8.67 x 1018 atoms Zn
calculate the number of representative particles or moles for each of the following

Answer:

b its radiant energy that heats up the earth.

Explanation:

Answer:

The answer is D

Explanation:

Heat from the Earth's core and radiation from the Sun is transferred to the surface of the Earth by conduction. The warm land and water radiates infrared, some of which is absorbed by the atmosphere, adding to its thermal energy.

This question is incomplete, the complete question is;

A 1.00 g sample of NH4NO3 is decomposedin a bomb calorimeter. The temperature increases by 6.12°C. What is the molar heat of decomposition for ammonium nitrate?

Molar mass, NH4NO3 80.0 g/mol

Calorimeter Constant   1.23 kJ/°C

Answer:

the molar heat of decomposition for ammonium nitrate is - 602.4 kJ/mol

Explanation:

Given that;

change in temperature ΔT = 6.12 °C

Calorimeter Constant C = 1.23 kJ/°C

Molar mass, NH4NO3 = 80.0 g/mol

we know that;

Heat gained by the calorimeter (Q1) = Heat lost by the decomposition of NH4NO3 (Q2)

Q1 = C × ΔT

Q1 = (1.23 kJ/K) × (6.12 K) = 7.53 kJ

Q value we get becomes negative since we are talking about reaction and not calorimeter

hence

Q1 = - 7.53 kJ

now

1 g NH4NO3 decomposed, - 7.53 kJ of heat is released

so if 80 g which is 1 mol NH4NO3 decompose, the heat will be;

(80 g/mol x -7.53 kJ) / 1 g = - 602.4 kJ/mol

Therefore the molar heat of decomposition for ammonium nitrate is - 602.4 kJ/mol

Answer:

69.09 g

Explanation:

First we calculate the mass of the sample of concentrated H₂SO₄, using the given volume and density:

There are 70.288 grams of solution, of which 98.3% is H₂SO₄. Thus the H₂SO₄ mass is:

Taking into account the definition of density and percentage by mass, the mass of H₂SO₄ in a 38.2 cm³ sample of concentrated sulfuric acid is 69.09 grams.

But first you must know the definition of density. Density is defined as the property that matter, whether solid, liquid or gas, has to compress into a given space.

In other words, density is a quantity that allows us to measure the amount of mass in a certain volume of a substance. Then, the expression for the calculation of density is the quotient between the mass of a body and the volume it occupies:

[tex]density=\frac{mass}{volume}[/tex]

In this case, you know that:

Density= 1.84 [tex]\frac{g}{cm^{3} }[/tex]

Volume= 38.2 cm³

Replacing in the definition of density:

[tex]1.84 \frac{g}{cm^{3} }=\frac{mass}{38.2 cm^{3} }[/tex]

Solving:

mass= 1.84 [tex]\frac{g}{cm^{3} }[/tex]×38.2 cm³

mass= 70.288 g

So, the mass of the solution is 70.288 grams.

The percentage by mass expresses the concentration and indicates the amount of mass of solute present in 100 grams of solution.

In other words, the percentage by mass of a component of the solution is defined as the ratio of the mass of the solute to the mass of the solution, expressed as a percentage.

The percentage by mass is calculated as the mass of the solute divided by the mass of the solution, the result of which is multiplied by 100 to give a percentage. This is:

[tex]percentage by mass=\frac{mass of solute}{mass of solution}x100[/tex]

In this case, you know:

percentage by mass=98.3%

mass of solute= ?

mass of solution= 70.288 grams

Replacing in the definition of percentage by mass:

[tex]98.3=\frac{mass of solute}{70.288 grams}x100[/tex]

Solving:

[tex]\frac{98.3}{100} =\frac{mass of solute}{70.288 grams}[/tex]

[tex]0.983=\frac{mass of solute}{70.288 grams}[/tex]

0.983× 70.288 grams= mass of solute

69.09 grams= mass of solute

The mass of H₂SO₄ in a 38.2 cm³ sample of concentrated sulfuric acid is 69.09 grams.

Learn more about

density:

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percentage by mass:

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Answer:

Add Items to it

Explanation:

Lol I took the test. Sorry If I'm incorrect

Answer:

add items to the box to increase its mass on the self it is on

Explanation: :p

Answer:

0.491 atm

Explanation:

Initial volume V1 = 571.5 mL = 0.5715 L

Initial Pressure P1 = 0.944 atm

Initial Temperature T1 = 10 oC + 273 = 283 K (Converting to kelvin units)

Final Temperature T2 = 32 oC + 273 = 305K (Converting to kelvin units)

Final volume V2 = 1.183 L

Final Pressure P2 = ?

These parameters related by the combined gas law;

P1V1 / T1   = P2V2 / T2

Mke P2 subject of formular;

P2 = P1 V1 T2 / V2 T1

P2 = 0.944 * 0.5715 * 305  /  1.183 * 283

P2 = 0.491 atm

Answer:

D. 1.48atm

Explanation:

Van der waals equation is given as:

(P +an²/v²) (v - nb) = nRT

Where;

P = pressure (atm)

V = volume (L)

R = gas constant (0.0821 Latm/molK)

a and b = gas constant specific to each gas

T = temperature (K)

n = number of moles

According to the given information; V = 22.4L, T = 0.00°C (273.15K), R = 0.0821 Latm/molK, a = 6.49L^2-atm/mol^2, b = 0.0562 L/mol, n = 1.5mol

Hence;

(P + 6.49 × 1.5²/22.4²) (22.4 - 1.5×0.0562) = 1.5 × 0.0821 × 273.15

(P + 6.49 × 2.25/501.76) (22.4 - 0.0843) = 33.638

(P + 0.0291) (22.316) = 33.638

22.316P + 0.649 = 33.638

22.316P = 33.638 - 0.649

22.316P = 32.989

P = 32.989/22.316

P = 1.478

P = 1.48atm

Answer: Two equatorial positions so as to minimize the repulsion.

Explanation:

Formula used for calculating number of electrons :

[tex]\frac{1}{2}[V+N-C+A][/tex]

where,

V = number of valence electrons present in central atom  = 8

N = number of monovalent atoms bonded to central atom = 4

C = charge of cation  = 0

A = charge of anion  = 0

Now we have to determine the hybridization of the [tex]XeF_4[/tex]   molecule.

[tex]\frac{1}{2}[8+4-0+0]=6[/tex]

Bond pair electrons = 4

Lone pair electrons = 2

The number of electrons are 6 that means the hybridization will be [tex]sp^3d^2[/tex] and the electronic geometry of the molecule will be octahedral.

The molecular geometry will be square planar as two alternate positio ns will be occupied by lone pair of electrons so as to minimize the repulsion.

Answer:54.82%

Explanation:

Percentage of carbon = mass of carbon in that compound/ mass of the compund *100

216/394*100 = 54.82%

Answer:

the answer is hot,dense points; each smaller than an atom

Explanation:

the big bang theory was proposed to suggest the expansion of the universe by describing the origin of all components of the universe and its planetary bodies. its suggested that the whole universe was in a state of high temperature and highly dense points (which were smaller than atoms) but continuously expanded by cooling down which gave rise to the formation of subatomic particles, atoms, etc.

btw I found this on brainly

Answer:

A, it is metal oxide

Answer:

Thermal energy

Explanation:

When gasoline, coal, batteries and logs are all burn they transform chemical energy to thermal energy.

The chemical energy is the energy held between chemical chains and bonds within an atom.

Answer:

a) 2.01 g

Explanation:

First we convert 0.0302 mol AgNO₃ to Na₂CO₃ moles, in order to calculate how many Na₂CO₃ moles reacted:

So the remaining Na₂CO₃ moles are:

Finally we convert Na₂CO₃ moles into grams, using its molar mass:

The closest answer is option a).

Answer: You should be able to find the answer on the internet

Answer: synthesis, decomposition, single-displacement, double-displacement, combustion and acid-base reactions.

Explanation:

Answer:

Explanation:

1) The ΔH shows the heat of reaction of the reaction illustrated in the question and the negative sign shows the reaction is an exothermic reaction, meaning heat is released in this reaction. The amount of heat released in this reaction is 851.5 kilojoules per mole of Al₂O₃ produced.

2) The thermal energy of this reaction is however very low when compared to the energy released when 2 moles of protons and 2 moles of neutrons combine to form 1 mole of alpha particles. This is because, the reaction illustrated in the (1) above is a normal chemical reaction while the one that involves the protons and neutrons (as described in this section 2) is a nuclear reaction which involves large amount of energy. Nuclear reactions usually involve way larger amount of energy than ordinary chemical reactions.

Answer:

The picture represents oxygen.

Explanation:

There are two notable ways you can figure this out:

1) Since there are eight protons, you can automatically know that you are looking for an element with an atomic number of 8. This is because the atomic number is the number of protons in an atom.

2) You can also note the number of electrons on the outer shell. These are called valence electrons. You can then see that the element has 6 valence electrons. Beginning with Lithium on the periodic table and count by ones going from left to right in period 2 of the periodic table until you get to 6. What element is that? It is indeed oxygen.

Answer:

Oxygen

Explanation:

Neons contain 8 protons and 10 ELECTRONS

Boron contains 5 protons an 5 electrons

calcium contains 20 electrons an 0 protons

Answer:

They need more oxhygen to fraction to incresse

Explanation:

Answer:

D. 2 NO3(aq)+Ca2+

Explanation:

Reaction of calcium nitrate and potassium phosphate produce calcium phosphate and potassium nitrate. The net ionic equation for this is written as : [tex]3 Ca^{2+} (aq) +2PO_{4} ^{3-} (aq) \rightarrow Ca_{3}(PO_{4} )_{2} (s)[/tex]. Thus option C is correct.

What is double displacement reaction?

In a double displacement reaction, two species or groups in reactant side are displaced in the products.

In a balanced chemical equation, all the reactants have to be in proper stochiometric ratio and the states of all species are mentioned in brackets.

In an ionic equation all the ions and charges are balanced both side and the number of each elements on both side too. The net ionic equation represents the formation of a solid product from its ions.

The balanced molecular equation and complete ionic equation are written for the given  reaction below:

[tex]3 Ca (NO_{3})_{2} (aq)+ 2K_{3} PO_{4} (aq) \rightarrow Ca_{3}(PO_{4} )_{2} (s) + 6 KNO_{3}(aq)[/tex]

[tex]3 Ca^{2+} (aq) +6 NO_{3}^{-} + (aq)+ 6K^{+} + (aq) 2PO_{4} ^{3-} (aq) \rightarrow Ca_{3}(PO_{4} )_{2} (s) + 6 NO_{3}^{-} (aq)+ 6K^{+} (aq)[/tex]

Now when the same species on both side is cancelled, then the net ionic equation is written as:

[tex]3 Ca^{2+} (aq) +2PO_{4} ^{3-} (aq) \rightarrow Ca_{3}(PO_{4} )_{2} (s)[/tex]

Therefore, the correct et ionic equation is option c.

To learn more about ionic equations, refer the link below:

https://brainly.com/question/15467511

#SPJ2

Answer:

C

Explanation:

I hope that helps!!! it kinda gave you the answer though

Answer:

Mn

Explanation:

The cation in the chemical formula MnSe is the Mn specie.

Answer:

d) none of the above

Explanation:

The law that describes the relationship between pressure and volume of an ideal gas (under constant temperature and amount of substance) is Boyle's law.

It states that pressure is inversely proportional to the volume. This would mean that a graph of P vs 1/V would be a line.

See the attached picture for a graph of P vs V.

A plot of pressure VS. volume for an ideal gas will result in d) none of the above

The following things should be considered:

Therefore we can conclude that a plot of pressure VS. volume for an ideal gas will result in d) none of the above

Learn more: brainly.com/question/23334479

Answer:

A and B

Explanation:

Trust me I just did it on a p e x

Answer: he’s correct it’s d and b for me but it’s the same answers

Explanation:

So to answer this question first let's decribe precision vs accuracy.

Precision in this case means exact and accurate; in this scenario all of the dots next to each other mean that it is highly precise.

Whereas Accuracy means aiming for the middle of the circle in this case. Thus   the accuracy is low, but the precision is high.

TLDR: It is highly precise but not accurate.

Look up "Accuracy vs. Precision: What’s the Difference?" for a better detailed example and solution.

Answer:

In a climatological sense, dryness is a function of both annual rainfall and evaporation

Answer:

H=mc∆T

H=15×4.18×20

H=1254J

Answer:

C. The reaction rate at known reaction concentrations

Explanation:

The rate of a reaction is the measure of the speed of a chemical reaction. To find the rate constant of a reaction, the concentration of the reactants must be known.

Answer:

C. ApE x Approved

Explanation:

Trust

The theoretical yield (in kilograms) of water produced from this reaction : 0.285 kg

Reaction

2C₁₂H₂₄O₁₁ + 25O₂ → 24CO₂ + 24H₂O

mass of C₁₂H₂₄O₁₁ - isomaltitol = 454 g

mol C₁₂H₂₄O₁₁(MW=344.31 g/mol) :

[tex]\tt mol=\dfrac{mass}{MW}\\\\mol=\dfrac{454}{344.31 g/mol}\\\\mol=1.319[/tex]

mol H₂O based on C₁₂H₂₄O₁₁ as limiting reactant(O₂-oxygen as an excess)

From the equation above, mol ratio of C₁₂H₂₄O₁₁  : H₂O = 2 : 24, so mol H₂O:

[tex]\tt mol~H_2O=\dfrac{24}{2}\times 1.319=15.828[/tex]

then mass H₂O (MW=18 g/mol) :

[tex]\tt mass=mol\times MW\\\\mass=15.828\times 18=284.904~g=0.285~kg[/tex]