How did life begin? Are we alone in the universe? What makes us human?

Answer:

Precipitation reactions are ones in which at least one of the reactants is in the aqueous phase (i.e., dissolved in water), and a solid forms on the product side which was not present on the reactant side. If all the reactants are solid, then a solid product forming should not be called a precipitate. To be called a precipitate, an insoluble product must form from within solution, either from a solid and solute interacting, or from an interaction strictly between solutes.

Explanation:

Answer:

D. C triple bond C.

Explanation:

The absorption frequency value is highest for carbon-carbon triple bond. The stretching frequencies are much higher than the bending frequency. It mainly depends upon the strength of the bonds as well as masses of the bonded atoms.

The triple bonds have higher stretching strength than the double bonds and double bonds have higher strength than single carbon to carbon bonds.

The triple bonds has a higher bond order, i.e. 3. So it has maximum stretching bonds.

Answer:

A person's skin color, hair color, dimples, freckles, and blood type are all examples of genetic variations that can occur in a human population.

Explanation:

Answer: 6.04 g

Explanation: In STP conditions, amoint of substance

n = V / Vm = 4.23 l / 22.41 l/mol = 0.188755 mol

Molar mass M(O2) = 32 g/mol  and

mass m = nM

Answer:

Bathypelagic

54% of the ocean lies in the Bathypelagic (aphotic) zone into which no light penetrates. This is also called the midnight zone and the deep ocean. Due to the complete lack of sunlight, photosynthesis cannot occur and the only light source is bioluminescence.

Explanation:

The small surface zone that has light is the photic zone. The entire rest of the ocean does not have light and is the aphotic zone.

Permanent darkness below 1000 meters with bioluminescent bacteria, bottom feeders, and angler fish is where no light reaches.

This is referred to the state of being dark as a result of absence of light in the area.

The light ray penetration decreases with increase in depth thereby making areas below 1000 meters dark with bioluminescent bacteria, bottom feeders, and angler fish which is why option C was chosen.

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Answer:

The reaction will proceed to the right to attain the equilibrium.

Explanation:

Step 1: Write the balanced equation

2 N₂(g) + 3 H₂(g) = 2 NH₃(g)

Step 2: Calculate the reaction quotient

The reaction quotient (Qc) is calculated in the same way as the equilibrium constant (Kc) but it uses the concentrations at any time.

Qc = [NH₃]² / [N₂]² × [H₂]³

Qc = 8.00² / 1.50² × 1.00³ = 28.4

Since Qc ≠ Kc, the reaction is not at equilibrium.

Since Qc < Kc, the reaction will proceed to the right to attain the equilibrium.

Answer:

Substances over 7 are categorized as basic, with 7 being the neutral point. Water has a pH level of 7. Substances with pH levels under 7 are categorized as acidic. Vinegar is acidic.

Explanation:

You can change it a little if you want. Hope this helps!

Vinegar is acidic. The only vinegar that has alkaline is apple cider vinegar, but all types of vinegar are acidic.

Answer:  Okay so i don't know how i can explain this but.. OK so Steven placed an ice cream scoop right? and put it under hot water so i would say it would make the ice cream scoop hot? and then using it to scoop the ice cream i could say it would be a melting affection i think

Explanation:

im am so sorry pls forgive me is i am wrong i tried my best so at least give me a like for effort.. i hope u have a great day :)

Answer:

Explanation:

The reaction is given as:

[tex]N_{2(g)} + 3H_{2(g)} \to 2NH_{3(g)}[/tex]

The reaction quotient is:

[tex]Q_C = \dfrac{[NH_3]^2}{[N_2][H_2]^3}[/tex]

From the given information:

TO find each entity in the reaction quotient, we have:

[tex][NH_3] = \dfrac{6.42 \times 10^{-4}}{3.5}\\ \\ NH_3 = 1.834 \times 10^{-4}[/tex]

[tex][N_2] = \dfrac{0.024 }{3.5}[/tex]

[tex][N_2] = 0.006857[/tex]

[tex][H_2] =\dfrac{3.21 \times 10^{-2}}{3.5}[/tex]

[tex][H_2] = 9.17 \times 10^{-3}[/tex]

∴

[tex]Q_c= \dfrac{(1.834 \times 10^{-4})^2}{(0.0711)\times (9.17\times 10^{-3})^3} \\ \\ Q_c = 0.6135[/tex]

However; given that:

[tex]K_c = 1.2[/tex]

By relating [tex]Q_c \ \ and \ \ K_c[/tex], we will realize that [tex]Q_c \ \ < \ \ K_c[/tex]

The reaction is said that it is not at equilibrium and for it to be at equilibrium, then the reaction needs to proceed in the forward direction.

We have that the statement that explains why NaCl dissolves in water even though the process is endothermic the given as,

Option A

Generally ,Sodium chloride  is crystalline salt, when  its dissolved is H20 , it dissociates its ion, the ions are scattered through out the solution which results in increased  in randomness .

Therefore, the entropy increases when NaCl dissolves in water,

Option A

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Explanation:

E=(98-15)×400×4.2

E=139440J

t=E/P

E=139440/500=278.88s

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Answer:

1) 1.5 kg

2) 0.6 kg

Explanation:

[tex](3)(30) = 60m, m = 90/60 = 1.5[/tex] kg

[tex](0.8)(15) = 20m, m = 12/20 = 0.6[/tex] kg

Answer:

[Kr] 4d4 5s1

Explanation:

Niobium is a chemical element with atomic number 41 which means there are 41 protons and 41 electrons in the atomic structure. The chemical symbol for Niobium is Nb. Neutron Number and Mass Number of Niobium Mass numbers of typical isotopes of Niobium are 93.

Name of Element : Niobium

Atomic Weight : 92.9

Atomic Number : 41

Group : Transition Elements

Electron Configuration: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d3

Answer:

Antarctic Peninsula, is one of the most important fossil sites on Earth.

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Fossils that would be expected to be found in Antarctica from more recent times, after it had moved much closer to the South Pole is Antartica peninsula.

Fossils are the preserved remains, impression, or trace of any once-living thing from many years ago. Examples of the fossils include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants.

There are four different types of fossils-

Mold fossils

Cast fossils

Trace fossils or Ichnofossils

True form fossils

Imprints, tracks, and trails can also become fossilized and are called Trace fossils. Dinosaur footprints or worm burrows are the examples.

Living things when get decomposed from the so many years ago and become dirt and rocks are fossils.

Therefore, Fossils that would be expected to be found in Antarctica from more recent times, after it had moved much closer to the South Pole is Antartica peninsula.

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Answer:

A

Explanation:

A scientist is a person who conducts scientific research to advance knowledge in an area of interest.

In classical antiquity, there was no real ancient analog of a modern scientist. Instead, philosophers engaged in the philosophical study of nature called natural philosophy, a precursor of natural science. It was not until the 19th century that the term scientist came into regular use after it was coined by the theologian, philosopher, and historian of science William Whewell in 1833.

examples are

Answer:

1.0 mole

Explanation:

From the question given above, the following data were obtained:

Volume (V) = 5 L

Temperature (T) = 205 K

Pressure (P) = 340 KPa

Gas constant (R) = 8.31 KPa.L/Kmol

Number of mole (n) =?

Using the ideal gas equation, the number of mole of the gas in the container can be obtained as follow:

PV = nRT

340 × 5 = n × 8.31 × 205

1700 = n × 1703.55

Divide both side by 1703.55

n = 1700 / 1703.55

n = 1.0 mole

Thus, the number of mole of the gas in the container is 1.0 mole

Answer:

is has around 1/5 lyrics of water

Answer:

[tex]1 \: mole \: = \: 6.02 \times {10}^{23} \: molecules \\ 0.350 \: moles \: = \: (0.350 \times 6.02 \times {10}^{23} ) \: molecules \\ = 2.107 \times {10}^{23} \: molecules[/tex]

Answer:

C₃H₈O

Explanation:

From the question given above, the following data were obtained:

Mass of compound = 1.031 g

Mass of CO₂ = 2.265 g

Mass of H₂O = 1.236 g

Empirical formula =?

Next, we shall determine the mass of carbon, hydrogen and oxygen in the compound. This can be obtained as follow:

For carbon, C:

Mass of CO₂ = 2.265 g

Molar mass of CO₂ = 44.01 g/mol

Molar mass of C = 12.01 g/mol

Mass of C =?

Mass of C = molar mass of C / molar mass of CO₂ × mass of CO₂

Mass of C = 12.01/44.01 × 2.265

Mass of C = 0.618 g

For hydrogen, H:

Mass of H₂O = 1.236 g

Molar mass of H₂O = 18.02 g/mol

Molar mass of H₂ = 2 × 1.01 = 2.02 g/mol

Mass of H =?

Mass of H = Molar mass of H₂ / Molar mass of H₂O × Mass of H₂O

Mass of H = 2.02/18.02 × 1.236

Mass of H = 0.139 g

For oxygen, O:

Mass of compound = 1.031 g

Mass of C = 0.618 g

Mass of H = 0.139 g

Mass of O =?

Mass of O = Mass of compound – (mass of C + mass of H)

Mass of O = 1.031 – ( 0.618 + 0.139)

Mass of O = 1.031 – 0.757

Mass of O = 0.274 g

Finally, we shall determine the empirical formula. This can be obtained as follow:

C = 0.618 g

H = 0.139 g

O = 0.274 g

Divide by their molar mass

C = 0.618 / 12.01 = 0.051

H = 0.139 / 1.01 = 0.138

O = 0.274 / 16 = 0.017

Divide by the smallest

C = 0.051 / 0.017 = 3

H = 0.138 / 0.017 = 8

O = 0.017 / 0.017 = 1

Therefore, the empirical formula of the compound is C₃H₈O

Based on the data provided, the empirical formula of the compound is C₃H₈O

The empirical formula of compound is its simplest formula showing the mole ratio of the elements in the compound.

First, the mass of carbon, hydrogen and oxygen in the compound is determined first as follows:

For carbon, C:

Mass of CO₂ = 2.265 g

Molar mass of CO₂ = 44.01 g/mol

Molar mass of C = 12.01 g/mol

Mass of C = 12.01/44.01 × 2.265

Mass of C = 0.618 g

For hydrogen, H:

Mass of H₂O = 1.236 g

Molar mass of H₂O = 18.02 g/mol

Molar mass of H₂ = 2 × 1.01 = 2.02 g/mol

Mass of H = 2.02/18.02 × 1.236

Mass of H = 0.139 g

For oxygen, O:

Mass of compound = 1.031 g

Mass of C = 0.618 g

Mass of H = 0.139 g

Mass of O = Mass of compound – (mass of C + mass of H)

Mass of O = 1.031 – ( 0.618 + 0.139)

Mass of O = 0.274 g

To determine the empirical formula of a compound, the mole ratio of the elements are determined as follows:

Mole ratio of the elements:

Carbon                Hydrogen         Oxygen

0.618 g/12.01    0.139 / 1.01         0.274 / 16

0.051                   0.138              0.017

Divide by the smallest ratio to convert to whole numbers

0.051 / 0.017     0.138 / 0.017  0.017 / 0.017

3           :            8           :               1

Therefore, the empirical formula of the compound is C₃H₈O

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Answer:

K2S(aq) + BaCl2(aq) = 2KCl(aq) + BaS(s)

In the image attached, it is explained how the solution is balanced.

The number of atoms of any element in the given chemical formula is the number that is written on the foot of the symbol of that element. The   balanced equation is

K[tex]_2[/tex]S(aq) + BaCl[tex]_2[/tex](aq)[tex]\rightarrow[/tex]2KCl(aq) + BaS(s)

Balanced equation is the one in which the total number of atoms of a species on reactant side is equal to the total number of atoms on product side.

The unbalanced equation is

K[tex]_2[/tex]S(aq) + BaCl[tex]_2[/tex](aq) [tex]\rightarrow[/tex]KCl(aq) + BaS(s)

The number of atoms of K on reactant side is 2 while on product side it is 1, so to balance K we need to multiply KCl by 2

K[tex]_2[/tex]S(aq) + BaCl[tex]_2[/tex](aq) [tex]\rightarrow[/tex]2KCl(aq) + BaS(s)

The atoms of sulfur on reactant and product side is 1, so it is balanced.

The atoms of Ba on reactant and product side is 1, so it is balanced.

The atoms of Cl on reactant and product side is 2, so it is balanced.

Therefore the balanced equation is

K[tex]_2[/tex]S(aq) + BaCl[tex]_2[/tex](aq)[tex]\rightarrow[/tex]2KCl(aq) + BaS(s)

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Answer: The event air molecules that are surrounding the metal will speed up, and the molecules in the metal will slow down would most likely take place over the next few minutes.

Explanation:

A process in which heat is evolved is called an exothermic process.

When hot metal plate at [tex]150^{o}C[/tex] is placed in air at room temperature then heat is given off by the metal plate due to which there will occur a decrease in kinetic energy of its molecules.

As a result, molecules in the metal will slow down.

Whereas heat is absorbed by the air molecules from the metal due to which kinetic energy of air molecules will increase.

Thus, we can conclude that the event air molecules that are surrounding the metal will speed up, and the molecules in the metal will slow down would most likely take place over the next few minutes.

Answer:

a. 2.44 nm

b. 15.33 nm²

Explanation:

a. Calculate the thickness (in nm) of the surface film

Since the volume of a teaspoon equals V = 4.93 cm³ and the area of the oil film is half an acre = 1/2 × 4046.86 m² = 2023.43 m²

The volume of the oil film, V' equals the volume of the oil in the teaspoon, V

V' = Ah where A = cross-sectional area of oil film = 2023.43 m² = 2023.43 × 10⁴ cm² and h = height of oil film

So, V' = V

Ah = V

h = V/A

= 4.93 cm³/2023.43 × 10⁴ cm²

= 0.00244 × 10⁻⁴ cm

= 2.44 × 10⁻⁷ cm

=  2.44 × 10⁻⁷ cm × 1m/100 cm

= 2.44 × 10⁻⁹ m

= 2.44 nm

b. The surface area (in nm2) occupied by an oleic acid molecule on water.

Since the height of the oil film equals the diameter of the oil molecule, and the molecule is assumed to be a sphere of radius, r. Its surface area is thus A = 4πr²

r = h/2 = 2.44 nm/2 = 1.22 nm

A = 4πr²

A = 4π(1.22 nm)²

A = 4.88π nm²

A = 15.33 nm²

Answer:

Attached below is the required diagram .

Explanation:

During the reaction of resorcinol and ethyl acetoacetate there is the production of a transesterification product, and this transesterification product is produced in other to increase the electrophicilty of the carbonyl center.

Attached below is the required diagram .

Answer:

See Explanation

Explanation:

We can write the molecular orbital configuration of molecules in the same way as we write the orbital electron configuration of atoms. The valence electrons in the molecule are filled into molecular orbitals of appropriate energy in accordance to the Aufbau principle.

For CO;

σ2s2, σ*2s2, Π2py2, Π2pz2, σ2px2

For NO;

σ2s2, σ*2s2, Π2px2, Π2py2, σ2pz2, Π*2px1

For CN-;

σ2s2, σ*2s2, Π2px2, Π2py2, σ2pz2

These are the ground state electron configurations of these molecules.

Answer:

Citric Acid is a weak acid with a chemical formula C6H8O7.

...

Properties of Citric Acid – C6H8O7.

C6H8O7 Citric Acid

Molecular Weight/ Molar Mass 192.124 g/mol

Density 1.66 g/cm³

Boiling Point 310 °C

Melting Point 153 °C

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Answer:

its called molding

Explanation:

Answer: 2.23 is the difference.

Explanation: Sodium has an electronegativity of 0.93 and Chlorine has an electronegativity of 3.16, so when Sodium and Chlorine form an ionic bond, in which the chlorine takes an electron away from sodium, forming the sodium cation, Na+, and the chloride anion, Cl-.

Answer:

Ksp = [Ca⁺²] × [C₂O₄⁻²]

Explanation:

Step 1: Write the balanced reaction for the dissociation of calcium oxalate

CaC₂O₄(s) ⇄ Ca⁺²(aq) + C₂O₄⁻²(aq)

Step 2: Write the expression for the solubility product constant (Ksp) of calcium oxalate

The solubility product constant is the equilibrium constant for the dissociation reaction, that is, it is equal to the product of the concentrations of the products raised to their stoichiometric coefficients divided by the product of the concentrations of the reactants raised to their stoichiometric coefficients. It doesn't include solids nor pure liquids because their activities are 1.

Ksp = [Ca⁺²] × [C₂O₄⁻²]

Answer:

x² = mutiphy by them self

Explanation: