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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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?
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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what is the free energy change G for the equilibrium between hydrogen iodine a hydrogen and iodine at 4:53
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:
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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.\
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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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).
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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Name the following Type 3 compound
1. PCIE
2. P406
3. SF6
4. SO3
5. SO2
6. N203
7. SiO2
8. O2F2
9. XeF6
Answer:
32
Explanation:
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
Answer:
Ptotal=P1+P2+… +Pn. + P nExplanation:
its c
How many atoms are in mercury (I) phospate?
The chemical formula is (Hg2)3(PO4)2
A)11
B)14
C)15
D)16
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 = 8Sum 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.
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 ---> 2H₂OThe 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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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
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 - decreaseGroup 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 metalsc) 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 latticed) 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 - decreaseLearn more:
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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
6. What is the molarity of 175 mL of solution containing 2.18 grams of NazS04-10H2O?
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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Which statement best describes the effect of radioactive decay on a nucleus?
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.
The process of returning mines to their original state is called ________________________.
Answer:
Mine Reclamation.Explanation:
The process of returning mines to their original state is called Mine Reclamation. HOPE THIS HELPS :)the amount of solute dissolved in a solvent
A. Concentration.
B.alloy
C.mixture
D.solution
Answer:
solution
Explanation:
solvent +solute =solution
What’s the answer to this? Pls help
Answer:
First choice
Explanation:
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.
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.
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
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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3.00 L of a gas is collected at 35.0 C and 0.93 atm. What is the volume at STP
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?
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.
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.
why does a Costal area have less variation in temperature
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:
Which factor is NOT important in the fossilization process?
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
After spending some time in the stomach, the food is sent to the blank
Answer:
the small intestine where nutrients are absorbed.
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?
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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how many nuetrons are in the nucleous of an atom number of 25?
Answer:
I believe there are 30
Explanation:
1.An object that produces electrical energy through redox reactions is called ____________.
oxidation
reduction
galvanic/voltaic cell
2.Which species undergoes oxidation?
Pb
Cu
[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]
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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?
2. Cells are the_____________ life units on this plane
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
Answer:
Neon 10, mass: 20.18
Explanation:
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.
Answer:
473 ml.
Explanation:
In gallons it’s equal to 0.125