During a reaction, ΔH for reactants is −750 kJ/mol and ΔH for products is 920 kJ/mol. Which statement is correct about the reaction? (5 points)

Group of answer choices

It is endothermic because the energy required to break bonds in the reactants is less than the energy released when the products are formed.

It is endothermic because the energy required to break bonds in the reactants is greater than the energy released when the products are formed.

It is exothermic because the energy required to break bonds in the reactants is less than the energy released when the products are formed.

It is exothermic because the energy required to break bonds in the reactants is greater than the energy released when the products are formed.

Answer:

348 inches³

Explanation:

From our previous knowledge of  units conversion:

We know that 1000 cm³ makes 1 Liter.

Thus, for  a 5.70 L automobile engine in cubic meters will be:

= 5.70 × 1000 cm³

= 5700 cm³

Now, the displacement of the automobile in cubic inches provided that 1 inch = 2.534 cm is:

⇒ 5700× (1/ (2.54)³) in³

= 5700×0.0610 in³

= 347.7 in³

≅ 348 inches³

Answer:

26.9 g

81%

Explanation:

The equation of the reaction is;

4 KO2(s) + 2 CO2(g) → 3 O2(g) + 2 K2CO3(s)

Number of moles of KO2= 27.9g/71.1 g/mol = 0.39 moles

4 moles of KO2 yields 2 moles of K2CO3

0.39 moles of KO2 yields 0.39 × 2/4 = 0.195 moles of K2CO3

Number of moles of CO2 = 57g/ 44.01 g/mol = 1.295 moles

2 moles of CO2 yields 2 moles of K2CO3

1.295 moles of CO2 yields 1.295 × 2/2 = 1.295 moles of K2CO3

Hence the limiting reactant is KO2

Theoretical yield = 0.195 moles of K2CO3 × 138.205 g/mol = 26.9 g

Percent yield = actual yield/theoretical yield × 100

Percent yield = 21.8/26.9 × 100

Percent yield = 81%

Answer:

The lone pairs on nitrogen in dimethylacetamide reside in sp3 orbitals which are coplanar with the methyl groups

Explanation:

The compound dimethylacetamide consists of oxygen bearing two lone pairs of electrons and a nitrogen atom bearing a lone pair of electrons and has two methyl groups attached to the nitrogen atom.

The lone pair on the nitrogen atom is accommodated in an sp3 orbital of nitrogen as shown in the question. This sp3 orbital is coplanar with the two methyl groups.

Answer:

Lewis structure of polyatomic formate anion.

Explanation:

To draw Lewis structure for any chemical species,

1)Count the total number of valence electrons present in it.

This can be obtained by adding valence electrons of each constituent atom.

2)Arrange those valence electrons in such a way that each atom should attain eight electrons around it to satisfy octet theory.

The structure of formate ion and its Lewis structure are shown below:

HCOO- is the formate ion.

It has total:

1+4+6+6+1 = 18 valence electrons.

Since, hydrogen has one, carbon has four and oxygen has six valence electrons and the charge of the anion is one.

Arrange this 18 electrons in such a way that each atom should get 8 electrons around it.

Resonance structures of formate ion:

Answer:

) Making a sandwich To prepare a liquid sample to IR analysis, firstly place a drop of the liquid on the face of a highly polished salt plate (such as NaCl, AgCl or KBr), then place a second plate on top of the first plate so as to spread the liquid in a thin layer between the plates, and clamps the plates together.

Answer:

1. Vacuole

2. chloroplast

3. Nucleus

4. Plasma membrane - cell membrane

5. Vacuole (same as #1 ?) could be vesicle

Explanation:

Answer:

9.5x10¹⁷ s

Explanation:

First we convert 3.41 cubic micrometers (um³) to liters (L), as such:

With the converted rate of 3.41x10⁻¹⁵ L/min, we can calculate how many minutes it would take to fill a 54 L vessel:

Finally we convert 1.58x10¹⁶ minutes to seconds:

Answer:

Throughout the explanations section below you will find a description of the question.

Explanation:

(1)

(2)

Answer:

density

Explanation:

The procedure that the student could use to examine an intensive property of a rectangular block of wood is to determine its density. Density is intensive because it is the ration between the mass and the volume.

Answer: find the mass option A

Explanation:

Answer:

yes

Explanation:

it is important for electrolysis

Answer:

Write a chemical equation for KOH(aq) showing how it is an acid or a base according to the Arrhenius definition.

Express your answer as a chemical equation. Identify all of the phases in your answer.

Write a chemical equation for NH4+(aq) showing how it is an acid or a base according to the Arrhenius definition.

Express your answer as a chemical equation. Identify all of the phases in your answer.

Explanation:

According to this theory, an acid is a substance that is a proton donor when the substance is dissolved in water.

The base is the one that gives OH- ions when dissolved in water.

KOH(aq) is a base.

Because it releases OH- ions when dissolved in water.

[tex]KOH(aq)->K^+(aq)+OH^-(aq)[/tex]

The ammonium ion is an acid.

It can donate a proton when dissolved in water.

[tex]NH_4^+(aq)->NH_3(aq)+H^+(aq)[/tex]

P=18000000/6 zeros. not sure how to do rest

Explanation:

a) [tex]n = \dfrac{PV}{RT} = \dfrac{(1.8×10^7\:\text{Pa})(3\:\text{L})}{(8310\:\text{L•Pa/mol•K})(300\:\text{K})}[/tex]

[tex]\:\:\:\:\:\:\:= 21.7\:\text{mol}[/tex]

b) [tex]P = \dfrac{nRT}{V}[/tex]

[tex]\:\:\:\:\:\:\:\:\:= \dfrac{(50\:\text{mol})(8310\:\text{L•Pa/mol•K})(300\:K)}{(3\:L)}[/tex]

[tex]\:\:\:\:\:\:\:\:\:=4.2×10^7\:\text{Pa}[/tex]

Answer:

M=0.549M

Explanation:

Hello there!

In this case, according to the given information, it turns out possible for us to perform this calculation by firstly assuming we have 1 kg of water as the solvent so that we have 0.550 moles of NaCl as well. Moreover, we realize we have 1000 grams of water and the correct mass of the solution can be calculated by converting 0.550 moles of NaCl to grams by using its molar mass:

[tex]m_{solute}=0.550mol*\frac{58.44 g}{1mol}= 32.14g\\\\m_{solution}=1000g+32.14g=1032.14g[/tex]

And subsequently, the volume in liters by using the density and the correct conversion factor:

[tex]V_{solution}=1032.14g*\frac{1mL}{1.03g} *\frac{1L}{1000mL} =1.002L[/tex]

Finally, the molarity will be:

[tex]M=\frac{0.550mol}{1.002L} =0.549M[/tex]

Regards!

Complete Question

Determine the end (final) value of n in a hydrogen atom transition, if the electron starts in n=4 and the atom emits a photon of light with a wavelength of 486 nm. Group of answer choices

Answer:

[tex]n=2[/tex]

Explanation:

From the question we are told that:

Wavelength [tex]\lambda=486nm=>486*10^{-9}[/tex]

Generally the equation for Atom Transition is mathematically given by

[tex]\frac{1}{\lambda}=R_{\infty }(\frac{1}{n_1^2}-\frac{1}{n_2^2})[/tex]

Where

Rydberg constant [tex]R_{\infty}=1.097*10^7[/tex]

Therefore

[tex]\frac{1}{486*10^{-9}}=1.097*10^7*(\frac{1}{n_1^2}-\frac{1}{4^2})[/tex]

[tex](\frac{1}{n_1^2}-\frac{1}{4^2})=\frac{1}{486*10^{-9}*1.097*10^7}[/tex]

[tex]n_1^2=3.98[/tex]

[tex]n=1.99[/tex]

[tex]n=2[/tex]

Using the Rydberg formula, the final state of the electron is n=2.

Using the Rydberg formula;

1/λ = R(1/nf^2 - 1/ni^2)

Where;

λ = wavelength

nf = final state

ni = initial state

R = Rydberg constant

When λ =  486 × 10^-9 m and ni = 4, R = 1.097  × 10^7 m-1

1/486 × 10^-9 =  1.097  × 10^7(1/nf^2 - 1/4^2)

0.188 = 1/nf^2 - 0.0625

1/nf^2 = 0.188 +  0.0625

nf = 2

Missing parts;

Determine the end (final) value of n in the hydrogen atom transition, if electron starts in n-4 and the atom emits a photon of light with a wavelength of 486.

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Answer:

e−(Ea/RT): the fraction of the molecules present in a gas which have energies equal to or in excess of activation energy at a particular temperature

Answer:

D. Temperature and activation energy is the correct answer

Explanation:

^_^

Answer:

heating of gases depends not only on the temperature difference, but also on the process as well as the amount of gas present.

Explanation:

The work done when a gas is heated does not only depends on the initial and final states of the gas but also on the process used to achieve the change of state of the gas.

Several processes can be applied in changing the state of a gas such as; adiabatic process, isobaric process, isochoric process and isothermal process.

Hence, the heating of a gas, depends not only on the temperature difference, as well as the amount of gas present according to the ideal gas laws but also on the process used to achieve the change of state.

Answer:

1920 Joules

Explanation:

* means multiply

^ means exponent

kinetic energy is in Joules or J

kinetic energy = 1/2 * mass * (velocity)^2

kinetic energy = 1/2 * 60 * (8)^2

kinetic energy = 1/2 * 60 * (8*8)

kinetic energy = 1/2 * 60 * (64)

kinetic energy = 1920 Joules or 1920 J

Answer:

KE = 1920 J

General Formulas and Concepts:

Energy

Kinetic Energy Formula: [tex]\displaystyle KE = \frac{1}{2}mv^2[/tex]

Explanation:

Step 1: Define

[Given] m = 60 kg

[Given] v = 8 m/s

Step 2: Find KE

Topic: AP Physics 1 Algebra-Based

Unit: Energy

Answer: See explanation

Explanation:

The explanation for why solid sodium chloride can't conduct electricity while molten sodium chloride can is explained below:

Ionic compounds that are in their solid state like sodium chloride have their ions fixed in position. Due to this reason, the able to move, therefore we can say that the solid ionic compounds cannot be able to conduct electricity.

On the other hand, ionic compounds in their molten state, are free to flow unlike when they're in their solid state and therefore we can say that molten sodium chloride can be able to conduct electricity.

Answer:

e. HCOOH and NaCHOO

Explanation:

For a buffer solution, both an acid and its conjugate base are required.

With the information above in mind, we can discard options a) and c), as those combinations are not of an acid and its conjugate base.

Now it is a matter of comparing the pKa (found in literature tables) of the acids of the remaining three acids:

The acid with the pKa closest to the desired pH is HCOOH, so the correct answer is e. HCOOH and NaCHOO

Answer:

the product is Mg(Clo3)2 + AgI

Answer:

[tex]n=6\ to\ n=3[/tex]

Explanation:

From the question we are told that:

Wavelength [tex]\lambda=274 *10^{-9}m[/tex]

Bohr's constant [tex]R = 1.097 × 10^7 / m (or m−1)[/tex]

Helium atom [tex]z=2[/tex]

Generally the equation for Wavelength is mathematically given by

 [tex]\frac{1}{\lambda}=Rz^2(\frac{1}{nf^2}-\frac{1}{nf^2})[/tex]

 [tex]0.083=(\frac{1}{nf^2}-\frac{1}{nf^2})[/tex]

Therefore

The Range of n fall at

 [tex]n=6\ to\ n=3[/tex]

Answer:

How many stereoisomers are possible for CHCl3 provided that the central carbon has tetrahedral geometry?

Explanation:

The stereoisomers are the molecules with the same molecular formula but the different spatial arrangements of atoms around the central atom.

For the given molecule, [tex]CHCl_3[/tex]

only one spatial arrangement is possible.

Hence, one stereoisomer is possible.

It is shown below:

Answer:

He chose pea plants because they were easy to grow, could be bred rapidly, and had several observable characteristics, like petal color and pea color.

Explanation:

Answer:

the answer is D .................

Answer:

n = 0.0814 mol

Explanation:

Given mass, m = 35.7g

The molar mass of Tin(IV) bromate, M = 438.33 g/mol

We need to find the number of moles of bromine. We know that,

No. of moles = given mass/molar mass

So,

[tex]n=\dfrac{35.7}{438.33}\\\\n=0.0814\ mol[/tex]

So, there are 0.0814 moles of bromine in 35.7g of  Tin(IV) bromate.

Water is in the solid phase at 0.25 atm and 0°C.

A pressure of 50 kPa and a temperature of 50 °C correspond to the “water” region—here, water exists only as a liquid. At 25 kPa and 200 °C, water exists only in the gaseous state.

Under standard atmospheric conditions, water exists as a liquid. But if we lower the temperature below 0 degrees Celsius, or 32 degrees Fahrenheit, water changes its phase into a solid called ice.

Learn more about the solid phase here https://brainly.com/question/13396621

#SPJ2

A is the answer

In an ozone molecule, the three atoms must be connected, so there must at least be a single bond between them. Place

dots in pairs around the oxygen atoms until each oxygen atom has eight valence electrons, starting with the atoms on the

outside and doing the central atom last if there are enough. Do not exceed the total number of valence electrons

identified in part A. Remember that the dashes between the oxygen atoms, which represent single bonds, each indicate

the presence of two valence electrons

Answer:

Explanation: i did it

Answer:

heating, thermal

Explanation:

the more molecules present, the greater amount from any given source increases the temperature as well as the thermal energy.