Calculate the percent composition (percent by mass of each element) of NH4Cl.

Round to the nearest ONES place ((example: 12.34% = 12%))

Answer:

Explanation:

The missing incomplete resonance structure is attached in the image below. From there, we can see the addition of the nonbonding electrons and its' formal charge which makes the resonance structure a complete resonance structure. The others two resonance structure that can be derived from the complete structure is also shown in the image. Out of these three structures, the structure that contributes most to the hybrid is the structure with the negative charge on the oxygen.

Answer:

Explanation:

To find the concentration; let's first compute the average density and the average atomic weight.

For the average density [tex]\rho_{avg}[/tex]; we have:

[tex]\rho_{avg} = \dfrac{100}{ \dfrac{C_{Fe} }{\rho_{Fe}} + \dfrac{C_v}{\rho_v} }[/tex]

The average atomic weight is:

[tex]A_{avg} = \dfrac{100}{ \dfrac{C_{Fe} }{A_{Fe}} + \dfrac{C_v}{A_v} }[/tex]

So; in terms of vanadium, the Concentration of iron is:

[tex]C_{Fe} = 100 - C_v[/tex]

From a unit cell volume [tex]V_c[/tex]

[tex]V_c = \dfrac{n A_{avc}}{\rho_{avc} N_A}[/tex]

where;

[tex]N_A[/tex] = number of Avogadro constant.

SO; replacing [tex]V_c[/tex] with [tex]a^3[/tex] ; [tex]\rho_{avg}[/tex] with [tex]\dfrac{100}{ \dfrac{C_{Fe} }{\rho_{Fe}} + \dfrac{C_v}{\rho_v} }[/tex] ; [tex]A_{avg}[/tex] with [tex]\dfrac{100}{ \dfrac{C_{Fe} }{A_{Fe}} + \dfrac{C_v}{A_v} }[/tex] and

[tex]C_{Fe}[/tex] with [tex]100-C_v[/tex]

Then:

[tex]a^3 = \dfrac { n \Big (\dfrac{100}{[(100-C_v)/A_{Fe} ] + [C_v/A_v]} \Big) } {N_A\Big (\dfrac{100}{[(100-C_v)/\rho_{Fe} ] + [C_v/\rho_v]} \Big) }[/tex]

[tex]a^3 = \dfrac { n \Big (\dfrac{100 \times A_{Fe} \times A_v}{[(100-C_v)A_{v} ] + [C_v/A_Fe]} \Big) } {N_A \Big (\dfrac{100 \times \rho_{Fe} \times \rho_v }{[(100-C_v)/\rho_{v} ] + [C_v \rho_{Fe}]} \Big) }[/tex]

[tex]a^3 = \dfrac { n \Big (\dfrac{100 \times A_{Fe} \times A_v}{[(100A_{v}-C_vA_{v}) ] + [C_vA_Fe]} \Big) } {N_A \Big (\dfrac{100 \times \rho_{Fe} \times \rho_v }{[(100\rho_{v} - C_v \rho_{v}) ] + [C_v \rho_{Fe}]} \Big) }[/tex]

Replacing the values; we have:

[tex](0.289 \times 10^{-7} \ cm)^3 = \dfrac{2 \ atoms/unit \ cell}{6.023 \times 10^{23}} \dfrac{ \dfrac{100 (50.94 \g/mol) (55.84(g/mol)} { 100(50.94 \ g/mol) - C_v(50.94 \ g/mol) + C_v (55.84 \ g/mol) } }{ \dfrac{100 (7.84 \ g/cm^3) (6.0 \ g/cm^3 } { 100(6.0 \ g/cm^3) - C_v(6.0 \ g/cm^3) + C_v (7.84 \ g/cm^3) } }[/tex]

[tex]2.41 \times 10^{-23} = \dfrac{2}{6.023 \times 10^{23} } \dfrac{ \dfrac{100 *50*55.84}{100*50.94 -50.94 C_v +55.84 C_v} }{\dfrac{100 * 7.84 *6}{600-6C_v +7.84 C_v} }[/tex]

[tex]2.41 \times 10^{-23} (\dfrac{4704}{600+1.84 C_v})=3.2 \times 10^{-24} ( \dfrac{284448.96}{5094 +4.9 C_v})[/tex]

[tex]\mathbf{C_v = 9.1 \ wt\%}[/tex]

Answer:

1. B 2.B

Explanation:

Answer:

1000 kJ.mmole / 1000 J.mole

Explanation:

To solve this, we need to analyze the given data.

We have a number which is 87.1 J/mmole.C (I'm assuming it has the J at the beggining because if not, then you are missing some data) and the final result is kJ/mol.C

The only unit that has not changed in the process was the °C, while the mole and J change respectively. In this case, we need to know the conversion factor of mmole to mole and J to kJ.

In the case of a mole:

1 mole --------> 1000 mmole

In the case of Joule:

1 kJ ----------> 1000 J

So the first thing we will do is to change from J to kJ:

87.1 J * 1 kJ / 1000 J = 0.0871 kJ

Now let's convert mmol to mole:

0.0871 kJ/mmole.C * 1000 mmole / 1 mole = 87.1 kJ/mole.C

As you can see, there's is practicly no change at all with the units, so putting all together it would be:

Hope this helps

the ph is gonna be your value and the 4 is gonna be your main subject

so as the ph is your value u gonna ad your ph and 7 and 4 toghter then multiple your answer 2 times  because ph represent multiple and your value  

Answer: Photosynthesizing organisms use carbon dioxide and water to produce glucose.

Explanation:

Photosynthesis is a phenomenon in which green plants containing chlorophyll use sunlight as a source of energy to convert carbon dioxide and water to form glucose and oxygen.

Photosynthesis is the process used by plants, algae and certain bacteria to convert energy from sunlight and turn it into chemical energy in the form of glucose which is used a s a source of energy by many organisms.

[tex]6CO_2+6H_2O\overset{sunlight}\rightarrow C_6H_{12}O_6+6O_2[/tex]

Answer:

Q= Magnesium R= Chlorine

Explanation:

The element Q should be magnesium and R is chlorine.

An ionic compound is a compound that is formed by the combination of a metal and non-metal. Such bonds forms when there is a transfer of electrons from the metals to the non-metals. This leaves a net positive charge on the metal and a negative charge on the non-metal.

The electrostatic attraction leads to the formation of the bond.

 To solve this problem, the hypothetical compound is QR₂

       Mg                        Cl

     2 8 2                    2 8 7

So, Mg transfers 2 electrons to two atoms of chlorine.

 This leads to the formation of the compound MgCl₂

The lethal dose and how ounces of soda in a can of soda is not given, however, the standard lethal dose and volume of soda are given as below:

Lethal dose: 10 gm of caffeine

The volume of soda per can =  12oz/can

Answer:

The correct answer is - 324.254 cans or round up to 325 cans. Ans.

Explanation:

Given:

2.57 mg caffeine / 1oz

12oz / 1can

Lethal dose: 10.0g or 10,000mg of caffeine

Solution:

Caffeine per soda can = (2.57 mg caffeine / 1oz) * (12oz / 1can) = 30.84 mg caffeine / 1can.

lethal dose would be in =

(10,000mg caffeine) * (1can / 30.84 mg caffeine) = 324.254 cans or round up to 325 cans. Ans.

Answer:

25 mM Tris HCl and 0.1% w/v SDS

Explanation:

A 10X solution is ten times more concentrated than a 1X solution. The stock solution is generally more concentrated (10X) and for its use, a dilution is required. Thus, to prepare a buffer 1X from a 10X buffer, you have to perform a dilution in a factor of 10 (1 volume of 10X solution is taken and mixed with 9 volumes of water). In consequence, all the concentrations of the components are diluted 10 times. To calculate the final concentration of each component in the 1X solution, we simply divide the concentration into 10:

(250 mM Tris HCl)/10 = 25 mM Tris HCl

(1.92 M glycine)/10 = 0.192 M glycine

(1% w/v SDS)/10 = 0.1% w/v SDS

Therefore the final concentrations of Tris and SDS are 25 mM and 0.1% w/v, respectively.

Answer:

M =  0.125 M

Explanation:

Given data:

Molarity = ?

Volume of solution = 2 L

Mass of K₂SO₄ = 43.55 g

Solution;

Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.

Formula:

Molarity = number of moles of solute / L of solution

Number of moles of solute:

Number of moles = mass/molar mass

Number of moles = 43.55 g / 174.26 g/mol

Number of moles = 0.25 mol

Molarity:

M =  0.25 mol / 2 L

M =  0.125 M

Answer:

0.41 atm

Explanation:

A reaction between liquid reactants takes place at 10.0 °C in a sealed, evacuated vessel with a measured volume of 5.0 L. Measurements show that the reaction produced 13. g of sulfur hexafluoride gas. Calculate the pressure of sulfur hexafluoride gas in the reaction vessel after the reaction. You may ignore the volume of the liquid reactants. Round your answer to 2 significant digits.

Step 1: Given data

Step 2: Convert "T" to Kelvin

We will use the following expression.

K = °C + 273.15

K = 10.0 °C + 273.15 = 283.2 K

Step 3: Calculate the moles (n) of SF₆

The molar mass of SF₆ is 146.06 g/mol.

13. g × 1 mol/146.06 g = 0.089 mol

Step 4: Calculate the pressure (P) of SF₆

We will use the ideal gas equation.

P × V = n × R × T

P = n × R × T/V

P = 0.089 mol × (0.0821 atm.L/mol.K) × 283.2 K/5.0 L = 0.41 atm

Answer:

e. I, At

Explanation:

Hello!

In this case, since the periodic trends of a series of elements belonging to the same group towards physical and chemical properties tend to be the same when closer in period, we notice that Mg and Al, Br and Kr and As and Br are close but in period, not in the same group; therefore e. I, At, iodine and astatine, are going to tend to exhibit the greatest similarity in their physical  and chemical properties.

Best regards!

Answer:

its C

Explanation:

1/74.44 * 79.75 = 1.07

The molarity (mol/L) of NaClO in the bleach, given the data is 1.07 mol/L (Option C)

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

Molarity = mole / Volume

Mass of solute = percent × mass of solution

Mass of NaClO = 7.25% × 1100

Mass of NaClO = 0.0725 × 1100

Mass of NaClO = 79.75 g

Mole = mass / molar mass

Mole of NaClO = 79.75 / 74.44

Mole of NaClO = 1.07 mole

Molarity = mole / Volume

Molarity of NaClO = 1.07 / 1

Molarity of NaClO = 1.07 mol/L

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Answer:

a) the increase in internal energy is 3211.78 J

b) dU = 3854.14 J

c) dU[tex]_{T}[/tex] = 1927.06 J

Explanation:

Given the data in question;

Foe a diatomic gas, the degree of freedom are as follow;

lets consider the positional degree of freedom

transitional df = 3

rotational df = 2

vibrational ff = 1

now, the internal energy given by;

U = Nf × 1/2NKT = Nf×1/2×nRT

where Nf is the number of degree of freedom

N is Number of atoms or molecules

n = number of molecules

L is Boltzmann constant

R is universal gas constant

so change in internal energy , change in T is given by

dU =  Nf × 1/2 × nT dT

n = 2.37 moles

dT = 65.2 K

R = 8.314 J/mol.J

a)

Find the increase in internal energy if only translational and rotational motions are possible

since rotational and transitional motion are involved ;

Nf = 3(trasitional) + 2(rotational) = 5

so,

dU = 5 × 1/2  × nRdT

we substitute

dU = 5 × 0.5  × 2.37 × 8.314 × 65.2

dU = 3211.78 J

Therefore, the increase in internal energy is 3211.78 J

b)

Find the increase in internal energy if translational, rotational, and vibrational motions are possible.

Nf = 3 + 2 + 1 = 6

dU = 6 × 1/2  × nRdT

dU = 6 × 0.5  × 2.37 × 8.314× 65.2

dU = 3854.14 J

c)  

How much of the energy calculated in (a) and (b) is translational kinetic energy?

dU[tex]_{T}[/tex] = 3 × 0.5  × 2.37 × 8.314 × 65.2

dU[tex]_{T}[/tex] = 1927.06 J

Answer: Percent recovery is 47.34 %

Explanation:

Percent yield is defined as the ratio of experimental yiled to theoretical yield in terms of percentage.

[tex]{\text{ percent yield}}=\frac{\text{amount recovered}}{\text{total amount}}\times 100[/tex]

Putting in the values we get:

[tex]{\text{ percent yield}}=\frac{0.732}{1.546}\times 100=47.34\%[/tex]

Therefore, the percent recovery is 47.34 %

Explanation:

Valence electrons is the number of electrons in the outermost shell of an atom. For the main group elements, the group number represents the number of valence electrons.

Beryllium

This belongs to the group 2 hence, it has valency of 2.

Nitrogen

This belongs to group 5, hence it has valency of 5.

Oxygen

This belongs to group 6, hence it has valency  of 6.

Fluorine

This belongs to group 7, hence it has valency of 7.

Magnesium

This belongs to group 2, hence it has valency of 2.

Phosphorus

This belongs to group 5, hence it has valency of 5

Sulphur

This belongs to group 6, it has valency of 6

Chlorine

This belongs to group 7, it has valency of 7

Answer:

Beryllium: 2 valence electrons.

Nitrogen: 5 valence electrons.

Oxygen: 6 valence electrons.

Fluorine : 7 valence electrons.

Magnesium : 2 valence electrons.

Phosphorus : 5 valence electrons.

Sulphur : 6 valence electrons.

Chlorine : 7 valence electrons.

Answer:

Unlike a permanent magnet, an electromagnet can be turned on and off using electrical current. Many variables affect the strength of this electromagnet, and there are some variables that do not affect the strength. ... Making the nail longer will not make the magnet stronger, unless you also add more turns to the coil.

electromagnet can be turned on and off using electrical current. Many variables affect the strength of this electromagnet, and there are some variables that do not affect the strength

Answer:

movement of charged particles through the wire .

Explanation:

When electricity is passed through the wire of electromagnet , moving electrons of the wire produces magnetic field . This magnetic field in increased due to high permeability of soft iron of the electromagnet . It is this magnetic field which creates magnetic force .

Answer:

C. Plate tectonic collisions can create mountains.

Answer:

They can make them larger

Explanation:

They go up under a mountain and then the mountains rise up

Answer: inside

Explanation:

Answer:

direct and indirect contact

Explanation:

if you touch a doorknob right after an infected person than you make be exposed to the disease.

The molecular formula of hydrate : CaCl₂.6 H₂O

So there are 6 molecules of H₂O

Given

54.7g CaCl₂ and 53.64 g H₂O

Required

The number of molecules H₂O

Solution

mol CaCl₂ :

= mass : MW

= 54.7 : 111 g/mol

= 0.493

mol H₂O :

= 53.64 : 18 g/mol

= 2.98

mol ratio H₂O : CaCl₂ :

= 2.98/0.493 : 0.493/0.493

= 6 : 1

Answer:

well heat travels by conduction, convection, and radiation but I think it's 2.

Explanation:

heat travels to colder things trying to make a balanced temperature for both of the objects.

Answer:

Explanation:

From the given information:

The accuracy depends on the internal diameter of the cylinder. The cylinder with the least internal diameter is obviously more precise.

Let's assume 1% is the error of measurement.

Then, to measure 70 mL from 10 mL cylinder

The error = [tex]10 \times \dfrac{1}{100} \times 7[/tex]

= 0.7 mL

However; for a 100 mL cylinder, the error = 1 mL

Now,

The total volume for 10 mL = (70 + 0.7) = 70.7 mL

The total volume for 100 mL = (70 + 1 ) = 71 mL

Suppose the density (d) is same for both

Then;

the mass of 10 mL = ( d × 70.7) g

the mass pf 100 mL = (d × 71) g

Thus, the mass of 100 mL is greater than that of 10 mL.

Answer:

116.78 grams.

Explanation:

1 mol of Strontium (Sr) = 87.62 grams

1.38 mol of Strontium = x

Cross Multiply

1 * x = 1.38 * 87.62

x = 116.78  grams

Answer:

B. The same exact

Explanation:

I think B because in order to be a clone of your parent you have to have the exact same DNA and chromosomes.

Hope this helps :D

A clone has the same exact chromosomes as its parent.

CLONING:

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its true

Potential energy is the stored or latent energy in an object at rest. It’s fundamental to many physics-related concepts because its laws hold true on any level, from the planetary to the atomic level. The potential energy of an object is measurable.