How many moles are 4.20 * 10 ^ 25 atoms of Ca?

Answers

Answer 1

Answer:

~69.744 moles of Ca

Explanation:

Using Avogadro's constant , we know that:

1 mole = 6.022 x 10^23 atoms

S0, the number of moles in 4.20 x 10^25 atoms of Ca:

=(4.20 x 10^25 x 1 )/(6.022 x 10^23)

~69.744 moles of Ca

Q2:How many atoms are in 0.35 moles of oxygen?

1 mole = 6.022 x 10^23 atoms

S0, the number of atoms in 0.35 moles of  oxygen:

=[0.35 x (6.022 x 10^23)]

=2.1077 x 10^23 atoms of Oxygen

Hope it helps:)


Related Questions

Write the equilibrium expression for the following reactions:
1. 4NH3 (g) + 5O2 (g) ↔ 4NO (g) +6H2O (g)
2. ZrI4 (s) ↔ Zr (s) + 2I2 (g)
3. NH3 (g) + HCl (g) ↔ NH4Cl (s)

Answers

Answer:

1. Kc = [NO]⁴ [H₂O]⁶ / [NH₃]⁴ [O₂]⁵

2. Kc = [I₂]²

3. Kc = 1/[NH₃] [HCl]

Explanation:

The equilibrium constant (Kc) is equal to the product of the concentrations of the products raised to their stoichiometric coefficients divided by the product of the concentrations of the reactant raised to their stoichiometric coefficients. It only includes gases and aqueous species.

1. 4 NH₃(g) + 5 O₂(g) ↔ 4 NO(g) + 6 H₂O(g)

Kc = [NO]⁴ [H₂O]⁶ / [NH₃]⁴ [O₂]⁵

2. ZrI₄(s) ↔ Zr(s) + 2 I₂(g)

Kc = [I₂]²

3. NH₃(g) + HCl(g) ↔ NH₄Cl(s)

Kc = 1/[NH₃] [HCl]

Which nuclear equation represents a spontaneous decay?

Answers

Answer:A

Explanation:

1. [tex]^{222}Rn_{86}[/tex] → [tex]^{218}Po_{84} + ^{4}He_{2}[/tex]

What is a spontaneous decay?

Spontaneous fission (SF) is a form of radioactive decay where an atom's nucleus splits into two smaller nuclei and generally one or more neutrons.Out of the given options, only option 1. [tex]^{222}Rn_{86}[/tex] → [tex]^{218}Po_{84} + ^{4}He_{2}[/tex] is an example of spontaneous decay since an atom nucleus is splitting into two daughter nuclei's.Spontaneous decay would refer to whether or not decay was stimulated by bombardment with neutrons or alphas while random decay refers to the selection of which nuclei actually decay

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Water moves on, above or under the surface of the Earth true or false ​

Answers

above because its above

This is true ! Hope it helps

What is the name of the molecule formed when two amino acids join
together?
O A. Peptide
B. Nucleic acid
C. Amine
O D. Disaccharide

Answers

the answer is peptide

Amino acids join together to form a molecule called a dipeptide. The C−N bond is called a peptide bond. The order of amino acids is by convention shown with the free amino group on the left and the free carboxyl group on the right.

Peptide is the name of the molecule formed when two amino acids join together. Therefore, the correct option is option A.

What is peptide?

Short strands of amino acids connected by peptide bonds are called peptidides. A polypeptide is a peptide chain that is longer, continuous, and unbranched. Proteins are polypeptides with a molecular weight of 10,000 Dalton or higher. Oligopeptides, which comprise dipeptides, tripeptides, and tetrapeptides, are chains of fewer than twenty amino acids.

Peptides, along with nucleic acids, oligosaccharides, carbohydrates, and others, belong to the vast chemical families of biological polymers or oligomers. Proteins are made up of one or even more polypeptides structured in a biologically useful manner. They are frequently coupled to other proteins, other macromolecules like DNA or RNA, or ligands like coenzymes and cofactors. Peptide is the name of the molecule formed when two amino acids join together.

Therefore, the correct option is option A.

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How many moles would be in 85.OmL of 0.750M KOH?

Answers

Answer: There are 0.0637 moles present in 85.0 mL of 0.750 M KOH.

Explanation:

Given: Volume = 85.0 mL (1 mL = 0.001 L) = 0.085 L

Molarity = 0.750 M

It is known that molarity is the number of moles of solute present in liter of a solution.

Therefore, moles present in given solution are calculated as follows.

[tex]Molarity = \frac{moles}{Volume (in L)}\\0.750 M = \frac{moles}{0.085 L}\\moles = 0.0637 mol[/tex]

Thus, we can conclude that there are 0.0637 moles present in 85.0 mL of 0.750 M KOH.

1.State two uses of water at home.
2. State two uses of water in industries.
3. What is water conservation?
4. What are some methods of water conservation?​
Helppppp!!!!!!

Answers

Answer:

1. Washing dishes and cooking

2. Water is used as a solvent in the manufacture of beverages and it is also largely used in agriculture.

3. Water conservation is the action of using water wisely and not wasting it.

4. i) Wash dishes in a tub of water instead of under a running tap.

ii) Use a pail of water to wash the car instead of spraying water from a hose.

iii) Make sure that there are no leaking or broken taps and pipes.

Answer:

Washing dishes and cooking

2. Water is used as a solvent in the manufacture of beverages and it is also largely used in agriculture.

3. Water conservation is the action of using water wisely and not wasting it.

4. i) Wash dishes in a tub of water instead of under a running tap.

ii) Use a pail of water to wash the car instead of spraying water from a hose.

iii) Make sure that there are no leaking or broken taps and pipes.

Explanation:

If the volume of water in a cylinder is 8.0mL, but changes to 10.0mL when a solid is carefully lowered into it, the volume of the solid is?

Answers

Answer:

2 mL.

Explanation:

From the question given above, the following data were obtained:

Volume of water = 8 mL

Volume of water + solid = 10 mL

Volume of solid =?

The volume of the solid can be obtained as follow:

Volume of solid = (Volume of water + solid) – (Volume of water)

Volume of solid = 10 – 8

Volume of solid = 2 mL

Therefore, the volume of the solid is 2 mL

What is the answers?
Is my answer right?

Answers

Answer:

I say the correct answers are primary and secondary and teriary.

Explanation:

I say you are right!!

Calculate the percent composition by mass of iron in Fe(NO3)3

Answers

Answer:

It's 23.14 percent

Explanation:

First, the mass of all the elements are:

N = 14

O = 16

Fe = 56

In this molecule you have 3 atoms of N, and 9 atoms of O, so:

3•14 = 42

16•9 = 144

The whole mass of the molecule is:

56 + 42 + 144 = 242

242/100 = 2.42, so 1% is 2.42

56/2.42 = 23.14%

Im stuck on these two questions anyone have the right answer?

Answers

17.) C 4-methylhex-1-ene

5.) D oct-3-ol-5-en

The base area of a pyramid is 1,225m2.if the pyramid is 11.3m high,what is it's volume​

Answers

Answer:

Volume = 4614 m³

Explanation:

The volume of a pyramide is given by the following formula:

Volume = 1/3 * base area * height

We are already given all the required information to calculate the volume by inputting the data:

Volume = 1/3 * 1225 m² * 11.3 mVolume = 4614 m³

The pyramid's volume is 4614 cubic meters.

Zirconium has an atomic number of 40, And an atomic mass of 91. How many electrons does zirconium have?

A. 91
B. 51
C. 40
D. 131

Answers

Answer: 40

Explanation: Whatever the atomic number is, that’s also the number of electrons and protons.

Answer:

40

Explanation:

because the atomic number is how many electrons

Many ski resorts and mountain cities can be reached directly by planes which deposit travelers a mile or more above sea level. This can result in altitude sickness due to hypoxemia, or reduced oxygen in the blood, caused by the unaccustomed exposure to the lower atmospheric pressure at high elevations. On a given day, the prevailing atmospheric pressure in Yellowstone, MT (elevation 2031 meters) might be 0.775 atm. Calculate this pressure expressed in mmHg and in torr.

Answers

Answer:

589 torr or mmHg.

Explanation:

We know that 1 atmospheric pressure is equal to 760 torr or 760 mmHg so calculate 0.775 atm pressure in term of mmHg and torr. We perform the following steps which is

1 atm -------- 760 torr or mmHg

0.775 atm ------- X

By cross multiplication we get

X = 760 x 0.775

X = 589 torr or mmHg

So we can conclude that if 0.775 atm is equals to 589 torr.

What is the perfect composition of calcium in calcium chloride?​

Answers

Answer: 63.96%.

Explanation:

In 111g of Calcium chloride, there is 40g of Calcium and 71g of Chlorine. Percentage Composition of Chlorine is 63.96%.

Hope This Helps!

1. Rearrange the letters to form a word.
1. OOTPSIL
2. BCDEROK
3. UHMSU
4. AOML
5. LCYA
science po ito

Answers

1- Topsoil

2- Bedrock

3- Humus

4- Loam

5- Acyl, Clay, or Lacy

Well that was fun :)

Answer:

Explanation:

1. TOPSOIL

2. BEDROCK

a buffer solution contain 0.1 mole per litres of acetic acid and 0.001 moles perlitre of sodium acetate.what will be its pH?(k=1.8×10-5)

Answers

Answer: The pH of the solution is 2.74.

Explanation:

To calculate the pH of the acidic buffer, the equation for Henderson-Hasselbalch is used:

[tex]pH=pK_a+\log (\frac{\text{[conjugate base]}}{\text{[acid]}})[/tex]         .......(1)

The power of the acid dissociation constant is the negative logarithm of the acid dissociation constant. The equation for it is:

[tex]pK_a=-log K_a[/tex]        ......(2)

The chemical equation for the reaction of acetic acid and NaOH follows:

[tex]CH_3COOH+NaOH\rightleftharpoons CH_3COONa+H-2O[/tex]

Given values:

[tex]K_a=1.8\times 10^{-5}[/tex]

Putting values in equation 2:

[tex]pK_a=-log (1.8\times 10^{-5})\\\\pK_a=4.74[/tex]

We are given:

[tex]CH_3COOH[/tex] = 0.1 M

[tex]CH_3COONa[/tex] = 0.001 M

Plugging values in equation 1:

[tex]pH=4.74+\log (\frac{0.001}{0.1})\\\\pH=4.74-2\\\\pH=2.74[/tex]

Hence, the pH of the solution is 2.74.

a. acidic
b. basic
; neutral
d. will not be affected
Find the molarity of 10% NaOH.[MOE 2003
a. 1.5
b! 2.5
c. 4
d. 0.4
10 ml of 2.5 N NaOH is mixed with 20 ml of
N HCI. The mixture is diluted to 100 ml. WI
is the nature of mixture?
IMOF 20​

Answers

1. You didn't post the question to Number 1.

2.

10% means There's 10g in 100ml of this solution.

This is the weight/volume(w/v) expression of concentration.

So

We have Mass =10g

volume =100ml

Molarity = Moles of solute/volume of solution(in LITRES)

Moles=Mass/Molar mass

Molar mass of NaOH=40g/mol

Mole=10/40

=0.25mole

Volume =100ml =0.1Litres

MOLARITY=0.25/0.1 =

=2.5M

OPTION B.

3. NOTE: THE MOLARITY AND NORMALITY OF NAOH AND HCL ARE THE SAME(This doesn't happen for all compounds tho)

So We can take 2.5N(Normality) of NaOH to be 2.5M(Molarity) NaOH

I think you forgot to write the Normality of the second one. I'll take it to be 1N. Maybe you can then Input supposed value when you're solving on your own

So

1N HCl is same as 1M HCL

We were given their respective volumes

2.5M NaOH can also be written as 2.5mole/volume(in Liters)

The volume of NaOH =10ml or 0.01L

Moles = 2.5mole/L x 0.01L

You notice that Liters on top and bottom cancels out... leaving the moles

So

Mole=0.01x2.5 = 0.025moles of NaOH

we're gonna do the same for 1N HCl in 20ml(0.02L)

So

Mole = 1 x 0.02 =0.02moles

Total Mole = 0.02 + 0.025 =0.045moles

The Final Volume is 100ml as stated in the question. It was diluted to 100ml or 0.1L

So

Final Concentration In Molarity

= Total Moles/Volume in L

=0.045/0.1

=0.45M.

How can we classify the group of elements by just looking at its valence configuration?

Answers

Electron configurations

Valence electrons are electrons used in forming bonds and are in the outer shell of an element.  

The bond that occurs can be either an ionic bond or a covalent bond  

Valence electron determination using electron configurations.  

The main group elements usually have valence electron configurations in the s and p subshells  

While the transition elements in the subshells (n-1) d  

Further explanation

The location of the elemental groups in the periodic system is determined by the number of valence electrons filling the last sub-shell  

The period of an element is determined from the valence shell (the biggest main quantum number (n) )

In an atom, there are levels of energy in the shell and subshell  

This energy level is expressed in the form of electron configurations.  

Writing electron configurations starts from the lowest to the highest sub-shell energy level. There are 4 sub-shells in the shell of an atom, namely s, p, d, and f. The maximum number of electrons for each subshell is  

s: 2 electrons  

p: 6 electrons  

d: 10 electrons and  

f: 14 electrons  

Charging electrons in the subshell uses the following sequence:  

1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d¹⁰, 4p⁶, 5s², 4d¹⁰, 5p⁶, 6s², etc.  

The solubility of an ionic compound can be expressed as the number of moles of the compound that will dissolve per liter of solution (molarity). The saturated solution has approximately____(a) sodium ions dissolved in it (give an estimate of the average value.) The solution (not the solid) contains approximately_____(b) moles of sodium ions.

Answers

Answer:

Number of moles  of sodium dissolved =  6.0 *10^23

Explanation:

The image for the question is attached

Solution

a) Total 181 ions of Na are dissolved

b)

The number of moles of sodium dissolved = 181/6.023 *10^23

Number of moles  of sodium dissolved = 5.987 * 10^23

Number of moles  of sodium dissolved =  6.0 *10^23

Calculate the pH when (a) 24.9 mL and (b) 25.1 mL of 0.100 M HNO3 have been added to 25.0 mL of 0.100 M KOH solution.

Answers

Answer:

Suppose you added some solid NaCl to a saturated solution of NaCl at 20℃ and warmed the mixture to 40℃. What would happen to the added NaCl?

Explanation:

can you help with this one

1. Phosphorous reacts with bromine to form phosphorous tribromide. If 35.0 grams of bromine
reacted and 27.9 grams of phosphorous tribromide are actually formed.
what is the percent yield of phosphorous tribromide (PBr3)?
2 P + 3 Br2 ---> 2 PBr3
(Note that the molar masses: P=30.97g, Br = 79.90g) Show your steps
*
Please help me

Answers

Answer:

70.6 %

Explanation:

First step, we define the reaction:

2P + 3Br₂  →  2PBr₃

We determine the moles of reactant:

35 g . 1mol / 159.8 g = 0.219 moles

We assume, the P is in excess, so the bromine is the limiting reagent.

3 moles of Br₂ can produce 2 moles of phophorous tribromide

Then, 0.219 moles may produce (0.219 . 2) /3 = 0.146 moles of PBr₃

We convert moles to mass:

0.146 mol .  270.67 g /mol = 39.5 g

That's the 100 % yield reaction, also called theoretical yield. The way to determine the % yield is:

(Yield produced / Thoeretical yield) . 100

(27.9 / 39.5) . 100 = 70.6 %


What does the number 7 mean in the following example-73Li?
a. The number of protons
b. The atomic mass
c. The atomic number
d. The number of electrons

Answers

Answer:

7 is the mass number of li and 3 is the atomic number

a 3

b 7

c 3

d 4

please help? Liquid, Chemical Properties, Compounds or Products?​

Answers

Answer:

They are compounds.

Explanation:

..........

Answer:

compounds!!

Explanation:

...........

Given the following equation: 3C12 (g) + 8NH3 (g) → N2(g) +
ONH4Cl (S)
How many moles of NH3 are required to produce 12 moles of
NH4Cl?

Answers

Answer:

The balanced equation will be your greatest asset in Solving this.

The Balanced Equation is

3Cl2 + 8NH3---> N2 + 6NH4Cl

So

From this reaction...

3 moles of NH3 is required to produce 6 moles of NH4Cl

Now the question asked.... How Many Moles of NH3 will be needed to produce 12moles of NH4Cl?...

The answer is simply 6moles of NH3.

Why?

Since 3moles of NH3 produce 6 moles of NH4Cl

It makes sense that

6moles of NH3 will produce 12moles of NH4Cl.

Its a simple Ratio.

Hope this helps...

I'm Open to questions if you have any.

Have a great Day!

Balance the following equation by LCM method.Mg + H2O = Mg(OH)2 + H2​

Answers

Answer:

Mg + 2H₂O —> Mg(OH)₂ + H₂

Explanation:

Mg + H₂O —> Mg(OH)₂ + H₂

The above equation can be balance as illustrated below:

Mg + H₂O —> Mg(OH)₂ + H₂

There are 2 atoms of H on the left side and a total of 4 atoms on the right side. It can be balance by writing 2 before H₂O as shown below:

Mg + 2H₂O —> Mg(OH)₂ + H₂

Now, the equation is balanced

****Check***

Element >>>>> Reactant >>>> Product

Mg >>>>>>>>>> 1 >>>>>>>>>>> 1

H >>>>>>>>>>> 4 >>>>>>>>>>> 4

O >>>>>>>>>>> 2 >>>>>>>>>>> 2

The balanced equation of Mg + H2O = Mg(OH)2 + H2​ is given as

Mg + 2H₂O —> Mg(OH)₂ + H₂

What is the balance equation?

Generally, the equation for the Chemical equation  is mathematically given as

Mg + H₂O —> Mg(OH)₂ + H₂

Therefore, We se that  we have on the LHS

Mg=1

H=2

O=1

and on The RHS

Mg=1

H=4

O=2

Therefore to balance, we add 2 to H and 1 to O giving

Mg + 2H₂O —> Mg(OH)₂ + H₂

Read more on Chemical equation

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are either positively charged or negatively charged species in which the number of protons and electrons are not equal. ____________ bonds are chemical bonds that results from the sharing of electrons. ____________ are positively charged ions with more ____________ than ____________ . ____________ ion is an example of a polyatomic anion. ____________ is the system of assigning an unambiguous name to a compound.

Answers

Answer:

1. Ions are either negatively or positively charged species in which the number of electrons and protons are not equal.

2. The chemical bond that arises due to the sharing of electrons is termed a covalent bond.

3. The positively charged ions are called cations, which comprise more protons than electrons.

4. An example of a polyatomic anion is the hydroxide anion.

5. The system of assigning an unambiguous name to a compound is called nomenclature.

Equal masses of gaseous N2 and Ar are placed in separate flasks of equal volume at the same temperature. Tell whether each of the following statements is true or false. a. There are more molecules of N2 present than atoms of Ar. Blank 1 b. The pressure is greater in the Ar flask. Blank 2 c. The N2 molecules collide more frequently with the walls of the flask than do the Ar atoms.

Answers

Answer:

c. The N2 molecules collide more frequently with the walls of the flask than do the Ar atoms.

Explanation:

The statements are:

a. There are more molecules of N2 present than atoms of Ar. FALSE. Because 1 mol of molecules of N2 = 28g and 1 mol of molecules of Ar = 40g. As there are equal MASSES, you will have more molecules of N2 than Ar molecules

b. The pressure is greater in the Ar flask. FALSE

Because pressure is directly proportional to amount of molecules. As molecules N2 > Molecules Ar. The pressure is greater in N2 flask

c. The N2 molecules collide more frequently with the walls of the flask than do the Ar atoms. TRUE

The collision probability of N2 is higher because there are more molecules presents

how will you know whether the crystallization point is reached​

Answers

Answer:

Place a glass rod in the solution, if the crystallisation point has been reached, you should notice small crystals formed on it.

Which one of the following is an example of a difficulty caused by thermal
expansion?
A. milkshakes melting
B. paint chipping off the side of a house
C. buckled railroad tracks on a hot day
D. sagging power lines on a cold day

Answers

Answer:buckled railroad tracks on a hot day

Explanation: i just did it

What type of decay changes the atomic number of the atom?
B. Translocation
C. Translation
D. Transuranium
A. Transmutation

Answers

Answer:

d

Explanation:did test

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