Billy and Susie heat a 78.9 g sample of Unobtanium at 18.0C. Using a lab burner, they burn propane and the unobtanium absorbs 13,240 J of heat untill the temperature reaches the melting point 109C. what is the specific heat of unobtanium

Answer:

liquid

Explanation:

it's not plasma, solid, or gas

so I think liquid

Answer:

Explanation:

Mol weight of HCl = 36.5

.90 g of HCl = .90 / 36.5 mole = .02465 mole

HCl      =    H⁺        +      Cl⁻

1 mole     1 mole

1 mole of HCl gives 1 mole of H⁺

.02465 mole of HCl will give .02465 mole of H⁺

.02465 mole of H⁺ in 5 litre soln

concentration of H⁺ =  .02465 / 5 = 4.93 x 10⁻³ M

pH = - log ( 4.93 x 10⁻³ )

= 3 - log 4.93

= 3 - .693

= 2.307

= 2.31

NaOH :

Mol weight of NaOH  = 40

.50 g of HCl = .50 / 40 mole = .0125 mole

NaOH     =    Na⁺        +      OH⁻

1 mole     1 mole

1 mole of NaOH gives 1 mole of OH⁻

.0125 mole of NaOH will give .0125 mole of OH⁻

.0125 mole of OH⁻ in 4 litre soln

concentration of OH⁻ =  .0125 / 4 = 3.125 x 10⁻³ M

pOH = - log ( 3.125 x 10⁻³ )

= 3 - log 3.125

= 3 - .495

= 2.505

pH = 14 - pOH

= 14 - 2.505

= 11.495 .

= 11.50

Answer:

The answer to this is solids!

Answer:

0.03947 atm

Explanation:

The relationship between mmHg and atm is given as;

1 atm = 760 mmHg

x atm = 30 mmHg

Upon solving for x;

x * 760 = 30 * 1

x = 30 / 760 = 0.03947 atm

Answer:

Red goes in the spiky yellow box. Green goes where the red circles are. Blue goes in the small yellow box that is pointing to the line.

Explanation:

The focus of an earthquake is where it starts in the earth. The epicenter is the part directly above the focus on the surface. The fault is the part where the earth's crust splits.

Answer:

3.0g remain

Explanation:

The half-life is defined as the time required for a reactant to decrease its concentration in exactly the half of the initial amount of reactant. Having this in mind:

In one half-life, the mass will be:

24.0g / 2 = 12.0g

In two half-lifes:

12.0g / 2 = 6.0g

And in three half-lifes, the mass that remain is:

6.0g / 2 =

Answer:

the change in energy of the gas mixture during the reaction is 227Kj

Explanation:

THIS IS THE COMPLETE QUESTION BELOW

Measurements show that the enthalpy of a mixture of gaseous reactants increases by 319kJ during a certain chemical reaction, which is carried out at a constant pressure. Furthermore, by carefully monitoring the volume change it is determined that -92kJ of work is done on the mixture during the reaction. Calculate the change of energy of the gas mixture during the reaction in kJ.

From thermodynamics

ΔE= q + w

Where w= workdone on the system or by the system

q= heat added or remove

ΔE= change in the internal energy

q=+ 319kJ ( absorbed heat is + ve

w= -92kJ

If we substitute the given values,

ΔE= 319 + (-92)= 227 Kj

With the increase in enthalpy and there is absorbed heat, hence the reaction is an endothermic reaction.

Answer:

60.88%

Explanation:

The balanced equation of the reaction is given as;

2 AgNO3 (aq) + BaCl2 (aq) → 2 AgCl (s) + Ba(NO3)2 (aq)

Since AgNO3 is in excess, the limiting reactant is BaCl2. From the reaction;

1 mol of BaCl2 produces 2 mol of AgCl

Converting to masses;

Mass = Number of mol * Molar mass

BaCl2;

Mass = 1 * 208.23 g/mol = 208.23 g

AgCl;

Mass = 2 * 143.32 g/mol = 286.64 g

208.23 g BaCl2 produces 286.64 g of AgCl

x g BaCl2 produces 7.123 g of AgCl

Solving for x;

x = 7.123 * 208.23 / 286.64 = 5.1745 g

Mass percent = Mass / Total mass of Mixture  * 100

Mass Percent = 5.1745 / 8.500 = 0.6088 * 100 = 60.88%

Answer:

A: Helium or Hydrogen

Explanation:

Terrestrial planets are the 4 inner most planets of the solar system which are mercury, venus, earth, Mars, while the giant planets are the 4 outer most which are Jupiter, Saturn, Uranus and Neptune.

Now, these outer most ones are the surface ones and are surrounded primarily by layers of hydrogen and helium gases.

Answer:

That is the Atomic mass

Explanation:

The element symbol is S, Element name is sulfur, and

Atomic number is 16

Answer:

3

Explanation:

2,8,6

Answer: the electrostatic potential energy is -3.26 × 10⁻¹⁸ J

Explanation:

Given the data in the question;

I think the value of electrostatic potential energy of calcium sulfide CaS formed will be less(more negative) than KCl because the Ca2+ and S2- ions has more charge that is +2 and -2 respectively when compared to Kcl which has +1 and -1 charge.so it will be more negative.

radius = r[tex]_{ca+2}[/tex] + r[tex]_{s-2}[/tex] = 100 + 184 = 284 pm = 2.84 × 10⁻¹⁰ m

we know that; k = 2.31 × 10⁻²⁸ J

q1 = 2  ( charge on Ca⁺² )

q2 = -2( charge on S⁻²)

so

Ep = k × q1q2/r

so we substitute

Ep = 2.31 × 10⁻²⁸ × (+2×-2) / 2.84 × 10⁻¹⁰

Ep = (2.31 × 10⁻²⁸ × -4) / 2.84 × 10⁻¹⁰

Ep = -9.24 × 10⁻²⁸ / 2.84 × 10⁻¹⁰

Ep = -3.26 × 10⁻¹⁸ J

Therefore, the electrostatic potential energy is -3.26 × 10⁻¹⁸ J

Based on the data provided, the electrostatic potential energy is -3.26 × 10⁻¹⁸ J

The electrostatic potential energy is the work done in moving the charge from infinity to that point against the electric field.

The electrostatic potential energy between any two charges q1, q2 separated by distance r is derived from Coulomb’s law and mathematically given as:

where

From the data provided:

ionic radii of Ca2+ r1 = 100 pm

ionic radii of S2– = 184 pm.

Chargeon Ca2+ = +2

Charge on S2_ = -2

From the data above, it most likely that the value of electrostatic potential energy of calcium sulfide CaS formed will be less(more negative) than KCl because the Ca2+ and S2- ions has a greater charge of +2 and -2 respectively compared to Kcl which has +1 and -1 charge.

Calculating the electrostatic potential energy, Ep:

radius = r1 + r2 = 100 + 184 = 284 pm

r = 2.84 × 10⁻¹⁰ m

k = 2.31 × 10⁻²⁸ J

q1 = 2  ( charge on Ca⁺² )

q2 = -2( charge on S⁻²)

Then:

Ep = k × q1q2/r

Substituting the values above in the equation:

Ep = 2.31 × 10⁻²⁸ × (+2 ×-2) / 2.84 × 10⁻¹⁰

Ep = (2.31 × 10⁻²⁸ × -4) / 2.84 × 10⁻¹⁰

Ep = -9.24 × 10⁻²⁸ / 2.84 × 10⁻¹⁰

Ep = -3.26 × 10⁻¹⁸ J

Therefore, the electrostatic potential energy is -3.26 × 10⁻¹⁸ J.

Learn more about electrostatic potential energy at: https://brainly.com/question/24648428

Hello. You forgot and show the compounds. The compounds are in the attached image.

Answer:

I < II < III

Explanation:

The stability of the presented compounds must be analyzed, taking into account the free electrons to form arrangements between the atoms. In this case, the molecules of greater stability follow the concept of valence and are characterized as those that manage to reach a large number of elements that manage to obey the octet rule.

Answer:

b

Explanation:

Combinations between two strands:

T - A

A - T

C - G

G - C

(so if one strand has A for example, then the other strand must have T in the same spot)

Bases   which are present on the other strand of DNA are TAT.

DNA or deoxyribonucleic acid is a hereditary material present in humans as well as all living beings. Almost every cell present in the body has DNA. Most DNA are located inside the cell , that is in the nucleus of the cell. But a small portion of DNA  can be found in the mitochondria of the cell as well.

The information in DNA is stored as a code which is composed of four chemical bases 1) adenine 2)guanine 3) cytosine  4) thymine . The human DNA consists of 3 billion bases . The order of of these bases determine information which is used for building and maintaining an organism.

The DNA bases can pair with each other .Adenine pairs with thymine   and guanine with cytosine to form units which are called as base pairs.Each base apart from other complementary base it also attaches itself to a sugar and a phosphate molecule.

Learn more about DNA ,here:

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#SPJ6

Answer:

4 is the answer

Explanation:

i am not sure for this question

Answer:

B) The family car

Explanation:

I hope this helps :)

Answer:

0.25 of the original

Explanation:

(0.5)^(90/45)

The fraction of iron-59 after 90 days is 0.25.

Iron-59 decays following first-order kinetics. Given the half-life ([tex]t_{1/2}[/tex]) of 45 days, we can calculate the rate constant (k) using the following expression.

[tex]k = \frac{ln2}{t_{1/2}} =\frac{ln2}{45day} = 0.015 d^{-1}[/tex]

For first-order kinetics, we can find the fraction of Fe ([Fe]/[Fe]₀) after and an elapsed time (t) of 90 days, using the following equation.

[tex]\frac{[Fe]}{[Fe]_0} =e^{-k \times t } = e^{-0.015 d^{-1} \times 90 d } \approx 0,25[/tex]

The fraction of iron-59 after 90 days is 0.25.

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Answer:

Answer: When water freezes, water molecules form a crystalline structure maintained by hydrogen bonding. Solid water, or ice, is less dense than liquid water. Ice is less dense than water because the orientation of hydrogen bonds causes molecules to push farther apart, which lowers the density.

Explanation:

Answer:

d. a brittle solid.

Explanation:

Hello!

In this case, since cesium fluoride is widely known as an ionic compound due to the large electronegativity difference, it is possible to discard a. due to its crystalline structure, b. because conducting solids are metals, c. because ionic compounds are not likely to be gases and e. because even when it is soluble in water, the problem is not referring to an aqueous solution; therefore, the answer is d. a brittle solid.

Best regards!

Answer:

Recycling.

Explanation:

When instead of getting rid of a product you find another use for the product, it is called recycling.

Recycling can be defined as a process which typically involves gathering, processing and transformation of materials or products that would otherwise be gotten rid of as waste materials or trash into new products that could be used for another purpose.

Basically, the recycling process involves turning a trash or unwanted product into a treasure (new product) that is capable of serving another purpose.

For example, the crown cork of a bottle could be gathered and processed into art forms that can be used for decorations.

Answer:

65.0cp

Explanation:

Answer:

false

Explanation:

An electric field may do work on a charged particle, while a magnetic field does no work.

Answer: The products of electrolysis are Zn(l) and [tex]Cl_2[/tex] gas

Explanation:

Electrolysis of a subastance is breaking it into its constituents by the action of electrical current.  

In the electrolysis of molten zinc chloride, zinc metal is produced at the cathode which is a negative electrode and chlorine gas produces as the anode which is a positive electrode.

[tex]ZnCl_2(l)\rightarrow Zn^{2+}+2Cl^-[/tex]

At anode : [tex]2Cl^-(l)\rightarrow 2e^-+Cl_2(g)[/tex]

At cathode : [tex]Zn^{2+}(l)+2e^-\rightarrow Zn(l)[/tex]

Answer:

Step 1 should be convert atoms to moles (n). Step 2 should be convert moles (n) to mass (m).

Step 1

Use dimensional analysis to convert the number of atoms to moles.

1 mole atoms = 6.022 × 10²³ atoms

n(Ag) = 2.3 × 10²⁴ Ag atoms × (1 mol Ag/6.022 × 10²³ Ag atoms) = 3.8193 mol Ag

Step 2

Convert the moles of Ag to mass.

mass (m) = moles (n) × molar mass (M)

n(Ag) = 3.8193 mol Ag

M(Ag) = atomic weight on the periodic table in g/mol = 107.868 g Ag/mol Ag

m(Ag) = 3.8193 mol × 107.868 g/mol = 412 g Ag = 410 g Ag rounded to two significant figures

The mass of 2.3 × 10²⁴ Ag atoms is approximately 410 g.

Explanation:

The number of moles that are present is 2.3 × 10²⁴ atoms of silver are 3.8193 moles that can be determined using Avogadro's law.

One mole:

A mole is defined as 6.022 × 10²³ of some chemical unit, be it atoms, molecules, ions, or others.

1 mole = 6.022 × 10²³ atoms

n(Ag) = 2.3 × 10²⁴ Ag atoms × (1 mol Ag/6.022 × 10²³ Ag atoms)

n(Ag) = 3.8193 mol Ag

Thus, the number of moles is 3.8193 moles.

Find more information about one mole here:

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Answer:

37.7 atm

Explanation:

Using the relation;

(P + an^2/V^2) (V - nb) = nRT

(P + an^2/V^2) = nRT/(V - nb)

a = 0.0341 atm dm^2 Mol^2

b = 0.0237 dm/mol

P = nRT/(V - nb) - an^2/V^2

P = [4.3 * 0.082 * 325 / (3.6 - (4.3 * 0.0237))] - (0.0341 * (4.3^2))/(3.6^2)

P = 114.595/(3.498) - 0.0487

P = 37.7 atm

Answer:

mH₂O = 6.4116 g

Explanation:

Let's write the given reaction:

2H₂ + O₂ -------> 2H₂O

The problem states that 5.7 g of oxygen reacts with excess hydrogen, hence, the limiting reagent is the oxygen. With this mass of oxygen, we can determine the moles, and then, the moles of water with the mole ratio:

moles = mass / atomic weight        AW of O₂ = 16 g/mol

Replacing we have:

moles O₂ = 5.70 / (16 * 2)

moles O₂ = 0.1781 moles

According to the balanced reaction, 1 mole of Oxygen produces 2 moles of water, so we have a mole ratio 1:2, therefore the moles of water would be twice the moles of oxygen:

moles H₂O = 0.1781 * 2 = 0.3562 moles

Finally the mass of water can be calculated solving for the mass from the expression of moles, and using molecular mass of water:

m = moles * MM          MM H₂O = 18 g/mol

m = 0.3562 * 18

Hope this helps

Answer:

Rocks are classified according to characteristics such as mineral and chemical composition, permeability, texture of the constituent particles, and particle size. This transformation produces three general classes of rock: igneous, sedimentary and metamorphic. Those three classes are subdivided into many groups.

Explanation: