us
If the mole fraction of NaCl in an
aqueous solution is 0.0927, what is
the weight/weight % (percent by
mass) of NaCl.
Molar Mass
Naci: 58.44 g/mol
H2O: 18.016 g/mol

Answer:

1. 0.74mol

2. 0.42mol

3. 2.125mol

4. 0.301mol

5. 4.52 × 10^23 particles

Explanation:

Number of moles (n) in a substance can be found using the formula:

mole (n) = mass/molar mass

Using this formula, the following moles are calculated:

1. Molar of Na = 23g/mol

mole = 17/23

mole = 0.74mol

2. Molar mass of Na2SO4 = 23(2) + 32 + 16(4)

= 46 + 32 + 64

= 142g/mol

Mole = 60/142

mole = 0.42mol

3. Molar mass of CO2 = 12 + 16(2)

= 12 + 32

= 44g/mol

mole = 93.5/44

mole = 2.125mol

4. Molar mass of sodium nitrate (NaNO3) = 23 + 14 + 16(3)

= 23 + 14 + 48

= 85g/mol

mole = 25.6/85

mole = 0.301mol

5. Number of particles in one mole of a substance is 6.022 × 10^23 particles. Hence, in 0.75mol of calcium hydroxide (Ca(OH)2, there will be;

0.75mol × 6.02 × 10^23

= 4.515 × 10^23

= 4.52 × 10^23 particles

Answer:

No

Explanation:

This does not mean that vinegar is insoluble totally. In fact, vinegar is soluble in water because water is a polar solvent.

For a substance to be soluble in another, it must obey the rule of solubility.

The rule states that "like dissolves like"

It implies that polar solvent will only dissolve polar solute.

Also, non-polar solvent will only dissolve non-polar solute.

Therefore, the answer is no, vinegar will dissolve in water.

Answer:

light

Explanation:

light is plasma, which is a state of matter

The temperature and the strength of the metallic link are the two most crucial variables that can impact how malleable a metal or alloy is.

A metal is a substance that has a shiny look when freshly processed, polished, or shattered, and conducts electricity and heat rather effectively. Generally speaking, metals are malleable and ductile.

The amount of pressure that a metal can sustain without breaking can be used to gauge its malleability. Varied metals have different degrees of malleability because of variations in their crystal structures.

The temperature of the metal and the strength of the metallic connection are the two parameters that define how malleable a metal or metal alloy will be.

Thus,  The kind of the metallic connection can have a significant impact on how easily metal atoms can rearrange themselves.

To learn more about metal, follow the link;

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Answer:

iconic bond is the answer

I hope it helps you ✌

Answer:

Partial pressures:

PCl₅ = 0.558 atm

PCl₃ = 0.22 atm

Cl₂ = 0.22 atm

Explanation:

From the given information:

The number of moles of PCl₅ associated with the evaporation is:

[tex]n_{PCl_5}= \dfrac {weight \ of \ PCl_5} {M.Wt. \ of \ PCl_5}[/tex]

[tex]n_{PCl_5}= \dfrac {2.69 \ g} {208.5 \ g/mol}[/tex]

[tex]n_{PCl_5}= 0.013 \ mol[/tex]

Temperature of the gas = 250° C = (250 + 273.15) K

= 523.15 K

Using the Ideal gas equation to determine the pressure exerted by the completely vaporized PCl₅

PV = nRT

[tex]P = \dfrac{nRT}{V}[/tex]

[tex]P = \dfrac{0.0013 \ mol \times 0.082 \ Latm^0 K^{-1} . mol ^{-1} \times 523.15 \ K}{1.0 \ L}[/tex]

P = 0.558 atm

Thus, at  250° C, decomposition of PCl₅ occurs.

In the container, PCl₅  decomposes to PCl₃ and Cl₂.

i.e.

[tex]PCl_{5(g)} \to PCl_{3(g)}+ Cl_{2(g)}[/tex]

Using Dalton's Law:

[tex]P_{total } =P_1 + P_2+P_3 +...[/tex]

[tex]P_1 = P_{Total} \times X_1[/tex]

where;

X = mole fraction

Then, the total no. of moles in the container is:

[tex]n = \dfrac{PV} {RT}[/tex]

[tex]n = \dfrac{1\ atm \times 1.0\ L}{0.0821 \ L \ atm \ K^{-1}.mol \times 523.15\ K}[/tex]

n = 0.023 mol

Now, the container contains a total amount of 0.023 mol where initially 0.013 mol are that of PCl₅ and remaining 0.005 mol of PCl₃ and 0.005 mol of Cl₂.

Thus, the partial pressure of  PCl₃  is:

[tex]P__{PCL_3} }= P_{total} \times \dfrac{no. \ of \ moles \ of PCl_5}{total \ no. \ of \ moles}[/tex]

[tex]P__{PCL_3}} = 1 \ atm \times \dfrac{0.005}{0.023}[/tex]

[tex]P__{PCL_3}} = 0.22 \ atm[/tex]

Thus, since the no of moles of PCl₃ and Cl₂ are the same, then the partial pressure for Cl₂ is = 0.22 atm

Answer:

25.8 g/dL

Explanation:

A chemist prepares a solution of aluminum sulfate by weighing out 116.0 g of aluminum sulfate into a 450. mL volumetric flask and filling the flask to the mark with water. Calculate the concentration in g/dL of the chemist's aluminum sulfate solution. Be sure your answer has the correct number of significant digits.

Step 1: Given data

Step 2: Convert "V" to dL

We will use the following conversion factors.

450. mL × 1 L/1000 mL × 10 dL/1 L = 4.50 dL

Step 3: Calculate the concentration (C) of aluminum sulfate if g/dL

We will use the following expression.

C = m/V = 116.0 g/4.50 dL = 25.8 g/dL

Answer:

What volume of water is produced when the CO2 reacts with the excess LiOH

X = 360 mL H2O

Explanation:

CO2 (g)       + 2 LiOH(s) ⇒ Li2CO3  (aq) + H2O(l)

20.0 mol        excess                                   x g

X = 360 mL H2O

x mL H20 = 20.0 mol CO2  (1 mol H2O /1 mol CO2)(18 g H2O/1 mol H2O)

(1 mL H2O /1 g H2O)

X = 360 mL H2O

Answer: Equation 1, because Zn being more reactive, replaces Ag from AgNO3

Explanation: I got it right on the quiz and it replaces it

Answer:

4

Explanation:

the one you ARE ON

Answer:

(a) 1s; has one orbital

(b) 4d; has five orbitals

(c) 3p; has three orbitals

(d) n=3 has nine orbitals

Explanation:

Electrons in an atom are always in constant motion, making it hard to predict there exact position. However, the most probable locations electrons can be be found are described with the terms shells, subshells and orbitals. A shell contains subshells and orbitals are found within subshells. The shells are given names such as K, L, M, N, which correspond to the principal quantum numbers, n = 1, 2, 3, and 4 respectively. There are 4 major types of subshells that can be found in a shell. They are named as s, p, d, f. Each subshell is composed of several orbitals.

a. 1s; the s subshell has only one orbital. Therefore, the 1s subshell has one orbital

b. 4d; the d subshell has five orbitals. Therefore, the 4d subshell has five orbitals

c. 3p; the p subshell has three orbitals. Therefore, the 3d subshell has  three orbitals

d. n = 3; the shell with n = 3 has the following subshells, 3s, 3p, 3d.the number of orbitals will be 1 + 3 + 5 = 9 orbitals. Therefore, the number of orbitals in n = 3 is nine orbitals

Answer:

See explanation

Explanation:

The valence electrons are electrons found on the valence (outermost) shell of an atom.

When an atoms form compounds, there is an exchange of valence electrons between the atoms of one element and the atoms of another element.

Let us consider a typical example, sodium has one valence electron and chlorine has seven valence electrons. This means that chlorine needs one electron to complete its octet while sodium needs to release one electron in order to attain the octet structure.

So, sodium gives out its one electron and becomes a stable sodium ion and chlorine accepts that electron and becomes a stable chloride ion. This is how the compound sodium chloride is formed.

Answer:

Silver Lake Picnic Area, Or C

Explanation:

The question is incomplete, the complete question is;

A student prepared several aqueous sodium chloride (NaCl) solutions to observe boiling point elevation at various molal concentrations, however, several errors were made throughout the procedure. Determine whether these errors would cause the observed boiling point to be increased or decreased relative to the expected boiling point, based on the procedure, or have no effect on the experimental results.

* The flask is washed with water but not thoroughly dried before preparing the solution

* The mass of NaCl used to prepare the solution is 5.400 grams instead of 4.400 grams

* Some of the prepared solution splashes out of the flask prior to observation of the boiling point

* When making the salt solution, 55.0 milliliters of water is added instead of 50.0 milliliters

Answer:

The flask is washed with water but not thoroughly dried before preparing the solution  - decrease

The mass of NaCl used to prepare the solution is 5.400 grams instead of 4.400 grams

-increase

Some of the prepared solution splashes out of the flask prior to observation of the boiling point- have no effect

When making the salt solution, 55.0 milliliters of water is added instead of 50.0 milliliters- decrease

Explanation:

If the flask is washed but not dried, then the solution will be further diluted than expected. As a result of this further dilution, the observed boiling point will be less than the expected boiling point because the boiling point depends on the solution's concentration.

If more solute is added than expected, the concentration of the solution is increased and the boiling point also increases above the expected boiling point due to the increase in amount of solute present.

If some of the solution splashes out of the flask prior to boiling, the boiling point is not affected because the concentration of the solution was not altered. The boiling point only changes when the concentration of the solution is changed.

If 55 ml of water is added instead of 50 ml, the solution is now more dilute than expected thereby reducing the concentration of the solution and the boiling point. Remember that, as the concentration of the solution decreases, the boiling point decreases accordingly.

Answer:

B

Explanation:

Answer:

Answer:

Reversible

Explanation:

Changes of state are physical changes in matter. Common changes of the state include melting, freezing, sublimation, deposition, condensation, and vaporization.

Answer:

0.41 atm

Explanation:

A reaction between liquid reactants takes place at 10.0 °C in a sealed, evacuated vessel with a measured volume of 5.0 L. Measurements show that the reaction produced 13. g of sulfur hexafluoride gas. Calculate the pressure of sulfur hexafluoride gas in the reaction vessel after the reaction. You may ignore the volume of the liquid reactants. Round your answer to 2 significant digits.

Step 1: Given data

Step 2: Convert "T" to Kelvin

We will use the following expression.

K = °C + 273.15

K = 10.0 °C + 273.15 = 283.2 K

Step 3: Calculate the moles (n) of SF₆

The molar mass of SF₆ is 146.06 g/mol.

13. g × 1 mol/146.06 g = 0.089 mol

Step 4: Calculate the pressure (P) of SF₆

We will use the ideal gas equation.

P × V = n × R × T

P = n × R × T/V

P = 0.089 mol × (0.0821 atm.L/mol.K) × 283.2 K/5.0 L = 0.41 atm

Answer:

5.27 g of NaCl

Explanation:

The balanced equation for the reaction is given below:

Na₂CO₃ + CaCl₂ —> 2NaCl + CaCO₃

Next, we shall determine the mass of CaCl₂ that reacted and the mass of NaCl produced from the balanced equation. This can be obtained as follow:

Molar mass of CaCl₂ = 40 + (35.5×2)

= 40 + 71

= 111 g/mol

Mass of CaCl₂ from the balanced equation = 1 × 111 = 111 g

Molar mass of NaCl = 23 + 35.5

= 58.5 g/mol

Mass of NaCl from the balanced equation = 2 × 58.5 = 117 g

Summary:

From the balanced equation above,

111 g of CaCl₂ reacted to produce 117 g of NaCl.

Finally, we shall determine the theoretical yield of NaCl. This can be obtained as follow:

From the balanced equation above,

111 g of CaCl₂ reacted to produce 117 g of NaCl.

Therefore, 5 g of CaCl₂ will react to produce = (5 × 117)/111 = 5.27 g of NaCl.

Thus, the theoretical yield of NaCl is 5.27 g.

Answer:

Explanation:

here's the answer hope it helps! :)

Answer:

See explanation

Explanation:

Chemical reactions are also referred to as chemical change. A chemical change often leads to the formation of new substances and is not easily reversible.

A chemical reaction may be accompanied by the emission of heat and light, formation of a precipitate, evolution of gas, or a color change.

These observable physical effects may tell us weather a chemical reaction has taken place or not so we have to observe the system closely for any of these effects stated above.

Answer: Energy of reactants = 30, Energy of products = 10

Exothermic

Activation energy for forward reaction is 10.

Explanation:

Exothermic reactions are defined as the reactions in which energy of the product is lesser than the energy of the reactants. The total energy is released in the form of heat and [tex]\Delta H[/tex] for the reaction comes out to be negative.

Energy of reactants = 30

Energy of products = 10

Thus as energy of the product < energy of the reactant, the reaction is exothermic.

Activation energy [tex](E_a)[/tex] is the extra energy that must be supplied to reactants in order to cross the energy barrier and thus convert to products.

[tex]E_a[/tex] for forward reaction is (40-30) = 10.

Answer:

Explanation:

The average kinetic energy for an ideal gas is directly proportional to the temperature. The average kinetic energy of the gas is a measure of the temperature of the gas molecule

Also, the average speed is usually proportional to the square root of temperature.

Similarly, there is a noticeable increase in K.E and speed in regard to temperature but sometimes it is not usually proportional.

However, provided that there is more temperature in Xe as compared to He, then after the mixture of both takes place at equilibrium; the temperature tends to fluctuate between (25 - 50)°C

Thus, since there is a decrease in temperature in Xe, both the average kinetic energy as well as the speed too will also decrease.

The ocean is not a part of Earth's layers.

Answer:

Ocean

Explanation:

Answer:

[tex]\%N=26.2\%\\\\\%H=7.5\%\\\\\%Cl=66.3\%[/tex]

Explanation:

Hello!

In this case, since the calculation of the percent composition of an element in a chemical compound is computing considering its atomic mass, subscript in the formula and molecular mass of the compound it is; for nitrogen, hydrogen and chlorine we have that ammonium chloride has a molar mass of 53.49 g/mol so the percent compositions are:

[tex]\%N=\frac{14.01*1}{53.49}*100\% =26.2\%\\\\\%H=\frac{1.01*4}{53.49}*100\% =7.5\%\\\\\%Cl=\frac{35.45*1}{53.49}*100\% =66.3\%[/tex]

Best regards!

Answer:

Explanation:

From the given information:

The accuracy depends on the internal diameter of the cylinder. The cylinder with the least internal diameter is obviously more precise.

Let's assume 1% is the error of measurement.

Then, to measure 70 mL from 10 mL cylinder

The error = [tex]10 \times \dfrac{1}{100} \times 7[/tex]

= 0.7 mL

However; for a 100 mL cylinder, the error = 1 mL

Now,

The total volume for 10 mL = (70 + 0.7) = 70.7 mL

The total volume for 100 mL = (70 + 1 ) = 71 mL

Suppose the density (d) is same for both

Then;

the mass of 10 mL = ( d × 70.7) g

the mass pf 100 mL = (d × 71) g

Thus, the mass of 100 mL is greater than that of 10 mL.

Answer:

Explanation:

a )

H₂O₂ (aq) + 2 Fe²⁺ (aq) + 2 H⁺  = 2H20 (l) + 2 Fe³⁺(aq)

Here oxidation number  of Fe is increasing from + 2 to + 3 so it is being oxidized . Hence H₂O₂ is acting as oxidizing agent here .

b )

5 H₂O₂ (aq) + 2 MnO₄⁻¹ (aq) + 6 H⁺ (aq) → 8 H20 (l) + 2 Mn⁺² (aq) + 5O₂ (g)

In this reaction,  oxidation number of Mn is reducing from + 7 to + 2 so it is being reduced . Here H₂O₂ is acting as reducing agent .

Answer:

See explanation below

Explanation:

There are several ways to know if an acid or base is strong. One method is calculating the pH. If the pH is really low, is a strong acid, and if it's really high is a strong base.

However we do not have a pH value here.

The other method is using bronsted - lowry theory. If an acid is strong, then his conjugate base is weak. Same thing with the bases.

Now, Looking at the 4 compounds, we can say that only two of them is weak and the other two are strong compounds. Let's see:

LiOH ---> Strong. If you try to dissociate :

LiOH ------> Li⁺ + OH⁻     The Li⁺ is a weak conjugate acid.

HF -----> Weak

HF --------> H⁺ + F⁻   The Fluorine is a relatively strong conjugate base.

HCl -----> Strong

This is actually one of the strongest acid.

NH₃ ------> Weak

Now writting the Ka and Kb expressions:

Ka = [H⁺] [F⁻] / [HF]

Kb = [NH₄⁺] [OH⁻] / [NH₃]

Finally, to calculate the [OH⁻] we need to use the following expression:

Kw = [H⁻] [OH⁻]

Solving for [OH⁻] we have:

[OH⁻] = Kw / [H⁺]

Remember that the value of Kw is 1x10⁻¹⁴. So replacing:

[OH⁻] = 1x10⁻¹⁴ / 7x10⁻⁶

[OH⁻] = 1.43x10⁻⁹ M

And now, multiplying by 10¹⁰ we have:

[OH⁻] = 1.429x10⁻⁹ * 1x10¹⁰

Hope this helps

Strong acids and bases are those which completely ionized in body fluid, and weak acids and bases are those who does not completely ionized in body fluid.

Ka expression is used to differentiate between strong and weak acids.

[tex]\bold{\dfrac{[H+][F-]}{[HF]}}[/tex]

[tex]\bold{\dfrac{[NH_4^+] [OH^-]}{[NH_3]} }[/tex]

Given, [tex]\bold{ [H^+]=1\times10^-^6\; at \;25^oC}[/tex]

We know, [tex]\bold{ [H^+]\times[OH^-]=1\times10^-^6\; at \;25^oC}[/tex]

[tex]\bold{[OH^-]=\dfrac{1\times10^-^1^4}{6.2\times10^-^6} = 1.43\times10^-^9}[/tex]

Now, multiplying the value by [tex]10^1^0[/tex]

[tex]\bold{( 1.429\times10^-^9) \times 1\times10^1^0= 14.29}[/tex]

Thus, the value is 14.29.

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Answer:

Incorrect

Explanation:

Mole ratios are derived from the coefficients in front of the number, N2O does not have a 2 in front of it, the real mole ratio would be 4/1

Answer:

Correct

Explanation:

I had the same problem and I put correct, and it was correct.

Answer:

C)Grassland biomes contain mostly grasses.

Explanation:

The main differences between a savanna biome and a grassland is that grasslands biomes contain mostly grasses.

Savanna are made up of both grasses and shrubs.