How many atoms of lead are present in 78.40 grams of lead?

Answers

Answer 1

mole = 78.40/207.2

= 0.379 mol

1 mol = 6.02 × 10^23 atoms

0.379 mol = X

X = 0.379/1 × 6.02 × 10^23

= 6.296 × 10^-25 atoms


Related Questions

Can someone help? Thank you.

Answers

that' the answer i don't need an explanation

An aqueous solution was prepared by dissolving 266.07 g of AgNO3 ( 169.88 g/mol) in enough water to make a total volume of 250.0 ml. What is the molarity of the solution

Answers

Answer:

The correct answer is 6.265 M.

Explanation:

To find the molarity of the solution, we first must recall that molarity represents the number of moles of solute divided by the number of liters of solution. Thus, our first step should be to convert the solute amount in grams to moles, using the given molar mass.

266.07 g * (1 mol/169.88 g) = 1.5662 mol

Now, we can find the molarity using the following formula:

Molarity = moles solute/liters solution

M = 1.5662 mol/0.25 L

M = 6.265 M

Therefore, the molarity of the solution is 6.265 M.

Hope this helps!

how do you Calculate the molarity of 250 ml of solution in which 2.7 g of MgCl2 are dissolved

Answers

Answer:

Molar mass of MgCl2 is 95 g/mol

Mg = 24 g/mol and Cl = 35.5 ×2 = 71 g/mol

moles = mass given/ molar mass

= 2.7/95 = 0.028 mol

volume = 250/1000 = 0.25 dm3 (ml is the same as dm3)

molarity of MgCl2 = moles/volume

= 0.028/0.25

= 0.112 mol/dm3

If the concentration of KMnO4 was 0.0235 M, calculate the number of moles of MnO4- ions that completely reacted with the H2C2O4

Answers

The number of moles of KMnO4 is  0.0006 moles.

The equation of the reaction is;

6 H^+(аq) + 2 МnO4^- (аq) + 5 Н2С2O4(аq) → 10 CO2 (g) + 8 H20 (l) + 2 Mn²+ (aq)

We can see that the volume of the titrant used = Final - initial burette reading

= 29.6 mL - 3.4 mL = 26.2 mL

Number of moles of H2C2O4 =  0.139 g/90 g/mol = 0.0015 moles

If 2 moles of  MnO4- reacts with 5 moles of H2C2O4

x moles of  MnO4- reacts with 0.0015 moles of H2C2O4

x =  2 moles ×  0.0015 moles / 5 moles

x = 0.0006 moles

Learn more: https://brainly.com/question/9743981

what is the chemistry of super glue

Answers

cyanoacrylate

When cyanoacrylate polymerizes, the cyanoacrylate sticks together on an atomic level, and it becomes solid. Super Glue solidifies in all the microscopic crevices of an object that it moved into when it was a liquid, and it can form chemical bonds with any anions in the object.

10 ml of solution of acetic acid is added to 250 ml volumetric flask , the concentration of diluted vinegar is 0.01 M. What is the % by mass of acetic acid in vinegar if the density of vinegar is 1.05 g/ml. ( C: 12 O:16 H: 1 )​

Answers

The percentage by mass of the acetic acid is 0.057%.

The given parameters:

Volume of the acetic acid = 10 mlVolume of the flask, = 250 mlConcentration of the diluted vinegar = 0.01 MDensity of the vinegar, ρ = 1.05 g/ml

The concentration of the acetic acid is calculated as follows;

[tex]C_1V_1 = C_2 V_2\\\\C_1 = \frac{ C_2 V_2}{V_1} \\\\C_1 = \frac{0.01 \times 250}{10} \\\\C_1 = 0.25 \ M[/tex]

The number of moles of acetic acid in the given concentration;

[tex]C = \frac{mol}{L} \\\\mole = CL\\\\mole = 0.25 \times 10 \times 10^{-3} \\\\mole = 0.0025[/tex]

The molar mass of acetic acid = 60 g/mol

The mass of acetic acid in the given number of moles is calculated as follows;

m = conc. x molar mass

m = 0.0025 x 60

m = 0.15 g

The mass of vinegar in the volume and density;

m = density x volume

m = 1.05 x 250

m = 262.5 g

The percentage by mass of the acetic acid is calculated as follows;

[tex]= \frac{0.15}{262.5} \times 100\%\\\\= 0.057 \%[/tex]

Thus, the percentage by mass of the acetic acid is 0.057%.

Learn more about percentage by mass here: https://brainly.com/question/22060503

To calculate the atomic mass of an element, the percent
abundance of etch isotope is needed. ?

Answers

Answer:

List the known and unknown quantities and plan the problem. Change each percent abundance into decimal form by dividing by 100. Multiply this value by the atomic mass of that isotope. Add together for each isotope to get the average atomic mass

Explanation:

Can someone help me with this please

Answers

Answer:

1.

a. Diagram A

b. Diagram A should stay still, but Diagram B should move/roll to the left.

__________________________________

2.

a. Diagram A and Diagram B are different because the object kg are different, one is 10kg and the other is 2kg.

b. Diagram B because its smaller making it lighter to move when Diagram A is 5 times larger, which will make it heavier.

__________________________________

3.

a. Diagram A and Diagram B compare because the object both equal 3kg.

b. Diagram A will have a greater acceleration because 80n > 40n

What is black powder made of? (Please provide percentage composition of elements as well) Will give brainliest

Answers

Answer:

Black powder has 3 main ingredients: Sulfur ([tex]S[/tex]), charcoal ([tex]C_{7}H_{4}O[/tex]), and potassium nitrate ([tex]KNO_{3}[/tex]).

Charcoal is basically just burnt wood and potassium nitrate can easily be displaced.

Keep in mind that this is BLACK POWDER and not actual gunpowder. The difference between the both is significant since gunpowder has a lot more refining processes it has to go through to be actually used in firearms and such.

The percentage composition of black powder should be 75% Potassium Nitrate, 10% Sulfur, and 15% charcoal.

Should be noted that black powder is not a safe compound to deal with, as static friction could ignite it.

There are other alternatives to Black powder such as nitroglycerin (used in dynamites) which is way more powerful and useful in doing mines and exploration but is an extremely tricky and reactive substance to work with.

I do hope this is just for educational purposes because you need to be certified to even just experiment with this (and there are laws to synthesize such as well, which I won't take any responsibility for)

Answer:

sulfur, charcoal and potassium nitrate

Explanation:

Payback

If 3.5 mols of P2O3 are formed, how many
moles of P4 reacted?

Answers

P2 is 3.5 for p4= 2p2 i.e 2*3.5=7

Answer;561gp203 are required to

produce 10.2 mol H3p03

Determine the frequency of light with a wavelength of 2.672 x 10^-7cm

Answers

Answer:

Determine the frequency of light with a wavelength of 2.775⋅10−7 cm. Answer in units of Hz?❤

9 Select the correct answer. Which statement correctly describes a physical change? O A involves breaking and creating chemical bonds but not changing a phase OB. may involve a change in phase but does not involve a change in the molecular structure OC. may involve converting two or more substances into new substances OD. involves changes at the molecular level O E. involves energy transfer and change in color Reset Next​

Answers

Answer: The statement that correctly describes a physical change is may involve a change in phase but does not involve a change in the molecular structure. The answer is letter B.

Explanation: trust me

Explanation:

OA- because there is breakdown of chemical bonds

A sample of CO2 gas at 100 degrees Celsius has a volume of 250 mL at 760 mm Hg. How many moles of CO2 are present

Answers

There are 8.16 × 10-³ moles of CO2 gas at 100°C with a volume of 250 mL at 760 mm Hg.

HOW TO CALCULATE NUMBER OF MOLES:

The number of moles of a sample of gas can be calculated using the following formula:

PV = nRT

Where;

P = pressure of gas (atm)V = volume (L)n = number of moles (mol)R = gas law constant (0.0821 Latm/molK)T = temperature (K)

According to this question;

P = 760mmHg = 1 atmT = 100°C = 100 + 273 = 373KV = 250mL = 0.250Ln = ?

1 × 0.250 = n × 0.0821 × 373

0.250 = 30.62n

n = 0.250 ÷ 30.62

n = 8.16 × 10-³mol

Therefore, there are 8.16 × 10-³ moles of CO2 gas at 100°C with a volume of 250 mL at 760 mm Hg.

Learn more about number of moles at: https://brainly.com/question/4147359

ghjguygyughyyhghygyuguyg

Answers

Sir! I would have to tell that this is a educational website/app so please don’t type random letters in the question bar if you don’t need help with nothing.

50 PTS!!!!!
What type of chemical reaction is Aerobic Cellular Respiration?

Answers

Answer: During aerobic respiration, catabolic reactions convert larger complex organic molecules into ATP, the chemical that drives most physiological processes in the body.

Explanation:

When the radiation isn't quite strong
enough to kill right away a terrible
Condition follows what is it called
and what is happening.

Answers

When radiation isn’t Enough to kill you but it’s too much for your body to handle you would get what is called radiation poisoning. the symptoms are vomiting, nausea, diarrhea, headache, and several others

What is the mass of an aluminum block if the density of aluminum is 2.70
g/cm and the volume of that block is 4.8 cm?

Answers

Answer: 50 M

Explanation:

Mass

Density×Volume2.7(4.8)11.6111.6g

Formula used

Density=Mass/Volume

A student reads that sodium atoms (Na) react with chlorine (Cl2) molecules to form the compound sodium chloride (NaCl). Which model should the student make to satisfy the Law of Conservation of Matter for the formation of sodium chloride, in simplest form?

Answers

Answer:

c

Explanation:

Law of Conservation of Matter for the formation of sodium chloride, in simplest form would be obeyed when 2 moles of sodium react with 1 ,mole of chlorine to form 2 moles of sodium chloride.

What is law of conservation of matter?

According to law of conservation of matter, it is evident that matter is neither created nor destroyed rather it is restored at the end of a chemical reaction .

Law of conservation of matter and energy are related as matter has mass and mass and energy are directly proportional which is indicated by the equation E=mc².Concept of conservation of matter is widely used in field of chemistry, fluid dynamics.

Law needs to be modified in accordance with laws of quantum mechanics under the principle of mass and energy equivalence.This law was proposed by Antoine Lavoisier in the year 1789.

Learn more about law of conservation of matter,here:

https://brainly.com/question/9434062

#SPJ2

How many grams of N2 are required to react with 4.2 moles of Mg in the following process?

3 Mg + N2 → Mg3N2? (Mg = 24.3 g/mol, N = 14.0 g/mol)

Answers

Answer:

x = 0.45*28/3 = 4.2 g

Explanation:

showing work

N2 = 28 g/mole

3Mg + N2 → Mg3N2

3moles .. 28 g

0.45 moles .. x

x = 0.45*28/3 = 4.2 g (answer)

patient requires blood transfusion. what is the next thing to do? discuss​

Answers

You have to find the blood type so you don’t cross contaminate

Describe echolocation. Give an example of an animal that uses echolocation.

Answers

dolphin and whales use echolocation

It takes 120 mL of 0.15 M of carbonic acid (H2CO3) to neutralize 300 mL of sodium hydroxide (NaOH) for the following balanced chemical reaction:

2NaOH + H2CO3 → N2CO3 + 2NaOH

The concentration of the sodium hydroxide _____.

Answers

First of all, you need to convert mL to L; 120mL = 0.12L, 300mL = 0.3L.

n (moles of carbonic acid) = C (concentration) x V (volume)
n = 0.15M (0.15 mol L-1) x 0.12L
n = 0.018 mol

C (conc. of NaOH) = 0.018 mol x 2 moles (because there’s 2x NaOH) = 0.036 mol
C = n / V
C = 0.036 mol / 0.3 L
C = 0.12 mol L-1

I NEED HELP WItH THIS 5th GRADE QUESTION ITS VERY VERY EASY no Links PLZ and I will Report any useless AWnser PLZ HELP WILL mARK AS BRAINLIST AND Will giVE 1000 Points if correct Answer
How is the mass of a solid measured?

By estimating
With a beaker
With a ruler
With a scale

Answers

Answer:

A Beaker or graduated cylinder

Explanation:

Place the solid into the graduated cylinder. Measure the amount of water in the graduated cylinder. The product is the solid's mass wich i mean by that is what number the water level is at.

Answer:

Beaker

Explanation:

need help with question please ..
-20 points

Answers

Answer:

B oklolol

[tex][tex]\purple{\rule{45pt}{7pt}}\purple{\rule{45pt}{999999pt}}[tex][/tex]

What holds the nucleus together? Group of answer choices alpha particles strong forces electrical forces between the protons beta particles

Answers

Answer:electrical forces between the protons

Explanation: The strong nuclear force pulls together protons and neutrons in the nucleus. At very small distances only, such as those inside the nucleus, this strong force overcomes the electromagnetic force, and prevents the electrical repulsion of protons from blowing the nucleus apart.

Which of the following best represents a ​chemical change?

A. Chopping wood
B. Silver tarnishing (changing color)
C. Grape kool-aid mix dissolving in water
D. Dry ice turning into a gas (sublimation- a change of state)

Answers

B. silver tarnishing

(Please someone help me!) (No links!)
Please ignore the blue dot, I accidentally pressed it and won't get rid of it!

Answers

Answer:

you picked the right one the net worth of force would be 10

Explanation:

how cuz you got 1 team with 6 force then aother 1 with 4 add em up u get 10

If the adoms dont work are they dead

Answers

Answer:  no

Explanation:

Atoms are not and have never been alive so they can't be considered dead. they simply do not meet any reasonable of life, primarily because they are not complex.

Which is better Epoxy or Super Glue?

Answers

Answer:

Personally, I use Superglue

Explanation:

As an electron in an atom moves from a higher energy state to a lower energy state, the atom
A
becomes a negative ion
В.
becomes a positive ion
С.
releases energy
D.
absorbs energy

Answers

Answer:B

Explanation:

Other Questions
Y = 4x + 9What is the slope and the y-intercept? 2000s kids-I'M BOUT TO THROW YOU BACK!!!!!!Which of these songs, older or new, do you remember??1. DJ Got Us Falling In Love - Usher2. So Sick - Ne-Yo3. Cry Me A River - Justin Timberlake4. Classic - MKTO5. do you have a 2000s or 2010s throwback song for #5? A limited partnership is an agreement between at least _____ general partner(s) and ______ limited partner(s). PLEASE HELP WITH ALGEBRA WILL GIVE BRAINLIEST describe the components of a molecule whose atoms are joined by covalent bonds. pls i cant do this more longer i need help i will give brainlist !!!!!!!!! Select all the statements that correctly describe a solution. Multiple select question. A. A solution is a mixture of substances dissolved in water. B. A solution may have more than one solute. C. Not all solutions are liquid. D. A solution is a homogeneous mixture of two or more substances. E. The solute is the substance present in the largest quantity. What were some of the ways that the Roman Catholic Church helped keep education from disappearing during the Middle Ages? Why was this important? Tom is stringing up Christmas lights on his house. The first 2 strings of light have the same number of light bulbs. The 3rd string of light has 12 more light bulbs;? 7 than the first 2 strings. There are a total of 88 light bulbs. How many light bulbs are on the first string? 2a+b+c=9 a+2b+c=8 a+b+2c=11 I NEED THIS ASAP How did nationalism cause revolutionary movements in the Ottoman Empire? People disagreed with the use of conscription to increase the number of soldiers. People wanted to be ruled by leaders who shared their language and culture. People wanted to create alliances to ensure they would be safe from war. People thought industrialization should provide them with higher wages. y describes the Jamestown colony; review the Unit material if needed. A board isThree boards are placed end to end to make a walkway. The first board is 2 feet 8 inches long, the second board is 6 feet 10 inches long, and the third board is 4 feet 9 inches long. How long is the walkway?93 inches long. How long is it in feet and inches? would it be D? in this dialogue what do the stage directions suggest about cecilia? True or false: Judaism is monotheistic. Gonzales v. CARHART explained please PLEASE HELP ME GET ANSWER Which sentence below best supports the idea that Christmas was considered an English holiday by early Americans?Which sentence below best supports the idea that Christmas was considered an English holiday by early Americans?A It wasn't until the 19th century that Americans began to embrace Christmas.B From 1659 to 1681, the celebration of Christmas was outlawed in Boston.C By contrast, in the Jamestown settlement, Captain John Smith reported that Christmas was enjoyed by all and passed without incident.D After the American Revolution, English customs fell out of favor, including Christmas. The first term of an AP is p & it's common difference is q. What it's 10th term? The deceleration of the dummy is less than the deceleration of the passenger compartment.Explain why this is of benefit for the safety of a passenger.