Why does the ice pack get colder when the inside barrier is broken and the chemicals mix together?

The two compounds that react are:

Potassium iodide: KI

Lead (II):

When the two solutions are mixed the following reaction takes place:

The resulting product is called lead (II) Iodide.

Explanation:

A nucleus consists o both electrons and proton. Therefore, an unstable nucleus undergoes radiation. And this causes a formation of a new atom. This is known as radioactive decay. Therefore, an unstable nucleus emits energy as it decays.

Answer:

The correct answer is B.herefore, an unstable nucleusherefore, an unstable nucleusR

To solve this problem, we could use the ICE table as follows:

First of all, the reaction that we're working with is:

Now, let's make the table:

As you can notice, the initial concentration of C6H5CO2H is 0.536002M, and as the products haven't been formed yet, their concentration is 0.

When the change happen, the concentration of the reactant will decay "x" and the concentration of the products will increase "x". (That's the reason of the signs).

And finally, the equilibrium.

We also know that:

And, this equilibrium constant comes from the following:

Where all concentrations are the equilibrium concentrations.

If we replace, we got that:

We're going to solve this equation for x:

And, using the quadratic formula we obtain that the value of x is 0.000587014 approximately.

Now, if x=0.000587014, that means that [H+] = 0.000587014

And finally, remember that the pH of a solution is defined as:

Therefore, the pH is 3.23.

To answer this question we have to find the value of ka, to do it, we can use the value of kb. The product of the kb of a base and the ka of its conjugated base is kw(1x10^-14):

Now, we have to use the equation of Hendersson and Hasselbach:

The reaction that involves the combustion of Magnesium will not start unless some amount of energy is added to it, therefore we need the Bunsen burner flame to be the source of the activation energy for the reaction properly occur, since the reaction would not occur in a spontaneous way. Therefore answer letter B

Explanation

Let us first define the different types of reaction.

A combination reaction is one in which two reactants combine to form a single product.

A decomposition reaction will be one in which a reactant breaks down into two or more products.

A simple displacement reaction will be one in which a reagent, which is in its natural state, displaces one element bound to another. As a product, we will have the previously linked element now in its free form.

In a double displacement reaction two linked elements move past each other and take each other's place.

Given Data

mass of solute Na 10.0 g

mass of solvent 1000.0g water

to calculate:

molality of solution

molalilty is defined as the mols of a solute divided by the Kg of the solvent

therefore mols of Na = mass/ molar mass

= 10.0g/22.98g/mol

= 0.44 mols

1 Kg = 10000. grams

Therefore molality of solution

= 0.44 mols/ 1 Kg

= 0.44 mols/Kg

Step 1: Identify the given and do necessary conversions.

• 27.mol of copper ,

we know that 1 = 1*10^-6 mole ,

So, 27.mol*1*10^-6 = 27*10 ^-6 mole of copper.

• Volume of the solution = 300ml ,

300ml/1000ml = 0.3L

Step 2: Calculate the concentration in mol/L

Molarity( M /mole/L) = moles of the solute / volume

=27*10 ^-6 mole/ 0.3 L

=0.00009mol/L

• Therefore ,Concentraion of copper(II) sulfate =9.0x10^-5mol/L

( 2 significant digits)

Significant figures correspond to the number of digits that a number contains. Zeros at the beginning and end of the number are not counted, only zeros are counted if they are in an intermediate position.

For this case, the number is written in scientific notation, the corresponding 10 of the scientific notation is not taken into account during the digit count, therefore the significant figures of this number will be:

Answer: In 5.9 x10^4 there are 2 significant figures.

Silver nitrate reacts with potassium chloride according as indicated by the balanced equation:

AgNO₃ + KCl -----> AgCl + KNO₃

How many grams of KCl would be required to react with 380 mL of 0.71 M AgNO₃ solution?.

First we have to find the number of moles in the solution of AgNO₃, then we can find the number of moles of KCl that will react with those moles of AgNO₃, and finally we can convert the moles of KCl into grams using the molar mass of KCl.

So, molarity is defined as the number of moles of solute divided the volume of solution in L.

Molarity = moles of AgNO₃/volume of solution in L

moles of AgNO₃ = molarity * volume of solution in L

We have 1000 mL in 1 L. We can use that conversion to find the volume of solution in L.

1000 mL = 1 L

Volume of solution in L = 380 mL * 1 L /1000 mL = 0.380 L

Volume of solution in L = 0.380 L

Now we can find the number of moles contained in 380 ml (or 0.380 L) of 0.71 M AgNO₃ solution.

moles of AgNO₃ = molarity * volume of solution in L

moles of AgNO₃ = 0.71 M * 0.380 L

moles of AgNO₃ = 0.270 moles

AgNO₃ + KCl -----> AgCl + KNO₃

We can compare the equation of a chemical reaction with a recipe. The coefficients are the quantities of that recipe. Since all the coefficients are 1, we can read our reaction like this: "1 mol of AgNO₃ will react with 1 mol of KCl to produce 1 mol of AgCl and 1 mol of KNO₃".

The reaction between AgNO₃ and KCl is 1 to 1. We will use that relationship to find the number of moles of KCl that will react with 0.270 moles of AgNO₃.

number of moles of KCl = 0.270 moles of AgNO₃ * 1 mol of KCl/(1 mol of AgNO₃)

number of moles of KCl = 0.270 moles of KCl

Since the reaction is 1 to 1, 0.270 moles of KCl will react with 0.270 moles of AgNO₃.

Finally we can find the mass of KCl. We need the molar mass of KCl.

atomic mass of K = 39.10 amu

atomic mass of Cl = 35.45 amu

molar mass of KCl = 74.55 g/mol

mass of KCl = number of molses of KCl * molar mass of KCl

mass of KCl = 0.270 moles * 74.55 g/mol

mass of KCl = 20.1 g

Answer: 20. g of KCl would be required.

Reading significant figures. When you're reading signif

Answer:

A

Explanation:

There are many definitions, and all of them are organic under some definition. The answer is probably A because it is the only one without hydrogen, and sometimes molecules without hydrogen are counted as being inorganic. A is CCl2F2, which is comprised of two chlorine atoms, two fluorine atoms, and a carbon atom.

To find the concentration we can do it in terms of molarity. Molarity is a way of expressing the concentration of a solute in a solution, it is expressed with the term M and can be described by the following equation:

So first we must find the moles of NaCl present in 1.00 grams, the moles of NaCl will be:

So, the molarity of the solution will be:

Answer: The concentration of the solution in molarity will be 0.17M

Please, look at the next drawing:

answer and explanation

the sum of pH and pOH is always equal too 14

and so if we apply that principle we have the following

pOH + pH = 14

and we are told that the pH is 0.0059 so we substitute this in the equation

pOH +0.0059 = 14

pOH = 14 - 0.0059

pOH = 13.99

If the question is asking us to find the element based on the quantum numbers of the last electron, we have these informations:

n = 4

l = 1

m = +1

s = -1/2

n represents the shell or level value, this value will generally go from 1 to 7, and since our value is 4, we are talking about an element whose valence shell is 4, so this element is in the 4th period

l represents the value of the orbital, this value can range from 0 to 3,

0 is the s orbital

1 is the p orbital

2 the d orbital

3 = f orbital

In out question we have l = 1, therefore the last electron of this element is in the p orbital and in the 4th period, now we are down to 6 elements, Gallium, Germanium, Arsenic, Selenium, Bromine and Krypton, all 6 elements are in the 4th period and have the p orbital as its last one

m represents the location of the electron within the orbitals, each orbital can hold 2 electrons only, p orbitals can hold 6 electrons in 3 pairs of 2, and the m value represents in which orbital the electron is, for l = 1, m can be -1, 0, +1

and in our question we have m = +1, therefore the electron is located in the last orbital, it can only be the 3rd electron or the 6th electron now, and now we are down to Arsenic and Krypton

s is the spin value of the electron, this value will tell us if the electron is pointing upwards or downwards in the orbital, this value can only be +1/2 (upwards) and -1/2 (downwards), and in our question, we have -1/2, which is the last electron of the orbital

Based on all that information, we conclude that this element is Krypton, with 36 of atomic number and electron configuration of [Ar]3d10 4s2 4p6

Answer:

D

Explanation:

as a transition metal, when put in dilute hydrochloric acid it will bubble vigorously and produce hydrogen gas

Its volume will be 12-fold.

From the Ideal Gas formula we know that:

- P is the pressure os the gas.

- V is the volume of the gas.

- T is the temperature of the gas.

So, we can replace the hypothetical values to calculate the volume of the gas:

Finally, its volume will be 12-fold.

Step 1

The reaction:

N2(g) + 3H2(g) → 2NH3(g) (balanced and completed)

All gases are assumed to be ideal and to be at STP conditions.

----------------

Step 2

STP conditions:

1 mole of gas = 22.4 L

----------------

Step 3

Information provided:

7 L of NH3 produced (ammonia)

Procedure:

By stoichiometry,

1 mole H2 = 22.4 L

1 mole NH3 = 22.4 L

N2(g) + 3H2(g) → 2NH3(g)

3 x 22.4 L H2 -------- 2 x 22.4 L NH3

X -------- 7 L NH3

X = 7 L NH3 x 3 x 22.4 L H2/2 x 22.4 L NH3 = 10.5 L

Answer: 10.5 L of H2 are consumed.

0.0000253moles

The decomposition of NI3 is given as shown below;

Given the following parameters

Mass of NI3 = 0.02 grams

Determine the moles of NI3

Acoording to stochiometry, 2 moles of NI3 preoduces 1 mole of nitrogen. The mole of nitrogen produced is;

Hence the moles of nitrogen produced is 0.0000253moles

Answer:

a.) 8 moles of carbon monoxide (CO).

b.) 20 moles of carbon monoxide (CO)

c.) C is the limiting reactant.

d.) The theoretical yield of CO would be 8 moles.

Explanation:

Let's write the chemical equation:

a.) You can see that 5 moles of carbon (C) reacted produces 4 moles of carbon monoxide (CO), so if we want to know how many moles of carbon monoxide can be produced, we can multiply each coefficient in the chemical equation by 2 (because we will have 10 moles of carbon):

The answer is that we will produce 8 moles of carbon monoxide (CO) by 10 moles of carbon (C).

b.) We can apply the same logic to this case. In the chemical equation, we have 2 moles of sulfur dioxide (SO2) reacted that produces 4 moles of carbon monoxide (CO), so if we want to know how many moles of carbon monoxide can be produced, we can multiply each coefficient by 5 so we will have 10 moles of sulfur dioxide:

The answer is that we will produce 20 moles of carbon monoxide (CO) by 10 moles of sulfur dioxide (SO2).

c.) We have already known that 10 moles of C will produce 8 moles of CO, and 10 moles of SO2 will produce 20 moles of CO. If we react 10 moles of C and 10 moles of SO2, you can note that we're going to have an excess of SO2 because we don't have enough amount of C to produce 20 moles of CO as SO2 do. So based on this logic, C is being consumed first and C would be the limiting reactant.

d.) Remember that the theoretical yield indicates the amount of a product obtained in a chemical reaction.

As we saw before, C is the limiting reactant if we react 10 moles of each reactant, so we have already known that 10 moles of C reacted produces 8 moles of CO, so the theoretical yield of CO would be 8 moles.

The displacement reaction is given as; [tex]2FeCl_{3} + 3Ba(OH)_{2} ----- > 2Fe(OH)_{2} (s) +3 BaCl2[/tex]. We can see that a precipitate was obtained in the reaction.

We know that a displacement reaction is a reaction that involves the combination of two compounds in which there is a kind of exchange between the reactants. We know in this case that this is a double replacement reaction. The anions that are in the system would exchange partners in the products.

Let us now look at the reaction and try to see how to be able to obtain the reaction. One more time the reaction is going to occur between the aqueous solutions of iron III chloride and barium hydroxide. We must recall that the insoluble product is iron III hydroxide.

We know that the product that is observed is a solid and an aqueous products from the reaction.

Learn ore about displacement reaction:https://brainly.com/question/29307794

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STEP-BY-STEP EXPLANATION

What to find? The electronic configuration of tin ion

Tin is an element with an atomic number of 50.

NB: Atomic number = number of proton

Hence, the number of proton of tin = 50

The above tin ion means it has lost two electrons, which make it has a total electron of 48

To write the electronic configuration of tin ion, we will be using the SPDF Notation

spdf are names given to orbitals that hold electrons in atoms.

s - orbital

p- orbital

d- orbital

f -orbital

4

beacause it is4 is teta and 7 is hepta

A diol molecule is a compound that contains two Hydroxyl groups (OH), and these hydroxyl groups are attached to a hydrocarbon chain, which makes the main chain of the compound. In this type of molecule, we can find two intermolecular forces

Between the Carbons and Hydrogens in the hydrocarbon chain we have a Van der Waals force, which is a weak force

In the Hydroxyl groups, we will have a Hydrogen bond, which will be connecting Hydrogens and Oxygens

Explanation:

The majority of nuclear reactors use the isotope uranium-235 as fuel; however, it is only a small part of the natural uranium mined. The concentration must be increased through a process called enrichment. Enrichment is the process of increasing the concentration of uranium-235 atoms in nuclear fuel.

Answer: D. Enrichment

Step 1

The reaction provided:

2 NaN3 (s) ⇨ 2 Na (s) + 3 N2 (g) (completed and balanced)

---------------------

Step 2

Information provided:

100.0 g NaN3 decomposes

-----

Information needed:

The molar masses of:

NaN3) 65.00 g/mol

N2) 28.00

(please, the periodic table is useful here)

---------------------

Step 3

Procedure

By stoichiometry,

2 NaN3 (s) ⇨ 2 Na (s) + 3 N2 (g)

2 x 65.00 g NaN3 ----------------- 3 x 28.00 g N2

100.0 g NaN3 ----------------- X

X = 100.0 g NaN3 x 3 x 28.00 g N2/2 x 65.00 g NaN3

X = 64.62 g

Answer: 64.62 g of N2 produced

Answer: the percent yield of the reaction is 30.7%

Explanation:

The question requires us to determine the percent yield of the reaction that produces copper(I) sulfide, given the theoretical yield and actual yield.

The following information was provided by the question:

Amount of Cu used = 0.0970 mol of Cu

Actual yield of reaction = 2.37 g of Cu2S

To solve this problem, we'll need to determine the theoretical yield of the reaction, considering the amount of copper (Cu) used and the balanced chemical equation for this reaction, and then calculate the percent yield of the reaction.

1) Determining the theoretical yield of reaction:

The reaction between copper and sulfur to produce copper (II) sulfide can be written as:

Considering that 0.0970 moles of Cu were used in excess of S, and the stoichiometry of the reaction, we can calculate the amount of Cu2S produced:

2 mol Cu ---------------------- 1 mol Cu2S

0.0970 mol Cu ------------ x

Solving for x, we have that 0.0485 moles of Cu2S should be obtained from the reaction.

2) Calculating the percent yield of the reaction:

The percent yield of a chemical reaction can be calculated using the following equation:

Note that the theoretical and actual yield values must be used in the same units. Thus, we need to convert the mass given for actual yield (2.37g) to number of moles, considering the molar mass of copper (I) sulfide (159.16 g/mol):

Therefore, the actual yield corresponds to 0.0149 moles of Cu2S.

Now, we can calculate the percent yield of the reaction:

Therefore, the percent yield of the reaction is 30.7%.

There are a lot of properties of ionic compounds to explain.

The most characteristic ones are:

- High melting points

- Hard and brittle

- Electrical conductivity

All of these can be explained by the forces in ionic compounds.

The forces that maintain the ions together are electrostatic forces, which come from the charged ions with opposite signs.

Electrostatic forces are very strong, so and in ions this occur in a crystal lattice, so we need a lot of energy to break this attraction. Because of that, we need a high temperature to make it has enough energy to break this attraction and melt.

This strong attraction also makes the ionic compounds hard to break, because we will need a lot of force to break the ions appart. However, once enough force is applied, its lattice structure is shifted and ions with same charge becomes close to each other, making a repulsive force that breaks them appart, giving them the brittle property.

An electrical conductivity happens when there are free charges in a system. The ionic compounds are composed by charged particles, so if they are free to move, they will conduct electricity. So, when the compound is melted of dissolved, the charged ions, that once were together by the electrostatic force, now can conduct electricity.I have finished answering the question.

Answer:

Smaller grid spacing closes the gap on observations in time and space, resulting in higher resolution model output that is more accurate and reliable.