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

Which two substances are reactants in the chemical reactions of cellular respiration?

Answers

Answer:

The answer is A and C.

Explanation:

The reactants in the process of cellular respiration are oxygen and glucose, respectively. It is ATP that serves as the primary product of cellular respiration, with carbon dioxide and water serving as waste products.

Sugar is a glucose.

Oxygen and glucose are the two  substances that are reactants in the chemical reactions of cellular respiration. Therefore, the correct options are options A, C.

What is cellular respiration?

Through the process of cellular respiration, organisms mix oxygen with food molecules, directing the chemical energy contained in these substances towards life-sustaining processes while excreting carbon dioxide and water as waste. Foods are broken down by microorganisms that do not require oxygen in a process known as fermentation.

Adenosine triphosphate (ATP), an energy-rich compound that absorbs the chemical energy generated by the decomposition of food molecules then releases it to power other cellular functions, is one goal of the breakdown of foodstuffs. ATP is created when the energy found inside chemical bonds is converted from one form to another. Oxygen and glucose are the two  substances that are reactants in the chemical reactions of cellular respiration.

Therefore, the correct options are options A, C.

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Which of the following does not change the rate of collisions between particles in a reaction?

A. Addition of catalyst
B. increase in surface area
C. increase in temperature
D. decrease in the reaction volume​

Answers

Answer: C

Explanation: trust me bro

Increase in temperature does not change the rate of collisions between particles in a reaction.

What is Collision?

The collision hypothesis offers suggestions for how to alter the rate of a reaction as well as an explanation for why certain reactions occur at various rates.

According to the collision theory, for a chemical reaction to take place, the reacting particles must come into contact with one another. The frequency of collisions affects the reaction's rate. According to the idea, responding particles frequently encounter without reacting.

Any analysis of an ordinary reaction mechanism must start with this rule. It explains why there are so few termolecular reactions. According to the kinetic theory of gases, there will only be one instance in which three molecules collide at once out of every 1000 binary collisions.

Therefore,  Increase in temperature does not change the rate of collisions between particles in a reaction.

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HELP I WILL MARK BRAINLIST
I HAVE 10 MINUTES

Which phrase correctly describes the effect of pressure on the solubility of a gas in a liquid?



1) proportional to the square root of the pressure of the gas above the liquid



2) directly proportional to the pressure of the gas above the liquid



3) inversely proportional to the pressure of the gas above the liquid



4) unrelated to the pressure of the gas above the liquid

Answers

Answer:

Answer is 2

Explanation:

directly pro

How many grams of sodium acetate NaCH3COO, , must be dissolved to prepare 200. mL of a 0.216 M aqueous solution of the salt? g

Answers

Answer:

Explanation:

You have to find the mass in the mole before the molarity and then in the mole.

A 1.__________ is a choice among possible alternative actions. Like planning decision-making is a challenge and requires careful consideration for both types of decision namely 2.____________________________ and 3.______________________. For effective planning in today’s dynamic environments. Different techniques and tools must be used, such as 4._________________, 5.______________________________, 6.______________________________, 7.________________________, 8.__________________. All planning types, without exception, make use of forecasting. Business periodicals publish forecasts such as employment and unemployment rates, increase or decrease of interest rates, stock market data, GNP/GDP data and others. Forecasts used may either be 9._________________, or 10.__________________. Risk or 11._________________________ compel the decision maker to do estimates regarding the possible occurrence of certain outcomes that may affect his or her chosen solution to a problem. All managers and workers/employees in organizations make decision or make choices that affect their jobs and organization they work for, they make decision by going through the 12.__________________________ of the decision-making process suggested by Robbins and Coulter (2009). 13._________________ is a process which begins with problem identification and ends with the evaluation of implemented solutions. 14.________________________ It is change in an attribute, condition, factor, parameter or value that represents crossing a threshold and actuates or initiates a mechanism or reaction that may lead to a radically different state of affairs. 15.________________________ Ideal conditions in deciding problems; these are situations in which a manager can make precise decisions because the results of all alternatives are known.

plzz help me​

Answers

Answer:1. Decission

2.Structured or programmed decision

3.Unstructured or non -programmed decisions

4.Forecasting

5.Contingency planning

6.Scenario planning

7.Bench marking

8.Participatory planning

9.quantitative

10.qualitative

11.Uncertainty conditions

12.eigt steps

13. Decision making

14.Trigger point

15.Certainty conditions

Explanation:

It's all about organization and management.

Explanation:

I hope it helps

1. Decission
2.Structured or programmed decision
3.Unstructured or non -programmed decisions
4.Forecasting
5.Contingency planning
6.Scenario planning
7.Bench marking
8.Participatory planning
9.quantitative
10.qualitative
11.Uncertainty conditions
12.eigt steps
13. Decision making
14.Trigger point
15.Certainty conditions

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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A 0.48-mole sample of helium gas occupies a volume of 11.7 L . What is the volume of 0.72 mol of helium gas under the same conditions

Answers

AnswerExplanation:I finsished d

Answer:

17.55L

Explanation:

0.48mol : 11.7

0.72mol :   x

0.48x = 8.424

x = 17.55

Br2(l) + 2Nal(aq) — 12(s) + 2NaBr(aq)
Which elements are oxidized and reduced in the reaction?
(1 point)

O Sodium (Na) is oxidized, and bromine (Br) is reduced.
O Bromine (Br) is oxidized, and iodine (1) is reduced.
O Bromine (Br) is oxidized, and sodium (Na) is reduced.
Olodine (I) is oxidized, and bromine (Br) is reduced.

Answers

Iodine (I) is oxidized, and bromine (Br) is reduced. The correct option is the last option - lodine (I) is oxidized, and bromine (Br) is reduced.

To determine which elements are oxidized and reduced,

First, we will define the terms Oxidation and Reduction

Oxidation is simply defined as the loss of electrons. It can also be defined as increase in oxidation number.

Reduction is defined as the gain of electrons. It can also be defined as decrease in oxidation number.

The given chemical equation is

Br₂(l) + 2NaI(aq) → I₂(s) + 2NaBr(aq)

Oxidation number of Bromine decreased from 0 to -1.

Therefore, Bromine is reduced.

Oxidation number of Iodine increased from -1 to 0.

Therefore, Iodine is oxidized.

Oxidation number of sodium did not change.

Therefore, Sodium is neither oxidized nor reduced.

Hence, Iodine (I) is oxidized, and bromine (Br) is reduced. The correct option is the last option - lodine (I) is oxidized, and bromine (Br) is reduced.

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What is the formula for sodium phosphate

Answers

Answer:

Explanation:

It''s chemical formula is Na3PO4

Suppose you have samples of three unknown solids. Explain how you could use their properties to
determine whether or not they are ionic solids.

Answers

Using melting and boiling temperature, hardness and electric current passing testing.

Ionic solids

Ionic solids are materials that have a strong bond between their ions, thus producing well-defined shapes.

In addition, due to this strong attraction, the boiling and melting temperatures of these materials are very high, in addition to the resistance to breakage presented by them.

Finally, ionic solids are also excellent conductors of electricity.

So, their properties used to determine whether or not they are ionic solids are  melting and boiling temperature, hardness and electric current passing testing.

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Which of the following is NOT a property of gases?


Which of the following is NOT a property of gases?

a. Constant shape
b. Fill their container
c. Have mass
d. Easily compressed

Answers

Answer:

a. Constant shape

How can you include osmosis in animal cell

Answers

As you will remember animal cells have partially permeable cell membrane. This means that if they are placed in pure water because their cytoplasm is a stronger solution than the pure water, water will pass into the cells by osmosis. The cells will therefore swell up n biology, osmosis is the movement of molecules from a zone of high water potential to a zone of lower water potential through a semi-permeable membrane. The phenomenon of osmosis occurs at different concentrations of water potential in animal cells and plant cells..

PLEASE HELPPPPPPPPPPPPPPPP

Answers

In this problem, you’re given a mass (m) and a force (F) applied to an object and you’re asked to calculate the acceleration (a). If we plug this into the provided equation:

F = ma
(7.3 N) = (3.2 kg)a
a = 2.3 m/s/s

The acceleration of the object is 2.3 m/s/s.

Hope this helps!

Consider the evaporation of water. The standard change in the free energy is positive with ΔG∘rxn=+8.59kJmol. One might expect this process to occur in the opposite direction, with water vapor condensing into liquid water. How can the evaporation be spontaneously under normal conditions?

Answers

Answer:

The partial pressure of water is much less than 1atm, so the free energy change for the process must be negative with ΔGrxn<0.

Explanation:

Water vapor will condense into liquid water when the water vapor is in its standard state, with a pressure of 1atm. Under normal circumstances, the partial pressure of water vapor is much less that 1atm. It is in a nonstandard state. The free energy change of this reaction has to be negative in order to make the reaction spontaneous.

The criteria of the spontaneous process are the change in the Gibbs free energy should be negative. Above the normal boiling point, the TΔS will be greater than ΔH and ΔG<0.

What is Gibbs's free energy?

Gibbs free energy can be described as a state function therefore it doesn’t depend on the path. The change in free energy is equal to the change in enthalpy minus the product of entropy change and temperature of the system.

ΔG = ΔH - Δ (TS)

If the process is carried out at constant temperature, ΔT = 0:

ΔG = ΔH – TΔS

ΔG > 0 for the reaction is non-spontaneous, ΔG < 0 for the reaction is spontaneous, exergonic and ΔG = 0 for the reaction is at equilibrium.

Spontaneous can be described as a reaction that occurs by itself without any external action towards it. The non-spontaneous process needs constant external energy applied to continue and as the external action, the process will cease.

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How many moles of KOH are in 21.0g of KOH?​

Answers

Answer:

HowHow many moles of KOH are in 21.0g of KOH?

Answer:

0.374 moles

Explanation:

I have included the dimensional analysis below, and by MM I mean Molar Mass of the atom.

Hope this helps!

Which of the following statements are true concerning product distribution in the halogenation of an alkane?

a. Halogenation of alkanes follows a chain mechanism.
b. The initiation process involves the formation of a halogen molecule.
c. Heat or UV light causes the weak halogen bond to break.
d. A radical is an intermediate with a single unpaired electron.
e. Halogenation of alkanes is a rearrangement reaction.

Answers

Halogens combine with alkanes to yield halogenoalkanes. It is a chain reaction.

Alkanes are a group of organic molecules whose functional group is the carbon - carbon single bond. The halogenation of alkanes refers to the process by which alkanes reacts with halogen molecules to yield halogenoalkanes.

The following are true statements regarding the halogenation of alkanes;

Halogenation of alkanes follows a chain mechanism.Heat or UV light causes the weak halogen bond to break.A radical is an intermediate with a single unpaired electron.

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why do you continuously gain exactly the amount of mass you consume with each meal

Answers

Answer:

It depends on how much the calories and fat there is in the meals and if you don't get enough physical activity of the same amount of food that you eat it can lead to weight gain

Explanation:

5. What is the systemic name for the following structure?

Answers

Answer:

You are not showing the question, but I believe the answer is cis-3,4-dimethyl-3-hexene.

Explanation:

since the substituents are on same side, it call cis. Followed by the name.

Which of the following describes how air resistance affects the motion of a falling object?

Air resistance opposes the force of gravity and causes falling objects to lose speed once they reach terminal velocity.
Air resistance opposes the force of gravity and causes falling objects to lose speed once they reach terminal velocity.

Air resistance may change the direction of a falling object but does not affect its speed.
Air resistance may change the direction of a falling object but does not affect its speed.

Air resistance works with gravity to pull a falling object towards the Earth.
Air resistance works with gravity to pull a falling object towards the Earth.

Air resistance opposes the force of gravity and causes an object to reach terminal velocity.
Air resistance opposes the force of gravity and causes an object to reach terminal velocity.

Answers

Air resistance opposes the gravity in a falling object hence the object loses speed once it reaches terminal velocity.

According to the experiment of Galileo, in the absence of air resistance, all objects that are thrown down from the same height will hit the ground at he same time due to the effect of gravity.

We know that the air resistance makes the acceleration of object to become less than the acceleration due to gravity. So, air resistance opposes the force of gravity and causes falling objects to lose speed once they reach terminal velocity.

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Answer:

The answer is D - Air resistance opposes the force of gravity and causes falling objects to lose speed once they reach terminal velocity.

Ill explain why -, for example ,

When the paper is smooth, it exposes a large surface to the air beneath it which slows its descent. Once it is crumpled, the surface which comes in contact with the air is much smaller, allowing it to fall much faster.  At first, you probably thought the book would touch the ground first since it is heavier However, once the piece of paper was crumpled, they hit the ground at the same time! Funny, since it is the same piece of paper and the book is still heavier. It all comes down to form. I hope this helped u with the test !!

For a process Arightwards harpoon over leftwards harpoonB, at 25 °C there is 10% of A at equilibrium while at 75 °C, there is 80% of A at equilibrium. Estimate enthalpy change of this reaction in kJ/mol

Answers

This question is describing the following chemical reaction at equilibrium:

[tex]A\rightleftharpoons B[/tex]

And provides the relative amounts of both A and B at 25 °C and 75 °C, this means the equilibrium expressions and equilibrium constants can be written as:

[tex]K_1=\frac{90\%}{10\%}=9\\\\K_2=\frac{20\%}{80\%} =0.25[/tex]

Thus, by recalling the Van't Hoff's equation, we can write:

[tex]ln(K_2/K_1)=-\frac{\Delta H}{R}(\frac{1}{T_2} -\frac{1}{T_1} )[/tex]

Hence, we solve for the enthalpy change as follows:

[tex]\Delta H=\frac{-R*ln(K_2/K_1)}{(\frac{1}{T_2} -\frac{1}{T_1} ) }[/tex]

Finally, we plug in the numbers to obtain:

[tex]\Delta H=\frac{-8.314\frac{J}{mol*K} *ln(0.25/9)}{[\frac{1}{(75+273.15)K} -\frac{1}{(25+273.15)K} ] } \\\\\\\Delta H=4,785.1\frac{J}{mol}[/tex]

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2. Cells are the_____________ life units on this plane

Answers

Answer:

Cell are the smallest life units on this planet

Explanation:

2. A solution NaF is add dropwise to a solution that is .0122 M in Ba . When the concentration of F exceeds ______M, BaF2 will precipitate. Neglect volume changes. BaF2 K

Answers

Explanation:

BaF2(s) <------> Ba2+(aq) + 2F-(aq)

Ksp BaF2 =  1.0 x 10^-6.

Ksp BaF2 = [Ba2+(aq)]×[F-(aq)]^2 at equilibrium

When Qsp >Ksp, BaF2 will precipitate

Qsp = [Ba2+(aq)]×[F-(aq)]^2

[Ba2+(aq)]×[F-(aq)]^2 > 1.0 x 10^-6.

0.0122 moldm-3 × [F-(aq)]^2 > 1.0 x 10^-6

[F-(aq)]^2 > 1×10^-6 / 0.0122 mol2dm-6

[F-(aq)]^2 > 81.96 × 10^-6 mol2dm-6

[F- (aq)] > 9.05 × 10^-3 moldm-3

So F- concentration should be more than 9.05 × 10^-3 moldm-3

Determine how many grams of Al(OH)3 will be required to neutralize 216 mL of 0.367 M HCl according to the reaction:

Answers

3HCl + Al(OH)3 > AlCl3 + 3H20

mol = conc × v

= 0.367 × 0.216

= 0.0792 mol HCl

3 mol HCl = 1 mol Al(OH)3

0.0792 mol HCl = x

x = 0.0792/3 × 1

= 0.0264 mol Al(OH)3

Al(OH)3 = 27 + 3(16 +1) = 78 g/mol

mass = mol x molar mass

= 0.0264 × 78

= 2.0592 g

I don't know if it's correct

A particular reaction has a DH o value of -164 kJ and DS o of -185 J/K at 298 K. Calculate DG o at 617 K in kJ (with 3 significant digits), assuming that DH o and DS o hardly change with temperature

Answers

Answer:

e

Explanation:

The distance between two adjacent peaks on a wave is called the wavelength. (2pts) a. The wavelength of ultraviolet light is 255nm. What is the wavelength in meters? b. The wavelength of a beam of red light is 683nm. What is its wavelength in angstroms?

Answers

Answer:

a.2.55e-7

b.6830

Explanation:

i want help with these questions thanks !​

Answers

Answer:

I will give you hints, as follows:

Explanation:

- two words: climate change

- methane smells funny

- the number of electric cars sold each year is increasing

- there´s a reason they´re call "renewable"

- GEOmetry, GEOlogy, GEOthermal

Hope this helps!

If such an ion is negatively charged and includes one or more oxygen atoms

Answers

Answer:

atom

Explanation:

The sodium atom has a single valence electron that it can easily lose. (If the sodium atom loses its valence electron, it achieves the stable electron configuration of neon.) The chlorine atom has seven valence electrons and can easily gain one electron.

list atleast two examples of Arrhenius acids?​

Answers

Answer:

HCl (hydrochloric acid) and H2SO4 (sulphuric acid)

I hope it helps.

An atom from the column 1 can form an iconic compound with another from column 18

True
Or
False

Answers

The Answer is False





Sodium hydroxide neutralises hydrochloric acid as shown in the equation:
NaOH(aq) + HCl(aq) i NaCl(aq) + H2O(l)
(4)
dm3
(3)
The student found that 27.20 cm3 of 0.100 moles per dm3 sodium hydroxide neutralised 5.00 cm3 of hydrochloric acid.
Calculate the concentration of the hydrochloric acid in moles per dm3.
Give your answer to three significant figures.

Answers

Explanation:

Mole ratio of NaOH : HCl = 1: 1

Moles of NaOH used = 0.1 mol/1000 cm3 × 27.20 cm3

= 2.72 × 10^-3 mol

Therefore moles of HCl used is also 2.72 × 10^-3 mol

So concentration of HCl can be found by dividing the no.of moles of HCl by the volume of HCl as follows

2.72 × 10^-3 mol/ 5cm3

1000cm3 = 1dm3

Therefore,

1cm3 = 1/1000 dm3

5cm3 = 5/1000 dm3

HCl conc. = 2.72 × 10^-3 mol/ 5×10^-3 dm3

= 0.544 moldm-3

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Which of the following is(are) NOT (an) output(s) for cellular respiration? Select all that apply. ATPsolar energy wateroxygen carbon dioxide ANSWER ASAPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPP help pleaseanybody? Graph the line with slope 3/4 passing through the point (1,5). 20 points! help please Do you think Oedipus has a tragic flaw?If so, explain whether you believe it to be anger, excessive pride, or another quality. If you do not think he has a specific tragic flaw, explain your reasoning.In 1-2 paragraphs, defend your position using at least two examples from the text as evidence.please help thank you In Spanish, answer the following questions with a s or a no using complete and detailed sentences. Ejemplo: Te gusta caminar por el parque?S, me gusta caminar por el parque. -o- No, no me gusta caminar por el parque.A ti, te gustan las verduras?Te gusta jugar deportes?A ti, te gusta dibujar?Te gusta ir a las fiestas?Te gusta el chocolate? Form1. Does the melody repeat?2 What form (12 bar blues, concerto, sonata, other) do you think this piece is in?please i rly need help Which of the following are advantages to societies who provide freedom of speech?i. greater availability of informationii. advances in societyii. ability to express support or oppositionA. ionlyB. ii onlyC. ii and ill onlyD. i, ii, and iii please help asap Social media is a good tool for all of the following EXCEPT _____.peer support for patientsto provide information on medicationsto advertise fee-based servicespatient education Which ratio is equivalent to 5:9?O 10:36O 10:27O 20:27O 20:36 In McCulloch v. Maryland, what did the State of Maryland argue?Banks cannot be created by Congress.States can determine which institutions within its borders must pay taxes.A federal bank must pay taxes to the state in which it is located.Banks may only be created by Congress, not by individuals. Which of the following examples demonstrates behavior that is dysfunctional?Multiple ChoiceoLyla is a lesbian, but she wishes that she liked boys so that she could have a traditional family and her parents wouldn't worry so much about her.Anabeth is so afraid of snakes that she has difficulty going out and getting into her car to go to work in the morning because she fears that there maybe a snake on the path to her car. She is running out of sick days.Michael likes to work out. He exercises every day. He has missed out on "get togethers" with friends, potential dates, and family events because oftime with his trainerCortney has tattoos all over her body. She has a total of 12 plercings, 6 of which are in her face. Her look has cost her several jobs becauseemployers have said that customers find her "menacing."< Prev3 45of 5 !!!Next > gip e dn v ch ny vi Vn dng nguyn l mi lin h ph bin vo hot ng thc tin cuc sng One cup of coffee needs 2 spoons of milk. If one bottle of milk has 50 spoons, write an inequality representing the possible cups of coffee one bottle of milk can make. Which of the following elements make people more likely to share on social media? (choose all applicable) a. Use of long paragraphs for better explanation b. Describing possible solution c. Having attractive and impressive headlines and images d. Use of emotion. Why can Marco hear the music, even though he is not in the same room as the speaker? Why is gdp necessary A rectangle has a length of 72 cm and a width of 56 cm. A second rectangle has the same area as this one, but its width is 21 cm. What is the length of the second rectangle? apush HELPEvaluate the relative importance of the causes of the Civil War in the period from 1830 to 1861.