Steel:
Propane:
Calcium chloride:
Water:

Answer:

[tex]\large \boxed{\text{-827.4 kJ}}[/tex]

Explanation:

We have three equations:

1. 2H₂S(g)            + O₂(g)   ⟶ 2S(s, rhombic) + 2H₂O(g) ; ∆H = -442.4 kJ

2. S(s, rhombic)  + O₂(g)   ⟶ SO₂(g);                                 ∆H = -296.8 kJ

3. PbO(s)             + H₂S(g) ⟶ PbS(s)               + SO₂(g);    ∆H =  -104.3 kJ

From these, we must devise the target equation:

4. 2PbS(s)            + 3O₂(g) ⟶2PbO(s)             + 2SO₂(g); ΔH = ?

The target equation has PbS(s) on the left, so you reverse Equation 3 and double it.

When you reverse an equation, you reverse the sign of its ΔH.

When you double an equation, you double its ΔH.

5. 2PbS(s) + 2H₂O(g) ⟶ 2PbO(s) + 2H₂S(g); ∆H = 208.6 kJ

Equation 5 has 2H₂O on the left. That is not in the target equation.

You need an equation with 2H₂O on the right, so you copy Equation 1.  

6. 2H₂S(g) + O₂(g) ⟶ 2S(s, rhombic) + 2H₂O(g) ; ∆H = -442.4 kJ  

Equation 6 has 2S(s, rhombic) on the right. That is not in the target equation.

You need an equation with 2S(s, rhombic) on the left, so you double Equation 2.  

7. 2S(s, rhombic)  + 2O₂(g) ⟶ 2SO₂(g); ∆H = -593.6 kJ

Now, you add equations 5, 6, and 7, cancelling species that appear on opposite sides of the reaction arrows.

When you add equations, you add their ΔH values.

You get the target equation 4:

5. 2PbS(s)  + 2H₂O(g)  ⟶ 2PbO(s) + 2H₂S(g);  ∆H =  208.6 kJ

6. 2H₂S(g) + O₂(g)        ⟶ 2S(s)     + 2H₂O(g) ; ∆H = -442.4 kJ

7. 2S(s)      + 2O₂(g)      ⟶ 2SO₂(g);                   ∆H = -593.6 kJ

4 . 2PbS(s) + 3O₂(g)      ⟶ 2PbO(s) + 2SO₂(g); ΔH = -827.4 kJ

[tex]\Delta H \text{ for the reaction is $ \large \boxed{\textbf{-827.4 kJ}}$}[/tex]

Answer:

limited resources

Explanation:

nonrenewable resources are those resources found inside the earth that are in a fixed amount. They are being used at a faster rate, and cannot be renewed. These resources include fossil fuels,natural gas, and coal.

// have a great day //

Answer:

It is called a compound.

Explanation:

A person having trouble breathing could be a sign of

d. All of the above(alcohol overdose, depressant overdose, or stimulant overdose)

Most instances of windedness are because of heart or lung conditions. These organs are engaged with shipping oxygen to your tissues and removing carbon dioxide, and issues with both of these cycles influence your relaxation.

At a party, if a person feels trouble breathing then it can be due to an alcohol overdose, depressant overdose, or stimulant overdose.

Thus, option D is correct.

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Answer: Definitely the answer is C. They both last for the same number of days.

Explanation: This requires the moon to complete a bit more than one orbit to be between the earth and the sun again. The period from new moon to full moon is one half a synodic month of 29.530/2 which is 14.765 days.

According to Avogadro's law, volume is directly proportional  to number of moles which is in relation with the grams of a compound.

Avogadro's law is a gas law which states that the total number of atoms or molecules has a direct proportion to the volume occupied by a gas at a constant temperature and pressure.

It is closely related to ideal gas equation as it links temperature, pressure, volume and the amount of substance.It is given as, V∝n,

The straight line graph of volume versus moles is a straight line passing through the origin which implies that zero moles of gas occupy zero volume.The law was proposed by Amedeo Avogadro in year 1811.

The law can be derived from the assumption of kinetic theory  of gases considering their ideal behaviour.

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Answer:

Units used to measure atomic radius:

Angstroms (Å): This the most common unit used. Equivalent to 1.0 x 10-10 meters.

Nanometer (nm): Equivalent to 1.0 x 10-9 meters.

Picometer (pm): Equivalent to 1.0 x 10-12 meters.

Answer:

True

Explanation:

The center receives pressure which is what creates convection currents

Answer:

98.6%

Explanation:

First we put down the equation representing the decomposition of sodium bicarbonate.

2NaHCO3(s) ----> Na2CO3(s) + H2O(l) + CO2(g)

We can see from the data provided that the mass of sodium bicarbonate reacted is 3.01 g.

The number of moles of sodium bicarbonate reacted= mass of sodium bicarbonate/ molar mass of sodium bicarbonate

Molar mass of sodium bicarbonate= 84.007 g/mol

Number of moles of sodium bicarbonate=3.01 g/ 84.007 g/mol

Number of moles of sodium bicarbonate= 0.0358 moles

From the balanced reaction equation,

2 moles of sodium bicarbonate yields 1 mole of sodium carbonate

Hence 0.0358 moles of sodium bicarbonate yields 0.0358/2 = 0.0179 moles of sodium carbonate

Theoretical yield of sodium carbonate = number of moles of sodium carbonate × molar mass of sodium carbonate

Molar mass of sodium carbonate= 105.9888 g/mol

Theoretical yield of sodium carbonate= 0.0179 moles × 105.9888 g/mol

Theoretical yield of sodium carbonate= 1.897 g

Actual yield of sodium carbonate= 1.87 g

%yield of sodium carbonate= 1.87/1.897 ×100

%yield of sodium carbonate= 98.6%

Answer:

It is calcualted based ion the  yield from the limiting reactant

Explanation:

Answer:

A

Explanation:

Hmm, so we have the following in the diagram

Pt(s)

Cl2(g)

Ag(s)

NaCl(aq)

AgNO3(aq)

Pt 2+, 4+, 6+  Though it states Pt is inert

Cl 2-

Ag 1+

Na 1+

NO3-

Anode definition: the positively charged electrode by which the electrons leave an electrical device.

Electrode definition: a conductor through which electricity enters or leaves an object, substance, or region.

Cations attracted to cathode pick up electrons

Anions attracted to anode release electrodes+

Reduction at Cathode (red cat gain of e)

Oxidation at Anode (ox anode loss of e)

So from the diagram we can see that the charge is being generated through the 2 metal plates.

So the answer is A, the anode material is Pt and the half reaction is 2Cl- = Cl2 + 2e-

Answer:

C. element. oxygen is an element

Explanation:

oxygen is element #8

Answer:

The new pressure is 3164.58 psi.

Explanation:

We have,

Initial pressure, [tex]P_1= 2975\ psi[/tex]

Initial temperature, [tex]T_1=25^{\circ}=298.15\ K[/tex]

The tank is left in a car in the  hot sun and the temperature increases to 44°C, [tex]T_2=44^{\circ} =317.15\ K[/tex]

Let [tex]P_2[/tex] is the final pressure in the tank. Gay Lussac's law,

[tex]P\propto T\\\\\dfrac{P_1}{P_2}=\dfrac{T_1}{T_2}\\\\P_2=\dfrac{P_1T_2}{T_1}[/tex]

Plugging all the values,

[tex]P_2=\dfrac{2975\times 317.15}{298.15}\\\\P_2=3164.58\ psi[/tex]

So, the new pressure is 3164.58 psi.

Answer:

Scientists with varied experimental processes and interests perceive things differently.

Explanation:

Scientists believe in proposing theories which contradict current theories. So the correct option is D.

Recently, the structure of atoms has been discovered. Before the ideal model of an atom was found, several others were proposed and abandoned.

Atomic Model of J.J. Thomson

Atomic Model of Rutherford

Therefore the correct option is D.

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Answer:

346.5 cm³ or 347cm³

Explanation:

v1/T1 = v2/T2

417/278 = v2/231

v2 = 346.5 cm³

Answer:B

Explanation:

You want different temperatures for each beaker but everything else the same

Answer:

After one-half life: 16 mg

After 2-half lives: 8 mg

After 3-half lives: 4 mg

After 4-half lives: 2 mg

After 5-half lives: 1 mg

(5 half-lives) x (8 days/half-life) = 40 days  

or doing it the mathematical way:  Let z be the number of days to be found:

1 mg = 32 mg x (1/2)^(z / 8 days)  

1/32 = (1/2)^(z / 8 days)  

log (1/32) = (z / 8 days) x log (1/2)  

z / 8 days = log (1/32) / log (1/2)

z = 8 days x log (1/32) / log (1/2) = 40 days

Explanation:

Iodine-131 has a half-life of 8 days, then it would it take for the number of unstable nuclei in the sample to be reduced from 1,000 to 125 is 512 days.

Total time of the reduction of any substance from an initial concentration to a particular concentration will be calculated as:

T = (t)ⁿ, where

n = number of half lives

t = half life time = 8 days

1st half life: 1000 → 500

2nd half life: 500 → 250

3rd half life: 250 → 125

So number of half life times is 3. On putting values we get,

T = (8)³

T = 512 days

Hence total duration of time is 512 days.

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Answer:

It would be gas b. The gas you are talking about is carbon dioxide and for the reaction to work the gas needs to be bubbled through into the lime water.

Explanation:

The carbon dioxide reacts with lime water which is a solution of calcium hydroxide to form the white precipitate of calcium carbonate CaCO 3.

Answer:

2HNO3 + Ba(OH)2 = Ba(NO3)2 + 2H2O

H3PO4 + Ca(OH)2 = Ca3(PO4)2 + 6H2O

3HCl + Fe(OH)3) = FeCl3 + 3H2O

Explanation:

H+

N3-

O2-

Ba2+

OH-

P 5+, 3+, 3-

Ca2+

Cl-

Fe  2+, 3+

2HNO3 + Ba(OH)2 = Ba(NO3)2 + 2H2O

H3PO4 + Ca(OH)2 = Ca3(PO4)2 + 6H2O

3HCl + Fe(OH)3) = FeCl3 + 3H2O

Answer:

Percent by mass of solute is (10/35) x 100 =  28.57%

Percent by mass of solvent is (25/35) x 100 = 71.43%

Explanation:

10.0 grams of solute

25.0 grams of solvent

Total Mass = 35 grams

percent by mass = (Mass A / Total Mass) x 100

Percent by mass of solute is (10/35) x 100 =  28.57%

Percent by mass of solvent is (25/35) x 100 = 71.43%

Answer: B. (A 25 kg ball)

Explanation:

Since [tex]KE = \frac{1}{2} mv^{2} \\[/tex], and velocity is the same for all four balls, the ball with the greatest mass will have the greatest kinetic energy (since mass and KE are directly related). Below shows these calculations:

A. m = 5

[tex]KE = \frac{1}{2} mv^{2} \\[/tex]

[tex]KE = \frac{1}{2} (5)v^{2} \\[/tex]

[tex]KE = 2.5v^{2} \\[/tex]

B. m = 25

[tex]KE = \frac{1}{2} mv^{2} \\[/tex]

[tex]KE = \frac{1}{2} (25)v^{2} \\[/tex]

[tex]KE = 12.5v^{2} \\[/tex]

C. m = 10

[tex]KE = \frac{1}{2} mv^{2} \\[/tex]

[tex]KE = \frac{1}{2} (10)v^{2} \\[/tex]

[tex]KE = 5v^{2} \\[/tex]

D. m = 1

[tex]KE = \frac{1}{2} mv^{2} \\[/tex]

[tex]KE = \frac{1}{2} (1)v^{2} \\[/tex]

[tex]KE = 0.5v^{2} \\[/tex]

Answer:

36 hours

Explanation:

Notice that you are given the actual table of how the isotope reduces , and it shows that for each period of 6 hours the isotope decays to half of the initial number.

EVery 6 hours, the reduction in number of mg of the isotope goes down in half'

100 mg, then 50 mg, then 25 mg, then 12.5 mg, then 6.25 mg, then 3.125 mg and finally (reaching 1.5625 mg

That was 6 periods of 6 hours each, which totals: 6 time 6 hours = 36 hours

Answer:

The two objects have the same electric charge.

Explanation:

Electrically charged objects repel if they are both of the same charge, ie plus plus or minus minus.

The statement, that describes two electrically charged objects repel one another is "the two objects have the same electric charge."

The feature of subatomic particles that causes them to experience a force when put in an electric and magnetic field is known as electric charge.

When one or more items are electrically charged, electrostatic interactions are widespread. Two items with opposing charges will attract each other.

Unlike the attractive force between two items with opposite charges, two objects with like charges repel each other. In other words, a positively charged object will repel another positively charged object. This repelling force will separate the two items.

Hence the correct answer is the two objects have the same electric charge.

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Answer:

Filtration

Explanation:

Filtration is used to separate solid substances from liquids or large molecules from small molecules. Since, Acid is a liquid and metal oxide is solid so Filtration can be used to separate these two.

The role of the salt bridge is to assure the neutrality of both compartments.

Answer:

You have no fuel cost and has low cost Maintenance

Explanation: