For a particular reaction, the change in enthalpy is â9kJmole and the activation energy is 13kJmole. The enthalpy change (ÎH) and activation energy (Ea) for the catalyzed reaction could be which of the following? a. â9kJmole,5kJmole. b. â9kJmole,19kJmole.c. â14kJmole,5kJmole.d. â14kJmole,â13kJmole.

Answer:

Identifies the number of protons a single atom of the element contains.

Explanation:

The atomic number helps people identify elements according to the number of protons one atom of the element has. It essentially defines the element.

While having a neutral charge, it also provides the number of electrons the element has (in one atom).

Answer:

453.031g

Explanation:

atomic mass (molar mass)- 196.97g/m

2.3(196.97)=453.031

Answer:

B

Explanation:

i hope this helps

Answer:

Explanation:  check my paage

Answer:

- 278.85 J  

Explanation:

Given that:

Pressure = 1.1 atm

The initial volume V₁ = 0.0 L

The final volume V₂ = 2.5 L

The work that takes place in a reaction at constant pressure can be expressed by using the equation:

W = P(V₂ - V₁ )

Since the volume of the gas is expanded from 0 to 2.5 L when 1.1 atm pressure is applied. Then, the work can be given by the expression:

W = - P(V₂ - V₁ )

W = -1.1 atm ( 2.5 - 0.0) L

W = -1.1 atm (2.5 L)

W = -2.75 atm L

Recall that:

1 atm L = 101.4 J

Therefore;

-2.75 atm L = ( -2.75 × 101.4 )J

= -278.85 J  

Thus, the work required at the chemical reaction when the pressure applied is 1.1 atm  = - 278.85 J  

Answer:

B) 1st C sp3 ; 2nd C sp3 ; O sp3

Explanation:

Both carbons in ethanol have an sp³ configuration of their orbitals, given that each carbon atom binds to four other atoms, as can be seen on the extended formula in the attachment.

In these carbons (1st and 2nd) one s orbital and three p orbitals are hybridized to form four hybrid orbitals sp³. These orbitals form four bonds and their bond angles are close to the tetrahedral value of 109.5º,as can be seen for methanol which also has an sp³ configuration.

The oxygen atom can also be described as having sp³ hybrid orbitals. Two of the four hybrid sp³ orbitals in oxygen are occupied by lone electron pairs, and two are used to form bonds with other atoms (in this case the oxygen is bonded to a carbon atom and a hydrogen atom).

Therefore, the three central atoms have an sp³ configuration.

Answer:

1) 1.4 × 10³ mL

2) 0.913 kg

3) 1.1 g

Explanation:

1)

Step 1: Calculate the volume of 1.3 kg of olive oil

The density of olive oil is 0.917 kg/L.

1.3 kg × (1 L/0.917 kg) = 1.4 L

Step 2: Convert the volume to mL

We will use the relationship 1 L = 10³ mL.

1.4 L × (10³ mL/1 L) = 1.4 × 10³ mL

2)

Step 1: Calculate the mass of the cannon ball

The density of iron is 7.87 g/cm³.

116 cm³ × 7.87 g/cm³ = 913 g

Step 2: Convert the mass to kg

We will use the relationship 1 kg = 10³ g.

913 g × (1 kg / 10³ g) = 0.913 kg

3)

Step 1: Calculate the mass of the helium in the balloon

The density of balloon is 0.18 g/L.

6.1 L × 0.18 g/L = 1.1 g

Answer:

B. the atmosphere

Explanation:

hope it helps

Answer:

Explanation:

mass of the solution m = 1.6 + 75 = 76.6 g

fall in temperature = 25 - 23.34 = 1.66°C

heat absorbed = mass x specific heat x fall in temperature

= 76.6 x 1.66 x 4.18

= 531.5 J .

= .5315 kJ .

mol weight of ammonium nitrate = 80 g

heat absorbed by 1.6 g = .5315 kJ

heat absorbed by 80 g or one mole = 26.575 kJ

enthalpy change ΔH = +26.575 kJ

b )

enthalpy of hydration = 2630 kJ / mol

lattice energy = enthalpy of hydration + enthalpy change

= 2630 + 26.575

= 2656.575 kJ  .

Answer:

A molecular compound.

Explanation:

Ice, H2O(s), is classified as ; ( B ) A molecular compound

Given that Ice and H₂O are the same element but in different forms therefore we can classify Ice, H₂O as been a molecular compound.

Ice and H₂O are not ionic compounds because ionic compounds are formed between metal and non-metal elements while H₂O and Ice are neither metals but are both Nonmetals

Hence we can conclude that Ice, H2O(s), is classified as A molecular compound

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Answer:

D

Explanation:

Answer:

Electron cloud

Explanation:

If you were to scale the size of the atom up to have the nucleus be about the size of a basket ball, then the placement of the actual electrons (about the size of a large marble at this scale) throughout the cloud would be many yards away from the nucleus.

Answer:

Gas (B)

Explanation:

Answer:

umm.. B. a base that generates a lot of hydroxide ions in water.

The descriptions best describes a weak base is a base that dissociates only slightly in water.

Bases are those substances which react with acids to neutralize them, generally bases are the compounds of oxides, hydroxides and carbonates of metal elements.

Bases shows dissocation in the aqueous soluition and pH of bases ranges from 7 to 14. Strong bases shows full dissociation into ions and having higher pH values and weak bases shows partial dissociation into ions & having lower pH values.

Hence, option (D) is correct.

To know more about bases, visit the below link:

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Answer:

2) (s)

3) PbBr2

Explanation:

2) This is a precipitation rxn which means if forms a solid, We use (s) for solid.

3) Refer to solubility table

Answer:  \(\left( \ce{F} \right)\), chlorine \(\left( \ce{Cl} \right)\), bromine \(\left( \ce{Cl} \right)\), iodine \(\left( \ce{I} \right)\), and astatine \(\left( \ce{At} \right)\)

Explanation:

Answer:

The immune system responds to antigens by producing cells that directly attack the pathogen, or by producing special proteins called antibodies. Antibodies attach to an antigen and attract cells that will engulf and destroy the pathogen. The main cells of the immune system are lymphocytes known as B cells and T cells.

Answer:

i am not sure but it seems D is the best

Answer:

A

Explanation:

It seems to be the most logical. My reasoning is that for B when it uses one parent cookie that produced genetically different offspring. That is what makes it incorrect. The other two options involve two parents which means that the reproduction would be sexual. A. would be the closest to the answer.

Please let me know if this is correct! Hope it helped.

Answer:

C. Bases are found in the pH range of 1-7 on the pH scale.

Explanation:

Acids are less than 7 on the pH scale, so 1-7. Bases are more than 7 on the pH scale, so 7-14. That's why C is incorrect, hope this helps!

Answer:

Explanation:

A calorimeter is an instrument used for measuring the heat of reactions and heat capacity. A calorimeter should contain an insulating cover, a thermometer, styrofoam cups (you could have that both on the inside and the outside in the case of a styrofoam calorimeter) and you could also have a conductivity probe (in the form of ignition wires and bulb).

A calorimeter is the analytical device used to measure the heat of the reaction. The construction of calorimeter requires cover, paper cup, thermometer, styrofoam cup, and conductivity probe.

In a chemical reaction, the amount of heat released or absorbed by the reaction helps in the analysis of various parameters. The calorimeter measures the heat of the reaction.

The construction of a calorimeter requires:

Learn more about calorimeter, here:

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Answer:

Point F

Explanation:

Point F is the maximum potential energy.

Point G is lots of kinetic energy.

Point H is low potenital energy and low kinetic energy.

Answer: A LOWER ENERGY

Explanation:

did the test

Answer:

A lower energy!

Explanation:

I know this is not much of an explanation but I took the test i hope you have an amazing day afternoon or night! Hope this helps :3

Answer:

695.8kJ/mol = Enthalpy of combustion

Final temperature = 407.4°C

Explanation:

Taken the reaction:

2CH₃NO₂ + 3/2 O₂ → 2CO₂ + 3H₂O + N₂

The enthalpy of the reaction is the heat released when 1 mole of nitromethane are in combustion.

We need to find the moles presents in 121L of nitromethane using its density and molar mass (61.04g/mol). As these moles releases 1.6x10⁶kJ, we need to find heat released per mole of nitromethane

Mass nitromethane:

121L = 121000cm³ * (1.16g/cm³) = 140360g

Moles:

140360g * (1mol / 61.04g) = 2299.5 moles of nitromethane

Heat released per mole of nitromethane:

1.6x10⁶kJ / 2299.5 mol = 695.8kJ/mol = Enthalpy of combustion

The symbol - is because the heat is released, a + symbol is when the heat is absorbed.

Using:

Q = m×C×ΔT

Where Q is heat (1.6x10⁶kJ = 1.6x10⁹J)

m is mass of water:

1kL = 1000L = 1x10⁶mL = 1x10⁶g

C is specific heat of water: 4.184J/g°C

And ΔT is change in temperature.

Solving for ΔT:

1.6x10⁹J = 1x10⁶g * 4.184J/g°C * ΔT

ΔT = 382.4°C

As initial temperature was 25°C, final temperature is:

382.4°C + 25°C =

407.4°C

Answer:Because the Earth is round and not flat, the Sun's rays don't fall evenly on the land and oceans. The Sun shines more directly near the equator bringing these areas more warmth. However, the polar regions are at such an angle to the Sun that they get little or no sunlight during the winter, causing colder temperatures.

Explanation:

Answer:

Forms and Functions

Explanation:

It refers to the direct relationship between the structure of a thing and the way it functions.

Answer:

If an object has a higher density than the fluid it is in (fluid can mean liquid or gas), it will sink. If it has a lower density, it will float. Density is determined by an object's mass and volume. If two objects take up the same volume, but have one has more mass, then it also has a higher density.

Explanation: