A friend is calculating the energy of reaction for a combustion reaction using bond energies, and the calculations are returning a positive for ?H. What, if anything, has your friend done incorrectly?

A. He or She used the wrong table of bond energies
B. Nothing, a combustion reaction should have a positive ?H
C. He or she may have subtracted the reactants from the products
D. Bond energies don’t apply to combustion reactants and should not be used.

Answer:

the answer is 11.111 and when you round it to the nearest one it’s 11, but to the nearest tenth it’s 10

Explanation:

Answer:

Invertebrates than eventually everything would die

Answer:

b.oil

Explanation:

oil is a nonrewnewable resource

Answer:

No. of moles, n = 7.52 moles

Explanation:

Given that,

Mass, m = 563.9 grams

Molar mass of arsenic = 74.92 g/mol

We need to find the number of moles in 563.9 grams of arsenic. Let it is denoted by n. It is equal to given mass divided by total molar mass.

[tex]n=\dfrac{563.9 }{74.92}\\\\=7.52\ \text{moles}[/tex]

So, there are 7.52 moles in 563.9 grams of arsenic.

Answer:

С3Н6.

Explanation:

Hello!

In this case, since addition reactions imply that a radical or some radicals are added to the parent chain, we notice that only unsaturated hydrocarbons are able to undergo addition whereas saturated ones undergo substitution reactions as they already have all the carbon bonds bonded to leaving groups.

In such a way, we can rule out C2H6, C3H8 and CH4 as they are all alkanes; therefore, only С3Н6 is able to undergo an addition reaction due to the C=C which is able to lose one of those bonds and allow an incoming radical to get included into the parent chain.

Best regards!

Answer:

1. Mass percent of ethanol = 28.02 %.

2. Mole fraction of ethanol = 0.13.

Explanation:

1. To find the mass percent we need to use the following equation:

[tex]\%_{m/m} = \frac{m_{e}}{m_{s}} \times 100[/tex]

Where:

[tex]m_{e}[/tex] is the mass of ethanol

[tex]m_{s}[/tex] is the mass of the solution

We need to calculate the mass of ethanol and the mass of the solution:

[tex] d = \frac{m_{s}}{V} [/tex]

Where:

d: is the density of the solution = 0.957 g/mL

V: is the volume = 1 L

[tex] m_{s} = d*V = 0.957 \frac{g}{mL}*\frac{1000 mL}{1 L}*1 L = 957 g [/tex]

Now, from the concentration we can find the mass of ethanol:

[tex] C = \frac{n_{e}}{V} = \frac{m_{e}}{M_{e}*V} [/tex]                      

Where:

[tex]M_{e}[/tex]: is the molar mass of ethanol = 46.07 g/mol

[tex]n_{e}[/tex]: is the number of moles of ethanol = m/M

[tex] m_{e} = C*M*V = 5.82 \frac{mol}{L}*46.07 \frac{g}{mol}*1 L = 268.13 g [/tex]

Finally, the mass percent of ethanol is:

[tex]\%_{m/m} = \frac{268.13 g}{957 g} \times 100 = 28.02 \%[/tex]

2. The mole fraction of ethanol is given by:

[tex] \chi_{e} = \frac{n_{e}}{n_{s}} [/tex]

The number of moles of ethanol is:

[tex]n_{e} = \frac{m_{e}}{M_{e}} = \frac{268.13 g}{46.07 g/mol} = 5.82 moles[/tex]

And the moles of the solution is:    

[tex] n_{s} = n_{e} + n_{w} [/tex]

Where w is for water

[tex] n_{s} = n_{e} + \frac{m_{w}}{M_{w}} [/tex]

[tex] n_{s} = n_{e} + \frac{m_{s} - m_{e}}{M_{w}} [/tex]

[tex]n_{s} = 5.82 moles + \frac{957 g - 268.13 g}{18 g/mol} = 44.09 moles[/tex]

Hence, the mole fraction of ethanol is:

[tex]\chi_{e} =\frac{5.82 moles}{44.09 moles}=0.13[/tex]

I hope it helps you!                                                          

Answer:

CH4

Explanation:

The ideal gas behavior of individual gases often depend on the magnitude of intermolecular interaction between the molecules of the gas as well as the presence or absence of polar bonds.

In CCl4, there are polar bonds and the presence of the more electronegative chlorine atom in the molecule and consequently a greater degree of intermolecular interaction at 400K compared to CH4 which contains only non polar bonds.

Therefore, CH4 displays greater ideal gas behavior at 400K than CCl4.

Answer:

Science is really reliable because there is research and math and brains. Actual science are results from experiments, so it's mainly always correct.

Explanation:

Answer:

C = 107.97 mol/L

Explanation:

Given data:

Volume of solution = 1.38 mL (1.38 mL× 1 L /1000 mL = 0.00138 L)

Mass of ammonium sulfite = 17.36 g

Concentration of solution =?

Solution:

We will calculate the number of moles of ammonium sulfite.

Number of moles = mass/molar mass

Number of moles = 17.36 g / 116.15 g/mol

Number of moles = 0.149 mol

Concentration:

C = n/V

C = concentration

n = number of moles of solute

v = volume in L

C = 0.149 mol / 0.00138 L

C = 107.97 mol/L

0.1621 mol FeCl₃

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Compounds

Atomic Structure

Step 1: Define

26.29 g FeCl₃ (iron (III) chloride)

Step 2: Identify Conversions

Molar Mass of Fe - 55.85 g/mol

Molar Mass of Cl - 35.45 g/mol

Molar Mass of FeCl₃ - 55.85 + 3(35.45) = 162.2 g/mol

Step 3: Convert

Step 4: Check

Follow sig fig rules and round. We are given 4 sig figs.

0.162084 mol FeCl₃ ≈ 0.1621 mol FeCl₃

Answer: 5.47x10^24 molecules

Explanation:

6.02214076x10^23 molecules CO2 = 44g

400g = (400/44)*6.02214076*10^23 = 5.47x10^24

According to the concept of Avogadro's number, there are 54.75 ×10²³ molecules of carbon dioxide are 400 grams of the substance.

Avogadro's number is defined as a proportionality factor which relates number of constituent particles with the amount of substance which is present in the sample.

It has a SI unit of reciprocal mole whose numeric value is expressed in reciprocal mole which is a dimensionless number and is called as Avogadro's constant.It relates the volume of a substance with it's average volume occupied by one of it's particles .

According to the definitions, Avogadro's number depend on determined value of mass of one atom of those elements.It bridges the gap between macroscopic and microscopic world by relating amount of substance with number of particles.

Number of atoms can be calculated using Avogadro's number as follows: mass/molar mass×Avogadro's number .Number of moles= 400/44=9.09 moles which is number of molecules =9.09×6.023×10²³= 54.75 ×10²³ .

Learn more about Avogadro's number,here:

https://brainly.com/question/28812626

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The percentage of water in the compound CaSO₄.6H₂O = 44.26%

Given

Compound CaSO₄. 6H₂O

Required

The percentage of water

Solution

MW CaSO₄. 6H₂O :

= 40 + 32 + 4.16 + 12.1 + 6.16

= 244

MW 6H2O :

= 12.1 + 6.16

= 108

%water = (108 : 244) x 100%

%water = 44.26

The percentage of water in the compound CaSO₄.6H₂O is 44.26%

Since MW CaSO₄. 6H₂O :

= 40 + 32 + 4.16 + 12.1 + 6.16

= 244

Now

MW 6H2O :

= 12.1 + 6.16

= 108

So, percentage of water = (108 : 244) x 100%

= 44.26

learn more about water here: https://brainly.com/question/5534000

Answer:

50.8 g

Explanation:

Equation of reaction.

[tex]CH_4 + 2O_2 \to CO_2 + 2H_2O[/tex]

From the given information, the number of moles of methane = mass/ molar mass

= 15.4 g /  16.04 g/mol

= 0.960 mol

number of moles of oxygen gas = 90.3 g / 32 g/ mol

= 2.82 mol

Since 1 mol of methane requires 2 moles of oxygen

Then 0.960 mol of methane will require = 0.960 mol × 2 = 1.92 mol of oxygen gas

Thus, methane serves as a limiting reagent.

2.82 mol oxygen gas will result in 2.82 moles of water

So, the theoretical yield of water = moles × molar mass

= 2.82 mol × 18.01528 g/mol

= 50.8 g

Answer:

hfghfhjcbnggf

Explanation:

layer1

layer 2

I don't know what you mean by the question, but in science it is Newton's second law.

"The second law explains how the velocity of an object changes when it is subjected to an external force."

I hope this helped!+*♡

Answer:Prokaryotic cells carry out cellular respiration within the cytoplasm and eukaryotic cells carry out respiration in the mitochondria

Explanation:

Answer:

[tex]M_{acid}=0.075M[/tex]

Explanation:

Hello!

In this case, since the reaction between NaOH and HNO3 is:

[tex]NaOH+HNO_3\rightarrow NaNO_3+H_2O[/tex]

Whereas there is a 1:1 mole ratio between the acid and base, thus, we can write:

[tex]M_{acid}V_{acid}=M_{base}V_{base}[/tex]

In such a way, solving for the concentration of the acid, HNO3, we obtain:

[tex]M_{acid}=\frac{M_{base}V_{base}}{V_{acid}}[/tex]

Therefore, by plugging in we obtain:

[tex]M_{acid}=\frac{0.12L*0.2M}{0.32L}\\\\ M_{acid}=0.075M[/tex]

Best regards!

0.125 mol Ca

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Step 1: Define

5.00 g Ca

Step 2: Identify Conversions

Molar mass of Ca - 40.08 g/mol

Step 3: Convert

Step 4: Check

Follow sig fig rules and round. We are given 3 sig figs.

0.12475 mol Ca ≈ 0.125 mol Ca

Answer: gas molecules will hit the container walls more frequently and with greater force

Explanation:

According to the postulates of  kinetic molecular theory:

1. The pressure exerted by a gas in a container results from collisions between the gas molecules and the container walls.

2. The average kinetic energy of the gas molecules is proportional to the kelvin temperature of the gas.

When the temperature is increased, so the average kinetic energy and the rms speed also increase. This means that the gas molecules will hit the container walls more frequently and with greater force because they are all moving faster. This increase the pressure.

Answer:

D) Gastropod

Explanation:

It's higher classification is Mollusca on go o gle

The given question is incomplete. The complete question is :

Which of the following Group 17 elements is the least reactive

a) Flourine

b) Chlorine

c) Astatine

d) Iodine

Answer: c) Astatine

Explanation:

Halogen is the name given to Group 17 family with general electronic configuration of [tex]ns^2np^5[/tex] which have 7 valence electrons and thus easily gain one electron to attain stable configuration.

As we move down the group from flourine to chlorine to bromine to iodine to astatine , the valence shell moves farther from nucleus and thus tendency to accept the electron decreases and thus reactivity also decreases.

Thus Astatine is the least reactive of all.

Answer:

The moles of ammonia present in a 1.284 g sample are 0.075.

Explanation:

Molar mass is the mass of one mole of a substance, which can be an element or a compound. If the molar mass of ammonia is 17,030 g / mol, then in 1 mole of ammonia there are 17,030 g.

So, in this case, the following rule of three can be applied: if by definition of molar mass in there are 17.030 g in 1 mole of ammonia, 1.284 g of ammonia in how many moles will it be?

[tex]moles=\frac{1.284 g*1 mole}{17.030 g}[/tex]

moles=0.075

The moles of ammonia present in a 1.284 g sample are 0.075.

Answer: Hydrogen molecules will have greatest average speed.

Explanation:

The formula for average speed is  :

[tex]\mu_{av}={\sqrt{\frac{8RT}{\pi\times M}}}[/tex]

R = gas constant  

T = temperature  

M = Molecular Mass

Now putting all the values:

[tex]\frac{\nu_{H_2}}{\nu_{O_2}}=\sqrt{\frac{8RT}{\pi\times M_{H_2}}}/{\sqrt{\frac{8RT}{\pi\times M_{O_2}}}[/tex]

[tex]\frac{\nu_{H_2}}{\nu_{O_2}}=\sqrt{\frac{16}{2}}[/tex]

[tex]\frac{\nu_{av}_{H_2}}{\nu_{av}_{O_2}}=8[/tex]

Thus average speed of hydrogen is 8 times the average speed of oxygen. Thus hydrogen molecules will have greatest average speed

Answer:

Net ionic equation: Ag⁺(aq) + Cl⁻(aq) → AgCl(s)

44.9% as AgNO₃

Explanation:

When sodium nitrate, NaNO₃ and silver nitrate, AgNO₃ are dissolved in water, the Na⁺, NO₃⁻ and Ag⁺ ions are formed.

Then, the addition of NaCl (Na⁺ and Cl⁻) produce AgCl⁻ as precipitate. The net ionic equation is:

If 2.54g of AgCl are formed and represents the 95.9% of yield. The real amount of AgCl is:

2.54g AgCl * (100% / 95.9%) = 2.65g AgCl.

In moles (Molar mass AgCl = 143.32g/mol):

2.65g AgCl * (1mol / 143.32g) = 0.0185 moles of AgCl = Moles of AgNO₃

Because all Ag comes from AgNO₃

Thus, the original mass of silver nitrate and its precentage is (Molar mass AgNO₃ = 169.87g/mol):

0.0185 moles AgNO₃ * (169.87g / mol) = 3.14g of AgNO₃

Percentage:

3.14g AgNO₃ / 7.00g * 100 =  

Answer:

Explanation:

C

[tex]4.9 \times 10^{23}[/tex]  are present in 18.4L of argon (Ar).

To calculate the amount of particles present in a given amount of volume, it is necessary to have knowledge of the molar volume:

                                          [tex]1 mol = 22.4L[/tex]

Thus, in 22.4L there is 1 mol of an element, remembering that:

                                   [tex]1 mol = 6\times10^{23}[/tex] particles

In this way, it is enough to relate the value of the molar volume given with the value requested by the question:

                                     [tex]\frac{6\times10^{23}particles}{xparticles} = \frac{22.4L}{18.4L}[/tex]

                                    [tex]x = 4.9 \times 10^{23}[/tex] particles

 So, [tex]4.9 \times 10^{23}[/tex] are present in 18.4L of argon (Ar).

Learn more about mole calculation in: brainly.com/question/15209553

Answer:

complimentary

Explanation:

Answer:

Proximal

Explanation:

Answer: 0.407 moles of aluminum chloride could be produced from 11.0 g of aluminum.

Explanation:

To calculate the moles :

[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]    

[tex]\text{Moles of aluminium}=\frac{11.0g}{27g/mol}=0.407moles[/tex]

[tex]2Al+3Cl_2\rightarrow 2AlCl_3[/tex]  

According to stoichiometry :

[tex]Al[/tex] is the limiting reagent as it limits the formation of product and [tex]Cl_2[/tex] is the excess reagent.

As 2 moles of [tex]Al[/tex] give = 2 moles of [tex]AlCl_3[/tex]

Thus moles of [tex]Al[/tex] give =[tex]\frac{2}{2}\times 0.407=0.407moles[/tex]  of [tex]AlCl_3[/tex]

Thus 0.407 moles of aluminum chloride could be produced from 11.0 g of aluminum.

126 g Fe

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Step 1: Define

2.25 mol Fe

Step 2: Identify Conversions

Molar Mass of Fe - 55.85 g/mol

Step 3: Convert

Step 4: Check

Follow sig fig rules and round. We are given 3 sig figs.

125.663 g Fe ≈ 126 g Fe