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In this question, we have a situation in which we have to use the Calorimetry formula, which is how much heat was released or absorbed (in Joules), after we had a change in temperature of a compound. The formula for this Calrimetry question is:

Q = mcΔT

Where:

Q = is energy as Heat

m = mass in grams

c = is the specific heat capacity

ΔT = the change in temperature, calculated as Final Temperature - Initial T

We have:

m = 75.0 grams

c = for water is 4.184 J/g°C

ΔT = 27.5 - 100 = -72.5°C

Now adding these values into the formula:

Q = 75 * 4.184 * (-72.5)

Q = - 22750.5 Joules, or -22.75 kJ

alkali metals has 6-p electrons

The alkali metals are elements of group 1 elements which are lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr).,

These elements are s-block elements because they have their outermost electron in an s-orbital.

The alkali metals are soft, shiny and highly reactive and  lose their outermost electron to create cations with charge +1, it can tarnish rapidly in the air due to oxidation by atmospheric moisture and oxygen.

Alkali metals are good conductors of heat and electricity, these elements are  specific, They are soft and can be cut by knife.

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Explanation:

One atm of pressure is equal to 760 torr. We can use this relationship to find the answer to our problem.

1 atm = 760 torr

P = 2.29 atm = 2.29 atm * 760 torr/(1 atm)

P = 1740 torr

Answer: The pressure of the tank in torr is 1740 torr.

In this diagram, we have a reaction occurring and 3 letters that represent Reactants, Activation Energy and Products. To determine which is which, first, we will almost always have the Activation Energy in the middle of the reaction, this is how much energy is required for the reaction to occur, therefore Activation Energy is represented by letter B

To determine the total change in enthalpy, we need to subtract the sum of all the enthalpy from the products, which is letter C, and the sum of all the enthalpy from the reactants, which is letter A

ΔH = C - A

In this graph, we have the energy increasing and more energy on the products side, this means that an input of energy was required, this is the description of an Endothermic reaction, therefore the sign will be Positive

Answer

C

Explanation

A higher ranked element in the activity series is more reactive in a single replacement reaction. We predict a single replacement reaction will occur when a less reactive element can be replaced by a more reactive element in a compound. Therefore since A is more reactive, it will replace B in a single replacement reaction.

So,

The elements that belong to group 18 of the modern periodic table can be considered as some of the best electric insulators since they all contain completely filled valence shells and are, therefore, stable.

In general, elements that make good insulators are nonmetals, and these are located at the right of the periodic table. Thus the correct answer is B.

To answer this question we have to convert pounds to grams using a conversion factor:

He gained 589.667g.

AgNO₃ + (NH₄)₂CrO₄ ----> Ag₂CrO₄ + NH₄NO₃

This is a double replacement equation, so there is an ion exchange. So the easiest way to balance this equation is to separate the compounds into their ions.

AgNO₃ + (NH₄)₂CrO₄ ----> Ag₂CrO₄ + NH₄NO₃

Ag⁺ + NO₃⁻ + 2 NH₄⁺ + CrO₄²⁻ ----> 2 Ag⁺ + CrO₄²⁻ + NH₄⁺ + NO₃⁻

Usually we balance the elements, but it is easier in this case to balance the ions.

AgNO₃ + (NH₄)₂CrO₄ ----> Ag₂CrO₄ + NH₄NO₃

Ag⁺: 1 Ag⁺: 2

NO₃⁻: 1 NO₃⁻: 1

NH₄⁺: 2 NH₄⁺: 1

CrO₄²⁻: 1 CrO₄²⁻: 1

Let's start balancing the ion Ag⁺, we have two ions Ag⁺ on the right and only one on the left, so we have to change the coefficient in front of AgNO₃ and write a 2 there.

2 AgNO₃ + (NH₄)₂CrO₄ ----> Ag₂CrO₄ + NH₄NO₃

Ag⁺: 2 Ag⁺: 2

NO₃⁻: 2 NO₃⁻: 1

NH₄⁺: 2 NH₄⁺: 1

CrO₄²⁻: 1 CrO₄²⁻: 1

That change balanced the ion Ag⁺, but unbalanced the NO₃⁻. We have two on the left and only one on the right. We have to change the coefficient in front of NH₄NO₃ and write a 2 there.

2 AgNO₃ + (NH₄)₂CrO₄ ----> Ag₂CrO₄ + 2 NH₄NO₃

Ag⁺: 2 Ag⁺: 2

NO₃⁻: 2 NO₃⁻: 2

NH₄⁺: 2 NH₄⁺: 2

CrO₄²⁻: 1 CrO₄²⁻: 1

And finally our equation is balanced.

Answer: 2 AgNO₃ + (NH₄)₂CrO₄ ----> Ag₂CrO₄ + 2 NH₄NO₃

Both fiber optic and metal are used to transmit signals across long distances. While fiber optic cables use light to carry signals making them much faster and higher quality.

pH = 7

pOH = 7

The formula for calculating the pOH of a solution is given as:

Given the following parameter

Substitute

Determine the pH of the solution

Recall that pH + pOH = 14, hence;

Hence the required pH and pOH of aqueous solution are 7 and 7 respectively

If we have 4.50 x 10²⁴ molecules of P₂O₅, we will have 5 times as much atoms of oxygen, because in each molecule of P₂O₅ there are 5 atoms of oxygen.

So, the number of atoms of oxygenm in total, is:

The atomic mass of oxygen is approximately 15.9994 g/mol. So, we first need to convert the number of oxygen atoms for number of moles of oxygen.

To do that, we divide the number of atomx of oxygen by Avogadro's Numver:

So, we have:

Now, we can convert to mass:

So, we have approximately 598 g of oxygen atom.

Answer

Chemical bonding is the process where atoms or molecules combine or bond together. A chemical bond may result from the electrostatic force between oppositely charged ions as in ionic bonds or through the sharing of electrons as in covalent bonds.

Explanation

Chemical bonding is the process where atoms or molecules combine or bond together, usually to form a new compound. The outer electron orbits or shells determine which elements or molecules combine and how well they bond together. There are several types of chemical bonding. A chemical bond may result from the electrostatic force between oppositely charged ions as in ionic bonds or through the sharing of electrons as in covalent bonds.

0.029397 kCal

According to the question, we are to convert Joules to kCal

Using the conversion factor:

1 Joule = 0.000239 Kcal

Next is to convert 123 Joules to kCal

To do that, we will multiply 123 Joules with the factor as 0.000239

123 Joules = (0.000239 * 123) kcal

123 Joules = 0.029397 kCal

Hence the value of 123 joules is equal to 0.029397 kCal

The formed amount of KCl from the reaction is 297.12 g which is not enough to kill someone.

A limiting reagent can be defined as a reactant that is exhausted completely from the mixture at the completion of a chemical reaction.

When quantities of reactant are not taken in stoichiometry, the limiting reactants in the chemical reaction will decide the maximum amount of product.

Given, a balanced equation of the decomposition of KClO₃ is:

[tex]KClO_3\longrightarrow KCl +O_2[/tex]

One mole of KClO₃ will produce one mole of KCl.

122.55 g of the KClO₃ will produce KCl = 74.55 g

Given, the amount of KClO₃ = 488.43 g

Then 488.43 g of KClO₃ will produce KCl  = (74.55/122.55) × 488.43

                                                                      = 297.12 grams

As given 420.45g of potassium chloride would be required to kill someone. Therefore,  there is not enough potassium chloride that Melanie killed the butler.

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Molar concentration or Molarity is a way to measure the concentration of a solution after some solute has been added to the solvent, the formula for Molarity is:

M = n/V

where:

M = molar concentration

n = number of moles

V = volume of the solution in Liters

In the question we are given the molarity and volume, let's add these information to our formula

0.6 M = n/2.5 L

n = 1.5 moles of Iodine should be added

Answer and Explanation

(a) At constant temperature and volume the pressure of a gas is directly proportional to the number of moles of gas.

P = n (RT/V) where P is the pressure, n is the number of moles, R is the gas constant, T is the temperature and V is the volume

So when the pressure in increased, the volume will be decreased, meaning there will be less space in the container, this will lead to more collisions inside a container, meaning, the number of moles will be increased.

(b) Given: initial number of moles (n1) = 4.0 moles

initial pressure (P1) = 1.6 atm

Final number of moles (n2) = 3.0 moles

Required: Final Pressure (P2)

solution

P1/n1 = P2/n2

P2 = P1*n2/n1

P2 = 1.6 atm*3.0 moles/4.0 moles

P2 = 1.2 atm

The groups of the periodic table from left to right are alkali metals, alkaline earth metals,transition metals,halogens and noble gases.

Periodic table is a tabular arrangement of elements in the form of a table. In the periodic table, elements are arranged according to the modern periodic law which states that the properties of elements are a periodic function of their atomic numbers.

It is called as periodic because properties repeat after regular intervals of atomic numbers . It is a tabular arrangement consisting of seven horizontal rows called periods and eighteen vertical columns called groups.

Elements present in the same group have same number of valence electrons and hence have similar properties while elements present in the same period show gradual variation in properties due to addition of one electron for each successive element in a period.

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The type of reaction involved in the illustration is a single displacement reaction.

Displacement reactions are chemical reactions in which an atom displaces another atom from a participating species of the reaction. Displacement reactions could be:

When you consider this reaction: [tex]Zn + AgNO_3 -- > ZnNO_3 + Ag[/tex]. Zn displaced Ag from the compound, [tex]AgNO_3[/tex]. Thus, it is a single displacement reaction.

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A blood test determines that Megumi’s magnesium reading is not right considering her symptoms then the Megumi has a magnesium deficiency

Magnesium deficiency is the condition in which blood level of magnesium is lower than usual and hypomagnesemia is the medical term for this disorder and magnesium shortage is an electrolyte disruption caused by a low magnesium content in the body and it can cause a variety of symptoms and the symptoms are palpitations, poor coordination, muscular spasms, lack of appetite, personality changes and because of low magnesium level the potassium level is also deceases

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Synthetic substances:

Synthetic fibers e.g. are made from organic synthetic high-molecular compounds and are made synthetically from raw materials such as petroleum oil or petrochemicals.

Until here the answer is: petroleum oil

At home, we can find synthetic fibers, ceramics, plastics, etc

We can find synthetic fibers (polyester, Rayon, Spandex, etc) in caps, raincoats, and ropes.

Plastic can be found in bottles, cups, etc.

The main way that could be told to do this is to actively show their presence in the campaign and get involved with the campaign with interest and enthusiasm.

Some other ways to tell the students of the region to do their part in a campaign are as follows:

These are some ways that could be told to the students of the region to take part in the campaign.

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Answer

16,200 seconds

Explanation

Conversion factor:

1 hour = 60 minutes

1 minute = 60 seconds

Therefore,

4.5 hours x 60 minutes/1 hour = 270 minutes

270 minutes x 60 seconds/1 minute = 16,200 seconds

It is necessary to use the Periodic Table of Elements to find the atom with atomic number of 16 and a mass number of 32, that is Sulfur (S).

The correct way to write it is using the mass number of the element, so sulfur can be written as sulfur-32.

Answer:

Explanation:

Here, we want to know the number of molecules of oxygen that was reacted with

From the question, we can see that the mole ratio is 2 to 1

Thus, the number of molecules of oxygen reacted will be half that of hydrogen

Hence, the number of molecules of oxygen will be:

Answer

The structural formula of 2-chloro-5,5-diethyloctan-4-ol is shown below

So,

Living things are made of four types of molecules, known as macromolecules. These macromolecules are:

1. Carbohydrates:

Carbohydrates, are sugar molecules. Along with proteins and fats, carbohydrates are one of three main nutrients found in foods and drinks. Your body breaks down carbohydrates into glucose. Glucose, or blood sugar, is the main source of energy for your body's cells, tissues, and organs. The building blocks units of Carbohydrates are called Monosaccharides, which are simple sugars. The next one is a picture that shows the structures of some Carbohydrates:

2. Lipids:

A lipid is any of various organic compounds that are insoluble in water. They include fats, waxes, oils, hormones, and certain components of membranes and function as energy-storage molecules and chemical messengers. The building block units of lipids are Fatty acids and glycerol.

We can see some structures for lipids below:

3. Proteins:

Proteins are large, complex molecules that play many critical roles in the body. They do most of the work in cells and are required for the structure, function, and regulation of the body's tissues and organs.

A protein is a naturally occurring, extremely complex substance that consists of amino acid residues joined by peptide bonds. Proteins are present in all living organisms and include many essential biological compounds such as enzymes, hormones, and antibodies as well. The building block units of proteins are called Aminoacids.

A protein has four structures shown below:

And, finally:

4. Nucleic acids:

Nucleic acids are naturally occurring chemical compounds that serve as the primary information-carrying molecules in cells.

They play an especially important role in directing protein synthesis. The two main classes of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA).

The building block units of nucleic acids are called Nucleotides.

The next one is their structure:

Explanation:

The energy of a photon of the violet light can be obtained as follows:

E = energy

h = Plank's constant

f = frequency

-------

Data provided:

f = 7.31x10^14 Hz

--

Data needed:

h = 6.63x10^-34 Js

So, E = h x f = 6.63x10^-34 Js x 7.31x10^14 Hz = 4.85x10^-19 J

Answer: 4.84x10^-19 J (nearest value)

Explanations: The first law of thermodynamics states that energy cannot be created or destroyed, hoever, it can only change its state.

A) Incorrect - this is not related to thermodynamics

B) Incorrect - has no correlations to energy being conserved.

C) Correct - energy state of the heat is transfered from the system to surrounding, this is an example of thermodynamic

D) Incorrect - no energy is conserved here.

Answer:

267 mmHg.

Explanation:

What is given?

Total pressure = 723 mmHg

Partial pressure of helium (He) = 194 mmHg.

Partial pressure of nitrogen (N) = 262 mmHg.

Step-by-step solution:

Let's see the formula of total pressure:

Let's write the formula to our context if we have 3 different gases:

We want to find the partial pressure of oxygen (O), so let's solve for Po which is the unknown value in the formula, and replace the given data:

The partial pressure of oxygen is 267 mmHg.

In World War 1, Chlorine gas was used as a toxic, poisonous gas to harm and terminate enemies.