How many lead atoms are present in a piece of lead of volume 1. 907 cm?


Useful data:


The density of Pb = 11. 34 g. Cm-3.


Avogadro's Number (NA) = 6. 022x1023 atoms. Mol-1


Give your answer to 3 significant figures


Giving your answer with specific significant figures. Use 'e' notation for powers of ten:


for example for 1. 23 x 104, enter 1. 23e4


for example for 6. 022 x 1023, enter 6. 022e23


for example for 1. 23 x 10-6, that is 0. 00000123, enter 1. 23e-6


note no gaps

Answer: 160.0g

Explanation:

130g < 160g

Answer:

Explanation:

A covalent compound is a compound formed by covalent bonds. A covalent bond is formed between two atoms where electrons are shared between the two atoms. This forms a molecule.

What determines whether two elements will form a covalent compound or not is the number of valence electrons present in each of the elements.

Fluorine will form a covalent compound with phosphorous because fluorine has 5 electrons in its outermost shell. It needs 3 more to become stable.

Phosphorous also has 5 valence electrons. It needs 3 more to become stable.

What happens is that 3 atoms of FLuorine combine with one atom of Phosphorus, sharing the valence electrons between themselves. This leads to the formation of the PF3 molecule.

Both the Phosphorous and the Fluorine are now stable.

Answer: Phosphorus

Explanation: since both are non-metals they would both create a covalent bond.

Approximately x% of the acid is dissociated in a 0.50 M solution of HA at 25°C.

The percent dissociation of an acid can be determined using the acid dissociation constant (Ka) and the initial concentration of the acid (HA). The mathematical expression for percent dissociation is:

Percent Dissociation = (Dissociated HA concentration / Initial HA concentration) * 100

In this case, we are given that the acid dissociation constant (Ka) for acid HA is known at 25°C, and we have a 0.50 M solution of HA. However, the value of Ka and specific acid are not provided, so we cannot calculate the exact percent dissociation.

To calculate the percent dissociation, you would need the value of Ka for the specific acid, which indicates the extent of dissociation at equilibrium. Based on this value and the initial concentration of HA, you can calculate the dissociated HA concentration and then use the mathematical expression mentioned above to determine the percent dissociation.

Learn more about  dissociated

brainly.com/question/32501023

#SPJ11

The computers that help control the machines in the factory

This chemical is known as lead (II) nitrate. It is an ionic assembly (salt compound) comprised of lead cations in the +2 oxidation state. With regard to the naming convention, each lead (II) cation is paired with two nitrate anions, each having a charge of -1.

Chemical nomenclature is a set of principles for naming chemical substances in a systematic manner. The International Union of Pure and Applied Chemistry designed and developed the most widely used nomenclature in the world (IUPAC).

The basic goal of chemical nomenclature is to guarantee that no ambiguity exists between a spoken or written chemical name and the chemical compound to which the name refers. Each chemical name should only relate to one substance.

It is required to indicate the charge of these cations or compounds containing these cations when identifying them. Ionic compounds are formed when cations and anions interact. The cation of an ionic compound is named first, followed by the anion. When writing their chemical formulae, they use the same format.

Learn more about naming conventions:
https://brainly.com/question/14326884
#SPJ1

The solution with 100 mL of 10 M NaCl is the most concentrated among the given options.

Molarity is defined as the number of moles of solute per liter of solution.

Calculating the number of moles for each solute in the given solutions:

1. For 2.0 mL of 10 M H₂SO₄:

  Number of moles = (10 mol/L)(0.002 L) = 0.02 mol

2. For 5.0 mL of 1.0 M PbSO₄:

  Number of moles = (1 mol/L)(0.005 L) = 0.005 mol

3. For 2.0 mL of 10.5 M H₂O₂:

  Number of moles = (10.5 mol/L)(0.002 L) = 0.021 mol

4. For 100 mL of 10 M NaCl:

  Number of moles = (10 mol/L)(0.1 L) = 1 mol

Calculating the mass of each solute:

1. For H₂SO₄:

  Mass = number of moles(molar mass) = 0.02 mol(98 g/mol) = 1.96 g

2. For PbSO₄:

 Mass = 0.005 mol(303 g/mol) = 1.515 g

3. For H₂O₂:

  Mass = 0.021 mol(34 g/mol)= 0.714 g

4. For NaCl:

  Mass = 1 mol (58 g/mol) = 58 g

Comparing the masses, we can see that the most concentrated solution is the one with the highest mass, which is 100 mL of 10 M NaCl with a mass of 58 grams. Therefore, the solution with 100 mL of 10 M NaCl is the most concentrated among the given options.

Learn more about molarity here:

https://brainly.com/question/28698457

#SPJ4

Answer:

All food chains start with a producer. The arrows in the food chain below depict the direction in which energy and nutrients flow, i.e. the arrow always points from the eaten to the eater.

hope this helps please mark me brainiest

Answer:

Consumeer

Explanation:

Answer:

C6H12O6 is molar mass of fructose

Explanation:

the major component of honey is fructose.180.16g/mol

Answer:

Oxidation: a type of chemical reaction where one or more electrons are lost.

Oxidation State / Number: a number assigned to an atom describing its degree of oxidation, meaning how many electrons it has gained or lost.

Reduction: a type of chemical reaction where one or more electrons are gained.

Oxidation-Reduction Reaction: a chemical reaction where oxidation and reduction occurs simultaneously

Explanation:

Reduction always occurs at cathode

Oxidation always occurs in anode

These two process occurs in same way independent of nature of cell whether voltaic or electrolytic.

Answer:

chemical formula

Explanation:

Acetic acid is the best option for making a buffer with pH 2.00. Option 3 is the answer.

What is the best weak acid option for making a buffer with pH 2.00?

To make a buffer with a pH of 2.00, we need to select a weak acid with a pKa close to this value. The pKa of an acid is the pH at which half of the acid molecules are dissociated.

For a buffer, we want to choose an acid where the pH is close to its pKa value because at this point, the concentration of both the acid and its conjugate base will be approximately equal.

The Henderson-Hasselbalch equation can be used to calculate the pH of a buffer solution:

\(\mathrm{pH} &= \mathrm{pKa} + \log{\left(\frac{[\mathrm{A^-}]}{[\mathrm{HA}]}\right)} \\\)

Where [A-] is the conjugate base concentration and [HA] is the weak acid concentration.

At pH 2.00, the [H+] concentration is 10⁻² M. Therefore, we need to choose a weak acid with a pKa close to 2.00.

One possible option is acetic acid (CH₃COOH), which has a pKa of 4.76. Using the Henderson-Hasselbalch equation, we can calculate the required ratio of [A-]/[HA]:

\(2.00 &= 4.76 + \log{\left(\frac{[\mathrm{A^-}]}{[\mathrm{HA}]}\right)}\)

\(\log{\left(\frac{[\mathrm{A^-}]}{[\mathrm{HA}]}\right)} &= -2.76 \\\\\frac{[\mathrm{A^-}]}{[\mathrm{HA}]} &= 10^{-2.76} \\\\\frac{[\mathrm{A^-}]}{[\mathrm{HA}]} &= 1.63 \times 10^{-3}\)

Thus, for a buffer with a pH of 2.00, we could mix acetic acid and its conjugate base (sodium acetate) in a 1:163 ratio, which is option 3.

The complete question is -
A student must make a buffer with a ph of 2.00. determine which weak acid is the best option at the specified pH?
1. Sodium disulfate monohydrate

2. Propionic acid

3. Acetic acid

4. Formic acid

To learn more about Acetic acid, visit: https://brainly.com/question/15231908

#SPJ4

Answer:
3Cu + 8HNO3 → 3Cu(NO3)2 + 2NO + 4H2O

Explanation:

In this equation, copper (Cu) reacts with trioxonitrate(V) (HNO3) to produce copper(II) nitrate (Cu(NO3)2), nitrogen monoxide (NO), and water (H2O).

During the reaction, the copper atoms are oxidized by the nitrate ions in nitric acid to form copper(II) ions (Cu2+), while the nitrate ions are reduced to nitrogen monoxide (NO). The water molecules are produced as a byproduct of the reaction.

Overall, the reaction between copper and trioxonitrate(V) is a redox reaction, where oxidation and reduction occur simultaneously. This reaction is commonly used in the laboratory for the preparation of copper(II) nitrate.

Answer:

+1

Explanation:

When discussing distance in the solar system,you use Relative Distance.This tells you the space between two objects with location.

D. Relative distance

The relative distance is the distance that you are felt to cover up, taking the time used to obtain there. Distance relative to a particular reference point, typically one in motion.

Relative distance is calculated measuring distance, using metrics such as time, effort, or cost.

In space, Relative distance means how far apart the planets are when compared to each other and the sun.

Thus, the correct option is D.

Learn more:

brainly.com/question/16347919

The Greeks made the first attempts to provide an explanation for why chemical changes take place.

French chemist Joseph Proust was the first to suggest that substances have specific chemical formulas in the late 1700s. Proust conducted numerous tests and discovered that, regardless of how he got different elements to interact with oxygen, they always did so in specific ratios.

French chemist Antoine Lavoisier's work between 1772 and 1794 led to the first major advancement in the understanding of chemical processes. Mass was discovered to be conserved in chemical reactions by Lavoisier.

To know more about chemical changes visit :-

https://brainly.com/question/29760166

#SPJ4

Answer:

20

Explanation:

(a) P(H2O) = P(HCl) = P(O2) = 0.2 atm The reaction is balanced, and there is no net tendency for the system to shift in either direction.

(b) P(HCl) = 0.3 atm, P(H2O) = 0.35 atm, P(Cl2) = 0.2 atm, and P(O2) = 0.15 atm

If Q < K, the system will shift to the right (forward reaction).

If Q > K, the system will shift to the left (reverse reaction).

If Q = K, the system is already at equilibrium.

To predict the direction in which the system will move to reach equilibrium, we need to compare the initial pressures with the equilibrium expression for the reaction:

2HCl(g) + O2(g) ⇌ 2H2O(g) + Cl2(g)

The equilibrium expression for this reaction is given by:

K = \([H2O]^2[Cl2] / [HCl]^2[O2]\)Now let's analyze each case:

(a) P(H2O) = P(HCl) = P(O2) = 0.2 atm

Since the initial pressures of all the species are equal, we can say that the system is already at equilibrium. The reaction is balanced, and there is no net tendency for the system to shift in either direction.

(b) P(HCl) = 0.3 atm, P(H2O) = 0.35 atm, P(Cl2) = 0.2 atm, and P(O2) = 0.15 atm. To determine the direction of the system's shift, we need to compare the calculated Q (reaction quotient) with the equilibrium constant (K).

Q =\([H2O]^2[Cl2] / [HCl]^2[O2]\)

Q = \((0.35)^2(0.2) / (0.3)^2(0.15)\)

Now compare Q to K:

If Q < K, the system will shift to the right (forward reaction).

If Q > K, the system will shift to the left (reverse reaction).

If Q = K, the system is already at equilibrium.

For more such questions on reaction

https://brainly.com/question/24795637

#SPJ11

The molar mass of oxygen is 15.999 u. (O). We are aware that the oxygen gas we breathe is a diatomic molecule, O2, as are the majority of other common elemental gases.

One mole of a certain material has a mass known as its molar mass.

Molar mass is the weight in grammes of one mole of a material. Every element has a distinct molar mass of their own. For instance, the molar mass of magnesium is 24.3050 g/mol while that of carbon is 12.011 g/mol. Remembering that various elements' atoms have varying quantities of protons, neutrons, and electrons can help us understand why these elements have varied molar weights. The atomic masses listed in the periodic table within this book's front cover correspond to the various weighted average masses of the atoms that make up each element naturally. Varying molar masses result from various atomic masses.

Learn more about Molar mass here:

https://brainly.com/question/12127540

#SPJ4

The distinction between a chemical change and a physical change is best illustrated by the sentence. A physical change will alter the state of matter, but a chemical change results in the formation of a new substance. Therefore, choice A is right.

How does chemistry change?

Chemical reactions between various substances have changed, leading to the creation of new chemicals. The chemical properties of the substance are unaffected by physical changes. Chemical compounds wouldn't alter as a result of the physical change. The matter's physical state may change as a result of the physical change.

A physical change causes the formation of a new substance, whereas a chemical change alters the state of matter.

A physical change occurs naturally, but a chemical change is exploited by scientists to make new compounds. A physical change will result in a different state of matter, but a chemical change produces a new substance.

So the phrase that contrasts a chemical change with a physical change is the most accurate. A physical change will alter the state of matter, but a chemical change results in the formation of a new substance.

Learn more about chemical change here:

https://brainly.com/question/1222323

#SPJ1

The weight percentage of piperazine in the commercial product is approximately 92.71%.

To calculate the weight percentage (wt%) of piperazine in the commercial product, we need to determine the mass of piperazine present in the precipitate and then calculate its percentage relative to the initial mass of the commercial product.

Given:

Mass of commercial product = 0.288 g

Mass of precipitate containing piperazine = 0.555 g

To find the mass of piperazine, we subtract the mass of the precipitate from the mass of the commercial product:

Mass of piperazine = Mass of precipitate - Mass of commercial product

= 0.555 g - 0.288 g

= 0.267 g

Now, we can calculate the weight percentage of piperazine:

wt% of piperazine = (Mass of piperazine / Mass of commercial product) x 100

Substituting the values:

wt% of piperazine = (0.267 g / 0.288 g) x 100

≈ 92.71%

Therefore, the weight percentage of piperazine in the commercial product is approximately 92.71%.

learn more about piperazine here

https://brainly.com/question/10817601

#SPJ11

Answer: Hot Rocks

Explanation:

Answer:

Unless they chemically react with each other, the individual gases in a mixture of gases do not affect each other’s pressure. Each individual gas in a mixture exerts the same pressure that it would exert if it were present alone in the container . The pressure exerted by each individual gas in a mixture is called its partial pressure.

Explanation:

The molar concentration of a 12% sodium chloride solution is approximately 2.05 M.

To determine the molar concentration of a 12% sodium chloride solution, we need to convert the given percentage concentration into molarity.

First, we need to understand that the percentage concentration refers to the mass of the solute (sodium chloride) relative to the total mass of the solution.

In this case, a 12% sodium chloride solution means that there are 12 grams of sodium chloride in 100 grams of the solution.

To convert this into molar concentration, we need to consider the molar mass of sodium chloride, which is 58.5 g/mol.

We can start by calculating the number of moles of sodium chloride in 12 grams:

Moles of sodium chloride = mass of sodium chloride / molar mass of sodium chloride

Moles of sodium chloride = 12 g / 58.5 g/mol = 0.205 moles

Next, we calculate the volume of the solution in liters using the density of the solution. Since the density is not provided, we assume a density of 1 g/mL for simplicity:

Volume of solution = mass of solution / density

Volume of solution = 100 g / 1 g/mL = 100 mL = 0.1 L

Finally, we calculate the molar concentration (Molarity) by dividing the number of moles by the volume in liters:

Molar concentration = moles of solute / volume of solution

Molar concentration = 0.205 moles / 0.1 L = 2.05 M

Therefore, the molar concentration of a 12% sodium chloride solution is approximately 2.05 M.


To learn more about molarity click here: brainly.com/question/31545539

#SPJ11

Answer:

IVA: nonmetal/other metals VIIA:halogens VIII: Nobel Gases

Explanation:makes sense

The volume of the fruit drink comes out to be 0.712 L which is calculated in the below section.

Using the dilution law,

M1 V1 = M2 V2......(1)

Here, M represents the molarity and V represents the volume.

The given parameters are as follows-

M1 = 0.2 M

V1 = 2.5 L

M2  = 0.7 M

To calculate the volume of the fruit drink after dilution, substitute the known values in equation (1) as follows-

0.2 M x 2.5 L = 0.7 M x V2

V2 = (0.2 M x 2.5 L) / 0.7 M

    = 0.5 / 0.7 L

     = 0.7142 L

The volume comes out to be 0.712 L.

To learn more about molarity check the link below-

https://brainly.com/question/30404105

#SPJ4

The p-value is greater than the significance level of 0.05, we do not reject the null hypothesis and conclude that all proportions are equal.

Firstly, let us conduct a Chi-square test of independence of categorical variables based on the information given above. We have three different cases of hypothesis testing that we have to solve one by one.

Case 1: HD​:pSun ​=rhoMan ​=pTue ​=pWed ​=pThu ​=pFri ​=pSat ​=71​
Ha​ : Not all proportions are equal.

Test Statistic
For this hypothesis, we need to compute the test statistic that is given as:
\($$\chi^2=\sum_{i=1}^{k}\frac{(O_i-E_i)^2}{E_i}$$\)  where k is the number of groups/categories. Since we have 7 days of the week, \(k = 7. $O_i$ and $E_i$\) are the observed and expected frequencies respectively.  
Here, we have equal proportions of 71 for each day of the week.
Therefore, the expected frequencies are also equal to 71.
\($$E_i = 71, i=1,2,3,4,5,6,7.$$\)

We also have to use the given information to compute the observed frequencies,
\($O_i$.$$O_1 = 90, O_2 = 99, O_3 = 122, O_4 = 123, O_5 = 130, O_6 = 160, O_7 = 126$$\)

Therefore, the test statistic can be computed as \($$\chi^2=\frac{(90-71)^2}{71} + \frac{(99-71)^2}{71} + \frac{(122-71)^2}{71} + \frac{(123-71)^2}{71} + \frac{(130-71)^2}{71} + \frac{(160-71)^2}{71} + \frac{(126-71)^2}{71}$$$$\chi^2=180.14\)

Now we have to find the p-value of this test. Since the number of degrees of freedom is k - 1 = 7 - 1 = 6, the p-value can be found using the chi-square distribution table with 6 degrees of freedom at the 0.05 significance level. The p-value is 0.000014. ConclusionSince the p-value is less than the significance level of 0.05, we reject the null hypothesis and conclude that not all proportions are equal.

The total number of accidents is \($$90+99+122+123+130+160+126=850$$\)

The percentage of accidents occurring on each day of the week can be found as follows:
\($$Sunday: $$\frac{90}{850}\times 100 = 10.59\%$$Monday: $$\frac{99}{850}\times 100 = 11.65\%$$Tuesday: $$\frac{122}{850}\times 100 = 14.35\%$$Wednesday: $$\frac{123}{850}\times 100 = 14.47\%$$Thursday: $$\frac{130}{850}\times 100 = 15.29\%$$Friday: $$\frac{160}{850}\times 100 = 18.82\%$$Saturday: $$\frac{126}{850}\times 100 = 14.82\%$$\)

From the above percentages, we can see that Friday has the highest percentage of traffic accidents.

Case 2:
HD​: Not all proportions are equal.

Ha​:pSun ​=pMon ​=pTue ​=rhoWed ​=pThu ​=rhoFri ​=rhoSat ​=71

Test Statistic

\($$E_1 = 78.57, E_2 = 86.57, E_3 = 106.86, E_4 = 107.43, E_5 = 113.57, E_6 = 139.43, E_7 = 109.14$$\)

We already know the observed frequencies,
\($$O_1 = 90, O_2 = 99, O_3 = 122, O_4 = 123, O_5 = 130, O_6 = 160, O_7 = 126.$$\)

The test statistic can be computed as:

\($$\chi^2=\frac{(90-78.57)^2}{78.57} + \frac{(99-86.57)^2}{86.57} + \frac{(122-106.86)^2}{106.86}+ \frac{(123-107.43)^2}{107.43} + \frac{(130-113.57)^2}{113.57} + \frac{(160-139.43)^2}{139.43} + \frac{(126-109.14)^2}{109.14} $$$$ \implies \chi^2=34.98$$\)
The p-value is 0.000001.
Conclusion- Since the p-value is less than the significance level of 0.05, we reject the null hypothesis and conclude that not all proportions are equal.

Case 3:

All proportions are equal.
Test Statistic
The expected frequency for each group is
\(E = \frac{850}{7} = 121.43\)
We already know the observed frequencies,
\($$O_1 = 90, O_2 = 99, O_3 = 122, O_4 = 123, O_5 = 130, O_6 = 160, O_7 = 126.$$\)

The test statistic is,

\($$\chi^2=\frac{(90-121.43)^2}{121.43} + \frac{(99-121.43)^2}{121.43} + \frac{(122-121.43)^2}{121.43} + \frac{(123-121.43)^2}{121.43} + \frac{(130-121.43)^2}{121.43} + \frac{(160-121.43)^2}{121.43} + \frac{(126-121.43)^2}{121.43}} \\\implies \chi^2=9.17$$\)

The p-value is 0.1664.

Since the p-value is greater than the significance level of 0.05, we do not reject the null hypothesis and conclude that all proportions are equal.

To know more about p-value visit:

https://brainly.com/question/30761573

#SPJ11

Answer:

4.949 g

Explanation:

One mole of any substance has 6.022 x \(10^{23}\) atoms or particles.

Setting up ratio between moles and atoms:

Moles    :    Atoms

  1          :     6.022 x \(10^{23}\)

  X         :     2.98 x \(10^{22}\)

X = (2.98 x \(10^{22}\))/(6.022 x \(10^{23}\))

X = 0.049 moles

The molar mass of KNO3 is : 39 + 14 + ( 16 x 3 ) = 101 g/mol

Moles   :   Mass

  1          :    101

  0.049  :      X

X = 0.049 x 101

X = 4.949 g

Answer:

it is less dense than oxygen gas.

Explanation:

Hydrogen is the simplest chemical element that exists. The symbol for the chemical element Hydrogen is "H" and it is a colourless, tasteless, odorless, and highly flammable gas.

Hydrogen is a chemical element found in group (1) of the periodic table and as such it has one (1) electrons in its outermost shell. Therefore, Hydrogen has an atomic number of one (1) and a single valence electrons because it has only one proton and one electron in its nucleus.

In Chemistry, the properties of a chemical element that can be observed and measured without changing its chemical nature is known as a physical property. It includes density, color, freezing point, opacity, smell, melting point, viscosity, etc.

Hence, the statement which describes a physical property of hydrogen is that it is less dense (density) than oxygen gas.