribution each gas in a mixture makes to the total pressure
C) The space occupied a gas in the mixture
D) The amount of gas particles present in a mixture
Answer:A
Explanation:
If the point of the nail can be approximated as a circle with a radius 2.00×10^-3m What is the pressure in MPa exerted on the wall if a hammer strikes the nail with a force of 104 N
Answer:
8.28 MPa
Explanation:
From the question given above, the following data were obtained:
Radius (r) = 2×10¯³ m
Force applied (F) = 104 N
Pressure (P) =?
Next, we shall determine the area of the nail (i.e circle). This can be obtained as follow:
Radius (r) = 2×10¯³ m
Area (A) of circle =?
Pi (π) = 3.14
A = πr²
A = 3.14 × (2×10¯³)²
A = 3.14 × 4×10¯⁶
A = 1.256×10¯⁵ m²
Next, we shall determine the pressure. This can be obtained as follow:
Force applied (F) = 104 N
Area (A) = 1.256×10¯⁵ m²
Pressure (P) =?
P = F / A
P = 104 / 1.256×10¯⁵
P = 8280254.78 Nm¯²
Finally, we shall convert 8280254.78 Nm¯² to MPa. This can be obtained as follow:
1 Nm¯² = 1×10¯⁶ MPa
Therefore,
8280254.78 Nm¯² = 8280254.78 Nm¯² × 1×10¯⁶ MPa / 1 Nm¯²
8280254.78 Nm¯² = 8.28 MPa
Thus, the pressure exerted on the wall is 8.28 MPa
Can someone help me ASAP.
Answer:
This type of mutation occurs when one or more base pairs are added to the gene sequence: insertion
This type of mutation occurs when one or more base pairs take the place of other base pairs in the gene sequence: substitution
anyone know how to do this?
Identify the problem that the cold pack must address
Just need 1-3 sentences
Answer:
A person's hand holding a cold pack on an ankle ... To determine if a reaction is exothermic or endothermic, you have to compare the ... Well, that also applies to energy of solution problems.
Explanation:
Answer:
To determine if a reaction is exothermic or endothermic, you have to compare
Explanation:
Which additional claim can be BEST supported by the evidence from the skulls in the whale fossil record?
A.
The fossil record shows differences in the skulls of the mammals, which shows that they are from three separate species that all lived at the same time.
B.
The fossil record shows similarities in the skulls of the mammals, which shows that they must have had similar habitats and environments.
C.
The fossil record shows that some mammals evolved so that their nostrils are further at the top of their skull for better breathing while in the water.
D.
The fossil record does not give enough evidence about the mammals to determine if there is a relationship between the three skulls.
Answer:
d
Explanation:
Answer:
B
Explanation:
I think it is B because it starts out with it's nostrils so it is on the mouth causing it not to be able to breathe but over time it's nostril moved to the top of the head so they could breather better
describe meteor showers
Answer:
a rain of asteroids coming from space
Explanation:
What is on the left side of the arrow 2H2+1O2 --> 2H2O
Answer:
The correct answer is - reactants.
Explanation:
In any chemical reaction, there is an arrow that distinguishes the two major components of the chemical equation by placed in between them. These two components are reactants and products.
OftenlThe reactants placed on the left side of a chemical equation and the products placed on the right side of a chemical equation. In this given case, the reactants 2H2 + 1O2 are placed on the left side of the equation.
An iron nail that has rusted is an example of a chemical reaction.
True
False
Answer:
True
Explanation:
1) In which state of matter will particles move the fastest?
Answer:
Gases
Explanation:
The particals will move around rapidly in all directions.
. How many grams of magnesium chloride can be produced by reacting 2 moles of chlorine gas with excess magnesium bromide? ____Cl2 + ____MgBr2 ___MgCl2 + ___Br2
Answer: 190 g of magnesium chloride can be produced by reacting 2 moles of chlorine gas with excess magnesium bromide.
Explanation:
The balanced chemical reaction is;
[tex]Cl_2+MgBr_2\rightarrow MgCl_2+Br_2[/tex]
[tex]Cl_2[/tex] is the limiting reagent as it limits the formation of product and [tex]MgBr_2[/tex] is the excess reagent.
According to stoichiometry :
1 mole of [tex]Cl_2[/tex] produces = 1 mole of [tex]MgCl_2[/tex]
Thus 2 moles of [tex]Cl_2[/tex] will produce=[tex]\frac{1}{1}\times 2=2moles[/tex] of [tex]MgCl_2[/tex]
Mass of [tex]MgCl_2=moles\times {\text {Molar mass}}=2moles\times 95g/mol=190g[/tex]
Thus 190 g of magnesium chloride can be produced by reacting 2 moles of chlorine gas with excess magnesium bromide
Describe the similarities and/or differences between heating and burning the magnesium metal. Did either heating or burning produce a chemical change?
Answer and Explanation:
Heating the magnesium metal is a physical change because after the process, the magnesium metal is still magnesium metal and no other substance is formed. When we heat the metal, we tranfer energy and the temperature is raised. It could include the melting of the metal, which is a change in the state of matter, but it is still a physical change because no chemical reactions occur.
Burning the magnesium metal is a chemical change because it involves the reaction with O₂ to form a different compound (a magnesium oxide).
Cu + HNO3 --> Cu(NO3)2 + NO + H2O
how to balance... WILL GIVE 15 POINTS
Answer:
3 Cu + 8 HNO3 --> 3 Cu(NO3)2 + 2 NO + 4 H2O
Explanation:
Make sure both sides are equal
3 Cu + 8 HNO3 --> 3 Cu(NO3)2 + 2 NO + 4 H2O
// start by those elements that change their oxidation degree
Cu and N
// also you can write reduction-oxidation reactions
[tex]Cu^{0}[/tex] + 2 [tex]e^{-}[/tex] --> [tex]Cu^{-2}[/tex] | 2
[tex]N^{+5}[/tex] - 3 [tex]e^{-}[/tex] --> [tex]N^{+2}[/tex] | 3
// write the numbers of electrons that are lost/gained as the coefficients of the opposite elements
// then check if H and O are the same on both sides
// adjust if they aren't.
Answer:
Explanation:
3Cu + 2HNO3 --> 3Cu(NO3)2 + 2NO + 2H2O
100 POINTS PLS HELP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Answer:
i need this im struggling with my work
Explanation:
Last one and the first
Describe 1 physical property and 1 chemical properties of a metal bicycle
Answer:
A physical property would be The metal, while a possible chemical property would be a chance of gallium. (Gallium is liquid on hot days)
Explanation:
Which of the following statements is TRUE about the loose rocks on the surface
of the earth? (SC.6.E.6.1
Both the large loose rocks and the small loose rocks used to be part
of earth's solid rock layer.
The large loose rocks used to be part of earth's solid rock layer, but
the small loose rocks were never part of the solid rock layer.
The small loose rocks used to be part of earth's solid rock layer, but
the large loose rocks were never part of the solid rock layer.
Neither the large nor the small loose rocks used to be part of earth's
solid rock layer
Answer:B
Explanation:
Answer:
Both large loose rocks and the small loose rocks used to be apart of the earths solid rock layer.
Explanation:
I WILL GIVE YOU BRANILY PLS
Answer:
what dose this even mean?
Explanation:
describe the three states of matter that are present when snow melts
Answer:
solid liquid and gas
Explanation:
ice is a solid then it melts to liquid and evaporates into gas
Answer:
Snow is basically water;
ice/snow is solid state
water is liquid state
vapour is gaseous state
Explanation:
How many atoms are in 1.22 moles of magnesium?
Answer:
7.34684 × 10^23 atoms
Explanation:
Well, one mole is basically
6.022 × 10^23 atoms. So 1.22 moles would be
6.022 × 10^23 ⋅ 1.22 atoms.
6.022 × 10^23 ⋅ 1.22 = 7.34684 × 10^23 atoms
The total number of atoms in 1.22 moles of magnesium is 7.34 × 10²³.
One mole of a substance is equal to 6.022 × 10²³ units of that substance (such as atoms, molecules, or ions).The number 6.022 × 10²³ is known as Avogadro's number or Avogadro's constant.Given:
1.22 moles of magnesium
[tex]1 \text{ mole}= 6.022*10^{23}\text{ atoms}\\\\1.22 \text{ moles}= 1.22*6.022*10^{23}\text{ atoms}\\\\1.22 \text{ moles}=7.34*10^{23}\text{ atoms}[/tex]
So, the total number of atoms in 1.22 moles of magnesium is 7.34 × 10²³.
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The freezing point of a substance is the
at
which it freezes.
Answer:
reff lagay mo yung ilalagay mo
Answer:
Freezing point is the temperature at which a liquid becomes a solid at normal atmospheric pressure. Alternatively, a melting point is the temperature at which a solid becomes a liquid at normal atmospheric pressure.
what is a method to isolate insoluble salts after a neutralisation reaction
Answer:
multiply
Explanation:
multiplacation
What is the formula for CNHO
Answer:
this is basically structure of iso cyanic acid
How many orbitals are in the subshell with the following quantum numbers: n=4,l=2,ml=−2,−1,0,1,2?
Select the correct answer below:
A. 1
B. 3
C. 5
D. 7
is there a better way to figure out the ratio of molecule types? What might that be?
What are the 3 Newton laws
Answer:
The laws are: (1) Every object moves in a straight line unless acted upon by a force.
(2) The acceleration of an object is directly proportional to the net force exerted and inversely proportional to the object's mass.
(3) For every action, there is an equal and opposite reaction.
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What is the motion of the particles in this kind of wave?
A.the particles will move up and down over large areas.
B.the particles will up and down over small areas.
C.the particles will move side to side over small areas.
D.the particles will move side to side over large areas.
Answer:
not sure sorry
Explanation:
What molecular geometry would be expected for BF3 and NH3?
Answer:
Boron trifluoride would have a trigonal planar geometry.Ammonia would have a trigonal pyramidal geometry.Explanation:
There are three valence electrons in a boron atom.
In boron trifluoride, the central boron atom did not achieve an octet with eight valence electrons. Rather, that boron atom would be electron deficient with only six valence electrons.
Each of the three fluoride atoms would have shared one valence electron with that boron atom, with a total of three boron-fluorine single bonds. On the other hand, all three of the valence electrons of that boron atom would be involved in bonding. Hence, there would be no extra valence electrons to act as lone pairs on that boron atom.
Hence, the central boron atom would have three electron domains (one for each boron-fluorine bond) with none of the electron domains coming from lone pairs. By the VSEPR theory, the geometry of the molecule would be trigonal planar. All four atoms in this molecule would be in the same plane.
There are five valence electrons in a nitrogen atom.
In ammonia, the central nitrogen atom is indeed able to achieve an octet (with eight valence electrons in total.) Three of the five valence electrons of nitrogen would form a total of three hydrogen-nitrogen bonds. The other two valence electrons would form a lone pair.
Hence the central nitrogen atom would have four electron domains (one for each of the three hydrogen-nitrogen bond, and one for the lone pair.) Hence, by the VSEPR theory, the geometry of this molecule would be trigonal pyramidal.
Which structures join with the cell’s membrane during exocytosis?
Answer:Exocytosis is also used to integrate new proteins into the cell membrane. In this process, the new protein is formed inside the cell, and migrates to phospholipid bilayer of the vesicle. The vesicle, containing the new protein as a part of the phospholipid bilayer, fuses with the cell membrane.
Explanation:
What happens during meiosis that does NOT happen during mitosis?
A new cells are formed
B two rounds of cell division
C DNA is passed on to the daughter cells
D parent cells grow in size before division
please help