Why does every chemical reaction require a certain amount of activation energy?

Answer:

it is option (d)

it has more mass than any of the other planets of the inner solar system

Explanation:

Science, any system of knowledge that is concerned with the physical world and its phenomena and that entails unbiased observations and systematic experimentation. In general, a science involves a pursuit of knowledge covering general truths or the operations of fundamental laws.

Answer:

CaO

Explanation:

Group 2 Carbonates decompose to form oxides of the Group 2 element and Carbon dioxide

Answer:

endothermic

Explanation:

endothermic reactions absorb heat from their surroundings, in this reaction the reactants are gas and solid and the products are liquid and gas, implying heat was absorbed to turn a solid to a liquid.

Answer:

0.535 atm

Explanation:

Since the volume of the tank is constant, we use Gay- Lussac's law to find the pressure at 180°C.

So, P₁/T₁ = P₂/T₂ where P₁ = pressure at S.T.P = 1 atm, T₁ = temperature at S.T.P = 273.15 K, P₂ = pressure of gas at 180 °C and T₂ = 180 °C = 273.15 + 180 K = 453.15 K

So, P₁/T₁ = P₂/T₂

P₂ = P₁T₂/T₁

Substituting the values of the variables into the equation, we have

P₂ = P₁T₂/T₁

P₂ = 1 atm × 453.15 K/273.15 K

P₂ = 1 atm × 1.66

P₂ = 1.66 atm

We now need to find the total number of moles of each gas present

number of moles of nitrogen = mass of nitrogen, m/molar mass of nitrogen molecule M

n = m/M

m = 2.5 g and M = 2 × atomic mass of nitrogen (since it is diatomic) = 2 × 14 g/mol = 28 g/mol

So, n = 2.5 g/28 g/mol

n = 0.089 mol

number of moles of chlorine, n' = mass of chlorine, m'/molar mass of chlorine molecule M'

n' = m'/M'

m' = 13.3 g and M = 2 × atomic mass of chlorine (since it is diatomic) = 2 × 35.5 g/mol = 71 g/mol

So, n' = 13.3 g/71 g/mol

n' = 0.187 mol

So, the total number of moles of gas present is n" = n + n' = 0.089 mol + 0.187 mol = 0.276 mol

So, the partial pressure due to nitrogen gas, P = mole fraction of nitrogen × pressure of gas at 180 °C

P = n/n" × P₂

P = 0.089 mol/0.276 mol × 1.66 atm

P = 0.322 × 1.66 atm

P = 0.535 atm

Answer:

276g of Br are present

Explanation:

To solve this question we need to find the moles of CaBr2 using its molar mass -CaBr2: 199.89g/mol-. As 1 mole of CaBr2 contains 2 moles of Br we can find the moles of Br and its mass:

Moles CaBr2:

345g * (1mol/199.89g) = 1.7259 moles CaBr2

Moles Br:

1.7259 moles CaBr2 * (2mol Br / 1mol CaBr2) = 3.4519 moles Br

Mass Br -Molar mass: 79.904g/mol-

3.4519 moles Br * (79.904g/mol) = 276g of Br are present

Answer:

(i) specific heat

(ii) latent heat of vaporization

(iii) latent heat of fusion

Explanation:

i. Q = mcΔT; identify c.

Here, Q is heat, m is the mass, c is the specific heat and ΔT is the change in temperature.

The amount of heat required to raise the temperature of substance of mass 1 kg by 1 degree C is known as the specific heat.  

ii. Q = mLvapor; identify Lvapor

Here, Q is the heat, m is the mass and L is the latent heat of vaporization.

The amount of heat required to convert the 1 kg liquid into 1 kg vapor at constant temperature.  

iii. Q = mLfusion; identify Lfusion

Here, Q is the heat, m is the mass and L is the latent heat of fusion.  

Here, Q is the heat, m is the mass and L is the latent heat of vaporization.

The amount of heat required to convert the 1 kg solid  into 1 kg liquid at constant temperature.  

(i) c is the molar heat capacity of the substance.

(ii) Lvapor is the latent heat of evaporation of the substance

(iii) Lfusion is the latent heat of fusion of the substance

All the 3 equations fall under Calorimetry.

In all the equation Q is the amount of heat required.

(i) First equation represents the amount of heat required to raise the temperature of a substance of mass m.

                          Q = mcΔT

       here c is the molar heat capacity of the substance and ΔT is the chnage in temperature.

(ii) Second equation represents the amount of heat required to convert a substance of mass m from liquid phase to vapour phase.

                          Q = mLvapor

        here Lvapor is the latent heat of evaporation of the substance

during evaporation no change in temperature occurs.      

(iii) Third equation represents the amount of heat required to convert a substance of mass m from solid phase to liquid phase.

                          Q = mLfusion

        here Lfusion is the latent heat of fusion or melting of the substance

during fusion no change in temperature occurs.    

Learn more about calorimetry:

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Answer:

i think its C polymer hope it helps

Answer:

in order of their atomic mass

The first periodic table created by Mendeleev was based on the atomic masses of elements. Later Mosely modified it based on the atomic number.

Periodic table is the classification of all the known  elements based on their atomic number. There are 118 elements in periodic table now. They are classified into different groups and periods.

Mendeleev was first to create periodic table for the easy classification of elements. He classified elements based on their atomic masses. At that time there were only 60-65 elements discovered.

Later Mosley modified it to modern periodic table based on the increasing order of atomic number of elements. Therefore, the first arrangement was based on atomic masses.

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Answer:

In complete combustion, there is a sufficient supply of oxygen which is able to react with the burning hydrocarbon allowing the reaction products H2O and CO2 to be formed. In incomplete combustion there is a lack of oxygen so when heat is applied carbon monoxide is released.

I hope this will help you......

The required temperature of the gas sample is -64.96 °C.

Ideal gas equation gives idea about the behavior of gas at different condition & represented as:

PV = nRT.

From the above equation it is clear that relation between temperature and pressure for this question is:

P₁/T₁ = P₂/T₂, where

P₁ & T₁ are the initial pressure and temperature.

P₂ & T₂ are the final pressure and temperature.

On putting values, we get

T₂ = (145)(-25) / (55.8) = -64.96 °C

Hence required temperature of the sample is -64.96 °C.

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Answer:

937.5g

Explanation:

No of moles = mass ÷ molar mass

According to this question, there are 15moles of the compound; AlCl

Molar mass of AlCl = 27 + 35.5

= 62.5g/mol

Using n = m/M.M

15 = m/62.5

m = 15 × 62.5

m = 937.5g

Answer:

B. O2 is reduced when it accepts electrons and forms water.

Explanation:

During cellular respiration water is formed when oxygen receives electrons and picks up protons at the conclusion of the electron transport chain. The electron transport chain will stop functioning if there isn't enough oxygen to receive electrons (for example, because a person isn't breathing in enough oxygen), and ATP will no longer be created by chemiosmosis. Cells can't carry out the reactions they need to function if they don't even have enough ATP, and they may perish after a long period of time.

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Answer:

co + H2 it is the answer may it helpfull

Answer:

d

Explanation:

because CO mixes with H2O

Answer:

Shift it toward the side with lower total mole concentration

Explanation:

The reaction will shift in a direction that is less affected by stress, so that the pressure is reduced. This means that the reaction will change towards where there is fewer gas molecules (the fewer gas molecules, the smaller the pressure).

Answer:

A. Shift it toward the side with lower total mole concentration

Explanation:

Answer:

letter d

Explanation:

hope it's help you

Answer:

I think option two (2) is the correct answer

Answer:

XY bond is the least polar

Explanation:

Given

[tex]W = 1.0[/tex]

[tex]X = 2.0[/tex]

[tex]Y = 2.5[/tex]

[tex]Z = 3.5[/tex]

Required

The least polar bond

First, we calculate the difference in the electronegativities

[tex]WX = X - W[/tex]

[tex]WX = 2.0 - 1.0[/tex]

[tex]WX = 1.0[/tex]

[tex]WY = Y - W[/tex]

[tex]WY =2.5 - 1.0[/tex]

[tex]WY =1.5[/tex]

[tex]WZ =Z-W[/tex]

[tex]WZ =3.5 - 1.0[/tex]

[tex]WZ =2.5[/tex]

[tex]XY = Y -X[/tex]

[tex]XY = 2.5 -2.0[/tex]

[tex]XY = 0.5[/tex]

[tex]XZ = Z -X[/tex]

[tex]XZ = 3.5 -2.0[/tex]

[tex]XZ = 1.5[/tex]

[tex]YZ = Z - Y[/tex]

[tex]YZ = 3.5 - 2.5[/tex]

[tex]YZ = 1.0[/tex]

The least of the above calculations will be the least polar.

Hence, XY is the least polar

Answer:

C

Explanation:

in the option C when we rearrange it then it will he C3H6O2

Answer:

yes its C

Explanation:

correct me if iam wrong

Answer:

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thank you

Answer:

=0.15M

Explanation:

To get the moles of the unknown LiOH, calculate the number of moles of HCl in 12.3mL.

Using the stoichiometric coefficient, mole ratio 1:1.

This means that the number of moles is the same. This number of moles is contained in 18mL. Then Calculate the molarity (concentration) which is in 1000mL

See the explanation from the image I have shared with you for calculations.

Answer:

Explanation:

Given : Density - 2.41 g/liter  

Temperature - 25° C  

Pressure : 770 mm Hg  

R = 0.0821 L atm mol-¹K-¹

Find : Molecular mass of gas

Solution : Ideal gas equation with respect to density will be : PM = dRT. In the formula, P is pressure, M is molecular mass, d is density, R is gas constant and T is temperature.

Keeping the values in equation-  

Pressure : 770 mm Hg = 1 atm  

Temperature : 273 + 25 = 298 K

M = dRT/P  

M = (2.41*0.0821*298)/1  

M = 58.96 gram/mol

Thus, the molecular mass of gas is 58.96 gram/mol.

Answer:

In both voltaic and electrolytic cells, oxidation occurs at the anode, while reduction occurs at the cathode. Thus, both these cells exhibit redox reactions. In both these cells, electrons flow from the anode to the cathode through the externally connected conductor.

Answer:

ELECTROLYTIC CELL

An electrochemical cell in which a non-spontaneous chemical reaction takes place when electric current is passed through the solution,is called an electrolytic cell.

EXAMPLE

Nelsons cell and Downs cell

VOLTAIC CELL OR GALVANIC CELL

The electrochemical cell in which a spontaneous chemical reaction takes place and generates electric current is called galvanic and voltaic cell.

EXAMPLE

Daniel cell

Explanation:

hey hi mate

wassup

answer is 4

explanation To calculate the pH of a solution, use the equation

p

H

=

−

log

[

H

3

O

+

]

Since we are given the hydronium ion (

H

3

O

+

) concentration of the solution, we can plug this value into the formula.

p

H

=

−

log

[

1.00

×

10

−

4

M

]

p

H

=

4

The pH of this solution is 4.

Added notes:

p

H

=

p

H

3

O

+

because hydrogen ions attach to water molecules for form hydronium ions.

Some other key things to remember for pH calculations include:

pH + pOH = 14

pH = -log[

H

+

]

pOH = -log[

O

H

−

]

[

H

+

]

=

10

−

p

H

[

O

H

−

]

=

10

−

p

O

H

Answer: The molecular weight of the dibasic acid is 89.6 g/mol

Explanation:

Normality is defined as the amount of solute expressed in the number of gram equivalents present per liter of solution. The units of normality are eq/L. The formula used to calculate normality:

[tex]\text{Normality}=\frac{\text{Given mass of solute}\times 1000}{\text{Equivalent mass of solute}\times \text{Volume of solution (mL)}}[/tex]      ....(1)

We are given:

Normality of solution = [tex]\frac{1}{20}=0.05N[/tex]

Given mass of solute = 0.56 g

Volume of solution = 250 mL

Putting values in equation 1, we get:

[tex]0.05=\frac{0.56\times 1000}{\text{Equivalent mass of solute}\times 250}\\\\\text{Equivalent mass of solute}=\frac{0.56\times 1000}{0.05\times 250}=44.8g/eq[/tex]

Equivalent weight of an acid is calculated by using the equation:

[tex]\text{Equivalent weight}=\frac{\text{Molar mass}}{\text{Basicity}}[/tex]   .....(2)

Equivalent weight of acid = 44.8 g/eq

Basicity of an acid = 2 eq/mol

Putting values in equation 2, we get:

[tex]44.8g/eq=\frac{\text{Molar mass}}{2eq/mol}\\\\\text{Molar mass}=(44.8g/eq\times 2eq/mol)=89.6g/mol[/tex]

Hence, the molecular weight of the dibasic acid is 89.6 g/mol