6. What is the percent composition of chlorine in calcium chloride, CaCl₂?a. 32%b. 36%c. 50%d. 64%

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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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.

Given the equation:

• Sn (NO2)4 + Pt3N4 → Sn3N4 + Pt(NO2)4

(1) The first thing we noticed is that this is a double replacement equation

• ,Sn combines with N4 to form Sn3N4, (,take note that Sn→ Sn3,)

• Pt3 combines with (NO2) to form Pt(NO2)4 ( ,take note that Pt3 → Pt)

(2) Balancing the equation

• Sn (NO2)4 + Pt3N4 → Sn3N4 + Pt(NO2)4 ....(,place 3 infront of Sn in the reactant side .)

• 3,Sn (NO2)4 + Pt3N4 → Sn3N4 + Pt(NO2)4...( ,then place 3 infront of Pt in the product side,)

• 3,Sn (NO2)4 + Pt3N4 → Sn3N4 + ,3,Pt(NO2)4

Check :

3Sn reactant : Sn3 Product

(NO2)4 reactant : (NO2)4 product

Pt3 reactant : 3Pt product

N4 reactant : N4 product

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.

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

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.

6. As we can see from the graph, if we have only 100 grams of water, at 30°C, we will have 10 grams of KClO3 being dissolved in water, therefore if we have 300 grams of H2O, we will have 30 grams of KClO3 being dissolved at 30°C

7. The least soluble substance will be the one that shows up first in the temperature "line", if you follow the temperature up, the first solute that is listed will be considered to least soluble, therefore the least one will be KClO3

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:

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:

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.

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

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:

Step 1 - Understanding % concentration in mass

% concentration in mass expresses the concentration of a solute by its percentage, in mass, in relation to the total mass of the solution.

Mathematically, we can find this percentage by the following relation:

Step 2 - Caculating the % concentration for the given solution

According to the exercise:

Setting these values in the equation:

Answer: the % concentration of NaCl in this solution is 3.38%.

Half life is the time period in which half of the initial amount of an element will decay into a new element due to instability. For I-131, the half life is 8 days.

From 200 to 25 grams, let's see how many half lives are there:

200g -> 100g

100g -> 50g

50g -> 25g

Therefore for 200g of I-131 reach 25 grams, 3 half lives are necesseray, 3 half lives or 24 days

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.

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:

Balls uhhh neutron but if theres a better answer take it cuz im prolly wrong

Explanation:

50/50 im right up to you to take the chance or jus search it on tha goog

2. (a) We are told that it is a double displacement reaction, so there will be two substitutions and Cl will exchange places with NO3.

Now, that will be the full reaction but we need to balance it. Count the atoms of each element on each side of the reaction. In the figure we can see that Chlorine, Nitrogen and Oxygen are not balanced.

We place the coefficient 2 in front of the AgCl molecule to balance the chlorides. You can see the picture.

Now we will balance the nitrogens. There are two nitrogens in the products. We place the coefficient two in the AgNO3 molecule. In the figure I will make the update.

Now the equation is balanced, so the balanced reaction will be:

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.

The question requires us to calculate the pOH value for a solution containing 0.01 moles of HCl in 2.5 L of solution.

To solve this problem, we'll need to go through the following steps:

I) calculate the molar concentration of the HCl solution to obtaine the concentration of H+ ions;

II) using the concentration of H+ ions, calculate the pH of the solution;

III) with the value obtained for pH, calculate the value of pOH for this solution.

Next, we'll go through the steps to solve the question:

I) Since the question provided the number of moles of HCl and the volume of the solution, we can calculate the molar concentration using the following equation:

Thus, applying the values provided:

Therefore, the concentration of the HCl solution is 0.004 mol/L.

Since HCl is a strong acid, we can expect it to completely dissociate in H+ and Cl-: the concentration of H+ ions for this solution would also be 0.004 mol/L ( [H+] = 0.004 mol/L).

III) The next step is calculate the pH of this solution. We'll use the following equation and apply the concentration of H+ ions obtained in the previous step ( [) using H+] = 0.004 mol/L):

Now, we know that the pH of the solution is 2.39.

III) The last step is use the pH value calculated (pH = 2.39) to calculate the pOH of the solution, using the following equation:

Therefore, the pOH of the HCl solution given is 11.6.

Answer

pH = 6

Explanation

Given that:

The concentration of the acid [H⁺] = 10⁻⁷ M

What to find:

The pH of the strong acid solution.

Step-by-step solution:

The pH of the strong acid solution whose concentration is 10⁻⁷ M can be calculated using the pH formula.

The pH formula is given by: pH = -log[H⁺]

Substitute [H⁺] as 10⁻⁷ M, we have:

pH = - log(10⁻⁷)

pH = -(-6)

pH = 6

The pH of the strong acid solution whose concentration is 10⁻⁷ M is 6.

In order to solve the question b):

We have the following reaction occuring:

We need to calculate the number of moles of aluminum needed to produce 30ml of H2 (hydrogen gas) at a temperature of 22°C and a pressure of 763mmHg.

To calculate the number of moles of hydrogen produced we use the ideal gas equation:

Where:

P is the pressure

V is the volume

n is the number of moles

R is the gas constant

T is the temperature

R is a constant and it's value is:

So we need to convert each variable to the units of this constant.

So now we calculate:

So we know that 0.00124 moles of H2 are formed.

Now we know that for every 2 moles of aluminum 3 moles of H2 are formed.

So we calculate the moles of Al needed:

So the answer is 0.000826 moles of Al°

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

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

He gained 589.667g.

Answer

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

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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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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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