Magnesium metal burns in air with an intense bright light according to the equation
2 Mg(s) + O2(g) → 2 MgO(s) + 1200 kJ

A.) What is the amount of energy in kJ produced when 4.5 mol of Mg is burned in the presence of excess oxygen?

Answers

Answer 1

The heat produced by 4.5 moles of magnesium when burnt is 2700 kJ.

A thermochemical reaction is a reaction in which the amount of heat lost or gained is included in the reaction equation. The thermochemical reaction equation for the combustion of magnesium is shown as follows;

2 Mg(s) + O2(g) → 2 MgO(s) + 1200 kJ

From the reaction equation;

2 moles of magnesium produced 1200 kJ of heat

4.5 moles of magnesium will produce 4.5 moles × 1200 kJ/2 moles

= 2700 kJ

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Related Questions

How many atoms are in mercury (I) phospate?
The chemical formula is (Hg2)3(PO4)2

A)11
B)14
C)15
D)16

Answers

Mercury (I) phosphate with the chemical formula  (Hg2)3(PO4)2 has 16 atoms.

Number of Hg atoms = 2x3 = 6Number of P atoms = 2 x 1 = 2Number of O atoms = 4x2 = 8

Sum of all the atoms = 6+2+8

                                   = 16 atoms

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Write a balanced chemical equation for this reaction by completing the reaction below. Add the missing products and coefficients. Do not include phases.

Answers

To balance a chemical equation you must pay attention that the algebraic equation has the same number of element atoms in reactant and the product.

A chemical equation is a term to refer to the symbolic description of a chemical reaction, that is, the written representation of symbols. For example:

2H₂ + O₂ ---> 2H₂O

The balance of an equation can be related to the law of conservation of matter, that is, the number of atoms of each element in the reactants is in the result.

Note: This question is incomplete, because the information some information is missing.

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10. Select the more polar bond in each of the following pairs: a) C and N or C and o b) N and F or N and O.

Answers

A) C and O
B) N and F

Learning Task 2: Read each statement or question below carefully and fill in the blank(s) with the best answer by choosing the words inside the box. Write your answers in a separate sheet of paper. cation 1 -ide -ine nonmetals O ion ionic compound anion metals root name 1. Any atom or molecule with a net charge, either positive or negative, is known as en 2. An atom that gains one extra electron forms an with a 1- charge. 3. A positive ion, called a is produced when one or more electrons are lost from a neutral atom. 4. Unlike a cation, which is named for the parent atom, an anion is named by taking the of the atom and changing the ending. 5. The name of each anions is obtained by adding the suffix to the root of the atom name. 6. The always form positive ions. 7. on the other hand, form negative ions by gaining electrons. 8. It is very important to remember that a chemical compound must have a net charge of​

Answers

Body surface area is calculated a) in m2 from weight and height. b) from height. c) from weight. d) in meters from weight and height.

why does a Costal area have less variation in temperature​

Answers

Answer:

*The coastal areas experience less variation in temperature as compared to land. ... It means that water takes more time to get hot or cold then land. Therefore areas near sea or ocean have more moderate temperature in the day time and less cooler at night

Explanation:

To what pH should you adjust a standard hydrogen electrode to get an electrode potential of -0.128 V ? (Assume that the partial pressure of hydrogen gas remains at 1 atm.) Express your answer using two decimal places.\

Answers

The pH of the standard hydrogen electrode that has electrode potential of -0.128 V  is 4.3.

The equation of the hydrogen electrode is;

2H^+(aq) + 2e ⇄ H2(g)

The standard electrode potential of hydrogen is 0.00 V

Using the Nernst equation;

Ecell = E°cell - 0.0592/n log Q

Now;

E°cell = 0.00 V

n = 2

Q = 1/[H^+]

-0.128 = 0.00 - 0.0592/2 log  1/[H^+]

-0.128 = 0.00 - 0.0296 log 1/[H^+]

 -0.128 =  - 0.0296 log 1/[H^+]

-0.128/  - 0.0296  =  log 1/[H^+]

1/[H^+] = Antilog (4.32)

[H^+] = 4.79 × 10^-5

Now;

pH = -log[H^+]

pH = -log (4.79 × 10^-5)

pH = 4.3

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After spending some time in the stomach, the food is sent to the blank

Answers

Answer:

the small intestine where nutrients are absorbed.

what is the free energy change G for the equilibrium between hydrogen iodine a hydrogen and iodine at 4:53

Answers

Answer:

Many chemical reactions are reversible; that is, the products of the reaction can combine to re-form the reactants. An example of a reversible reaction is that of hydrogen with iodine to form hydrogen iodide:

H2(g) + I2(g) 2 HI(g)

We can study this reversible reaction by placing hydrogen and iodine in a reaction vessel and then measuring the concentrations of H2, I2, and HI at various times after the reactants are mixed. Figure 13.8 is a plot of the concentrations of reactants and products of this reaction versus time. The concentration of hydrogen iodide increases very rapidly at first, then more slowly, and finally, after the time indicated by the vertical line marked "Equilibrium," remains constant. Similarly, the concentrations of hydrogen and iodine are large at the start of the reaction but decrease, rapidly at first, and then more slowly. Finally, they, too, become constant.

If this reaction were not reversible, the concentrations of hydrogen and iodine would have continued to decrease and the concentration of hydrogen iodide to increase. This process does not happen. Instead, as soon as any molecules of hydrogen iodide are formed, some decompose into hydrogen and iodine. Two reactions are taking place simultaneously: the formation of hydrogen iodide and its decomposition. When the concentrations of all these components become constant (at the equilibrium point in Figure 13.8), the rate of the forward reaction (H2 + I2 2 HI) must be equal to the rate of the reverse reaction (2 HI H2 + I2). A state of dynamic chemical equilibrium has then been reached, one in which two opposing reactions are proceeding at equal rates, with no net changes in concentration.

PICTURE 13.8

FIGURE 13.8 Concentration changes during the reversible reaction

H2(g) + I2(g) 2 HI as it proceeds toward equilibrium.

We have encountered this criterion for equilibrium before. In the equilibrium between a liquid and its vapor, the rate of vaporization is equal to the rate of condensation. In the equilibrium of a saturated solution with undissolved solute, the rate of dissolution is equal to the rate of precipitation. In the equilibrium of a weak acid with its ions, the rate of dissociation is equal to the rate of recombination. Note that none of these reactions is static: Two opposing changes are occurring at equal rates.

B. The Characteristics of Chemical Equilibrium

1. Equal rates

At equilibrium, the rate of the forward reaction is equal to the rate of the reverse reaction.

2. Constant concentrations

At equilibrium, the concentrations of the substances participating in the equilibrium are constant. Although individual reactant molecules may be reacting to form product molecules and individual product molecules may be reacting to re-form the reactants, the concentrations of the reactants and the products remain constant.

3. No free energy change

At equilibrium, the free energy change is zero. Neither the forward nor the reverse reaction is spontaneous and neither is favored. Consider the ice-water change. Above 0°C, ice melts spontaneously to form liquid water; G for this change is negative. Below 0°C, the change from ice to water is not spontaneous; G is positive. At 0°C, the two states are in equilibrium. The rate of melting is equal to the rate of freezing: the amount of ice and water and the amount of liquid water present remain constant, and the free energy change is zero as long as no energy is added to or subtracted from the mixture.

C. The Equilibrium Constant

In Chapter 12, we introduced the mathematical relationship between the concentrations of the components of an equilibrium, known as the equilibrium constant, Keq. We said that, for the general equation of a reversible reaction

Explanation:

sorry(: hope to help

Which factor is NOT important in the fossilization process?

Answers

Answer:

Things like the age of the organism, the organism's diet, style of movement (walking or swimming) do not affect how it fossilizes. Answer 2: Fossilization happens when small chunks of rock (such as sand) enter the spaces in a body or plant that would have hosted resin, air, or soft tissue, preserving the body or plant

1.An object that produces electrical energy through redox reactions is called ____________.

oxidation

reduction

galvanic/voltaic cell


2.Which species undergoes oxidation?

Pb

Cu

Answers

[tex] \huge \bf༆ Answer ༄[/tex]

Question : - 1

An object that produces electrical energy through redox reactions is called Galvanic cell

Question : - 2

Pb undergoes Oxidation

[tex]꧁ \: \large \frak{Eternal \: Being } \: ꧂[/tex]

how many nuetrons are in the nucleous of an atom number of 25?

Answers

Answer:

I believe there are 30

Explanation:

6. What is the molarity of 175 mL of solution containing 2.18 grams of NazS04-10H2O?​

Answers

Answer:

[tex]Molarity\,\,of\,\,the\,\,solution\,\,is\,\,S=0.039M[/tex]

Explanation:

[tex]W=2.18 g\\M=322g\\V=175mL=0.175L\\\\S=\frac{W}{MV} \\=>S=\frac{2.18}{322*0.175} \\So,S=0.039M[/tex]

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What are the dependent and independent variables in this experiment? How are outside factors being controlled in this experiment to make sure that the results test only the dependent variable?

Answers

Answer:

1. An independent variable is manipulated, or changed. The dependent, or responding variable, changes based on the independent variable. The dependent variable is examined.

2. It is a controlled experiment.

Explanation:

In a controlled experiment all variables are kept the same, except for the one being tested, which is called the experimental variable , or independent variable . This group is the experimental group . The group that is not affected by the experimental variable is the control group .

Very often a graph will be used to analyze the results of the experiment. The independent/experimental variable is placed on the x-axis and the dependent variable is placed on the y-axis. The dependent variable is what is measured as a result of the application of the experimental variable.

A variable that is independent is altered. Based on the independent variable, the responding variable, or dependent variable, alters. Examining the dependent variable. The experiment is carefully controlled.

What is an independent variable ?

In mathematical modeling, statistical modeling, and experimental sciences, there are dependent and independent variables. Dependent variables get their name because, during an experiment, their values are investigated under the presumption or requirement that they are dependent on the values of other variables due to some law or rule.

A variable that is independent is precisely what it sounds like. It is a stand-alone variable that is unaffected by the other variables you are attempting to assess. Age, for instance, could be an independent variable.

When doing an experiment, the independent variable is what you alter, and the dependent variable is what changes as a result of that change. This is an easy way to conceive of independent and dependent variables.

Thus, based on the independent variable, the responding variable, or dependent variable, alters.

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3.00 L of a gas is collected at 35.0 C and 0.93 atm. What is the volume at STP

Answers

2.47L

Hope this helped have a great day :)

The process of returning mines to their original state is called ________________________.

Answers

Answer:

Mine Reclamation.

Explanation:

The process of returning mines to their original state is called Mine Reclamation. HOPE THIS HELPS :)

Explain how the following properties change across the periodic Table from group 1 to group 2, and give reasons for the increase or decrease thereof:
a) Ionic radius
b) Ionization enthalpy
c) Density
d) Melting point
e) Electropositive character​

Answers

The following properties change across the periodic Table from group 1 to group 2

a) Ionic radius - decreaseb) Ionization enthalpy - increasec) Density - increased) Melting point - increasee) Electropositive character​ - decrease

Group 1 are alkali metals that have one valence electron in the outermost orbit whereas alkaline earth metals are in group 2 have two valence electrons in the outermost orbit.

a) Ionic radius:

The atomic and ionic radii of alkaline earth metals are fairly large though smaller than those of the corresponding alkali metals.  

b) Ionisation enthalpy:

Alkali metals have low Ionisation energy.in the case of alkaline earth metals Ionisation energy is higher compared to alkali metals  

c) Density:

The alkaline earth metals are denser than the alkali metals due to the smaller size and better packing of the atoms in the crystal lattice  

d) Melting point:

Melting points of alkaline earth metals are low but higher than those of alkali metals.  

e) Electropositive character:

all alkali metals are strongly Electropositive due to their low Ionisation enthalpies.alkaline earth metals are less Electropositive than alkali metals.

Thus, changes in properties are:

a) Ionic radius - decreaseb) Ionization enthalpy - increasec) Density - increased) Melting point - increasee) Electropositive character​ - decrease

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Which statement best describes the effect of radioactive decay on a nucleus?

Answers

When radioactive decay occurs, the original nucleus splits into daughter nuclei and the resulting nucleus is more stable than the original nucleus. The nucleus can be of a different element than the original.

Unstable nuclei often undergo radioactive decay. In a radioactive decay, the unstable nucleus is broken up into other nuclei. Usually, the nuclei formed during radioactive decay are smaller in mass compared to the original nucleus.

Also, the resulting nucleus is more stable than the original nucleus. The nucleus can be of a different element than the original.

The effect is that the nucleus changes into the nucleus of one or more other elements. These daughter nuclei have a lower mass and are more stable (lower in energy) than the parent nucleus.

You have three gases in a mixture where P1= 100 kPa, P2 = 50 kPa, and P3 = 75
kPa. What is the total pressure of the gas mixture?

A. 225 kPa
B. 25 kPa
C. 75 kPa
D. None of the above

Answers

Answer:

Ptotal=P1+P2+… +Pn. + P nExplanation:

its c

Mixtures of hydrogen and oxygen in varying concentrations can be sparked to produce water. Define mixture and compound, and then explain the differences between a mixture of hydrogen and oxygen and the compound dihydrogen monoxide (also known as water).

Answers

Explanation:

Mixture is the physical Combination Of two or Substance

Example

a mixture of sugar and water.

Compound is the chemical combination of two or more metals.

Example.

a mixture of hydrogen and water.

A mixture of hydrogen and oxygen forms water or H2O

whereas The dihydrogen monoxide parody involves calling water by an unfamiliar chemical name, most often "dihydrogen monoxide" (DHMO), and listing some of water's properties in a particularly alarming manner, such as accelerating corrosion (rust) and causing suffocation (drowning). The parody often calls for dihydrogen monoxide to be banned, regulated, or labeled as dangerous. It plays into chemophobia and demonstrates how a lack of scientific literacy and an exaggerated analysis can lead to misplaced fears. The parody has been used with other chemical names such as hydrogen hydroxide, dihydrogen oxide, hydroxic acid, hydric acid and oxidane.

A Mixture of hydrogen and oxygen in varying concentrations can be sparked to produce water. This is formed due to the property of chemical combination.

A Mixture is the physical Combination Of two or Substance whereas a Compound is the chemical combination of two or more metals.

Example of a mixture is a mixture of sugar and water. And, Example of an compound is A mixture of hydrogen and oxygen forms water or H₂O

Water is also called as dihydrogen monoxide. The prefix mono and di are used to indicate a single atom and combination of two atoms respectively.   Some of its properties includes such as accelerating corrosion (rust) and causing suffocation (drowning).

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the amount of solute dissolved in a solvent
A. Concentration.
B.alloy
C.mixture
D.solution

Answers

Answer:

solution

Explanation:

solvent +solute =solution

0 000
which explains why it is important to eat a full healthy meal before an oron o ping po
Food provides the carbon dioxide that is a product of cellular respiration
Food provides the oxygen that is a product of cellular respiration
Food provides the glucose that is a reactant in cellular respiration.
Food provides the energy that is a reactant in cellular respiration.

Answers

Answer:

A healthy diet is essential for good health and nutrition. It protects you against many chronic noncommunicable diseases, such as heart disease, diabetes and cancer. Eating a variety of foods and consuming less salt, sugars and saturated and industrially-produced trans-fats, are essential for healthy diet.

2. Cells are the_____________ life units on this plane

Answers

Answer:

Cell are the smallest life units on this planet

Explanation:

what is the mass number of an atom with 3 protons,4 nuetrons, and 3 electrons

Answers

Answer:

Neon 10,  mass: 20.18

Explanation:

For the given reactions determine if the entropy increases or decreases.

A) 2 KClO3 (s)⇌2 KCl (s)+3 O2 (g)

B) CoCl2 (s)+6 H2O (g)⇌CoCl2⋅6H2O

Answers

Entropy increases in reaction 1 due to increase in the number of particles while entropy decreases in reaction 2 due to decrease in the number of particles.

Entropy refers to the degree of disorderliness in a system. The higher the entropy, the more disorderly the system is and the lower the entropy, the less disorderly the system is. We must note that entropy increases with increase in the number of particles.

In the reaction,  2 KClO3 (s)⇌2 KCl (s)+3 O2 (g), entropy increases because one of the products is a gas and the number of particles increases from left to right. In the second reaction, CoCl2 (s)+6 H2O (g)⇌CoCl2⋅6H2O, entropy decreases because the number of particles decreases.

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Name the following Type 3 compound
1. PCIE
2. P406
3. SF6
4. SO3
5. SO2
6. N203
7. SiO2
8. O2F2
9. XeF6

Answers

Answer:

32

Explanation:

What’s the answer to this? Pls help

Answers

Answer:

First choice

Explanation:

please i need this now ill give you brainlest ​

Answers

Answer: The following information should be included;

What is the difference between the greenhouse effect, climate change and global warming?

What proof do we have that climate change is happening?

Why is it happening?

Converting from the US customary system to the metric system, 16 fluid ounces is approximately equal to a) 1 gallon. O b) 160 milliliters. c) 480 milliliters. O d) 960 milliliters.

Answers

Answer:

473 ml.

Explanation:

In gallons it’s equal to 0.125

Calcium has an electronegativity value of 1.0.

Oxygen has an electronegativity value of 3.5.

What type of bond will form between the two atoms?

Answers

Answer:

ionic bond

Explanation:

Calcium gives its two valence electrons to oxygen and forms an ionic bond with oxygen. An ionic bond formed when one atom transfers one or more electrons from itself to its neighboring atom, and an ionic bond formed between the two atoms of the compound.

4. A system contracts from an initial volume of 15.0 L to a final volume of 10.0 L under a constant external pressure of 0.800 atm. The value of w, in J, is?

Answers

The value of the work done in joule is 405.3 J.

We know that the work done is obtained using the relation;

w = PΔV

Where;

w = work done

P = pressure

V = volume

Now, substituting values,

w = 0.800( 15.0 -  10.0)

w = 4 atm L

Since;

1 L atm = 101.325 J

4 atm L  = 4 atm L × 101.325 J/1 L atm

= 405.3 J

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