Please tell the answer​

Answer:

Al(s)<NaF(s)<HF(g)<SiH4(g)<SiF4(g)

Explanation:

Hello,

In this case, we can arrange the increasing order of entropy at 25 \°C by taking into account, at first, that since solids are more molecularly organized than gases, the first we have solid sodium fluoride and solid aluminium, but in this case, as the higher the molar mass, the higher the entropy, the molar mass of aluminium is 27 g/mol and 42 g/mol for sodium fluoride, therefore, we first have:

Al(s)<NaF(s)

Afterwards, since the molar mass of hydrogen fluoride (HF), silicon fluoride (SiF4) and silane (SiH4) are 20, 104 and 32 g/mol respctively, since silicon fluoride has the greater molar mass, it also has the higher entropy. In such a way, the overall order turns out:

Al(s)<NaF(s)<HF(g)<SiH4(g)<SiF4(g)

Best regards.

Answer:

[tex]T_b=-88.48\°C[/tex]

Explanation:

Hello,

In this case, since the entropy of vaporization is defined in terms of the enthalpy of vaporization and the boiling point of the given substance, nitrous oxide, as shown below:

[tex]\Delta _{vap}S=\frac{\Delta _{vap}}{T_b}[/tex]

Solving for the boiling point of nitrous oxide, we obtain:

[tex]T_b=\frac{\Delta _{vap}H}{\Delta _{vap}S}=\frac{16.53\frac{kJ}{mol}*\frac{1000J}{1kJ} }{89.51\frac{J}{mol} } \\ \\T_b=184.67K[/tex]

Which in degree Celsius is also:

[tex]Tb=184.67-273.15\\\\T_b=-88.48\°C[/tex]

Best regards.

The question is incomplete,the complete question is as follows:

A piece of solid Fe metal is put into an aqueous solution of Cu(NO3)2. Write the net ionic equation for any single-replacement redox reaction that may be predicted. Assume that the oxidation state of in the resulted solution is 2 . (Use the lowest possible coefficients for the reaction. Use the pull-down boxes to specify states such as (aq) or (s). If a box is not needed, leave it blank. If no reaction occurs, leave all boxes blank and click on Submit.)

Answer:

Fe(s) + Cu^2+(aq) => Fe^2+(aq) + Cu(s)

Explanation:

An ionic equation is a chemical equation which shows clear image of reactions of the electrolytes in aqueous solution.

Molecular reaction equation for the reaction between iron and copper II nitrate is as follows:

Fe(s) + Cu(NO3)2(aq) => Fe(NO3)2(aq) +Cu(s)

The net ionic equation for any single-replacement redox reaction is as follows:

Fe(s) + Cu^2+(aq) => Fe^2+(aq) + Cu(s)

[tex] \LARGE{ \boxed{ \rm{ \pink{Solution:}}}}[/tex]

We know, 1 m³ of space can hold 1000 l of the substance.

⇛ 1 m³ = 1000 l----(1)

And, 1 l is 1000 times more than 1 ml

⇛ 1 l = 1000 ml------(2)

So, From (1) and (2),

⇛ 1 m³ = 1000 × 1000 ml

⇛ 1m³ = 1000000 ml

We had to find,

⇛ 1.40 m³ = 1.40 × 1000000 ml

⇛ 1.40 m³ = 140/100 × 1000000 ml

⇛ 1.40 m³ = 1400000 ml

⇛ 1.40 m³ = 14,00,000 ml / 14 × 10⁵ ml / 1.4 × 10⁶ ml

☃️ So, 1.40 m³ = 14 × 10⁵ ml / 1.4 × 10⁶ ml.

━━━━━━━━━━━━━━━━━━━━

Answer:

D. Acetone is captured and cooled.

The correct answer is option D: Acetone is captured and cooled.

Distillation is a method of separation based on the difference in boiling point of two liquids.

The liquid that has a lower boiling point is first separated from the mixture. It vaporizes, cooled and collected before the liquid that has a higher boiling point.

In this case, acetone is captured and cooled before water since it has a boiling point of 56ºC and water has a boiling point of 100ºC.

https://brainly.com/question/15187318

Answer:

CO =Coordinate Covalent Bond ,H2O = Water , NE= Nickel or Neon ,KCL=Potassium Chloride and O2 = Water

Explanation:

hope you wiill get help from me please follow me

Answer:

I think b acid makers

Explanation:

hope it will help you

Answer:

0.17 lb

Explanation:

78 g * (1 lb/454 g)=0.17 lb

If you want additional help with chemistry or another subject for FREE, check out growthinyouth.org.

Answer:

One carbon atom and the nitrogen atom have nonzero formal charges.

Explanation:

The compound Acetonitrile has sixteen valence electrons as is easily San from its structure. It contains a carbon nitrogen triple bond with a lone pair of electrons on nitrogen. All atoms satisfy the octet rule and there is no hyper valent atom in the molecule.

The formal charge an carbon and nitrogen is calculated as follows;

No. of valence electron on atom - [non bonded electrons + no. of bonds]

Therefore, for carbon and nitrogen, we have;

formal charge on carbon = 4 - (0 + 4) = 0

formal charge on nitrogen = 5 - (2 + 3) = 0

Hence carbon and nitrogen both possess zero formal charges.

Answer:

1. metals

2. atom

3. homogeneous

4. compounds

5. lustrous

6. saturated

7. colloidal

8. homogeneous

Explanation:

Answer:

n = 0.207 mole

Explanation:

We have,

P = 1 atm

V = 5 liter

R = 0.0821 L.atm/mol.K

T = 293 K

We need to find the value of n. The relation is as follows :

PV = nRT

Solving for n,

[tex]n=\dfrac{PV}{RT}\\\\n=\dfrac{1\times 5}{0.0821 \times 293}\\\\n=0.207\ \text{mol}[/tex]

So, the value of n is 0.207 mol.

Answer: Mn is getting reduced.

Explanation:

Oxidation-reduction reaction or redox reaction is defined as the reaction in which oxidation and reduction reactions occur simultaneously.

Oxidation reaction is defined as the reaction in which a substance looses its electrons. The oxidation state of the substance increases.

Reduction reaction is defined as the reaction in which a substance gains electrons. The oxidation state of the substance gets reduced.

[tex]MnO_4^-(aq)+H_2C_2O_4(aq)\rightarrow Mn^{2+}(aq)+CO_2(g)[/tex]

Oxidation : As Manganese has an oxidation state of +7 in [tex]MnO_4^-[/tex] and +2 in [tex]Mn^{2+}[/tex], the oxidation state is decreasing and hence it is getting reduced.

Reduction : As carbon has an oxidation state of +3 in [tex]H_2C_2O_4[/tex] and +4 in [tex]CO_2[/tex], the oxidation state is increasing and hence it is getting oxidized.

The element which is reduced in the redox reaction is Mn.

The redox reaction is shown below:

MnO₄⁻(aq) + H₂C₂O₄(aq) → Mn²⁺(aq) + CO₂(g)

A redox reaction is the type of reaction which involves oxidation processes

occurring with a corresponding reduction process.

Oxidation reaction involves the reaction in which a substance loses its

electrons to become positively charged with an increase in the oxidation

state.

Reduction reaction is defined as the reaction in which a substance gains

electrons to become positively charged with a decrease in the oxidation

state.

MnO₄⁻ has an oxidation state of +7 and Mn²⁺ having an oxidation state of +2

signifies a decrease in the oxidation state.

Read more on https://brainly.com/question/10354645

Answer:

Yah, it's a neutral oxide

Explanation:

[tex]{ \bf{2H_{2(g)} +O_{2(g)} \: →2H _{2}O _{(l)} }}[/tex]

Answer:158 days (D)

Explanation:

It will take 158 days for grass contaminated with Sr-90 to be safe for cattle to eat. Therefore, option (A) is correct.

The half-life of a radioactive material is defined as the time that is needed to reduce the initial quantity of a radioactive element to half after disintegration.

The half-life of a radioactive element can be described as the characteristic of the element and does not influence by the initial amount of the radioactive substance.

Given, the half-life of the Strontium-90 = 28 days

The rate constant of the decay can be determined as:

[tex]t_{\frac{1}{2} } =\frac{0.693}{k}[/tex]

[tex]k=\frac{0.693}{t_{\frac{1}{2} } }[/tex]

k = 0.693/28

k = 0.025 day⁻¹

The concentration of Strontium-90 reduced to less than 2% is safe. Therefore final concentration [A] = 2 % = 0.02

[tex]t = \frac{2.303}{k} log \frac{[A_o]}{[A]}[/tex]

[tex]t = \frac{2.303}{0.02475} log \frac{1}{[0.02]}[/tex]

t = 158 days

Learn more about the half-life period, here:

brainly.com/question/14521252

#SPJ5

Answer:

The correct answer is -341.2 kJ per mole.

Explanation:

The reaction given is:  

CO (g) + Cl₂ (g) ⇔ COCl₂ (g)

Kp = 5.62 × 10³⁵

T = 25 °C or 298 K

The formula for calculating ΔG is,  

ΔG° = -RTlnKp

ΔG° = -8.314 × 298 ln (5.62 × 10^35)

ΔG° = -203.9 kJ/mol

ΔG° = ∑nΔG°f (products) -∑nΔG°f (reactants)

ΔG° = ΔG°f (COCl₂ (g)) - [ΔG°f (CO(g)) + ΔG°f (Cl₂(g))]

ΔG°f (COCl₂ (g)) = ΔG° + [ΔG°f (CO (g)) + ΔG°f (Cl₂(g))]

ΔG°f (COCl₂ (g)) = -203.9 + (-137.28 + 0.00)

ΔG°f (COCl₂ (g)) = -341.2 kJ/mol

The standard Gibbs free energy [tex]\mathbf{\Delta G^o_f}[/tex] for COCl2 at 25°C is -341.25 kJ/mol

The given equation for the chemical reaction is

CO(g) + Cl2(g) ⇌ COCl2(g)

At the temperature of 25°C = (273 + 25) K, the equilibrium constant [tex]\mathbf{K_p = 5.62\times 10^{35}}[/tex]

Consider the expression for the relationship between [tex]\mathbf{\Delta G^o}[/tex] and [tex]\mathbf{K_p }[/tex] for the equilibrium reaction can be expressed as:

[tex]\mathbf{\Delta G^o = - RT In K_p}[/tex]

where;

∴

[tex]\mathbf{\Delta G^o = - (8.314 \times 10^{-3}\ kJ/K.mol \times 298 \ K) \times In (5.62 \times 10^{35} )}[/tex]

[tex]\mathbf{\Delta G^o = -2.477572\ K \times 82.31680992}[/tex]

[tex]\mathbf{\Delta G^o = 203.95 \ kJ}[/tex]

Thus, the standard free energy for the reaction is 203.95 kJ/mol

For a given reaction, the standard Gibbs free energy can be calculated by using the formula:

[tex]\mathbf{\Delta G^o_{rxn} = \sum n \Delta G^o_f (products) - \sum m \Delta G^o_f (reactants) }[/tex]

[tex]\mathbf{\Delta G^o_{rxn} =\Big [\Delta G^o_{f} (COCl_{2(g)} ) -\Big(\Delta G^o_{f} (CO)_{(g)} + \Delta G^o_{f} (Cl)_{2(g)} ) \Big ) \Big ] }[/tex]

replacing the values of and solving for COCl2 at standard free energy of formation of substances, we have:

[tex]\mathbf{-203.95 \ kJ/mol =\Big [\Delta G^o_{f} (COCl_{2(g)} ) -\Big(-137.3 kJ/mol + 0 \ kJ/mol\Big ) \Big ] }[/tex]

Collecting like terms, we have:

[tex]\mathbf{\Delta G^o_{f} (COCl_{2(g)} ) = -203.95 \ kJ/mol -137.3 kJ/mol }[/tex]

[tex]\mathbf{\Delta G^o_{f} (COCl_{2(g)} ) = -341.25 \ kJ/mol }[/tex]

Therefore, we can conclude that the standard Gibbs free energy [tex]\mathbf{\Delta G^o_f}[/tex] for COCl2 at 25°C is -341.25 kJ/mol

Learn more about standard Gibbs free energy here:

https://brainly.com/question/13318988?referrer=searchResults

Answer:

Option D. A lipid with three unsaturated fatty acid.

Explanation:

The molecule in the diagram above contains three fatty acid.

A careful observation of the molecule reveals that each of the three fatty acids contains a double bond.

The presence of a double bond in a compound shows that the compound is unsaturated.

Thus, we can say that the molecule is a lipid with three unsaturated fatty acid.

Answer:

An electrochemical cell that takes in energy to carry out a nonspontaneous redox reaction

Answer:

(CH3)3N

Explanation:

Hydrogen bonding can be called a type of intracellular force of the attraction. It is the force that occur between molecules. It is the bonding between the molecules and of hydrogen and electronegative items in the covalent bond. This is called the hydrogen donor. An electro-negative hydrogen atoms may be a hydrogen bonded. It is also called a hydrogen acceptor.

Thus in (CH3)3N, the hydrogen atoms becomes bonded with carbon. Carbon is not electronegative atoms. Thus it does not play as donor. Nitrogen is electronegative and play as hydrogen acceptor. But there is no presence of hydrogen acceptor. Thus there is no molecules that exhibit hydrogen molecules bonding.

[tex]\bold {(CH_3)_3N}[/tex] does not have hydrogen bonding because of the absence of electronegativity difference.

Hydrogen bond:

It is an inter-molecular bond. It is due to the difference in electronegativities of constituent atoms. This creates dipole in the atoms so, atoms start to attract each other.

In [tex]\bold {(CH_3)_3N}[/tex], the hydrogen atoms are bonded with carbon. The difference between the electronegativities Carbon and hydrogen is very less.

Therefore, [tex]\bold {(CH_3)_3N}[/tex] does not have hydrogen bonding because of the absence of electronegativity difference.

To know more about Hydrogen Bond,

https://brainly.com/question/3464712

Taking into account the definition of molarity and the stoichiometry of the reaction, the correct option is option C) 0.44 L of 6.9 M NaOH is needed to completely titrate 0.42 L of 2.39 M phosphoric acid.

The balanced reaction is:

H₃PO₄ (aq) + 3 NaOH (aq) → Na₃PO₄ (aq) + 3 H₂O(aq)

Then, by stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

Molarity is the number of moles of solute that are dissolved in a given volume.

Molarity is determined by:

[tex]Molarity=\frac{number of moles of solute}{volume}[/tex]

 Molarity is expressed in units [tex]\frac{moles}{liter}[/tex].

In this case, 0.42 L of 2.39 M phosphoric acid reacts. So, by definition of molarity, the number of moles that participate in the reaction is calculated as:

[tex]2.39 \frac{moles}{liter}=\frac{number of moles of phosphiric acid}{0.42 liters}[/tex]

Solving:

number of moles of phosphiric acid= 2.39 [tex]\frac{moles}{liter}[/tex]* 0.42 liters

number of moles of phosphiric acid= 1.0038 moles ≅ 1 mole

Approaching 1 mole of the amount of phosphoric acid required, then by stoichiometry of the reaction, 3 moles of NaOH are necessary to react with 1 mole of the acid.

Then by definition of molarity and knowing that 6.9 M NaOH is needed, you can calculate the necessary volume amount of NaOH by:

[tex]6.9 \frac{moles}{liter} =\frac{3 moles}{volume}[/tex]

Solving:

6.9 [tex]\frac{moles}{liter}[/tex]* volume= 3 moles

[tex]volume=\frac{3 moles}{6.9\frac{moles}{liter} }[/tex]

volume= 0.44 L

The correct option is option C) 0.44 L of 6.9 M NaOH is needed to completely titrate 0.42 L of 2.39 M phosphoric acid.

Learn more about molarity with this example: https://brainly.com/question/15406534?referrer=searchResults

Answer:

(1) -12 Kcal/mol

Explanation:

Our answer options for this question are:

(1) -12 Kcal/mol

(2) -13 Kcal/mol

(3) -15 Kcal/mol

(4) -16 Kcal/mol

With this in mind, we can start with the chemical reaction (Figure 1). In this reaction, two bonds are broken, a C-H and a Br-Br. Additionally, a C-Br and a H-Br are formed.

If we want to calculate the enthalpy value, we can use the equation:

ΔH=ΔHbonds broken-ΔHbonds formed

If we use the energy values reported, its possible to calculate the energy for each set of bonds:

ΔHbonds broken

C-H = 94.5 Kcal/mol

Br-Br = 51.5 Kcal/mol

Therefore:

105 Kcal/mol + 53.5 Kcal/mol = 146 Kcal/mol

ΔHbonds formed

C-Br = 70.5 Kcal/mol

H-Br = 87.5 Kcal/mol

Therefore:

70.5 Kcal/mol + 87.5 Kcal/mol = 158 Kcal/mol

ΔH of reaction

ΔH=ΔHbonds broken-ΔHbonds formed=(146-158) Kcal/mol = -12 Kcal/mol

I hope it helps!

Answer:

The number of moles of excess reagent NO₂ that are present after the reaction has completed is 7 moles.

Explanation:

The balanced reaction is:

3 NO₂ + H₂O → 2 HNO₃ + NO

By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of reactants and products participate in the reaction:

The limiting reagent is one that is consumed in its entirety first, determining the amount of product in the reaction. When the limiting reagent ends, the chemical reaction will stop.

In other words, the limiting reagent is that reagent that is consumed first in a chemical reaction, determining the amount of products obtained. The reaction depends on the limiting reagent, because the other reagents will not react when one is consumed.

You can apply the following rule of three: if by stoichiometry of the reaction 3 moles of NO₂ react with 1 mole of H₂O, 13 moles of NO₂ react with how many moles of H₂O?

[tex]moles of H_{2}O=\frac{13 moles of NO_{2}*1 mole of H_{2}O }{3 moles of NO_{2}}[/tex]

moles of H₂O= 4.33 moles

But 4.33 moles of H₂O are not available, 3 moles are available. Since you have less moles than you need to react with 13 moles of NO₂, water H₂O will be the limiting reagent.

To determine the number of moles of excess reagent NO2 that are present after the reaction is complete, you can apply the following rule of three: if by stoichiometry of the reaction 1 moles of H₂O react with 3 mole of NO₂, 3 moles of H₂O react with how many moles of NO₂?

[tex]moles of NO_{2}=\frac{3 moles of NO_{2}*3 mole of H_{2}O }{1 mole of H_{2}O}[/tex]

moles of NO₂= 6 moles

If 6 moles of NO₂ react and 13 moles of the compound are present, the amount that remains in excess is calculated as: 13 moles - 6 moles= 7 moles

The number of moles of excess reagent NO₂ that are present after the reaction has completed is 7 moles.

Answer:

The role of Chemistry in the field of Economics is as a driving force in all industries, from basic materials for industrial machinery to industrial raw materials.

Answer:

CH3CH=NH2+>CH3CH2NH3 +

Explanation:

There are certain structural features that determine the stability of cationic species. These features that lead to the stability and higher acid strength of cations are those features that stabilize the cation.

CH3CH=NH2+ is more acidic than CH3CH2NH3 + owing to the fact that CH3CH=NH2+ contains a double bond in close proximity with the hydrogen that can be lost as a proton. Electron withdrawal by the double bond (greater s character) makes it easier for this hydrogen to be lost as a proton compared to CH3CH2NH3 +.

Using Charles law

[tex]\boxed{\sf \dfrac{V_1}{T_1}=\dfrac{V_2}{T_2}}[/tex]

[tex]\\ \sf\longmapsto V_1T_2=V_2T_1[/tex]

[tex]\\ \sf\longmapsto 1(40)=27V_2[/tex]

[tex]\\ \sf\longmapsto V_2=\dfrac{40}{27}[/tex]

[tex]\\ \sf\longmapsto V_2=1.48\ell[/tex]

Answer:B. Burning toast is a chemical change; straining orange juice is a physical change.

Explanation:

A Physical change Is a type of change on a substance that does not affect its composition but can only change the appearance of the substance.

While

A  Chemical changes is one that changes the substance to  an entirely new substance.

Now 1.  Burning toast is a chemical change, This is because First, Burning is a chemical reaction on its own . The toast also is a different substance from the white bread itself to a brown substance .

2. Straining orange juice is a physical change because no new substance is being formed only a SEPARATION of the orange pulp from the juice.

See related answer here:   https://brainly.in/question/12042978

We have that Burning toast is a chemical change; straining orange juice is a physical change.

The correct option is Option B

Physical change

This Refers to a change to the Physical Characteristics of a substance

While

Chemical change is a change Chemical Characteristics of a substance

and

Physical changes tends to undergo reversible processes while

chemicals do not

Therefore

The correct option is Option B

Burning toast is a chemical change; straining orange juice is a physical change.

For more information on this visit

https://brainly.com/question/17756498?referrer=searchResults

Answer:

7.50 L

Explanation:

The balloon has a volume of 1.20 L (V₁) when the pressure at the sea floor is 6.25 atm (P₁). When it reaches the surface, the pressure is that of the atmosphere, that is, 1.00 atm (P₂). If we consider the gas to behave as an ideal gas and the temperature to be constant, we can calculate the final volume (V₂) using Boyle's law.

P₁ × V₁ = P₂ × V₂

V₂ = P₁ × V₁ / P₂

V₂ = 6.25 atm × 1.20 L / 1.00 atm

V₂ = 7.50 L

Answer:

The scientist is observing an intensive property of a superconductor.

Explanation:

An intensive property is a bulk property of matter. This means that an intensive property does not depend on the amount of substance present in the material under study. Typical examples of intensive properties include; conductivity, resistivity, density, hardness, etc.

An extensive property is a property that depends on the amount of substance present in a sample. Extensive properties depend on the quantity of matter present in the sample under study. Examples of extensive properties include, mass and volume.

Resistance of a superconducting material has nothing to do with the amount of the material present hence it is an intensive property of the superconductor.

Answer:

The scientist is observing an intensive property of a superconductor.

Explanation:

its the only one that makes logical sense

Answer:

73.1707317073%

=> Approximately 73.2%

Explanation:

Total = 60 + 10 + 12

=> 82

Test tubes are 60/82

=> 30/41

=> 73.1707317073%

=> Approximately 73.2%

Answer:

73.17%

Explanation:

To find the percentage of test tubes to the overall glassware, we need to get the number of test tubes divided by the total number of glassware.

12 beakers + 10 flasks + 60 test tubes = 82 glassware

% test tube = 60 / 82 = .7317 ==> 73.17 %

So 73.17 % of the glassware was test tubes.

Cheers.

Answer:

2200 L

Explanation:

Ideal gas law:

PV = nRT,

where P is absolute pressure,

V is volume,

n is number of moles,

R is universal gas constant,

and T is absolute temperature.

The initial number of moles is:

(110 atm) (80 L) = n (0.0821 L atm / K / mol) (30 + 273.15) K

n = 353.58 mol

After some gas is removed, the number of moles remaining is:

(80 atm) (80 L) = n (0.0821 L atm / K / mol) (30 + 273.15) K

n = 257.15 mol

The amount of gas removed is therefore:

n = 353.58 mol − 257.15 mol

n = 92.43 mol

At normal conditions, the volume of this gas is:

PV = nRT

(1 atm) V = (92.43 mol) (0.0821 L atm / K / mol) (273.15 K)

V = 2162.5 L

Rounded, the volume is approximately 2200 liters.

Answer:

[tex]\boxed {\boxed {\sf 3.7 * 10^{22} \ molecules \ NaCl}}[/tex]

Explanation:

We are asked to find how many molecules are in 3.6 grams of sodium chloride.

First, we convert grams to moles using the molar mass. These values are equivalent to atomic masses on the Periodic Table, but the units are grams per moles instead of atomic mass units. Look up the molar masses of the individual elements: sodium and chlorine.

There are no subscripts in the chemical formula (NaCl), so we simply add the 2 molar masses.

Now we will convert using dimensional analysis. First, set up a ratio using the molar mass.

[tex]\frac {58.4397693 \ g \ NaCl}{ 1 \ mol \ NaCl}[/tex]

We are converting 3.6 grams to moles, so we must multiply the ratio by this value.

[tex]3.6 \ g \ NaCl *\frac {58.4397693 \ g \ NaCl}{ 1 \ mol \ NaCl}[/tex]

Flip the ratio so the units of grams of sodium chloride cancel.

[tex]3.6 \ g \ NaCl *\frac { 1 \ mol \ NaCl}{58.4397693 \ g \ NaCl}[/tex]

[tex]3.6 *\frac { 1 \ mol \ NaCl}{58.4397693}[/tex]

[tex]\frac { 3.6}{58.4397693} \ mol \ NaCl[/tex]

[tex]0.06160188589 \ mol \ NaCl[/tex]

Next, we convert moles to molecules using Avogadro's Number. This is 6.022 × 10²³ and it tells us the number of particles (atoms, molecules, formula units, etc). In this case, the particles are molecules of sodium chloride. Let's set up another ratio.

[tex]\frac {6.022 \times 10^{23} \ molecules \ NaCl}{ 1 \ mol \ NaCl}[/tex]

Multiply by the number of moles we calculated.

[tex]0.06160188589 \ mol \ NaCl * \frac{6.022 \times 10^{23} \ molecules \ NaCl}{1 \ mol \ NaCl}[/tex]

The units of moles of sodium chloride cancel.

[tex]0.06160188589 * \frac{6.022 \times 10^{23} \ molecules \ NaCl}{1 }[/tex]

[tex]3.70966557*10^{22} \ molecules \ NaCl[/tex]

The original measurement of grams (3.6) has 2 significant figures, so our answer must have the same. For the number we found, that is the tenths place. The 0 in the hundredth place tells us to leave the 7 in the tenth place.

[tex]3.7 * 10^{22} \ molecules \ NaCl[/tex]

There are [tex]3.7 * 10^{22} \ molecules \ NaCl[/tex] in 3.6 grams and the correct answer is choice D.