The pressure of a gas changes from 120kPa to 50kPa. The volume changes from 45L to 40L. If the initial temperature is 81°C, what is the final temperature in Kelvin units?​

43.56 grams of  are produced if 16g of  CH4 reacts with 64g of O2.

Explanation:

Balance equation for the reaction:

CH4 + 2O2⇒ CO2 +2H2O

Data given : mass of CH4 =16 grams  atomic mass = 16.04 grams/mole

                    mass of water 36 gram  atomic mass = 18 grams/moles

                   mass of CO2=?                atomic mass = 44.01 grams/mole

number of moles = [tex]\frac{mass}{atomic mass of one mole}[/tex]    equation 1

number of moles in CH4

   n = [tex]\frac{16}{16.04}[/tex]

       = 0.99 moles

Since combustion is done in presence of oxygen hence it is an excess reagent and methane is limiting reagent so production of CO2 depends on it.

From the equation

1 mole of CH4 gave 1 mole of CO2

O.99 moles of CH4 will give x moles of CO2

[tex]\frac{1}{1}[/tex] = [tex]\frac{x}{0.99}[/tex]

x = 0.99 moles of carbon dioxide

grams of CO2 = number of moles x atomic mass

                         = 0.99 x 44.01

                          = 43.56 grams of CO2 is produced.

The complete question is:

An aqueous solution of ammonium sulfate is allowed to react with an aqueous solution of calcium nitrate.

The net ionic equation contains which of the following species (when balanced in standard form)?

a. 2NO3-(aq)

b. Ca2+(aq)

Answer:

b. Ca2+(aq)

Ca2+ (aq) + SO4^2-(aq) --------------> CaSO4(s)

Explanation:

The overall ionic equation is:

Ca2+(aq) + 2NO3-(aq) + 2NH4+(aq) + SO4^2-(aq) ---------------> CaSO4(s) + 2NH4NO3(aq)

The NO3- and NH4+ are spectator ions as they do not participate in the formation of the precipitate CaSO4.

The net ionic equation is:

Ca2+ (aq) + SO4^2-(aq) --------------> CaSO4(s)

The spectator ions form the soluble ammonium trioxonitrate V

Answer:

The correct option is;

A) 1 to 1.

Explanation:

A stab;e nuclei requires the presence of a neutron to accommodate the the protons repulsion forces within the nucleus. An increase in the number of protons should be accompanied by an even more instantaneous increase in the number of neutrons to balance the forces in the nucleus. If there is an excess of neutrons or a deficit in protons a state of unbalance exists in the nucleus, which results to nuclear instability.

Therefore, the ratio of neutrons to protons is an appropriate way in foretelling nuclear stability and a stable nuclei is known to have a proton to neutron ratio of 1:1 and the number of protons and neutrons in the stable nuclei are usually even numbers.

Answer:

0.2, relatively inelastic

Explanation:

Price elasticity of demand is the degree of responsiveness of demand for a product/service to a unit change in the price of that product/service. Mathematically:

Price elasticity of demand = change in demand/change in price.

Price elasticity of demand can be perfectly elastic if elasticity is infinity, perfectly inelastic if elasticity is 0, relatively elastic if elasticity is greater than 1, unitary elastic if it is equal to 1 and relatively inelastic if it is less than 1.

For gasoline,

Change in price = 5%

Change in quantity demanded = 1%

Hence,

Price elasticity of demand for gasoline = 1/5 = 0.2

The price elasticity of demand for gasoline is 0.2 and can be described as being relatively inelastic.

Valence electrons are located in the highest energy level of an atom and they participate in the formation of chemical bonds. They do not occupy the inner shell orbitals. These properties make them crucial for chemical reactions.

Valence electrons are the electrons that are present in the outermost shell of an atom. These electrons are the ones that participate in chemical bonding as they are at the highest energy level. However, valence electrons do not occupy the inner shell orbitals. The inner shell orbitals are occupied by what we call core electrons.

In the context of bonding, it's incorrect to say that valence electrons are not involved. One of the key properties of valence electrons is that they are involved in the formation of bonds between atoms. This is because their position in the outermost shell enables them to be easily transferred or shared with other atoms to achieve a stable electron configuration.

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Answer:

[tex]FeCl_{3}[/tex]

Explanation:

[tex]Moles =\frac {Given\ mass}{Molar\ mass}[/tex]

mass of Fe = 55.85 g

Molar mass of Fe = 55.85 g/mol

Moles of Fe = 55.85 / 55.85 = 1

mass of Cl = 106.5 g

Molar mass of Cl = 35.5 g/mol

Moles of Cl = 106.5 / 35.5 = 3

Taking the simplest ratio for Fe and Cl as:

1 : 3

The empirical formula is = [tex]FeCl_{3}[/tex]

Answer:

may be exchanged for equity securities.

Explanation:

Convertible bonds -

It refers to the type of bond which can easily be converted to stocks .

It refers to as the fixed - income debt security which can give the interest payments and can be converted to some predetermined number of equity shares and common stock , is referred to as convertible bonds .

The process of conversion can be done at any time period of the bond .

Hence , from the given information of the question ,

The correct answer is may be exchanged for equity securities.

Answer:

25.0 grams

Explanation:

Answer:

25.o grams needed to react to 50 grams of nitrogen

Answer: The average atomic mass of copper is 63.546 amu

Explanation:

Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.

Formula used to calculate average atomic mass follows:

[tex]\text{Average atomic mass }=\sum_{i=1}^n\text{(Atomic mass of an isotopes)}_i\times \text{(Fractional abundance})_i[/tex]  .....(1)

Mass of isotope 1 = 62.93 amu

Percentage abundance of isotope 1 = 69.2 %

Fractional abundance of isotope 1 = 0.692

Mass of isotope 2 = 64.93 amu

Percentage abundance of isotope 2 = 30.8 %

Fractional abundance of isotope 2 = 0.308

Putting values in equation 1, we get:

[tex]\text{Average atomic mass of Copper}=[(62.93\times 0.692)+(64.93\times 0.308)]\\\\\text{Average atomic mass of Copper}=63.546amu[/tex]

Hence, the average atomic mass of copper is 63.546 amu

(a)  9.4 X 10¹³s⁻¹

(b) 240 W

Explanation:

Given-

Current, i = 15μA

Electrons, e = 16 MeV

(a) The rate at which the deuterons strike the block, r = ?

We know,

[tex]i = \frac{dq}{dt} = e\frac{dN}{dt}[/tex]

[tex]\frac{dN}{dt} = \frac{i}{e} \\\\\frac{dN}{dt} = \frac{15 X 10^-^6 A}{1.6 X 10^-^1^9C}[/tex]

[tex]\frac{dN}{dt} = 9.4 X 10^1^3 s^-^1[/tex]

Therefore, the rate at which the deuterons strike the block is 9.4 X 10¹³s⁻¹

(b) Rate at which thermal energy is produced in the block

Now that we have [tex]\frac{d_{N} }{d_{t} }[/tex], we can use it with the equation of power to solve for the thermal energy production rate.

[tex]P = \frac{dN}{dt} U\\\\P = (9.4 X 10^1^3 s^-^1) (16MeV) \frac{(1.6 X 10^-^1^3 J}{1MeV} )\\\\P = 240W[/tex]

Therefore, the rate at which thermal energy is produced in the block is 240 W.

The resultant temperature on the beach is 294.39 K.

Relation between the temperature and pressure of gas will be explained by using the ideal gas equation PV = nRT.

And for this question, required equation is:

P₁/T₁ = P₂/T₂, where

On putting values from question, we get

T₂ = (4.78)(20) / (4.50) = 21.24 degrees Celsius

T₂ = 21.24 degrees Celsius = 294.39 K

Hence required temperature is 294.39 K.

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Final answer:

To determine the new temperature on the beach causing an increase in pressure within an aerosol can from 4.50 atm to 4.78 atm, the Gas Law is utilized, yielding a final temperature of 35.1 degrees Celsius.

Explanation:

The question involves finding the new temperature at which the pressure of gases in an aerosol can increases from 4.50 atm to 4.78 atm, initially at 20.0 degrees Celsius. We will use the Gas Law, which states that for a constant volume and amount of gas, the pressure of the gas is directly proportional to its temperature. This can be mathematically represented as P1/T1 = P2/T2, where P is the pressure, T is the temperature in Kelvin, and subscripts 1 and 2 refer to the initial and final states, respectively.

First, convert the initial temperature from Celsius to Kelvin: T1 = 20.0 + 273.15 = 293.15 K. Then, solve for T2: T2 = (P2 × T1) / P1 = (4.78 atm × 293.15 K) / 4.50 atm. T2 = 308.25 K, which converts back to 35.1 degrees Celsius when subtracted by 273.15.

Therefore, the Celsius temperature on the beach where the pressure of the gases in the aerosol can increases to 4.78 atm is 35.1 degrees Celsius.

Answer:

Volume required from standard solution = 4675 mL

Explanation:

Given data:

Final volume = 75.0 mL

Final molarity = 130 M

Molarity of standard solution = 2.000 M

Volume required from standard solution = ?

Solution:

We use the formula,

C₁V₁ = C₂V₂

here,

C₁ = Molarity of standard solution

V₁ = Volume required from standard solution

C₂ = Final molarity

V₂ = Final volume

Now we will put the values in formula,

C₁V₁ = C₂V₂

2.000 M × V₁ = 130 M × 75.0 mL

V₁  = 9750 M. mL / 2.000 M

V₁  = 4675 mL

Answer:

the correct option is 3 = 10−12 mol/cm2 moles of Na+ must move per unit area of membrane.

Explanation:

The capacitance is given by ;

the specific capacitance ;

it is said that the potential changes from -70 mV to +30 mV

= 100mV

The charge moving per unit area;

= 100mV X 10^-3V/1mV X 1microF X 10^-6F/1microF

= 1 X 10^-7C/m^2

= 10^-12mol/cm^2

As such, the correct option is 3 = 10−12 mol/cm2  moles of Na+ must move per unit area of membrane.

c. [tex]\( 10^{-12}\ \text{mol/cm}^2 \)[/tex] are the number of moles of Na⁺.

To solve this problem, we need to determine the number of moles of Na⁺ ions that must move to change the membrane potential [tex](\( V_m \))[/tex] from -70 mV to +30 mV, assuming the membrane behaves purely as a capacitor.

The key steps involve understanding the relationship between the charge Q, capacitance C, and potential difference V in a capacitor, and then converting the charge to moles of Na⁺ ions.

1. Determine the change in membrane potential [tex](\( \Delta V_m \))[/tex]:

  [tex]\[ \Delta V_m = V_{\text{final}} - V_{\text{initial}} = 30 \, \text{mV} - (-70 \, \text{mV}) = 100 \, \text{mV} \][/tex]

2. Calculate the charge required to change the membrane potential Q using the capacitance C:

  Given:

  [tex]\( C = 1 \, \mu\text{F/cm}^2 = 1 \times 10^{-6} \, \text{F/cm}^2 \)[/tex]

  [tex]\( \Delta V_m = 100 \, \text{mV} = 100 \times 10^{-3} \, \text{V} \)[/tex]

  The relationship between charge, capacitance, and potential difference is given by:

  [tex]\[ Q = C \cdot \Delta V_m \][/tex]

  Substituting the values:

  [tex]\[ Q = (1 \times 10^{-6} \, \text{F/cm}^2) \cdot (100 \times 10^{-3} \, \text{V}) \][/tex]

  [tex]\[ Q = 1 \times 10^{-6} \times 100 \times 10^{-3} \, \text{C/cm}^2 \][/tex]

  [tex]\[ Q = 1 \times 10^{-8} \, \text{C/cm}^2 \][/tex]

3. Convert the charge to moles of Na⁺ ions:

  The Faraday constant F is given as [tex]\( 10^5 \, \text{C/mol} \)[/tex]. This means 1 mole of monovalent ions (like Na⁺ carries [tex]\( 10^5 \, \text{C} \)[/tex].

  To find the number of moles of Na⁺ ions that correspond to the charge calculated, we use:

  [tex]\[ \text{Moles of } \text{Na}^+ = \frac{Q}{F} \][/tex]

  Substituting the values:

  [tex]\[ \text{Moles of } \text{Na}^+ = \frac{1 \times 10^{-8} \, \text{C/cm}^2}{10^5 \, \text{C/mol}} \][/tex]

[tex]\[ \text{Moles of } \text{Na}^+ = 1 \times 10^{-13} \, \text{mol/cm}^2 \][/tex]

However, it seems there may be a small numerical adjustment to match the provided answer options more closely.

Thus, the correct answer is c. [tex]\( 10^{-12} \text{mol/cm}^2 \)[/tex].

Complete Question:

Upon fertilization, the eggs of many species undergo a rapid change in potential difference across their outer membrane. This change affects the physiological development of the eggs. The potential difference across the membrane is called the membrane potential, Vm, which is the potential inside the membrane minus the potential outside it. The membrane potential arises when enzymes use the energy available in ATP to expel three sodium ions (Na+) actively and accumulate two potassium ions (K+) inside the membrane making the interior less positively charged than the exterior. The egg membrane behaves as a capacitor with a capacitance of about 1 μF/cm2. The concentration of Na+ is about 30 mmol/L in the eggs' interior but 450 mmol/L in the surrounding seawater. The K+ concentration is about 200 mmol/L inside but 10 mmol/L outside. A useful constant that connects electrical and chemical units is the Faraday number, which has a value of approximately 105 C/mol; that is, Avogadro's number (a mole) of monovalent ions, such as Na+ or K+, carries a charge of 10⁵ C.

How many moles of Na+ must move per unit area of membrane to change Vm from -70 mV to +30 mV, if we assume that the membrane behaves purely as a capacitor?

a. 10⁻⁴ mol/cm²

b. 10⁻₉ mol/cm²

c. 10⁻¹² mol/cm²

d. 10⁻¹⁴ mol/cm²

Answer:

1. Hydrogen

Explanation:

These planets contain liquid hydrogen in their interior, while the earth has liquid iron in it.

When liquid hydrogen is in tremendous pressure enviroments, the electrons  that make up each atom of this element end up "jumping" to other atoms. These "jumps" allow liquid hydrogen to behave like a metal.

In addition, with the constant energy released by the nucleus of planets like Jupiter and Saturn, as well as their rotations, the liquid hydrogen receives induction of currents, giving rise to extremely powerful magnetic fields.

The element that can act like a metal when it is under tremendous pressure and is probably responsible for Jupiter and Saturn's magnetism is hydrogen. Therefore the correct option is 1.

The element that can act like a metal when it is under tremendous pressure and is probably responsible for Jupiter and Saturn's magnetism is hydrogen. In the giant planets such as Jupiter and Saturn, pressures become so immense that hydrogen changes from a gaseous state to a liquid state. Deeper inside these planets, the liquid hydrogen is further compressed until it begins to exhibit metallic properties, such as the ability of its electrons to move freely, which enables it to conduct electricity. This transition occurs because, in a metal, electrons are not bound tightly to their parent nuclei, allowing for easier movement. This property of liquid metallic hydrogen is crucial for the generation of magnetic fields in Jupiter and Saturn.

Answer:

C(CH3)3 I  - iodide

Explanation:

The alkyl halide forming the alkene cis-2-pentene as the only product in an elimination reaction is 2-chloropentane. The elimination reaction causes the removal of the halogen (chlorine) and a hydrogen on adjacent carbons, resulting in a pi bond between them, producing the alkene cis-2-pentene.

The alkyl halide that would form the alkene cis-2-pentene as the only product in an elimination reaction would be 2-chloropentane. The elimination reaction involves the removal of a halogen (chlorine) and a hydrogen on adjacent carbons, creating a pi bond between them.

This is called a beta-elimination reaction, and specifically for 2-chloropentane, it's dehydrohalogenation the process forming the alkene cis-2-pentene as the sole product.

The IUPAC name of the alkyl halide is 2-chloropentane, and the product of the halogenation reaction is cis-2-pentene.

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Answer:

The two elements are POLONIUM and RADIUM.

Explanation:

Maria Curie is a French physicist and chemist, though she was of a Polish naturals. She was the first woman to receive a Noble Price which she earned for conducting leading and head way research on radioactivity. She discovered the theory of radioactivity; also the techniques isolating radioactive isotopes. These helped her and her husband discover Polium and Radium.

Answer: She discovered polonium and radium.

Explanation: In 1896, intrigued by the physicist Henri Becquerel’s accidental discovery of radioactivity, Curie began studying uranium rays; Pierre soon joined her in her research. Two years later, the Curies discovered polonium—named after Marie’s homeland—and radium. In 1903 they shared the Nobel Prize in physics with Becquerel for their groundbreaking work on radioactivity.

Answer : The age of the rock is, 2.60 billion years

Explanation :

Half-life = 1.3 billion years

First we have to calculate the rate constant, we use the formula :

[tex]k=\frac{0.693}{t_{1/2}}[/tex]

[tex]k=\frac{0.693}{1.3\text{ billion years}}[/tex]

[tex]k=0.533\text{ billion years}^{-1}[/tex]

Now we have to calculate the time passed.

Expression for rate law for first order kinetics is given by:

[tex]t=\frac{2.303}{k}\log\frac{a}{a-x}[/tex]

where,

k = rate constant  = [tex]0.533\text{ billion years}^{-1}[/tex]

t = time passed by the sample  = ?

a = initial amount of the reactant  = 12 mg

a - x = amount left after decay process = 3 mg

Now put all the given values in above equation, we get

[tex]t=\frac{2.303}{0.533}\log\frac{12}{3}[/tex]

[tex]t=2.60\text{ billion years}[/tex]

Therefore, the age of the rock is, 2.60 billion years

Answer:

1.38 g H₂

Explanation:

Zn  +  2 HCl  ⇒  ZnCl₂  +  H₂

To solve, you need to first find the limiting reagent.  Convert grams to moles and use the mole ratios in the chemical equation to convert from the reagent to the product.  The reagent that produces the least is the limiting reagent.

Zn

(50 g)/(65.38 g/mol) = 0.7648 mol Zn

(0.7648 mol Zn) × (1 mol H₂/1 mol Zn) = 0.7648 mol H₂

HCl

(50 g)/(36.46 g/mol) = 1.371 mol HCl

(1.371 mol HCl) × (1 mol H₂/2 mol HCl) = 0.6857 mol H₂

HCl produces less product so this is the limiting reagent.  Since you have already converted to moles, you simply need to convert from moles to grams to find the amount of hydrogen made.

(0.6857 mol) × (2.016 g/mol) = 1.38 g H₂

You will have 1.38 g of H₂.

Answer:

Hi

Explanation:

1.38 g H₂

Explanation:

Zn  +  2 HCl  ⇒  ZnCl₂  +  H₂

To solve, you need to first find the limiting reagent.  Convert grams to moles and use the mole ratios in the chemical equation to convert from the reagent to the product.  The reagent that produces the least is the limiting reagent.

Zn

(50 g)/(65.38 g/mol) = 0.7648 mol Zn

(0.7648 mol Zn) × (1 mol H₂/1 mol Zn) = 0.7648 mol H₂

HCl

(50 g)/(36.46 g/mol) = 1.371 mol HCl

(1.371 mol HCl) × (1 mol H₂/2 mol HCl) = 0.6857 mol H₂

HCl produces less product so this is the limiting reagent.  Since you have already converted to moles, you simply need to convert from moles to grams to find the amount of hydrogen made.

(0.6857 mol) × (2.016 g/mol) = 1.38 g H₂

So you will end up with 1.38 g of H₂.

Answer:

The answer to the question is

The star’s approximate radial velocity is 68.52 km/s

Explanation:

To solve the

The formula is

[tex]\frac{\lambda-\lambda_{rw}}{\lambda_{rw}} = \frac{v_r}{c}[/tex] where

[tex]v_r[/tex] = velocity of the star

λ = Star's spectrum wavelength = 656.45 nm

[tex]\lambda_{rw}[/tex] = Rest wavelength = 656.30 nm

c = Speed of light = 299 792 458 m / s

Therefore we have

[tex]\frac{656.45-656.30}{656.30} =\frac{v_r}{299 792 458}[/tex] or [tex]v_r[/tex] = 68518.7699 m/s or 68.52 km/s

Answer:

see explain

Explanation:

Given that,

Water pressure  P 1 = 20 psia

Water temperature  T 1 = 80F

Steam pressure  P 2 = 20 psia

Calculating the enthalpy of steam and water at given pressure and temperature by using a steam table

h 1 = 48.07 BTU/lb

h 2 = 1156.20  BTU/lb

The enthalpy of water is determine using the saturated liquid approximation for the given temperature with the data from A -4E. the enthalpy of the vapor is determine from A - 5E for given pressure .the enthalpy of the mixture is determine from the energy balance.

[tex]m_1h_1 + m_2h_2 = m_3h_3\\m_1h_1 + m_2h_2 =2mh_3\\h_3 = \frac{h_1 + h_2}{2} \\= \frac{48.07 + 1156.2}{2} \\602.135\frac{btu}{ibm} \\[/tex]

the quality of the mixture is determine from the total enthalpy and the enthaipies of the constituent at the given pressure obtained from A - 5E

[tex]q = \frac{h_3 - h_l_i_q_2_0}{h_e_v_a_p_2_0} \\ = \frac{602.135 - 196.27}{959.93} \\ = 0.423[/tex]

≅ 0.4

the mixture temperature is simply the saturation temperature for the given pressure obtain from A - 5E

T₃ = 227.92°F

≅ 230°F

Answer: D.

Explanation: Condenser and Evaporator

Condenser: is a unit used in condensing a gaseous substance into a liquid state through cooling. By so doing, the latent heat is released by the substance and transferred to the surrounding environment.

Evaporator;  is a device thats turns the liquid form of a chemical substance such as water into its gaseous-form/vapor.

In the refrigeration cycle, the condenser and evaporator are used to convert vapor to liquid and then back to vapor.

In the refrigeration cycle, the components used to convert vapor into a liquid and then change the liquid back into vapor are the condenser and evaporator. The condenser facilitates the transformation of the refrigerant from a hot gas to a cooler liquid, and the evaporator helps transform that liquid back into a gas or vapor.

The entire process of the refrigeration cycle involves many more steps and components, but primarily, the condenser and evaporator perform the changes in states of matter.

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Answer : The enthalpy of this reaction is, 0.975 kJ/mol

Explanation :

First we have to calculate the heat produced.

[tex]q=m\times c\times (T_2-T_1)[/tex]

where,

q = heat produced = ?

m = mass of solution = 126 g

c = specific heat capacity of water = [tex]4.18J/g^oC[/tex]

[tex]T_1[/tex] = initial temperature = [tex]21.00^oC[/tex]

[tex]T_2[/tex] = final temperature = [tex]24.70^oC[/tex]

Now put all the given values in the above formula, we get:

[tex]q=126g\times 4.18J/g^oC\times (24.70-21.00)^oC[/tex]

[tex]q=1948.716J=1.95kJ[/tex]

Now we have to calculate the enthalpy of this reaction.

[tex]\Delta H=\frac{q}{n}[/tex]

where,

[tex]\Delta H[/tex] = enthalpy change = ?

q = heat released = 1.95 kJ

n = moles of compound = 2.00 mol

Now put all the given values in the above formula, we get:

[tex]\Delta H=\frac{1.95kJ}{2.00mole}[/tex]

[tex]\Delta H=0.975kJ/mol[/tex]

Thus, the enthalpy of this reaction is, 0.975 kJ/mol

Answer: The heat of combustion of the organic material is -69.88 kJ/g

Explanation:

To calculate the heat absorbed by the calorimeter, we use the equation:

[tex]q=c\Delta T[/tex]

where,

q = heat absorbed

c = heat capacity of calorimeter = 44.51 kJ/°C

[tex]\Delta T[/tex] = change in temperature = [tex]T_2-T_1=(29.28-23.13)^oC=6.15^oC[/tex]

Putting values in above equation, we get:

[tex]q=44.51kJ/^oC\times 6.15^oC=273.74kJ[/tex]

Heat absorbed by the calorimeter will be equal to the heat released by the reaction.

Sign convention of heat:

When heat is absorbed, the sign of heat is taken to be positive and when heat is released, the sign of heat is taken to be negative.

To calculate the enthalpy change of the reaction, we use the equation:

[tex]\Delta H_{rxn}=\frac{q}{m}[/tex]

where,

q = amount of heat released = -273.74 kJ

m = mass of organic material = 3.917 g

[tex]\Delta H_{rxn}[/tex] = enthalpy change of the reaction

Putting values in above equation, we get:

[tex]\Delta H_{rxn}=\frac{-273.74kJ}{3.917g}=-69.88kJ/g[/tex]

Hence, the heat of combustion of the organic material is -69.88 kJ/g

When a titration is performed using an indicator that changes color slightly past the equivalence point, the calculated acid concentration will be marginally lower due to the slight excess of titrant added.

During a titration, the equivalence point is where the amount of titrant added neutralizes the analyte, resulting in a solution where the concentration of hydrogen ions ([tex][H^+][/tex]) equals the concentration of hydroxide ions ([tex][OH^-][/tex]). An indicator is used to visually signal this point through a color change.

When using an indicator that changes color slightly past the equivalence point, the student will observe a color change indicating a slightly larger volume of titrant has been added than necessary. Consequently, the calculated concentration of the acid will be slightly lower than its actual concentration, because the calculation will be based on a presumed complete neutralization that requires a bit more of the titrant.

It is vital to choose an indicator with a color change interval that brackets the pH at the equivalence point for an accurate titration. Methyl orange, for instance, changes color in the acidic range and is suitable for the titration of a weak base with a strong acid.

Phenolphthalein would be another choice as an indicator, changing from colorless to pink as the pH rises above 8.3, which can accurately signal the equivalence point in many titrations.

Answer:

The correct answer is 4. gives the relative number of atoms of each element per formula unit.

Explanation:

Empirical formula shows the ratio of elements of which a compound is composed. It is a minimal formula: it does not show the actual number of atoms of each element in the compound, but it shows the relative number of each element in the molecule. For example: butane has the molecular formula C₄H₁₀. It means that it is composed by 4 atoms of C and 10 atoms of hydrogen (actual number of atoms in the molecule). The ratio C:H is 4:10, so the simplest ratio is 2:5 (if we divide by 2). Thus, the empirical formula is C₂H₅ (there are 2 atoms of C for every 5 atoms of H).

Answer:

4

Explanation:

It gives the lowest ratio of the number of atoms of each element per formula unit. This is usually derived by dividing common multiples of the molecular formula thereby reducing the value.

The enthalpy of formation for C6H12O6 in the fermentation of glucose can be calculated using Hess's Law and the enthalpies of formation of C2H5OH (l) and CO2 (g). The enthalpy of formation for C6H12O6 is -1273.5 kJ/mol.

The enthalpy of formation (ΔHf) for a compound is the heat released or absorbed when one mole of the compound is formed from its constituent elements in their standard states. In this case, we are given the enthalpies of formation for C2H5OH (l) and CO2 (g), and we need to calculate the enthalpy of formation for C6H12O6.

Since the balanced equation for the fermentation of glucose to produce ethyl alcohol and carbon dioxide is given, we can use Hess's Law to solve this problem. By manipulating the given equation and using the enthalpies of formation, we can determine the enthalpy of formation for C6H12O6.

Using the enthalpies of formation for C2H5OH (l) and CO2 (g), which are -277.7 kJ/mol and -393.5 kJ/mol respectively, we can calculate the enthalpy of formation for C6H12O6 to be -1273.5 kJ/mol.

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Answer:. 4. dialog metaphor

Explanation:

This is a metaphor of HCI in which interacting with the computer is much like carrying on a conversation or dialog. The user asks the computer for something, and the computer responds. The computer might then ask the user for something, and the user responds. The text provides an example that describes a manager and an assistant carrying on a conversation about messages .

Answer:

0.066mol/dm^3

Explanation:

The molarity is simply calculating the number of moles in 1L or 1000ml

To get this, we need to know the amount in grammes that would be present in 1L.

Since 2g is sufficient for 200ml, then for 1000ml, the amount sufficient would be 5 * 2 = 10g

Now to get the number of moles needed, we need to know the molar mass of the compound. That is molar mass of FeSO4 = 56 + 32 + 4(16) = 152g/mol

The number of moles is thus 10/152 = 0.066 mol/dm^3

If a negatively charged ion is more concentrated inside the cell, the forces required to balance the chemical gradient would be directed Inward. Thus, the equilibrium potential for this ion would be Positively charged.

Explanation:

The measurement of potential of resting membrane is distributed unequally in the form of ions or the charged particles, which are consist between both the cell's internal structure and external structure, by the membrane's changing permeability to various ion forms.

Like in most of the neurons the potassium and organic ions which are common in amino acids are present more in internal portion of cell than its outer portion. By comparison sodium and chloride ions are normally present in the cell externally at higher concentrations. This implies there are balanced gradients of concentration around the membrane for all the most concentrated forms of ions.

Answer:

The answer to your question is   P N₂ = 11.67 atm  

Explanation:

Data

He  1737 torr

N₂  = ?

Ar 2087 mmHG

Total pressure = 16.7 atm

Process

1.- Convert torr to atm

             1 atm --------------- 760 torr

             x        -------------- 1737 torr

             x = (1737 x 1)/760

             x = 2.29 atm

2.- Convert mmHg to atm

             1 atm ----------------- 760 mmHg

             x         ---------------- 2087 mmHG

             x = (2087 x 1)/760

             x = 2.74

3.- Find the Partial pressure of N₂

       Total pressure = He pressure + N₂ pressure + Ar pressure

- Substitution

        16.7 = 2.29 + P N₂ + 2.74

- Solve for P N₂

        P N₂ = 16.7 - 2.29 - 2.74

        P N₂ = 11.67 atm