Need help with these three pls!!

Answer:

The Eocene Period is experiencing net gain in energy while Cryogenian Period is experiencing a net loss in energy.

Explanation:

In Eocene Period, the population of mammals such as horses , whales and bats etc were high due to the presence of high amount of food and good atmospheric condition such as high temperature while the population of animals were low in Cryogenian Period due to the presence of very low temperature which experiencing loss of energy. Most of area of the earth consist of icy desert.

Answer: 780 kcal are required to produce 12.00 mol of [tex]Cl_2O_7[/tex]

Explanation:

Endothermic reactions are defined as the reactions in which energy of the product is greater than the energy of the reactants. The total energy is absorbed in the form of heat and written along with reactants.

The balanced chemical reaction is:

[tex]2Cl_2(g)+7O_2(g)+130kcal\rightarrow 2Cl_2O_7(g)[/tex]

According to stoichiometry :

2 moles of [tex]Cl_2O_7[/tex] are produced by absorption of energy = 130 kcal

Thus 12.00 moles of [tex]Cl_2O_7[/tex] are produced by absorption of energy = [tex]\frac{130}{2}\times 12.00=780kcal[/tex]

Thus 780 kcal are required to produce 12.00 mol of [tex]Cl_2O_7[/tex]

Answer:

19.47%

Explanation:

The percentage by mass of [tex]H_2SO_4[/tex] would be 19.47%.

The percentage by mass of a substance in solution is calculated as:

   [tex]\frac{mass of substance}{mass of substance + water} * 100%[/tex]

Given that the mole fraction of [tex]H_2SO_4[/tex] = 0.432

The total number of mole fraction of a solution = 1

Hence, mole fraction of water = 1 - 0.432 = 0.568

Mass of water = molar mass x mole

                              = 98.079 x 0.432 = 42.37 g

Mass of [tex]H_2SO_4[/tex] = molar mass x mole

                          = 18.02 x 0.568 = 10.24 g

Hence,

%mass of [tex]H_2SO_4[/tex] = [tex]\frac{10.24}{10.24 + 42.37} * 100[/tex]

                         = 19.47%

Answer:

2.31M

Explanation:

The following data were obtained from the question:

Mole of K2SO4 = 0.450 mole

Volume of water = 195.0 mL = 195/1000 = 0.195L

Molarity =...?

Molarity is defined as the mole of solute per unit litre of the solution. This can be expressed as:

Molarity = mole /Volume

With the above formula we can calculate the molarity of the K2SO4 solution as follow:

Molarity = mole /Volume

Molarity = 0.450/0.195

Molarity = 2.31M

Answer:

There are 0.12269 Liters of Iron

Explanation:

First, by means of the molecular weight equation, the grams of iron corresponding to 17.3 moles can be calculated:

[tex]MW=\frac{mass(grams)}{moles}[/tex]

[tex]mass=MW*moles=55.845\frac{g}{mol} *17.3mol=966.119 g[/tex]

Then using the density equation the iron milliters are calculated:

[tex]d=\frac{mass(g)}{volume(mL)}[/tex]

[tex]volume=\frac{mass}{density}=\frac{966.119g}{7.874\frac{g}{mL} } =122.69 mL[/tex]

Milliliters to liters are converted:

122.69 mL = 0.12269 L of Iron.

Answer:

[tex]V_{Fe}=0.125L[/tex]

Explanation:

Hello,

In this case, given the moles of iron, we need to use it atomic mass (55.845  g/mol) and density (7.874 g/cm³) in order to firstly convert from moles to grams and secondly from grams to cubic centimetres:

[tex]V_{Fe}=17.6molFe\times \frac{55.845gFe}{1molFe}*\frac{1cm^3}{7.874gFe}=124.8cm^3[/tex]

Finally, we obtain the volume in litres by:

[tex]V_{Fe}=124.8cm^3*\frac{1L}{1000cm^3} \\\\V_{Fe}=0.125L[/tex]

Best regards.

Answer:

5.9 kg  

Explanation:

We must work backwards from the second step to work out the mass of oxygen.

1. Second step

Mᵣ:                                     55.84

            Fe₂O₃ + 3CO  ⟶  2Fe  +  3CO₂

m/kg:                                    7.0

(a) Moles of Fe

[tex]\text{Moles of FeO} = \text{7000 g Fe} \times \dfrac{\text{1 mol Fe}}{\text{55.84 g Fe}} = \text{125 mol Fe}[/tex]

(b) Moles of CO

[tex]\text{Moles of CO} = \text{125 mol Fe} \times \dfrac{\text{3 mol CO}}{\text{2 mol Fe}} = \text{188 mol CO}[/tex]

However, this is the theoretical yield.

The actual yield is 72. %.

We need more CO and Fe₂O₃ to get the theoretical yield of Fe.

(c) Percent yield

[tex]\begin{array}{rcl}\text{Percent yield} &=& \dfrac{\text{ actual yield}}{\text{ theoretical yield}} \times 100 \, \%\\\\ 72. \, \% & = & \dfrac{\text{188 mol}}{\text{actual yield}} \times 100 \,\%\\\\0.72 &= &\dfrac{\text{188 mol}}{\text{actual yield}}\\\\\text{Actual yield} & = & \dfrac{\text{188 mol}}{0.72}\\& = & \textbf{261 mol}\\\\\end{array}[/tex]

We must use 261 mol of CO to get 7.0 kg of Fe.

2. First step

Mᵣ:                32.00

            2C   +  O₂   ⟶  2CO

n/mol:                             261

(a) Moles of O₂

[tex]\text{Moles of O}_{2} = \text{261 mol CO} \times \dfrac{\text{1 mol O}_{2}}{\text{2 mol CO}} = \text{131 mol O}_{2}[/tex]

(b) Mass of O₂

[tex]\text{Mass of O}_{2}= \text{131 mol O }_{2} \times \dfrac{\text{32.00 g O}_{2}}{\text{1 mol O}_{2}} = \text{4180 g O}_{2}[/tex]

However, this is the theoretical yield.

The actual yield is 71. %.

We need more C and O₂ to get the theoretical yield of CO.

(c) Percent yield

[tex]\begin{array}{rcl}71. \, \% & = & \dfrac{\text{188 mol}}{\text{actual yield}} \times 100 \,\%\\\\0.71 &= &\dfrac{\text{4180 g}}{\text{actual yield}}\\\\\text{Actual yield} & = & \dfrac{\text{4180 g}}{0.71}\\\\& = & \text{5900 g}\\& = & \textbf{5.9 kg}\\\end{array}[/tex]

We need 5.9 kg of O₂ to produce 7.0 kg of Fe.

Answer:

D. Wind Speed

Explanation:

When the question brings up 35 m/h, the m/h stands for Miles per Hour. What option can you measure the miles per hour. Here's a hint, it applies to cars as well when cops give your parents speeding tickets. Miles per Hour = Speed. So, you are measuring the wind speed.

Answer:

HDHERFEHFFFHRF

Explanation:

Answer:

 24He

Explanation:

When a nuclide is bombarded with alpha particles, we notice an increase in its mass and charge since an alpha particle has a mass of four and a charge of +2. recall that nuclear equations must be balanced. That is, the masses and charges on the left hand six and the right hand side of the nuclear reaction equation must be exactly the same.

Looking at the nuclear reaction at hand, the total mass on the left hand side has to be 246 while the total charge on the left hand side of the equation will be 98. Coming over to the right hand side, the total masses are also found to be the same as a neutron with no charge and a mass of 1 is produced. Hence the nuclear reaction equation is balanced when an alpha particle (helium nucleus) is substituted for X in the equation.

Answer:

24HE

I took the test!

Answer:

Greenhouse gases such as carbon dioxide and water vapor make an atmosphere around the earth and make less heat escape

Explanation:

Answer:

0.479 M or mol/L

Explanation:

So Molarity is moles/litres of solution...often written as M=mol/L

So here we are given grams of BaCl2 which we have to convert to moles. To convert to moles of BaCl2 we have to divide 63.2 g BaCl2 by molar mass of BaCl2 which is 208.23 g/mol so you get 63.2/208.23 = 0.3035 moles of BaCl2

Second step is converting the 634mL to litres by simply dividing by 1000 because we know 1 litre has 1000ml so 634/1000 = 0.634L

Now we just plug these guys in our molarity formula M=mol/L

M= 0.3035/0.634 = 0.479 M or mol/L

Answer:

Interestingly enough, I'm not getting

0.0341% w/v

either. Here's why.

Start by calculating the percent composition of chlorine,

Cl

, in calcium chloride, This will help you calculate the mass of chloride anions,

Cl

−

, present in your sample.

To do that, use the molar mass of calcium chloride, the molar mass of elemental chlorine, and the fact that

1

mole of calcium chloride contains

2

moles of chlorine atoms.

2

×

35.453

g mol

−

1

110.98

g mol

−

1

⋅

100

%

=

63.89% Cl

This means that for every

100 g

of calcium chloride, you get

63.89 g

of chlorine.

As you know, the mass of an ion is approximately equal to the mass of the neutral atom, so you can say that for every

100 g

of calcium chloride, you get

63.89 g

of chloride anions,

Cl

−

.

This implies that your sample contains

0.543

g CaCl

2

⋅

63.89 g Cl

−

100

g CaCl

2

=

0.3469 g Cl

−

Now, in order to find the mass by volume percent concentration of chloride anions in the resulting solution, you must determine the mass of chloride anions present in

100 mL

of this solution.

Since you know that

500 mL

of solution contain

0.3469 g

of chloride anions, you can say that

100 mL

of solution will contain

100

mL solution

⋅

0.3469 g Cl

−

500

mL solution

=

0.06938 g Cl

−

Therefore, you can say that the mass by volume percent concentration of chloride anions will be

% m/v = 0.069% Cl

−

−−−−−−−−−−−−−−−−−−−

I'll leave the answer rounded to two sig figs, but keep in mind that you have one significant figure for the volume of the solution.

.

Explanation:

Answer:

As the temperature of a sample of gas falls from 45.0ºC to 30.0ºC, its pressure falls to 300.

Explanation:

Answer:

fermentation

Explanation:

Answer:

b

Explanation:

hope it helps

Answer: Gold is shiny and bright just like the sun. Gold is yellow.

Explanation:

Answer:

The metals have the tedency to lose electrons and become positive ions

Explanation:

In order to attain noble gases electronic configuration, metals of group I A lose one electron and II A lose 2 electrons with ionization energy.

Answer:

Move rapidly or move fast and farther apart. Hope this helps.

Answer: vibrate more rapidly

Explanation:

Answer:

coal is made from compressed plant matter and how exactly did plants grow on the surface of an ocean. (as there is no land mass beneath the arctic.)

Explanation:

it would be like finding a fly in an ice cube to simplify it.

They were surprised to find coal in arctic because ordinarily coal was supposed to be found in warm or hot environments and not cold region like the arctic.

The arctic is located at the far northern part of the world which is characterized by its extreme cold weather.

A limited vegetation of plants such as grasses, mosses and lichens are found in this region irrespective of the extreme cold weather through out the year.

Coal is a type of fuel gotten from fossils and deposits of plant vegetation.

Scientist has discovered that continents do move over time through a process called continental drift. This is the reason why limited vegetaion is found in the arctic leading to the formation of coal.

Learn more here:

https://brainly.com/question/22647554

Answer:

grond water

Explanation:

Answer:

A

Explanation:

Answer:c

Explanation:

Answer:

Both are equal

Explanation:

Mass of starting material i.e Aluminium is [tex]4.480 * 10^{-23}[/tex] grams

The weight of oxygen is [tex]2.65 * 10^{-23}[/tex]

There are 4 atoms of aluminium and 3 atoms of oxygen

Thus, the total mass of starting material is

[tex]4 *[/tex] mass of one atom of aluminium [tex]+ 6 *[/tex] mass of one atom of oxygen

[tex]4 * 4.480 * 10^{-23} + 6* 2.65 * 10^{-23}[/tex]

[tex]35.1 * 10^{-23}[/tex] grams

Mass of new substance is also equal to

[tex]4 *[/tex] mass of one atom of aluminium [tex]+ 6 *[/tex] mass of one atom of oxygen

[tex]4 * 4.480 * 10^{-23} + 6* 2.65 * 10^{-23}[/tex]

[tex]35.1 * 10^{-23}[/tex] grams

o advance counterterrorism efforts in other countries

Answer:

D

Explanation:

E2020

Answer:

The correct answer is The pressure of the gas will increase

The volume of the gas will increase

Explanation:

Step 1: Data given

The gas in a container is heated, this means the temperature increases

Suppose we start with a temperature of 100 K and a pressure of 1 atm and a volume of 1L

Step 2:

V1/T1= V2/T2

⇒V1 = the initial  volume = 1L

⇒T1 = the initial temperature = 100 K

⇒V2 = the new volume = TO BE DETERMINED

⇒T2 = the increased temperature = 200 K

1/100 = V2 / 200

V2 = 2 L

This means when the temperature increases, the volume will increase

P1/T1 = P2/T2

⇒P1 = the initial pressure = 1 atm

⇒T1 = the initial temperature = 100 K

⇒P2 = the new pressure = TO BE DETERMINED

⇒T2 = the increased temperature = 200 K

1/100 = P2 / 200

P2 = 2 atm

This means when the temperature increases, the pressure will increase

The correct answer is The pressure of the gas will increase

The volume of the gas will increase

C. The concentrations of liquid water and water vapor are stable. it describes the fact that liquid water and water vapor are at equilibrium.

Hence, option (c) is correct. The concentration of liquid water and water vapor will become stable.

Learn more about water vapor:

https://brainly.com/question/17259832

Answer: Diamonds were first discovered and mined in India over 2,400 years ago.

Explanation: Over time, diamonds were found in many other areas around the world, including many in Africa. In today's trade, Africa, Russia, Australia, and Canada produce the most diamonds.

~Wonderopolis

Answer:

Diamonds are formed when under the heat and pressure of the earth's gravity.  Diamonds have to be underground to be formed so they should be underground. Digging to Y11 is deep enough to find diamonds .

Answer:

The molecules in a solid are stuck in a specific structure or arrangement of atoms. The atoms still vibrate and the electrons fly around in their orbitals, but the entire atom will not change its position.

Answer:

higher temperature → less kinetic energy → less space between particles higher volume

Explanation:

Answer:

The correct ones are:

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|V

V

Explanation:

Answer:

1 for and 5

Ex

Study island