While balancing a chemical equation, we change the _____ to balance the number of atoms on each side of the equation.

Answer:

D) 65.7%

Explanation:

Based on the reaction:

2H2(g)+O2(g)⟶2H2O(l)

2 moles of hydrogen produce 2 moles of water assuming an excess of oxygen.

To find percent yield of the reaction we need to find theoretical yield (The yield assuming all hydrogen reacts producing water). With theoretical yield and actual yield (32.8g H₂O) we can determine percent yield as 100 times the ratio between actual yield and theoretical yield.

Theoretical yield:

Moles of 5.58g H₂:

5.58g H₂ ₓ (1 mol / 2.016g) = 2.768 moles H₂

As 2 moles of H₂ produce 2 moles of H₂O, if all hydrogen reacts will produce 2.768 moles H₂O. In grams:

2.768 moles H₂O ₓ (18.015g / mol) =

49.86g H₂O is theoretical yield

Percent yield:

Percent yield = Actual yield / Theoretical yield ₓ 100

32.8g H₂O / 49.86g ₓ 100 =

65.7% is percent yield of the reaction

Answer:

X₅Y₂Z₃

Explanation:

The formula of a compound is determined as the whole number ratio between moles of each element present in the molecule.

The molecule is made from X, Y and Z. To fin the ratio we will divide the given moles in the moles of Y (0.197 moles), because is the element with the low number of moles.

X = 0.492 moles / 0.197 moles = 2.5

Y = 0.197 moles / 0.197 moles = 1

Z = 0.295 moles / 0.197 moles = 1.5

But, as the formula is given just with whole numbers, if we multiply each number twice:

X = 2.5*2 = 5

Y = 1*2 = 2

Z = 1.5*2 = 3

The formula is:

Answer:

[tex]\mathbf {density \ d =4.4845 \ g/cm^3}[/tex]

Explanation:

Let recall the crystal structure of CsBr obtains a BCC structure. In a BCC structure, there exist only two atom per cell.

The density d of CsBr in g/cm³ can be calculated by using the formula:

[tex]\mathtt{ density \ d = \dfrac{z \times molar\ mass \ (M)}{ edge \ length \ (a) \ \times avogadro's \ number \ (N)}}[/tex]

where;

z = 1 mole of CsBr

edge length = 428.7 pm = (4.287 × 10⁻⁸)³ cm

molar mass of CsBr = 212.81 g/mol

avogadro's number = 6.023 × 10²³

[tex]\mathtt{ density \ d = \dfrac{1 \times 212.81}{(4.287 \times 10^{-8})^3 \times 6.023 \times 10^{23}}}[/tex]

[tex]\mathtt{ density \ d = \dfrac{ 212.81}{47.4540533}}[/tex]

[tex]\mathbf {density \ d =4.4845 \ g/cm^3}[/tex]

Answer:

zero

Explanation:

In a unit cell, an atom that is located at the center of a cube edge is not involved in sharing unit cells because a central atom of a unit cell belongs to the entire cell and only to that unit cell of the lattice.

Hence, the center atom of a unit cell do not share any unit cell and the correct answer is "Zero".

Explanation:

An atom undergoes alpha decay by losing a helium atom.

So when bismuth undergoes alpha decay, we have;

²¹⁰₈₃Bi --> ⁴₂He + X

Mass number;

210 = 4 + x

x = 206

Atomic number;

83 = 2 + x

x = 81

The element is Thallium. The symbol is Ti.

For the second part;

X --> ⁴₂He + ²³⁴₉₀Th

Mass number;

x = 4 + 234 = 238

Atomic Number;

x = 2 + 90 = 92

The balanced nuclear equation is;

²³⁸₉₂U --> ⁴₂He + ²³⁴₉₀Th

Answer:

W = 278.64375 Joules

Explanation:

The information given in this problem are;

Initial volume = 0L

Final volume = 2.50L

ΔV = 2.50 - 0 = 2.50 L

External pressure, P =  1.10 atm

Work = ?

These parameters are related by the equation;

w = - P ΔV

W = - (1.10 )(2.50)

W = 2.75 L atm

Upon conversion to joules;

1 liter atmosphere is equal to 101.325 joule

W = 278.64375 Joules

Answer:

А It is hard because its ions are held together by strong electrostatic attractions.

B It is malleable because its atoms can easily move past one another without disrupting the bonding.  

Explanation:

These are correct explanations of the properties of magnesium.

C is wrong. Mg is a good conductor of electricity and it has metallic bonds.

D is wrong. Mg has no molecules. It has no intermolecular forces.

Answer:

well, first off. the formula for carbon tetrachloride is CCl4

We need to find the molar mass of carbon tetrachloride

1(Mass of C) + 4(mass of chlorine)

1(12) + 4(35.5)

12 + 142

154 g/mol

Number of moles of CCl3 in 543.2g CCl3

n = given mass / molar mass

n = 543.2/153

n = 3.53 moles

always remember to brainly the questions you find helpful

Answer:

3.53 moles

Explanation:

Answer:

d. condensation of water on a wind shield of a car

Explanation:

Condensation involves the conversion of moist air into liquid.

Gas has a higher energy compared to liquid. This is why Gas particles move at random motion and faster in relation to solid and liquid particles due to the high energy content.

The conversion of the gas to liquid means that there was loss or release of energy which validates the answer.

Answer:

Jesseca Kusher, an 18-year-old researcher from Spartansburg, S.C., invented a paint-on coating for roofing shingles. Her formula could reduce a home's cooling costs and possibly cut ozone pollution in urban areas...

SUPPORT ME ...........

Answer:

Jesseca created mixtures containing graphite, gypsum, and mica that could be painted on roof shingles.

Explanation:

Hope this helped!!

Answer:

HClO 7.54

Explanation:

Hypochlorous acid (HClO) is a weakest acid because the pKa value of Hypochlorous acid is very high among the options given in the activity. pKa is a method which is used in order to identify the strength of an acid. The higher the value of pKa of a liquid, lower the strength of an acid while lower the value of pKa of chemical, higher the strength of an acid. In the options, HClO2  is a strong acid due to high lower pKa value.

Answer:

Lime water, [tex]Ca(OH)_{2}_({aq} )[/tex] is formed.

Explanation:

Lime-water is a clear and colourless dilute solution of aqueous calcium hydroxide salt.

Small amounts of calcium hydroxide salt,  [tex]Ca(OH)_{2}_(s)[/tex]  is sparsely soluble at room temperature when dispersed vigorously. if in excess, a white suspension called 'milk of lime'is formed.

I hope this explanation is helpful.

Answer:

[tex]\Delta G=-359\frac{kJ}{mol}[/tex]

Explanation:

Hello,

In this case, we must remember that the Gibbs free energy is defined in terms of the enthalpy, temperature and entropy as shown below:

[tex]\Delta G=\Delta H -T\Delta S\\[/tex]

In such a way, for the given data, we obtain it, considering the conversion from J to kJ for the entropy in order to conserve the proper units:

[tex]\Delta G=-292\frac{kJ}{mol} -(298)(224\frac{J}{mol}*\frac{1kJ}{1000J} )\\\\\Delta G=-359\frac{kJ}{mol}[/tex]

Best regards.

Answer:

B- 358 kj

Explanation: I took the test

Answer:

0.14%

Explanation:

The computation of % is shown below:

As we know that

     HClO <=> H+ + ClO-

I         0.015          0      0

C          -a            +a     +a

E      0.015-a        a       a

Now

[tex]Ka = \frac{[H+][ClO-]}{[HClO]}[/tex]

[tex]= \frac{a^{2}}{(0.015 - a)} \\\\= 3.0 \times 10^{-8}[/tex]

[tex]a^{2} + 3.0 \times 10^{-8}a - 4.5 \times 10^{-10} = 0[/tex]

Now Solves the quadratic equation i.e.

[tex]a = 2.120 \times 10^{-5}[/tex]

[tex][H+] = a = 2.120 \times 10^{-5} M[/tex]

So,

% ionization is

[tex]= \frac{[H+]}{[HClO]}_{initial} \times 100\%\\\\= 2.120 \times 10^{-5}\div0.015 \times 100\%[/tex]

= 0.14%

Hence, the percentage of hypochlorous ionization is 0.14%

Answer:

Explanation:

[tex]H_3O^+[/tex] also known as hydronium ion is formed as a result of the reaction between an hydrogen proton and a water molecules.

i.e [tex]\mathtt{H^+ + H_2O \to H_3O^+}[/tex]

(molecular geometry for the hydronium ion shows that the lewis structure of hydronium ion possess a three hydrogen ion bonded to a central atom known as oxygen. The oxygen possess a lone pair with a positive ion. So we have three hydrogen atoms and a lone pair attached to the oxygen. We can now say that there are four groups as the steric number in which one of them is a lone pair. This give rise to the trigonal pyramidal shape of the [tex]H_3O^+[/tex] (hydronium ion) with a bond angle of about 109,5°

Similarly, [tex]NH_3[/tex] on the other hand also known as ammonia has a shape that can be also determined by the Lewis structure.

IN ammonia,  there are three hydrogen  and a lone pairs of electron spreading out as far away from each other  from the centre nitrogen. In essence, the valence shell electron pair around hydrogens tend to repel each other. Hence, giving it a trigonal pyramidal shape.

From above the similarities between H3O and NH3 is in their molecular geometry in which both  H3O and NH3 have the same shape.

These molecules are called isoelectronic. Why?

Isoelectronic molecules are molecules having the same number of electrons and same electronic configuration  structure. As a result H3O and NH3 possess the same  number of electrons in the same orbitals and they also posses the same structure.

Answer:

The answer is D) Electrolytic cell

Explanation:

An electrolytic cell is a device used for the decomposition by the electrical current of ionized substances called electrolytes.

When the two electrodes are connected by a wire, electrical energy is produced, and a flow of electrons takes place from the electrode.

These cells are the closest thing to a galvanic battery.

Answer:

b. voltaic cell

Explanation:

Founders Education answer. had to take this quiz 4 times

Answer: make a drainage system or make sure that the ground does not absorb the water from the rain and cause a landslide.

Explanation: To prevent frequent landlides you have to make suee there is and area for the rain to go so it does not get stuck in the mud and destabalize the mud

B. Plant vegetation on the slops that expreience landslides.

E. Reduce the sloped where landslides occur.

Hope this helped, please mark brainiest!

Answer:

B. 21.07 x 10²³ molecules

Explanation:

Avogadro's Number: 6.022 x 10²³

Step 1: Set up equation

[tex]3.5 mols CO_2(\frac{6.022(10^{23}) moleculesCO_2}{1 mol CO_2})[/tex]

Step 2: Multiply and cancel out units

3.5(6.022 x 10²³) = 21.07 x 10²³ molecules CO₂

Step 3: Convert to proper scientific notation

≈ 2.11 x 10²³ molecules CO₂

Answer:

  30. 5 planes are shown

  31. 1 plane

  32. CEF

  33. on line AB

  34. E or F

   35. ABCD or BCEF or CDEF or ACEF

Explanation:

30. Each of the surfaces of the rectangular pyramid is a plane. There are 5 planes.

__

31. 3 points define one plane only.

__

32. The only points shown on the same line segment are points E, F, and C.

__

33. If G is to be collinear with A and B, it must lie on line AB.

__

34. The only points shown that are not on plane N are points E and F. Either of those will do.

__

35. There are three planes that have 4 points shown on them. The four points that are on the same plane are any of ...

Plane ACEF is not shown on the diagram, but we know that those 4 points are also coplanar. (Any point not on line CE, together with the three points on that line, will define a plane with 4 coplanar points.)

The question is missing. Here is the complete question.

Which balanced redox reaction is ocurring in the voltaic cell represented by the notation of [tex]Al_{(s)}|Al^{3+}_{(aq)}||Pb^{2+}_{(aq)}|Pb_{(s)}[/tex]?

(a) [tex]Al_{(s)}+Pb^{2+}_{(aq)} ->Al^{3+}_{(aq)}+Pb_{(s)}[/tex]

(b) [tex]2Al^{3+}_{(aq)}+3Pb_{(s)} -> 2Al_{(s)}+3Pb^{2+}_{(aq)}[/tex]

(c)[tex]Al^{3+}_{(aq)}+Pb_{(s)} ->Al_{(s)}+Pb^{2+}_{(aq)}[/tex]

(d) [tex]2Al_{(s)}+3Pb^{2+}_{(aq)} -> 2Al^{3+}_{(aq)}+3Pb_{(s)}[/tex]

Answer: (d) [tex]2Al_{(s)}+3Pb^{2+}_{(aq)} -> 2Al^{3+}_{(aq)}+3Pb_{(s)}[/tex]

Explanation: Redox Reaction is an oxidation-reduction reaction that happens in the reagents. In this type of reaction, reagent changes its oxidation state: when it loses an electron, oxidation state increases, so it is oxidized; when receives an electron, oxidation state decreases, then it is reduced.

Redox reactions can be represented in shorthand form called cell notation, formed by: left side of the salt bridge (||), which is always the anode, i.e., its half-equation is as an oxidation and right side, which is always the cathode, i.e., its half-equation is always a reduction.

For the cell notation: [tex]Al_{(s)}|Al^{3+}_{(aq)}||Pb^{2+}_{(aq)}|Pb_{(s)}[/tex]

Aluminum's half-equation is oxidation:

[tex]Al_{(s)} -> Al^{3+}_{(aq)}+3e^{-}[/tex]

For Lead, half-equation is reduction:

[tex]Pb^{2+}_{(aq)}+2e^{-} -> Pb_{(s)}[/tex]

Multiply first half-equation for 2 and second half-equation by 3:

[tex]2Al_{(s)} -> 2Al^{3+}_{(aq)}+6e^{-}[/tex]

[tex]3Pb^{2+}_{(aq)}+6e^{-} -> 3Pb_{(s)}[/tex]

Adding them:

[tex]2Al_{(s)}+3Pb^{2+}_{(aq)} -> 2Al^{3+}_{(aq)}+3Pb_{(s)}[/tex]

The balanced redox reaction with cell notation [tex]Al_{(s)}|Al^{3+}_{(aq)}||Pb^{2+}_{(aq)}|Pb_{(s)}[/tex] is

[tex]2Al_{(s)}+3Pb^{2+}_{(aq)} -> 2Al^{3+}_{(aq)}+3Pb_{(s)}[/tex]

Answer:

The liquid that is often used in thermometers is chrome.

It is khwon for raising its volule when the temperature raises and vice-versa. ● the temperature and the volume are proprtional to each other so using Mathematics, scientists have figured out a way to benefit from it to make a thermometer.

Answer:

K2CO3  and NaF

Explanation:

In order to ascertain which salt would form a basic solution we have to identify the classification of each of the salts.

- NH4Br: is the salt of a weak base (NH3) and a strong acid (HBr). This means that it would form an acidic solution.

- Pb(NO3): This is a normal salt, hence would not form a basic solution.

-  K2CO3: This is salt that forms a strongly alkaline/basic solution.

- NaF: it is the salt of a strong base, NaOH, and a weak acid, HF. This means this would form a basic solution.

The compounds capable to form basic solutions are[tex]\rm \bold {K_2CO_3 }[/tex] and NaF. Thus, options C and D are correct.

The basic solution has been given with the presence of a high number of hydroxide ions, while the acidic solution has been the presence of hydrogen ions.

The solution has been considered as basic when the compound has been constituted of a strong base. The constituents of the following compounds have been:

The compounds capable to form basic solutions are[tex]\rm \bold {K_2CO_3 }[/tex] and NaF. Thus, options C and D are correct.

For more information about the basic solution, refer to the link:

https://brainly.com/question/3595168

Answer:

Each energy sublevel contains a different number of electrons. For example, sublevel D can contain up to 10 electrons

Explanation:

The atoms are surrounded by propellers that within each propeller there is a certain number of electrons, these electrons jump from orbit to orbit according to the amount of energy they have. The four levels that make up the electronic cloud that surrounds an atom are: s p d f.

When these electrons change orbit or level they release energy in the form of light, which is known as a photon.

Answer:

[tex]r_A=-1\frac{M}{s}[/tex]

Explanation:

Hello,

In this case, given the rate of production of C, we can compute the rate of consumption of A by using the rate relationships which include the stoichiometric coefficients at the denominators (-1 for A and 2 for C) as follows:

[tex]\frac{1}{-1} r_A=\frac{1}{2}r_C[/tex]

In such a way, solving the rate of consumption of A, we obtain:

[tex]r_A=-\frac{1}{2} r_C=-\frac{1}{2}*2\frac{M}{s}\\ \\r_A=-1\frac{M}{s}[/tex]

Clearly, such rate is negative which account for consumption process.

Regards.

Answer:

THE FINAL TEMPERATURE OF WATER IS -4.117 °C

Explanation:

Mass of the aluminium = 50 g

c = 0.88 J/g C

Initial temperature of aluminium = 225 °C

Volume of water = 100 ml

Density of water = 1 g/ml

Mass of water = density * volume of water

Mass of water = 1 * 100 = 100 g of water

Initial temperature of water = 20 C

It is worthy to note that the heat of a system is constant and conserved as no heat is lost or gained by a closed system,

So therefore,

heat lost by aluminium = heat gained by water

H = mass * specific heat capacity * temeprature change

So:

m c ( T2- T1) = m c (T2-T1)

50 * 0.88 * ( T2 - 225) = 100 * 4.18 *( T2 - 20)

44 ( T2 - 225 ) = 418 ( T2 - 20)

44 T2 - 9900 = 418 T2 - 8360

-9900 + 8360 = 418 T2 - 44 T2

-1540 = 374 T2

T2 = - 4.117

So therefore the final temperature of water is -4.117 °C

CHECK COMPLETE QUESTION BELOW

At a given temperature the vapor pressures of benzene and toluene are 183 mm Hg and 59.2 mm Hg, respectively. Calculate the total vapor pressure over a solution of benzene and toluene with Xbenzene = 0.580.

Answer:

The total vapor pressure is [tex]81.3 mmHg[/tex]

Explanation:

We will be making use of Dalton and Raoults equation in order to calculate the total pressure,

Which is [tex]PT= (PA × XA) +(PB ×XB)[/tex]

PT= total vapor pressure

From the question

Benene's Mole fraction = 0.580

then to get Mole fraction of toluene we will substract the one of benzene from 1. because total mole fraction is always 1.

= (1 - 0.580) = 0.420

Vapor pressure of benzene given = 183 mmHg

Vapor pressure of toluene given= 59.2 mmHg

If we substitute those value into above equation, we have

PT=(183×0.580)+(59.2×0.420)

=81.3mmHg

Therefore,, the total vapor pressure of the solution is 81.3 mmHg

Answer:

d. 8 moles of H2O on the product side

Explanation:

Hello,

In this case, we need to balance the given redox reaction in acidic media as shown below:

[tex]MnO_4^{1-} (aq) + Cl^{1-} (aq) \rightarrow Mn^{2+} (aq) + Cl_2 (g)\\\\(Mn^{7+}O^{2-}_4)^{1-} (aq) + Cl^{1-} (aq) \rightarrow Mn^{2+} (aq) + Cl_2 (g)\\\\\\\\(Mn^{7+}O^{2-}_4)^{1-} (aq)+8H^++5e^- \rightarrow Mn^{2+}+4H_2O\\\\2Cl^{1-}\rightarrow Cl_2^0+2e^-\\\\2*[(Mn^{7+}O^{2-}_4)^{1-} (aq)+8H^++5e^- \rightarrow Mn^{2+}+4H_2O]\\\\5*[2Cl^{1-}\rightarrow Cl_2^0+2e^-]\\\\\\\\2(Mn^{7+}O^{2-}_4)^{1-} (aq)+16H^++10e^- \rightarrow 2Mn^{2+}+8H_2O\\\\10Cl^{1-}\rightarrow 5Cl_2^0+10e^-\\[/tex]

Then, we add the half reactions:

[tex]2(Mn^{7+}O^{2-}_4)^{1-} (aq)+16H^++10Cl^{1-} \rightarrow 2Mn^{2+}+8H_2O+5Cl_2^0[/tex]

Thereby, we can see d. 8 moles of H2O on the product side.

Best regards.

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.

Explanation:

To obtain the empirical and molecular formula of this compound from the percent composition of the elements, we follow the steps below;

Step 1: Divide the percentage composition by the atomic mass

Sulphur = 31.42 / 32 = 0.9819

Oxygen = 31.35 / 16 = 1.9594

Flourine = 37.23 / 19 = 1.9595

Step 2: Divide by the lowest number

Sulphur = 0.9819 / 0.9819 = 1

Oxygen = 1.9594 / 0.9819 ≈ 2

Flourine = 1.9595 / 0.9819 ≈ 2

This means the ratio of the elements is 1 : 2: 2

The empirical formular (simplest formular of a compound) of the compound is;

SO₂F₂

To obtain the molecular formular (Actual formular of a compound);

(SO₂F₂)n = 102.1

Inserting the atomic masses and solving for n;

(102)n = 102.1

n ≈ 1

The molecular formular is; (SO₂F₂)₁ = SO₂F₂