The number of atoms in a 158.4 g sample of CO2 gas at STP is:

1.277 x 1025 atoms

2.167 x 1024 atoms

6.502 x 1024 atoms

6.651 x 1024 atoms

Answer:

Explanation:

Here we'll use our formula for specific heat, Q=mcΔT.

Q= Heat (Joules), m=mass (g), c=specific heat

ΔT= (final temperature - initial temperature)

When we add a heated piece of metal in water at a lower temperature, the metal will lose heat and the water will absorb that heat. Over time they will eventually reach an equilibrium, here we have it at 21.9 C. If you recall in thermodynamics, , when we lose heat it is exothermic and the values of exothermic reactions are negative, and the values of endothermic reactions are positive. So we can say the heat of the metal is exothermic and releasing heat into the water until they reach equilibrium, thus they are equal. Keeping in mind Q= heat,

-Q metal = Q water.

We can expand this equation to -mcΔT= mcΔT.

Our equation reflects what is happening to the metal and the water.

Before we start, it might be helpful to remember that the

c=specific heat of water= 4.186 J/g C

Let's plug in what we know and solve for c=specific heat of metal. I'll start with the left side then go to the right side.

-(23.9g)(c)(29.9-97.8) = (52.4g)(4.184)(29.9 - 21.9)

-(23.9gc)(29.9-97.8) = (52.4g)(4.184)(29.9 - 21.9)

-(23.9g)(c)(-67.9) = (52.4g)(4.184)(29.9 - 21.9)

1623c = (52.4g)(4.184)(29.9 - 21.9)

1623c = (52.4g)(4.184)(8)

1623c = 1754

c= [tex]\frac{1754}{1623}[/tex]

c= 1.08

This means it takes less heat to raise the temperature of the piece of metal ( in comparison to the water, which require more ).

Answer:

C: francium-221

Explanation:

First of all to get a broader perspective, every isotope of francium usually undergoes decay to form astatine, radium, or radon.

Now, Francium-223 and francium-221 are it's only isotopes that occur in nature.

However, francium-221 is the one that undergoes alpha decay to produce astatine-217.

Answer:

b < c < a < d

Explanation:

The weak acid with the lowest pKa will be the most acidic. In the other way, the conjugate base which the acid is weak will be strong.

The weak base with the lowest pKb will be the most basic. And the conjugate base of the weak base will be a strong acid.

Ka Acetic acid = 1.8x10-5

Ka HCN = 1.9x10-10

Kb pyridine = 1.7x10-9

Kb NH3 = 1.8x10-5

NH4Br is the conjugate base of a weak base. That means is a strong acid.

NH4Br has the lowest pH

NaBr is the conjugate base of a strong acid, HBr. That means NaBr is neutral

The most basic between the conjugate base of the acetic acid, NaCH3CO2 and KCN is KCN because the acetic acid is the stronger acid regard to HCN.

The rank is:

NH4Br < NaBr < NaCH3CO2 < KCN

Answer:

P-block

Explanation:

Chlorine

Atomic number (Z) 17

Group group 17 (halogens)

Period period 3

Block p-block

Answer:

What does "in which block does chlorine lies"? That question has no way to answer it because there is no question content lol

Explanation:

Answer:

According to the kinetic molecular theory of gases, the average speed and kinetic energy of gas molecules would INCREASE.

Explanation:

In the kinetic molecular theory of gases, assumptions were made based on macroscopic properties of gas (pressure, volume and temperature) which are as a result of the microscopic properties like the position and the speed of the gas molecules. The kinetic molecular theory explains the behaviour of gases through the following 5 assumptions made about an ideal gas;

--> Molecules of a gas are in constant and rapid motion in straight lines until they collide with one another and with the walls of their containers.

--> The actual volume occupied by the had is negligible compared with the volume of the container.

--> Forces of attraction or repulsion between the molecules of a gas are negligible

--> The collision between the molecules is perfectly elastic.

--> The average kinetic energy of the gas molecules is proportional to the temperature of the gas.

Because gas molecules are in constant motion, it has kinetic energy which can be altered when there is increase in pressure. An increase in pressure will cause gas molecules to collide more frequently with one another. This in turn leads to increase in average speed and the kinetic energy of the individual molecules.

Answer:

conduction

Explanation:

The size, length, and height of the figure are the main factors which determine the shadow of a organism.

The size, length, and height of the figure are the main factors which determine the shadow of a organism.

A shadow is a dark area where light from a light source is blocked by an opaque object. It occupies all of the three-dimensional volume behind an object with light in front of it. The cross section of a shadow is a two-dimensional silhouette, or a reverse projection of the object blocking the light.

A point source of light casts only a simple shadow, called an "umbra". For a non-point or "extended" source of light, the shadow is divided into the umbra, penumbra, and antumbra. The wider the light source, the more blurred the shadow becomes. If two penumbras overlap, the shadows appear to attract and merge. This is known as the shadow blister effect.

Learn more about shadow,here:

https://brainly.com/question/20323273

#SPJ2

Answer:

The main similarity between carbohydrates, proteins and fats is that they are all used for energy.

Explanation:

I hope this helps, have a blessed day.

Answer: element 68 is Erbium, should there be a picture attached?

Explanation:

Answer: 56 grams of gaseous ammonia (NH3), has 3.28 moles and [tex]19.80 \times 10^{23}[/tex] molecules.

Explanation:

Given: mass of [tex]NH_3[/tex] = 56 g

Molar mass of [tex]NH_3[/tex] is 17.03 g/mol.

As moles of a substance are its mass divided by the molar mass. Therefore, moles of [tex]NH_3[/tex] are calculated as follows.

[tex]No. of moles = \frac{mass}{molar mass}\\= \frac{56 g}{17.03 g/mol}\\= 3.28 mol[/tex]

According to the mole concept, 1 mole of every substance contains [tex]6.022 \times 10^{23}[/tex] molecules. Hence, number of molecules present in 3.28 moles of [tex]NH_3[/tex] are calculated as follows.

[tex]No. of molecules = no. of moles \times 6.022 \times 10^{23}\\= 3.28 mol \times 6.022 \times 10^{23}\\= 19.80 \times 10^{23}[/tex]

Therefore, we can conclude that 56 grams of gaseous ammonia (NH3), has 3.28 moles and [tex]19.80 \times 10^{23}[/tex] molecules.

Answer:

every 4 years we add an extra day, February 29th, to our calendars these extra days called leave days help synchronize our human created calendars with us orbit around the sun and the actual passing of our seasons

Answer:

In a physical change the appearance or form of the matter changes but the kind of matter in the substance does not. However in a chemical change, the kind of matter changes and at least one new substance with new properties is formed.

Answer:

Rubidium and cesium

Explanation:

It is noteworthy to say here that larger cations have more stable superoxides. This goes a long way to show that large cations are stabilized by large cations.

Let us consider the main point of the question. We are told in the question that the reason why potassium reacts with oxygen to form a superoxide is because of its low value of first ionization energy.

The implication of this is that, the other two metals that can be examined to prove this point must have lower first ionization energy than potassium. Potassium has a first ionization energy of 419 KJmol-1, rubidium has a first ionization energy of 403 KJ mol-1 and ceasium has a first ionization energy of 376 KJmol-1.

Hence, if we want to validate the hypothesis that potassium's capacity to form a superoxide compound is related to a low value for the first ionization energy, we must also consider the elements rubidium and cesium whose first ionization energies are lower than that of potassium.

Answer:

False

Explanation:

The question is incomplete, the complete question is;

A student determines the number of moles of water in a

hydrated metal oxide by weighing a clean, dry crucible

and lid while the crucible is empty, then reweighing the

crucible and lid with a sample of the hydrate, heating the

crucible and lid with a Bunsen burner and then

reweighing the crucible and lid with the sample after

cooling to room temperature. Which error will result in

too high a value for the amount of water of hydration?

(A) The heating is conducted only once instead of the

three times recommended by the procedure.

(B) The lid is left off the crucible when it is weighed

with the hydrated oxide.

(C) The metal oxide reacts partially with oxygen in the

air, forming a compound in a higher oxidation state.

(D) Some of the heated oxide is spilled from the crucible

before it can be weighed.

Answer:

(D) Some of the heated oxide is spilled from the crucible

before it can be weighed.

Explanation:

It is possible to determine the number of moles of water in a hydrated metal oxide by weighing a clean, dry crucible and lid while the crucible is empty, then reweighing the crucible and lid with a sample of the hydrate. The crucible and lid with the sample are heated, cooled and reweighed.

As this process is going on, suppose some of the heated oxide is spilled from the crucible, then the mass of heated or anhydrous oxide decreases leading to a consequent increase in the number of moles of water in the hydrated metal oxide, hence the answer above.

The too high a value for the amount of water of hydration error is occur due to heating of given hydrated sample.

Hydrated compounds are those compounds in which water molecule is present with the normal compound.

To get the correct value of weight of hydrated compound, first we have to weigh the empty crucible and lid and then with sample of compound in the crucible and lid. After this substract empty weigh of crucible & lid from the sample-crucible-lid weigh. If we substract the weigh from heated sample crucible and lid, then we get the error because the hydrated water molecule may decompose due to heating and moles of water increases.

Hence, error will occur if we heat the sample.

To know more about hydrated compound, visit the below link:

https://brainly.com/question/16275027

Answer:

Far as I know coefficients are unitless. sorry if this don't help ;)

Answer:

sdfhioupsdfiuhikdfjsdfhsdksdflk";d089sdfojskdfk

pls give brainlyest

Explanation:

200 IQ intellectual right here ^^

Answer:

B.Urea

Explanation:

When an amino acid is broken down, the nitrogen it contains is converted into urea by the liver which then is excreted via the kidneys.

Answer:

urea

Explanation:

when u eat proteins the body breaks them down into amino acids . Ammonia is produced from leftover amino acids and it must be removed from the body. the liver produces many chemicals (enzymes) that change ammonia into a form called ureas

Answer:

1.19 is the answer

Explanation:

Answer:

[tex] \huge\pink{ \mid{ \underline{ \overline{ \tt Answer :- }} \mid}}[/tex]

=> First Aid enables you to assist persons who become injured in the event of an accident or emergency situation until help arrives.

[tex] \huge\blue{ \mid{ \underline{ \overline{ \tt Situations :- }} \mid}}[/tex]

=> If an accident happens in the workplace, in your home or in a public space, you can use the help of a first aid kit.

=> In situations such as when someone ingests a harmful substance, suffers from a heart attack, a seizure or stroke, is involved in a motor vehicle accident or is caught in a natural disaster, a person trained and knowledgeable in even the very basics of First Aid can be of extreme importance in assisting the injured person(s) until emergency responders arrive.

Answer:

No the graph does not support Charles' Law.  Both volume and temperature increase so it would be a direct relationship.

Explanation:

Answer:

Bubv amp hindi marunong amp

Answer:

2,6–dimethylcyclohexanol

Explanation:

To name the compound given in the question above, we must first obtain the following:

1. Determine the functional group of the compound.

2. Locate the longest continuous carbon chain.

3. Identify the substituent group attached to the compound.

4. Locate the position of the substituent group.

5. Combine the above to obtain the name of the compound.

Now, we shall determine the name IUPAC name of the compound. This can be obtained as follow:

1. The compound contains the –OH group. Thus, the compound is an alcohol.

2. The compound is a cyclic compound with six carbon forming the ring. Thus, the parent name of the compound is cyclohexane. Thus, the presence of the –OH group changes the parent name of the compound to cyclohexanol.

3. The substituent group attached to the compound is methyl (–CH₃)

NOTE: There are two –CH₃ groups attached to the compound.

4. The position of the 1st –CH₃ group is at carbon 2, while the 2nd is at carbon 6.

NOTE: Counting is done from the carbon bearing the functional group.

5. Therefore, the name of the compound is:

2,6–dimethylcyclohexanol

Answer:

a. True

Explanation:

Distillation process is a process that is used to separate the components or the substances from the liquid mixtures by using selectively boiling and condensation.

While fractional precipitation is a process which separates the ions from solution based on the different solubilities.

Therefore, the answer is true.

Answer:

H₂(g) + F₂(g) ⇒ 2 HF(g)   ΔH°rxn = -542 kJ

Explanation:

Let's consider the unbalanced equation that occcurs when H₂(g) reacts with F₂(g) to form HF(g).

H₂(g) + F₂(g) ⇒ HF(g)

In order to get the balanced equation, we will multiply HF(g) by 2.

H₂(g) + F₂(g) ⇒ 2 HF(g)

To convert a balanced equation into a thermochemical equation, we need to add the standard enthaply of the reaction, considering that 542 kJ of energy are evolved for each mole of H₂(g) and there is 1 mole of H₂(g) in the balanced equation. By convention, when energy is released, it takes a negative sign. The thermochemical equation is:

H₂(g) + F₂(g) ⇒ 2 HF(g)   ΔH°rxn = -542 kJ

Answer: THE STANDARD HEAT OF SOLUTION OF SODIUM HYDROXIDE IN WATER IS -7.68 KJ PER MOLE.