PLEASE HELP!
In a monomolecular reaction A->B , at t =250C, the initial concentration decrease at 25% in t =52 min. Calculate:

a) the constant rate;

b) the time after the initial concentration decrease with 75%;

c) the initial reaction rate, if the initial concentration of the reactant is 2.5 mol/L·s.

Scientists are looking for ways to help increase the amount of calcium carbonate in oceans so that coral reefs can be healthy ecosystems again mount of calcium carbonate in the ocean decreasing because increased amounts of carbon dioxide cause reactions to happen in the water that decrease the pH and the amount of calcium carbonate

Calcium carbonate is a compound CaCO₃ found in nature as calcite and aragonite and in plant ashes, bones and shells and used especially in making lime and portland cement and as a gastric antacid and as ocean acidification increases available carbonate ion bond with excess hydrogen resulting in fewer carbonate ion available for calcifying organisms to build and maintain their shells, skeletons, and other calcium carbonate structures

Ocean acidification describe the lowering of sweater pH and carbonate saturation that result from increasing atmospheric CO₂ concentration and that's why increased amounts of carbon dioxide cause reactions to happen in the water that decrease the pH and the amount of calcium carbonate.

Know more about ecosystems

https://brainly.com/question/28917786

#SPJ1

Answer: Its C I did my research and that's what makes sense to me. because increased amount of carbon dioxide decreases the PH and the amount of calcium carbonate.

The empirical formula of the glucose molecule is written as [tex]CH_{2} O[/tex].

Let us recall that glucose is the molecule that is response for the quick release of energy in the body. It is also the molecule that is first formed in the process of photosynthesis.

The term carbohydrate actually means a compound that is a hydrate of carbon and it is composed of glucose molecules. The empirical formula shows the relationship or the ratio of the atoms that could be found in a compound. We can see that we can obtain the ratio from the number of each of the atoms present.

Learn more about empirical formula:https://brainly.com/question/27749976

#SPJ1

Answer:

a) Upon adding silver nitrate, a white precipitate is observed

b) Upon adding ammonium hydroxide, the white precipitate dissolves to give a clear, colorless solution

Explanation:

Here, we want to state the observations when testing for chloride ions

From what we have:

a) When silver nitrate is added, a white precipitate is formed

This is as a result of the following chemical reaction:

The AgCl is the white precipitate formed

b) Upon the addition of the ammonium hydroxide solution, a colorless and clear solution is observed showing that the white precipitate has dissolved

When two or more substances are together in the same place but are not chemically combined they form a mixture.

The word mixture is used in chemistry to denote a combination of two or more elements that conserve their original properties, which is fundamental to achieving the separation of such elements in the future.

Therefore, with this data, we can see that a mixture is a mix or combination of two or more elements that still conserve their physical and chemical properties, thereby allowing their separation through different techniques.

Learn more about the meaning of mixture here:

https://brainly.com/question/24647756

#SPJ1

According to the given statement Mass of one atom of gold in grams is 196.78 g.

A chemical element is uniquely defined by its atoms, that are small bits of substance. An atom is made up of a core nucleus one and or more negatively charged electrons that orbit it. The positively charged, relatively hefty protons and neutrons that make it up the nucleus may be present.

Up until the 1800s, this idea of tiny, indivisible pieces of matter remained. The contemporary atomic idea was really started by the eminent chemist John Dalton (1766–1844). But his atom was like a rock-solid ball.

Molar mass is the weight in grams of one mole of an atom.

1 mole = 6.022×10²³ atoms

Molar mass of Gold (Au)

= mass of an atom × number of atoms

=3.207×10-²²×6.022×10²³

=196.78g.

To know more about Atom visit:

https://brainly.com/question/13654549

#SPJ13

Temperature is a measure of how hot a substance or radiation is expressed numerically.

There are three different types of temperature scales:

those that depend only on macroscopic properties and thermodynamic principles, like Kelvin's original definition;

those that depend on practical empirical properties of particles rather than theoretical principles;

and those that are defined by the average translational kinetic energy per freely moving microscopic particle, like an atom, molecule, or electron, in a body, like the SI scale.

How much heat is gained or lost by a sample can be calculated using the equation q = mcΔT, where m is the mass of the sample, c is the specific heat, and T is the temperature change (q).

Therefore,

q = m*c*ΔT

102.3 = 335 * 4.184 * ΔT

ΔT = 0.073 °c

To know more about temperature, click on the link below:

https://brainly.com/question/7127420

#SPJ9

Let's see that the formula to find the volume using density and mass is:

In this case, the problem is asking about the volume in mL but remember that mL is the same that cm^3, so using the formula we're going to obtain:

The volume of 5.52 g of acetone is 7.02 mL.

The temperature of land far from water is hotter than land near water.

The lower heat capacity of land often allows them to cool the nearby water temperature so it takes less energy to change the temperature of land compared to water bodies. This means that land heats and cools more quickly as compared to water. This difference affects the climate of different areas on Earth. Large bodies of water like oceans, seas and large lakes can affect the climate of the nearby regions such as coastal regions. Water heats and cools more slowly than land regions. The coastal regions will stay cooler in summer season and warmer in winter season, which creates moderate climate on the coastal regions.

So we can conclude that the temperature of land far from water is different from land near water because of cooling effect of water bodies.

Learn more about temperature here: https://brainly.com/question/24746268

#SPJ1

Answer:

flammability, toxicity etc..

Explanation:

are chemical changes

We can care for the pH meter electrode by;

1) Making sure that the electrode remains moist

2) The electrode should be stored in a 4M solution of KCl

3) Electrodes should not come in contact with deionized water.

The term pH has to do with the negative logarithm of the hydrogen ion concentration. Now we know that the pH of a solution tells us the amount of the hydrogen ions or the hydroxyl ions that is present in the solution. The pH mete is the instrument that we could use to be able to measure the pH of the solution.

The pH scale runs between 0 - 14. The points on the scale that have been labeled from 0 - 6 tells us that the solution is an acidic solution and contains more hydrogen ions.  If the solution has a pH of 7, then it is neutral and contains equal concentration of hydrogen and hydroxyl ions. A solution of pH 8 - 14 is basic and contains more hydroxyl than hydrogen ions.

Learn more about pH:https://brainly.com/question/15289741

#SPJ1

Answer: nbhhvyyvub

Explanation:

Answer: .509

Explanation: Im pretty sure

The molar change in enthalpy of reaction is 99.6 kJ/mol.

the formula for the specific heat capacity expressed as :

Q = mcΔT

where,

m , mass = 104.153 g

c, specific heat = 4.184 J/g °C

dt, change in temperature = 22.9  °C

Q = 104.153 × 4.184 × 22.9

Q = 9969.7 J = 9.96 kJ

now, the molar change in enthalpy is give by:

Q = ΔH / n

n is no. of moles

morality of HCl = 2.2 M

v = 50 mL = 0.05 L

n = 0.05 × 2.2

   =  0.11 moles

no. of moles of NaOH = mass / molar mass

                                    = 4.039 / 40

                                    = 0.100

NaOH is limiting reactant.

using the formula we get:

Q = ΔH / n

ΔH = Q / n

ΔH  =  9.96 kJ/ 0.10

ΔH, change in enthalpy  = 99.6 kJ/mol

Thus, combine 50.0 mL H₂O, 50.0 mL of 2.2 M HCl(aq), and 4.039 g NaOH(s) (molar mass of NaOH = 40.00 g/mol) in a Styrofoam calorimeter, recording a maximum solution temperature change of 22.9 °C and a final solution mass of 104.153 g (c solution = 4.184 J/g°C).  the molar change in enthalpy of reaction is 99.6 kJ/mol.

To learn more about change in enthalpy here

https://brainly.com/question/17134425

#SPJ1

There are three possible values for the l and there are nine possible values for ml.

The term quantum numbers has to do with the description that shows the most probable position of the electron in an atom. We know that the orbital is a region in space, where there is a high probability of finding the electrons.

Given that the values of l must be in the range of 0 to n - l and the values of ml must be in the rang of -l to + l. we then can use this to know the  number of the possible combinations of  l and ml when n = 3.

Learn more about quantum numbers:https://brainly.com/question/16977590

#SPJ1

I a chemical reaction, we have the reactants in the left part,followed by an arrow and then the products.

So, the reactants are the two that are in the left part of the equation:

Sodium hydroxide and Hydrochloric acid

The molarity of NaOH solution that required 20.15mL is 0.0004032M.

Molarity is the concentration of a substance in solution, expressed as the number moles of solute per litre of solution.

Molarity of a solution can be calculated by dividing the number of moles in the solution by the volume as follows:

Molarity = no of moles ÷ volume

According to this question, 0.325g of KHP required 20.15ml of NaOH for neutralization. The number of moles in this mass can be calculated as follows:

no of moles = 0.325g ÷ 40g/mol

no of moles = 0.008125mol

Molarity = 0.008125mol ÷ 20.15mL

Molarity = 0.0004032M

Therefore, 0.0004032M is the molarity of the solution.

Learn more about molarity at: https://brainly.com/question/16727614

#SPJ1

No, Atoms of different element can not have same atomic number because only same type of atoms combine to form element.  Atoms belonging to different element can have different atomic number.

Element generally consist of atoms or we can  atoms combine to form element. Atoms of an element is always same, means all the properties of all atoms of one type of element is same. Two or more than two atoms with different physical or chemical properties can not combine together to form an element.

So we can say that atomic number of all atoms that is constituting an element is same. It can never be different.

Thus Atoms of different element can not have same atomic number.

To know more about element, here:

https://brainly.com/question/8460633

#SPJ1

Answer:

Explanation:

Here, we want to get the number of moles

Mathematically:

We have that as:

1) The calculate rate constant is  9.22 * 10^-5 s-1

2) In the period of  is 15033 s 75% is used up

3) From the calculation, there is an initial 9.22 * 10^-5 M.

In chemistry, the rate of reaction would give the idea that the reaction is proceeding quickly or slowly. If a reaction has a large rate of reaction then it tends to move on to completion.

From the question, it  is clear that there is 25% in t =52 min.

Initial concentration [A]o =  [A]o

Final concentration =  [A]o - 0.25  [A]o = 0.75 [A]o

Time taken = 52 min or 3120 s

From the formula that can be applied to a first order reaction;

ln[A] = -kt + ln[A]0

k = -(ln[A] -  ln[A]0)/t

k = - (ln0.75 [A]o/A]0)/3120

k = 9.22 * 10^-5 s-1

b)

Then we have  to find  the time after the initial concentration decrease with 75%

[A] =  [A]o - 0.75  [A]o = 0.25 [A]o

ln[A] = -kt + ln[A]0

t = -(ln[A] -  ln[A]0)/k

t = - (ln0.25 [A]o/A]0)/9.22 * 10^-5

t = 15033 s

c)  Given that in this case, the initial concentration of the reactant is 2.5 mol/L·s

k = - (ln0.25 (2.5)/ln(2.5))/15033

k = 9.22 * 10^-5 M

Learn more about rate of reaction:brainly.com/question/8592296

#SPJ1

In order to answer this question we will need to use the molar mass of Calcium bromide (CaBr2), which is 199.89 g/mol, now we can find how much of this mass is only Bromide, so what is the percentage of Bromide that makes up this whole compound, to do so we will also use the molar mass of Bromide (Br2) which is 159.8 g/mol

199.89 g/mol = 100% of the compound

159.8 g/mol = x %

x = roughly 80% (is like 79.9%)

So, regardless of the mass of CaBr2, bromide needs to be 80% of its mass, now solving our question

395 g = 100%

x grams = 80%

x = 316 grams is the mass of Bromide in the compound

The volume of NaOH required is 80ml.

Sulfuric acid is a dibasic acid and NaOH is monoacidic base.

M1V1 = M2V2

where, M1 = initial concentration,

V1 = initial volume,

M2 = concentration after mixing

V2 = total final volume.

This formula is used for calculating the final volume or molarity after mixing two solutions.

Given the question,

M1 = 0.505M

V1 =?

M2 = 0.505M

V2 = 40 ml

M1V1 = 2×M2V2

0.505 × V2 = 2 × 0.505 × 40

V2 = 2×0.505×40

            0.505

V2 = 80ml

To know more about molarity visit the link:

https://brainly.com/question/8732513?referrer=searchResults

#SPJ1

Taking into account definition of percent yield, the percent yield of carbon dioxide is 30.90%

In first place, the balanced reaction is:

2 CH₃CH₃ + 7 O₂ → 4 CO₂ + 6 H₂O

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

The molar mass of the compounds is:

Then, by reaction stoichiometry, the following mass quantities of each compound participate in the reaction:

The limiting reagent is one that is consumed first in its entirety, determining the amount of product in the reaction. When the limiting reagent is finished, the chemical reaction will stop.

To determine the limiting reagent, it is possible to use a simple rule of three as follows: if by stoichiometry 224 grams of O₂ reacts with 60 grams of CH₃CH₃, 16.7 grams of O₂ reacts with how much mass of CH₃CH₃?

mass of CH₃CH₃= (16.7 grams of O₂× 60 grams of CH₃CH₃)÷ 224 grams of O₂

mass of CH₃CH₃= 4.47 grams

But 4.47 grams of CH₃CH₃ are not available, 2.71 grams are available. Since you have less mass than you need to react with 16.7 grams of O₂, CH₃CH₃ will be the limiting reagent.

The percent yield is the ratio of the actual return to the theoretical return expressed as a percentage.

The percent yield is calculated as the experimental yield divided by the theoretical yield multiplied by 100%:

percent yield= (actual yield÷ theoretical yield)×100%

where the theoretical yield is the amount of product acquired through the complete conversion of all reagents in the final product, that is, it is the maximum amount of product that could be formed from the given amounts of reagents.

Considering the limiting reagent, the following rule of three can be applied: if by reaction stoichiometry 60 grams of CH₃CH₃ form 176 grams of CO₂, 2.71 grams of CH₃CH₃ form how much mass of CO₂?

mass of CO₂= (2.71 grams of CH₃CH₃× 176 grams of CO₂)÷ 60 grams of CH₃CH₃

mass of CO₂= 7.96 grams

Then, the theoretical yield of CO₂ is 7.96 grams.

In this case, you know:

Replacing in the definition of percent yields:

percent yield= (2.46 grams÷ 7.96 grams)×100%

Solving:

percent yield= 30.90%

Finally, the percent yield for the reaction is 30.90%.

Learn more about percent yield:

brainly.com/question/14408642

#SPJ1

Equilibrium constant is the only concept that is to be used here to calculate partial pressure of nitrogen. The partial pressure of Nitrogen comes out to be  1.17atm

Equilibrium constant is a rate constant at equilibrium shows the values of reaction with respect to the atmospheric pressure and concentration

[tex]K_{c}[/tex]  is equilibrium constant with respect to concentration.

[tex]K_{p}[/tex] is equilibrium constant with respect to atmospheric pressure.

Mathematically,

[tex]K_{p}=\frac{[N_{2}][Br_{2} ] }{[NBr_{3}] }[/tex]

Substituting values

(4.8×1.10atm)÷ 4.50atm=[tex]{[N_{2}][/tex]

1.17atm=[tex]{[N_{2}][/tex]

Thus the equilibrium partial pressure of N₂ is 1.17atm.

To know more about equilibrium constant, here:

https://brainly.com/question/19671384

#SPJ1

To calculate the total change in binding energy we must apply the following equation:

This equation tells us that the energy change will be equal to the sum of the potential energy of the product bonds minus the sum of the potential energy of the reagent bonds.

Now, let's calculate each term separately.

So, the change in bond energy will be:

We have a negative value in the result, when this happens it means that the reaction is exothermic, that is to say, that it releases heat and the energy of the products is greater than that of the reagents.

When we have a positive value the reaction will be endothermic, this means that it needs energy.

Answer: 0.132 moles of Na2SO4

Explanation:

Multiply the grams of Na2SO4 by the 1/molar mass of Na2SO4, which is the sum of all the elements 2(Na)+S+4(O)= 142.04.

Based on the conversion factor, the number of ounces of paper an average college student uses per day is  14 ounces of paper per day

A conversion factor is a value that is used to make the conversion from one unit of measurement to another.

The conversion factor from pounds to ounces is given below as follows:

1 pound = 16 ounces

Also, the conversion factor from years to days is given below as follows:

1 year = 365 days

Hence, the ounces of paper an average college student uses per day are calculated as follows;

320 pounds = 320 * 16 ounces

320 pounds = 5120 ounces

Ounces of paper per day = 5120 / 365

Ounces of paper per day = 14 ounces per day

Learn more about conversion factors at: https://brainly.com/question/17739692

#SPJ1

33.6 g grams of O2 are needed to react with 24.0 g of NH3.

The molecular mass of NH3 = 14 + 3 = 17g

Given mass of NH3 = 24g

Firstly, we will calculate the number of moles.

Moles is defined as the ratio of given mass of substance to the molecular mass of substance.

Moles = given mass/ molecular mass

Number of moles of NH3 = 24/17

= 1.4 mole

4 NH3(g)+302(g) → 2N2(g)+6H₂O(1)

4 moles of NH3 require 3 moles of O₂ to react.

1 moles of NH3 require 3/4 moles of O₂ to react.

1.4 moles of NH3 require 1.05 moles of O₂ to react.

Now we calculate the grams of O₂.

1.05 × 32 = 33.6 g.

Thus, we concluded that the 33.6 g grams of O2 are needed to react with 24.0 g of NH3.

learn more about moles:

https://brainly.com/question/15209553

#SPJ13

Answer:

0.834 mole = 13293.32 mg

2,600 mg = 0.16 mole

Explanation:

1 mole of K = 39.098 g

=> 0.34 mole has (0.34)(39.098) = 13.29332g

13.29332 g x 10^3 = 13293.32 mg

so 0.834 mole of K = 13293.32 mg

mole of 2,600mg = (0.834)(2,600)/(13293.32) = 0.16311952168 or 0.16 mole