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You are traveling at a speed of 60 m/s, how long is it going to take for you to travel 12 m?​

Answer:

See the answers below

Explanation:

13.5 g of NH4Cl was dissolved in 315 mL of water.

Moles of NH4Cl present in the solution = mass/molar mass

Molar mass of NH4Cl = 54.49 g/mol

a) Moles of NH4Cl = 13.5/54.49

            = 0.25 mole

b) Molarity of solution = moles of solute/volume of solution

moles of NH4Cl = 0.25

volume of solution = 315 mL = 0.315 L

molarity = 0.25/0.315

             = 0.79 M

c) moles required = 0.0500 mole

molarity = 0.79 M

molarity = moles x volume

volume = molarity/moles

         = 0.79/0.0500

         = 15.8 L = 15,800 mL

Answer: D

Explanation: because the earth is slanted and at the north and south pole do not get that much sunlight so that makes it colder than most places on earth

One major characteristic they have in common is they are metals.

Answer:

Most higher risk volcanoes are far from California’s largest cities and several produce heat that’s used to generate electricity in what are the world’s most productive geothermal power plants, such as the Salton Buttes, 160 miles southeast of Los Angeles, and the Clear Lake Volcanic Field 85 miles north of San Francisco that powers the Geysers steam field.

Explanation:

Answer:

Beta particles

Explanation:

A beta emission is said to occur when a neutron is converted into a proton. When a beta emission takes place, the daughter nucleus increases it's atomic number by 1. A neutrino is also produced.

Since the mass number remain the same but the daughter nucleus has it's atomic number increased by 1, then the particle is a beta particle.

All solutions are mixtures of two or more substances, but unless the mixture has a homogeneous distribution of solutes in the solvent, then the mixture is not a solution. Therefore, all mixtures are not solutions.

Answer:

153.56g

Explanation:

Number of moles = mass/molar mass

To get the number of moles of the molecule, we divide the number of molecules contained by Avagadro's number, which is 6.02 × 10^23 molecules.

moles = 4.12 × 10^24 ÷ 6.02 × 10^23

number of moles = 0.684 × 10^(24-23)

number of moles = 0.684 × 10^(1)

number of moles = 6.84mol

If the molar mass of the molecule is 22.45 g/mol, the mass of the molecule can be calculated thus:

mass = moles × molar mass (MM)

mass = 6.84 × 22.45

mass = 153.558

mass = 153.56g

Answer:

138mL are required to make the solution

Explanation:

A solution of 0.270M contains 0.270 moles of solute (NaCl in this case), per liter of solution.

To solve this problem we need to determine the moles of NaCl in 2.18g. With these moles and molarity we can find the volume required to prepare the solution:

Moles NaCl -Molar mass: 58.44g/mol-:

2.18g * (1mol / 58.44g) = 0.0373moles NaCl

Volume of solution:

0.0373moles NaCl * (1L / 0.270moles) = 0.138L

Answer:

The ability of an atom to accept an electron.

Explanation:

Electron affinity is measured by observing the energy change of a substance when an electron is added to it in its neutral gas form. For example, elements that are on the far right of the periodic table (excluding noble gases) are more likely to accept electrons rather than give them up. This is why Fluorine has the highest electron affinity of all atoms on the periodic table.

Answer:

Bond cleavage, or bond fission, is the splitting of chemical bonds. This can be generally referred to as dissociation when a molecule is cleaved into two or more fragments. In general, there are two classifications for bond cleavage: homolytic and heterolytic, depending on the nature of the process. ... The singlet excitation energy of a silicon–silicon sigma bond is lower than.

Answer:

212 degrees Fahrenheit

Explanation:

When liquid water reaches a low enough temperature, it freezes and becomes a solid—ice. When solid water is exposed to enough heat, it will melt and return to a liquid. As that liquid water is further heated, it evaporates and becomes a gas—water vapor.

Answer:

D. Upper right

Explanation:

The position the student should look for such element is in the upper right corner before the noble gases.

Specifically, the group of halogens will react vigorously with lithium.

Answer:

D. Upper right

Explanation:

I had the exact same question

Explanation:

Because of this, DNA and RNA can easily dissolve in water. ... Adding ethanol helps the Na+ and PO3- ions come together, because ions travel easier in ethanol than water. The supernate is removed and new ethanol is added in the second washing. This removes any residual salt that remained on the pelleted DNA.

Answer:

DNA is polar due to its highly charged phosphate backbone. Its polarity makes it water-soluble (water is polar) according to the principle "like dissolves like". ... This fact makes water a very good solvent for charged compounds like salts.

Your DNA's sugar phosphate backbone is charged. By adding salt, we help neutralize the DNA charge and make the molecule less hydrophilic, meaning it becomes less soluble in water. The salt also helps to remove proteins that are bound to the DNA and to keep the proteins dissolved in the water.

It is well known that Ethanol has a lower dielectric constant than water, making it to promote ionic bond formations between the Na+ (from the salt) and the PO3- (from the DNA backbone), further, causing the DNA to precipitate.

Explanation:

Ideally DNA needs to be precipitated with pellet and should not remain in supernatant. DNA is acidic in nature and therefore, needs optimum salt concentration in the buffer to be pelleted from a solution. At very low salt concentration or without salt DNA would remain in supernatant.

Answer:

A) 900 J

B) 27.96 J

C) 1,628 J ≅ 1.63 kJ

Explanation:

The heat absorbed by the metal (silver) - or energy required to heat it -  is calculated as:

heat = mass x Cp x ΔT

Where Cp is the heat capacity (0.24 J/°C ·g) and ΔT is the change in temperature (final T - initial T).

A) Given:

mass = 150.0 g

final T = 298 K = 25°C

initial T = 273 K = 0°C

We calculate the energy in J to raise the temperature:

heat = mass x Cp x (final T - initial T)

       = 150 .0 g x 0.24 J/°C ·g x (25°C - 0°C )

       = 900 J

B) Given:

moles Ag= 1.0 mol

ΔT = 1.08°C

We first calculate the mass of silver (Ag) by multiplying the moles of Ag by the molar mass of Ag (MM = 107.9 g/mol)

mass = moles x MM = 1.0 mol Ag x 107.9 g/mol Ag = 107.9 g

Then, we calculate the heat required:

heat = mass x Cp x ΔT = 107.9 g x 0.24 J/°C ·g x 1.08°C = 27.96 J

C) Given:

heat = 1.25 kJ = 1,250 J

final T = 15.28°C

initial T = 12.08°C

We first calculate the change in temperature:

ΔT = final T - initial T = 15.28°C - 12.08°C = 3.2°C

Then, we calculate the mass of silver:

mass = heat/(Cp x ΔT) = 1,250 J/(0.24 J/°C ·g x 3.2°C) = 1,628 J ≅ 1.63 kJ

Taking into account the definition of calorimetry:

A) the energy required to raise the temperature of 150 g Ag from 273 K to 298 K is 900 J.

B) the energy required to raise the temperature of 1.0 mole of Ag by 1.08 °C is 27.96 J.

C) the mass of the sample of silver is 1627.60 g.

Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.

Sensible heat is defined as the amount of heat that a body absorbs or releases without any changes in its physical state (phase change).

So, the expression that allows to calculate heat exchanges is:

Q = c× m× ΔT

where Q is the heat exchanged by a body of mass m, made up of a specific heat substance c and where ΔT is the temperature variation.

In this case, you know:

Replacing:

Q= 0.24[tex]\frac{J}{Cg}[/tex] × 150 g× 25 C

Solving:

Q= 900 J

In summary, the energy required to raise the temperature of 150 g Ag from 273 K to 298 K is 900 J.

In this case, you know:

Replacing:

Q= 0.24[tex]\frac{J}{Cg}[/tex] × 107.87 g× 1.08 C

Solving:

Q= 27.96 J

In summary, the energy required to raise the temperature of 1.0 mole of Ag by 1.08 °C is 27.96 J.

In this case, you know:

Replacing:

1250 J= 0.24[tex]\frac{J}{Cg}[/tex] × m× 3.2 C

Solving:

m= 1250 J÷ (0.24[tex]\frac{J}{Cg}[/tex] × 3.2 C)

m= 1627.6 g

In summary, the mass of the sample of silver is 1627.60 g.

Learn more about calorimetry:

The declaration that shows the correct conversion of 170°C to kelvins is 443 K. Thus, the correct option for this question is C.

The conversion of Celcius to kelvin required the utilization of the formula which is as follows:

Sterilization of surgical instruments at 170°C for 1.5 hours helps in the process of elimination of contaminated or unwanted impurities from the surface of the instruments in order to conduct error-free experiments.

According to the question,

The temperature of sterilization is = 170°C.

Now, it is required to convert 170°C into kelvin.

∴ Kelvin = 170°C + 273.15 = 443.15 ≅ 443 K.

Therefore, the declaration that shows the correct conversion of 170°C to kelvins is 443 K. Thus, the correct option for this question is C.

To learn more about Sterilization, refer to the link:

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Answer:

The adhesive is made up of two different layers.

The lower layer is made up of vertically aligned nanotubes.

The upper layer is made up of curly, spaghetti-like, nanotubes.

Answer:

B,C,D

Explanation:

Answer:

V₂ = 520.42 mL

Explanation:

Given data:

Initial volume = 350.0 mL

Initial pressure = 840 mmHg

Initial temperature = 33°C (33 +273 = 306 K)

Final temperature = 52°C (52+273 = 325 K)

Final volume = ?

Final pressure = 600 mmHg

Formula:  

P₁V₁/T₁ = P₂V₂/T₂  

P₁ = Initial pressure

V₁ = Initial volume

T₁ = Initial temperature

P₂ = Final pressure

V₂ = Final volume

T₂ = Final temperature

Solution:

V₂ = P₁V₁ T₂/ T₁ P₂  

V₂ = 840 mmHg × 350.0 mL × 325 K / 306 K × 600 mmHg

V₂ = 95550000 mmHg.mL.K /183600 K.mmHg

V₂ = 520.42 mL

Answer:

Thermal

Explanation:

When something heats up its atoms become further apart making it melt when something heats up or gets heat or loses heat that's thermal energy

Answer:

3.69 g

Explanation:

Given that:

The mass m = 325 g

The change in temperature ΔT = ( 1540 - 165)° C

= 1375 ° C

Heat capacity [tex]c_p[/tex] = 0.490 J/g°C

The amount of heat required:

q = mcΔT

q =  325 × 0.490 × 1375

q = 218968.75 J

q = 218.97 kJ

The equation for the reaction is expressed as:

[tex]C_2H_{2(g)} + 5O_{2(g)} \to 2CO_{2(g)} + H_2O_{(g)} \ \ \ \ \ \Delta H^o_{reaction} = -1544 \ kJ[/tex]

Then,

1 mole of the ethyne is equal to 26 g of ethyne required for 1544 kJ heat.

Thus, for 218.97 kJ, the amount of ethyne gas required will be:

[tex]= \dfrac{26 \ g}{1544 \ kJ} \times 218.97 \ kJ[/tex]

= 3.69 g

The observations of the tree's characteristics would be useful in determining its identity with a dichotomous key is its leaves are long and narrow. The correct option is B.

Observation is a process of recognizing and recording an event or fact that frequently involves measuring it with tools. Recognizing and recording an event, or fact frequently involves measuring with tools. Field notes are written observations made while participating in field observations or immediately afterward.

They are crucial for understanding phenomena that have been seen in the field. Field notes frequently take the form of scratch notes, diaries, and notebooks. In the scientific field, observation is a crucial step.

Therefore, the correct option is B. Its leaves are long and narrow.

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Answer:

A

Explanation:

because The law of conservation of energy, also known as the first law of thermodynamics, states that the energy of a closed system must remain constant—it can neither increase nor decrease without interference from outside

Answer:

(A) 28

Explanation:

To solve this problem we use the PV=nRT equation, where:

We input the data:

And solve for n:

Now we calculate the gas' mass:

Finally we calculate the unknown gas' molar mass, using its mass and its number of moles:

So the answer is option (A).

Answer: Cul2 + Br2 ->

Explanation:

Answer:

i believe the answer is a

Explanation:

Answer:

5.61 e⁻³

Explanation:

Given that:

The barrier length = 0.681 nm = 6.81 × 10⁻¹⁰

The difference between the height of the barrier & the energy of the electron is;

[tex]V - E = 0.554 \ eV (1.6 \times 10^{-19} )[/tex]

= 8.864 × 10⁻²⁰ V

where;

m = 9.1 × 10⁻³¹ kg

The probability[tex]P = e^{-2 \ kd}[/tex]

[tex]k = 2 \pi \sqrt{\dfrac{2m (V-E)}{h^2} }[/tex]

[tex]k = 2 \pi \times \dfrac{\sqrt{2 \times 9.1 \times 10^{-31} \times 8.864 \times 10^{-20}}}{6.63 \times 10^{-34}}[/tex]

k = 3.806 × 10⁹

[tex]P = e^{-2 \ kd}[/tex]

[tex]P = e^{2 \times 3.806 \times 10^9 \times 6.81 \times 10^{-10}}[/tex]

P = 0.005606

P = 5.61 × 10⁻³

P = 5.61 e⁻³

Answer:

87.5 %

Explanation:

Step 1: Given data

Step 2: Calculate the percent yield

When working with chemical reactions, we can determine the efficience in obtaining a product measuring the percent yield. The theoretical yield is the maximum amount of product that we could obtain according to the stoichiometry, whereas the real yield is the amount of product that we actually obtain when we carry out the process. We can calculate the percent yield usign the following expression.

%yield = real yield / theoretical yield × 100%

%yield = 105 kg / 120 kg × 100%

%yield = 87.5 %

Explanation:

₇N = 1s² 2s² 2p³

Therefore,

Option C is correct ✔

Answer:

A) 0.801

Explanation:

The reaction that takes place is:

First we calculate the H₂SO₄ moles that reacted:

Now we convert H₂SO₄ moles to NaOH moles:

Finally we calculate the molarity of the NaOH solution:

So the answer is option A.

The molarity of the NaOH solution used in the neutralization reaction has been 0.801 [tex]\rm \times\;10^-^3[/tex] M. Thus, option A is correct.

The neutralization reaction has resulted in the formation of the salt and water on reacting an acid with a base. In the neutralization reaction, the strength of acid and base can be given as:

[tex]\rm 2\;NaOH\;+\;H_2SO_4\;\rightarrow\;Na_2SO_4\;+\;H_2O[/tex]

For the neutralization of 1 mole of sulfuric acid, 2 moles of NaOH has been required.

The moles of sulfuric acid can be given as:

Moles = Molarity × Volume

Given, the molarity of acid ([tex]\rm H_2SO_4[/tex]) = 0.355 M

Volume of acid = 28.2 ml = 0.0282 L

Volume of base (NaOH) = 25 ml = 0.025 L

Moles of [tex]\rm H_2SO_4[/tex] = 0.355 × 0.0282 mol

Moles of [tex]\rm H_2SO_4[/tex] = 10.011  mol.

Since, 1 mole [tex]\rm H_2SO_4[/tex] = 2 moles NaOH

10.011 moles [tex]\rm H_2SO_4[/tex] = 10.011 × 2 moles NaOH

10.011 moles [tex]\rm H_2SO_4[/tex] = 20.022 moles NaOH.

The neutralization of 0.355 M [tex]\rm H_2SO_4[/tex] requires 20.022 moles NaOH. The strength of the NaOH solution will be:

Molarity = [tex]\rm \dfrac{Moles}{Volume\;(L)}[/tex]

Molarity of NaOH = [tex]\rm \dfrac{20.022}{0.025}[/tex]

Molarity of NaOH = 0.801 [tex]\rm \times\;10^-^3[/tex] M.

The molarity of the NaOH solution used in the neutralization reaction has been 0.801 [tex]\rm \times\;10^-^3[/tex] M. Thus, option A is correct.

For more information about the neutralization reaction, refer to the link:

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Answer:

Average atomic mass  = 57.79 amu

Percent contribution of Ni-60 = 26.45%

Percent contribution of Ni-5 =  73.55%

Explanation:

Given data:

Number of atoms of Ni-60 = 32

Number of atoms of Ni-57 = 89

Percent distribution of both isotopes = ?

Average atomic mass of sample = ?

Solution:

Percent contribution:

Total number of atoms = Ni-60 + Ni-57

Total number of atoms = 32 +89 = 121

Percent contribution of Ni-60 = 32/121×100

                                             =   26.45%

Percent contribution of Ni-57 = 89/121×100

                                             =  73.55%

Average atomic mass:

Average atomic mass = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass)  / 100

Average atomic mass  = (26.45×60)+(73.55×57) /100

Average atomic mass =  1587 + 4192.35 / 100

Average atomic mass  = 5779.35 / 100

Average atomic mass  = 57.79 amu.

Nuetrons, Electrons, and Protons.