Given the density of iron (Fe) is 7.87 g/cm3, determine the mass of iron (in grams) in a rectangle block with the dimensions of 12.5 in long, 3.50 in wide, and 2.50 in high. (1in = 2.54 cm).

Answer:

Based on the given question, the dimensions of the plate is 15 cm in length, 12.5 cm in width, and 3.50 mm in thickness (0.350 cm). Now the volume of the plate will be,  

V = 15 cm × 12.5 cm × 0.350 cm = 65.62 cm³

A hole of diameter 2.50 cm is drilled through the center of the plate, at the height of 3.50 mm or 0.350 cm. Now the volume of the hole is π(r)²h,  

= 22/7 × (1.25 cm)² × 0.350 cm = 1.72 cm³

Thus, the volume of the plate will be determined by subtracting the volume of plate with the volume of hole, which will be,  

65.62 cm³ - 1.72 cm³ = 63.9 cm³

The density of the alloy is 8.80 g/cm³, therefore, the mass of the alloy can be determined by using the formula, mass = density * volume  

mass = 8.80 g/cm³ × 63.9 cm³ = 562.32 grams

Of the total alloy, 0.090 percent is Si, that is,  

(0.090/100) × 562.32 g = 0.506 grams of Si

The natural abundance of the element is not determined by mass but by the number of atoms it possess. For this Avogadro's number and atomic mass of Si is used. Now the number of atoms of Si present is,  

(0.506 g) (1 mol/28.0855 g) (6.023 × 10²³ atoms /mol) = 1.08 × 10²² Si atoms

Of these Si atoms, 3.10 percent are Si-30 so,  

= (3.10 / 100) × (1.08 × 10²² atoms) / 1000 = 3.34 × 10²⁰ atoms of Si-30. or 3.4 × 10²⁰ atoms

Answer:

The appropriate reagent is: H3PO2.

Explanation:

H3PO2 is in charge of eliminating the amino group by diazotization, remember that the amino group had previously achieved bromination at positions m; that is to say that it achieved in the beginning that the three bromine atoms of 1,2,4 tribromobenzene were introduced in the meta positions among themselves, which finally corresponds as part of the last reaction to the 1,3,5-tribromobenzene position.

Answer:

25,50,25

Explanation:

Answer:

Boron

Explanation:

Answer: a. boron

Explanation: bc the Boron Family is named after the first element in the family. atoms in this family have 3 valence electrons. this family includes a metalloid (boron), and the rest are metals.

Answer:

1. Acid-Base Reaction

Explanation:

Fe(OH)2(s) + HCl(aq) = FeCl2(aq) + H2O(l)

base               acid

This a reaction between base and acid.

Ferrous hydroxide is an inorganic alkaline compound whereas hydrochloric acid is an acid. The reaction between Fe(OH)₂and HCl is an acid-base reaction. Thus, option 1 is correct.

An acid-base reaction is a chemical change that occurs and takes place when the reactant constitutes an acid and a base. They are characterized by the exchange of protons that results in the formation of conjugate bases and acids or salt.

The acid-base chemical reaction is shown as,

Fe(OH)₂(s) + HCl(aq) ⇒ FeCl₂(aq) + H₂O(l)

Here, ferrous hydroxide is a base with hydroxide ions and hydrochloric acid is an acid with hydrogen ions. HCl donates its proton to form water molecules with hydroxide ions of ferrous hydroxide.

Therefore, in option 1. the reaction is an acid-base reaction.

Learn more about acid-base reaction, here:

https://brainly.com/question/14276012

#SPJ2

Answer:

THE VOLUME OF NaOH NEEDED TO BE ADDED TO CITRIC ACID TO REACH THE EQUIVALENT POINT IS 4.725 L

Explanation:

The titration is between citric acid (H3C6H507) and NaOH

mass of citric acid = 0.306 g

Volume of citric acid = 250 mL = 250 /1000 = 0.25 L

Concentration of NaOH = 0.1000 M

Volume = unknown

First calculate the molar mass of citric acid

( 1 * 3 + 12* 6 + 1*5 + 16*7) = (4 + 72 + 5 + 112) = 193 g/mol

Since,

Concentration in moles/dm3 = concentration in g/dm3 / RMM

So the molarity of citric acid is:

Molarity = 0.306g / 0.25dm3  / Rmm

Molarity = 1.224g/dm3 / 193 g/mol

Molarity = 0.0063 M

Equation for the reaction is:

C3H5O(COOH)3 + 3NaOH → Na3C3H5O(COO)3 + 3H2O

Using the formula:

CaVa / CbVb = na/ nb

Ca = 0.0063 M

Cb = 0.1000 M

Va = 0.25 L

Vb = unknown

na = 1

nb = 3

Vb = Ca Va nb/ Cb na

Vb = 0.0063 * 0.25 * 3 / 0.1000 * 1

Vb = 0.4725 / 0.1000

Vb = 4.725 L

The volume of NaOH needed to reach the equivalent point is therefore 4.725 L

Answer: 5

Explanation:

It just is

Answer:

5

Explanation:

Bc valence electron means last # in the electron configuration

Answer:

THE HEAT REQUIRED TO CHANGE 2 KG OF ETHANOL FROM 26 °C TO THE BOILING POINT AND TO VAPOR AT THAT TEMPERATURE IS 1965.175 KJ.

Explanation:

Boiling point of ethanol = 78.29 °C = 78.29 + 273 K = 351.29 K

Mass = 2 kg = 2000 g

Final temp. = 26.0 °C = 26 + 273 K= 299 K

Change in temperature = (78.29 - 26) °C = 52.29 °C

1. Heat required to raise the temperature from 26 °C to the boiling point?

Heat = mass * specific heat * change in temperature

Heat = 2000 * 2.44 * 52.29

Heat = 255 175.2 J

2. Heat required to change the liquid to vapor at that temperature?

Heat = mass * enthalphy of vaporization

Heat = 2000 * 855

Heat =1 710000 J

The total heat required to raise the temperature of 2 kg of ethanol from 26 °C to the boiling point and then to change the liquid to vapor at that temperature will be:

Heat = mcT + m Lv

Heat = 255 175.2 J + 1710000 J

Heat = 1965175.2 J

Heat = 1965.175 kJ of heat.

Answer:

THE HEAT OF THIS REACTION PER MOLE OF SUCROSE IS 4868.75 KJ OF HEAT.

Explanation:

To answer this question:

First calculate the total heat given off by sucrose:

         Total energy/ heat = heat capacity * change in temperature

Heat capacity = 7.50 kJ/ °C

Change in temperature = 20.5 °C

Heat = 7.50 kJ * 20.5 °C

Heat = 153.75 kJ of heat.

Next is to calculate the heat of reaction per mole of the sucrose

Equation of the reaction:

               C12H22011 (s) + 12 O2 (g) ---------> 12 CO2 (g) + 11 H20(l)

Since 1 mole of sucrose will be the molar mass of sucrose, then we should calculate the molar mass of sucrose.

Molar mass of sucrose = ( 12* 12 + 1 * 22+ 16*11) g/mol

Molar mass = 342 g/mol of sucrose

Since 10.8 g of sucrose produces 153.75 kJ of heat, 342 g will produces how many joules of heat?

10.8 g of sucrose = 153.75 kJ of heat

342 g of sucrose = ( 342 * 153.75 kJ / 10.8)

= 52 582.5 kJ / 10.8

= 4868.75 kJ of heat

So therefore, 1 mole of sucrose will produce 4868.75 kJ of heat.

Answer:

see explanation below

Explanation:

In the first case, we have a reaction where we have the 3-chloro-3-methylpentane reacting with t-butoxide. The t-butoxide is a very voluminous base, so the strength of substracting a hydrogen atom is reduced. Therefore, the reaction taking place here will be an E2 but instead of substracting the hydrogen from the carbons 2 or 4, it will substract it from the methyl group, cause it has less steric hindrance there and the reaction will go faster.

In the second case, the sodium ethoxide is a strong base, so it will rapidly substract an atom of hydrogen from carbon 2 or 4 to form the (Z) - 3 - methyl - 2- pentene and the substitution product.

Look picture for mechanism and products.

Answer:

(B.) and (C.)

b. So that clean NMR spectra can be obtained that do not contain solvent peaks.

c. So that the yield can be determined.

Explanation:

The solvent used in Nuclear Magnetic Resonance (NMR) spectrometer is Trimethyl silane (TMS), a neutral solvent which doesn't give off any signals. Other solvents could have interactions with the radiation, and disrupt the spectra.

Furthermore, for accurate determination of the actual yield and overall percentage yield, solid must be separated from the solvent, dried and weighed.

I hope this was explanatory enough.

Answer: [tex]y = \frac{1}{4}x-3[/tex]

Explanation:

To find the inverse of an equation, follow these steps:

We are given the equation [tex]f(x) = 4x + 12[/tex] , so replace f(x) with x.

Then, replace x with y.

Your new equation:

[tex]x = 4y + 12[/tex]

Now, solve for y:

[tex]x = 4y + 12\\\\4y = x - 12\\\\y = \frac{1}{4}x-3[/tex]

This equation is the inverse of f(x), or g(x).

Answer:the volume of the gas particles is negligible compared with the total volume of the  gas.--D

Explanation:

According to the Kinetic Molecular Theory for ideal gases, it states that

--Gases are composed of larges  molecules which are in constant random motion  in a straight line

--The volume of the gas particles is negligible compared to the total volume in which the gas is contained.

-----The  Attractive and repulsive forces between gas molecules is insignificant ie There are no interactive forces.

----The collisions of the particles  are perfectly elastic and energyis  being transferred between the particles but the total energy remaining constant

From the  statements of the kinetic Molecular theory of ideal gases, it can be seen that the statement which describes the particles of an ideal gas is option D  which is The volume of the gas particles is negligible compared with the total volume of the  gas--- ---This gives the reason why  gases  can be compressed. Since there are no  inter molecular forces between them. The particles of an  ideal gas will move at the same random motion  resulting to high pressures, compressing the gas and making the volume negligible or insignificant.

Answer:

Final temperature of the solution = 26.43°C

Explanation:

Concentration of HCl = 0.662 M, Volume = 200 mL= 0.200 L

Concentration of Ba(OH)₂ = 0.331 M, Volume = 200 mL = 0.200 L

Initial temperature of solution = 22.00°C

Specific Heat capacity of water = 4.184 J/g°C

Heat of neutralization = -56.3 KJ/mol of H₂O produced.

The full calculations is found in the attachment below

Answer:

A

Explanation:

Arsenic is in the same group as Nitrogen - group 5. They all have 5 valence electrons in their outermost shell. To achieve its most stable state - 8 valence electrons (octet rule - elements are most stable when the entire shell is filled) - arsenic needs to gain 3 electrons. Since electrons have a negative charge, the charge of an As ion would be -3.

Try observing the periodic table and how many valence electrons that each element has. From there, you can determine the charges of the elements lithium and strontium. You can guess, I'll help you with those once you attempt to find the charge of those ions.

Answer:

Explanation:

Step 1: NaCl(s) → Na(s) + 1/2 Cl2(g)  ΔHf   (ionization energy) in this step energy is required to change the phase of the compound

Step 2: Na(s) + 1/2 Cl2(g) → Na(g) + 1/2 Cl2(g)  ΔHa  (elements needed to be in gaseous state for born-haber cycle so metal changes from solid to gas state by changing the enthalpy.

Step 3: Na(g) + 1/2 Cl2(g) → Na(g) + Cl (g)  1/2ΔHd  

Step 4: Na(g) + Cl(g) → Na⁺(g) + Cl⁻(g)  IE+EA  ( in this step both ionization energy and electron affinity was involved because in metal (Na) electron is added which needs the energy and this energy draw from the step 3 and Chlorine require releasing electron to be in ionic state so when electron leaves the orbit energy releases.

Step 5: final step is Hess Law which is the combination of all the steps which step 4 again go back to step 5 and this cycle continues by repeating same steps    Na⁺(g) + Cl⁻(g)→NaCl(s)

at this step heat of formation is calculated

Heat of formation= atomization energy+ dissociation energy+ sum of ionization energies + sum of electron affinity + lattice energy.

2:  if we look at the electron configuration of the nitrogen it has 5 electrons in its outermost shell which indicates it can make 5 bonds 4 bonds and 1 lone pair usually and Oxygen has 6 electrons in its outermost shell. So nitrate ion have the total number of 24 electrons including the 1 electron which shows on the compound.

So when they make nitrate ion NO₃⁻¹ it shows that nitrate has 3 resonance structures. Nitrogen's three sigma bonds are attached to oxygen and fourth one make 1 pie bond which can rotate, delocalized and change its position anytime from one Oxygen atom to other oxygen atom.

Answer:

Molar mass = 71.76 g/mol

Explanation:

The relationship between molar mass and rate of effusion is given as;

Vh / Vu = √ (Mu / Mh)

The rate of effusion of a gas is inversely proportional to the square root of the mass of its particles.

Rate = volume /  time (Assuming Volume = 1)

Vh = Rate of effusion of Hydrogen = 1 / 2.42

Vu = Rate of effusion of unknown gas = 1 / 14.5

Mh = Molar mass of hydrogen = 2

Mu = Molar mass of unknown gas = x

Substituting into the formular, we have;

(1 / 2.42) / (1 / 14.5) = √ ( x / 2)

5.99 = √ ( x / 2)

35.88 = x / 2

x = 71.76

Answer:

Molarity: 0.111M

% (w/w): 0.666

Explanation:

The reaction of NaOH with acetic acid (CH₃COOH) is:

NaOH + CH₃COOH → CH₃COO⁻Na⁺ + H₂O

where 1 mole of NaOH reacts per mole of acetic acid producing 1 mole of water and 1 mole of sodium acetate.

As 39.26mL ≡ 0.03926L of 0.1062M are required to titrate the solution of acetic acid. Moles are:

0.03926L × (0.1062mol / L) = 4.169x10⁻³ moles of NaOH. As 1 mole of NaOH reacts per mole of acetic acid:

4.169x10⁻³ moles of CH₃COOH.

Molarity is defined as ratio between moles of substance and volume of solution in liters. Thus, molarity of acetic acid solution is:

4.169x10⁻³ moles of CH₃COOH / 0.03754L = 0.111M

As molar mass of acetic acid is 60g/mol, 4.169x10⁻³ moles weights:

4.169x10⁻³ moles × (60g / mol) = 0.2501 g of acetic acid

Now, assuming density of solution as 1.00g/mL, 37.54mL weights 37.54g.

Thus, percent by weight is:

0.2501g CH₃COOH / 37.54g × 100 = 0.666% (w/w)

The molarity of acetic acid is 0.11M and the percent by weight is 0.666%.

Molarity of any solution is used to define their concentration and it will be calculated as:

M = n/V, where

n = moles

V = volume

Molarity of acetic acid will be calculated as:

M₁V₁ = M₂V₂, where

M₁ = molarity of acetic acid = ?

V₁ = volume of acetic acid = 37.54mL = 0.037L

M₂ = molarity of NaOH = 0.1062M

V₂ = volume of NaOH = 39.26mL = 0.039L

On putting all these values on the above equation we can calculate the molarity as:

M₁ = (0.1062)(39.26) / (37.54) = 0.11M

Now we calculate the moles of acetic acid by using the molarity formula as:

n = 0.11M × 0.037L = 0.00407 moles

Molar mass of acetic acid = 60g/mole

Mass of 0.00407 moles of acetic acid = 4.1x10⁻³ moles×(60g / mol) = 0.2501 g

Density of solution = 1.00 g/mL

So, 37.54mL in 1g/mL = 37.54g/mL

Percent by weight will be calculated as:

%w/w = 0.2501g CH₃COOH / 37.54g × 100 = 0.666% (w/w)

Hence, molarity and %(w/w) of acetic acid is 0.11M and 0.666% respectively.

To know more about percent weight, visit the below link:

https://brainly.com/question/5493941

Based on the information above provided, the best predictions correct whether a sample of pure tungsten will melt at 3723 K is The sample will mel because T>

Tungsten is a very hard and brittle material. It properties include a very high melting point, a low vapor pressure and the highest hardness and strength of all metals. Tungsten has good corrosion resistance against most acids and alkalis.

Learn more about tungsten:

https://brainly.com/question/11014899

Answer:

0.5 mole

Explanation:

The question isn't even clear

But I'm guessing you want to ask the number of moles

n= Number of molecules/ Avogadros number

n= 1/2

Answer:

[tex]0.745~M[/tex]

Explanation:

In this case, we have a dilution problem. So, we have to use the dilution equation:

[tex]C_1*V_1=C_2*V_2[/tex]

Now, we have to identify the variables:

[tex]C_1~=~14.9~M[/tex]

[tex]V_1~=~25~mL[/tex]

[tex]C_2~=~?[/tex]

[tex]V_2~=~0.5~L[/tex]

Now, we have different units for the volume, so we have to do the conversion:

[tex]0.5~L\frac{1000~mL}{1~L}=~500~mL[/tex]

Now we can plug the values into the equation:

[tex]C_2=\frac{14.9~M*25~mL}{500~mL}=0.745~M[/tex]

I hope it helps!

Answer:

1.The electrode on the right is positive

2. 0.058V

Explanation:

The above cell is a concentration cell.

A concentration cell is an electrolytic cell that is made of two half-cells with the same electrodes, but differs in concentrations of the solutions. A concentration cell functions by diluting the more concentrated solution and concentrating the more dilute solution, creating a voltage as the cell reaches an equilibrium thereby transferring the electrons from the cell with the lower concentration to the cell with the higher concentration.

In the above cell, electrons flow from the left electrode (less concentrated) to the right electrode (more concentrated). Therefore, the right electrode is the positive electrode (cathode).

Part 2: Please, see the attachment below for the calculations.

Answer:

Amide

Explanation:

O=NH2 is the Amide group versus NH2, which is the amine group.

Answer:

Butamide

Explanation:

C3H7-C(=O)-NH2 IUPAC NAME

C4H9NO

     H   H   H

H - C - C - C - C = O

     H   H   H   N - H

                      H

But amide

Amide because R-CO-NH2 ie C(=O)-NH2

But because 4 Cabon

The voltage of an electrolytic cell with copper and magnesium electrodes is 2.71 v. Therefore, option B is correct.

The electrolytic cell is a type of cell that performs a redox reaction while using electrical energy. When electrical energy is applied, a redox reaction occurs in molten NaCl. It is therefore an electrolytic cell.

An electrolyte, two electrodes, and an electrolytic cell make up an electrolytic cell (a cathode and an anode). The electrolyte is typically a mixture of ions that have been dissolved in water or another solvent. Electrolytes can also be molten salts, like sodium chloride.

The standard reduction potential, E° of the metals are as below:

Mg²⁺ + 2e⁻ ⇌  Mg; E° = -2.372

Cu²⁺ + 2e⁻ ⇌  Cu; E° = +0.337

Therefore, magnesium has the the lower E°, it will serve as the anode in the electrolytic cell while copper will serve as the cathode.

At the anode; Mg ⇌  Mg²⁺ + 2e⁻, E° = -2.372

At the cathode; Cu²⁺ + 2e⁻ ⇌  Cu, E° = +0.337

EMF of the cell = E° cathode - E° anode

= 0.337 - (-2.372) = 2.71 V

Therefore, EMF of the cell is 2.71 V

Thus, option B is correct.

To learn more about the electrolytic cell, follow the link;

https://brainly.com/question/4030224

#SPJ1

Answer: the exciation of molecules is brount by absorption of energy  in spectroscpy

Explanation:

Answer:

E. The ratio of [HNO2] / [NO2-] will increase

D. The pH will decrease.

Explanation:

Nitrous acid ( HNO₂ ) is a weak acid and NaNO₂ is its salt . The mixture makes a buffer solution .

pH = pka + log [ salt] / [ Acid ]

= 3.4 + log .32 / .42

= 3.4 - .118

= 3.282 .

Now .16 moles of nitric acid is added which will react with salt to form acid

HNO₃ + NaNO₂ = HNO₂ + NaNO₃

concentration of nitrous acid will be increased and concentration of sodium nitrite ( salt will decrease )

concentration of nitrous acid = .42 + .16 = .58 M

concentration of salt = .32 - .16 = .16 M

ratio of [HNO₂ ] / NO₂⁻]

= .42 / .32 = 1.3125

ratio of [HNO₂ ] / NO₂⁻] after reaction

= .42 + .16 / .32 - .16

= 58 / 16

= 3.625 .

ratio will increase.

Option E is the answer .

pH after reaction

= 3.4 + log .16 / .58

= 2.84

pH will decrease.

Answer:

[Ne] 3s² 3p⁴

Electrons per shell: 2,8,6

Answer : 2,8,6 (Sulphur Atom)

                2,8,8 (Sulphur Ion)