How would you measure the specific latent heat of vaporisation of a liquid?

Answer:

[tex]1.63 \times {10}^{24} [/tex]

one atom of an element = 6.02 \times {10}^{23} atom

The mass of one atom of sulphur = 32g

The mass of one atom of aluminium = 27g

so one atom of aluminium = 6.02 \times {10}^{23}

27g of AL = 6.02 \times {10}^{23} atom

2.70g of AL = X atoms

Then you cross multiply ........

and get the answer

.

The mole is used to measure small particles like atoms and molecules.  The 4 moles of silver is equivalent to [tex]\bold{2.408 x 10^2^4 }[/tex] atoms.

Given here,

The number of atoms

[tex]\bold{2.408 x 10^2^4 }[/tex]

Number of moles = ?

1 mol of substance = [tex]\bold{ 6.02 x10^2^3}[/tex]

Hence,

moles of silver,

[tex]\bold {= \dfrac {2.408 x 10^2^4 } { 6.02 x10^2^3} }}\\\\\bold {= 4 mol}[/tex]

Therefore, the 4 moles of silver is equivalent to [tex]\bold{2.408 x 10^2^4 }[/tex] atoms.

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Answer:

Uses of Functional Groups Involving Oxygen

Explanation:

From the table given above, we obtained the following:

1. The functional group of each compound contains oxygen.

2. The table shows the uses of each compound.

From the observations made above, we can say that the most appropriate title for the table is:

Uses of Functional Groups Involving Oxygen.

Answer:

Explanation:

first guy is right give him brainliest

Answer:Drinking straw

Explanation: my quiz said so

The object that represents the best model of one of the phloem cells is the drinking straw.

Phloem may be defined as a type of vascular tissue in plants that significantly conducts the passage of sugars and other metabolic products from the leaves to the roots. This mediates the migration of sugar which is synthesized in the leaves during photosynthesis.

Apart from this, the phloem also regulates the movement of nutrients from the roots to the upper part of the body. This function of phloem cells shares homology with the object known as a drinking straw that mediates the transport of any fluid in both directions.

Therefore, a drinking straw is an object that represents the best model of one of the phloem cells.

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Your question seems incomplete. The most probable complete question is as follows:

Answer: I wanna say D because pangea was tectonic plates that moved and reshaped the earth

Explanation:

I hope that helps

Answer

D on edge

Explanation:

Answer:

C. The tea cools to room temperature, the ice cream melts and warms to room temperature.

Explanation:

The tea's temperature was higher than room temperature. The ice cream's temperature was lower than room temperature. After some time, both items will become room temperature, which results in cooling and melting.

Answer:

When volume is kept constant (kept the same), Gay-Lussac's law states that the pressure of gas varies directly with the temperature of the gas. The equation would be [tex]\frac{P1}{T1}=\frac{P2}{T2}[/tex], Where P is the pressure (in atm) and T is the temperature (in K°).

Explanation:

Answer:

When volume is kept constant (kept the same), Gay-Lussac's law states that the pressure of gas varies directly with the temperature of the gas. The equation would be , Where P is the pressure (in atm) and T is the temperature (in K°).

Explanation:

Answer:

because your parents carry the recessice gene or they are blond

Explanation:

it could also be ffrom a mutation or just because you dyed your hair

Answer:

172.385 g/mol

Explanation:

Magnesium Tartrate is C4H4MgO6

C - 12.01 g/mol

H - 1.01 g/mol

Mg - 24.305 g/mol

O - 16.00 g/mol

12.01(4) + 1.01(4) + 24.305 + 16(6) = 172.385 g/mol

Answer:

172.38

Explanation:

[tex]C_4H_4MgO_6\\C=12.01\\H=1.01\\Mg=24.30\\O=16.00\\\\4(12.01)+4(1.01)+24.30+6(16.00)\\48.04+4.04+24.30+96\\=172.38[/tex]

C = 12.01

H=1.01

Mg=24.30

O =16.00

4(12.01)+4(1.01)+24.30+6(16.00)

48.04 +4.04+24.30+96

=172.38

Answer:

The answer to the question is explained below

Explanation:

A chemical is any substance or an element that can occur naturally or can be created artificially. Chemicals are found in many places like the soil, water, air. They can be found solely as an element without being combined with other elements, and they can also be found as a mixture in compounds.

Exposure to chemicals can be made possible through direct contact with the eye, broken skin. It can also be possible through Inhalation of gases, also through the mouth.

Long-term effects occur when an individual has been exposed to harmful chemicals over a long period of time, with the effect often fatal. Long-term exposure to chemicals include:

1. The weakening of the immune system

2. can cause cancer. For example, Carcinogens that cause cancer in humans, are gotten from exposures to Carbon Tetrachloride, Chloroform.

3. It can cause brain damage

4. It can lead to reproductive disorders

5. It can lead to eye damage, skin problems, and respiratory problems

Short-term effects occur when an individual has been exposed to harmful chemicals accidentally, or within a short period of time. As such, depending on the type of chemical, the amount the individual is exposed to, the effect is usually less fatal and can be addressed. Short-term exposure to chemicals include:

1. Skin or eye irritation

2. Headache

3. Nausea

4. Cough

5. Dizziness

6. Physical injuries

The required  complete ionic equation of the reaction

Pb(NO3)2+2KI---->PbI2+2KNO3   is   Pb2+(aq) + 2 I−(aq) → PbI2(s)

A chemical equation in which the electrolytes in aqueous solution are expressed as dissociated ions.

Spectator ions in above equation are as follows- K +and NO3−

Define spectator ions.

Ions that are not involved in the actual chemical reaction are called spectator ions.

Net ionic equation of given reaction isPb⁺²+2I ⁻¹⟶PbI₂It shows only the ions which involves in the chemical reaction.

Therefore, K⁺ and NO3⁻ are spectator ions.

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Answer:

The biological sample that pregnancy tests use to detect pregnancy is urine

Answer:

yes

Explanation:

the urine in the the tester will find hormones to determine if pregnant or not

Heterogeneous 'mixtures' (because they don't meet the definition  of mixtures) are mixtures substances that aren't completely uniformly spread out. They haven't reacted with the solvent to become a solution.

Explanation: There are 2 types of heterogeneous solutions, A Colloid and a suspension.

Colloid: You can check if a mixture is heterogeneous by passing a light ray through it. This may cause the Tyndall effect (If the mixture is a colloid) when the Colloidal Heterogeneous mixture's particles are so small that they refract the beam of light and the path of light will be visible, like if you add 3 drops of milk in a glass of Water and shine a laser light through it. This is because the particles are too small to be seen by the unaided eye but big enough to scatter you laser light. However that particles won't settle down or will be separated by a filter paper due to particles' small size.

Suspension: A solution will be a solution when the particles of the Mixture is big enough to be seen by the unaided eye. Like if you mix sand and Water, the sand will eventually settle down due to Gravity. The mixture's solute will be big enough to pass through a filter paper.

Answer:

In First compound the longest chain contains 7 C atoms.

In the Second compound the longest chain contains 9 C atoms.

In the Third compound the longest chin contains 7C atoms.

Explanation:

In first compound the longest chain contains 7 carbon atoms.In the second compound the longest chain contains 9 carbon atoms.In the third compound the longest chin contains 7 carbon atoms.

An atom is defined as the smallest unit of matter which forms an element. Every form of matter whether solid,liquid , gas consists of atoms . Each atom has a nucleus which is composed of protons and neutrons and shells in which the electrons revolve.

The protons are positively charged and neutrons are neutral and hence the nucleus is positively charged. The electrons which revolve around the nucleus are negatively charged and hence the atom as a whole is neutral and stable due to presence of oppositely charged particles.

Atoms of the same element are similar as they have number of sub- atomic particles which on combination do not alter the chemical properties of the substances.

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Answer:

Kinetic energy of boy just before hitting the ground is [tex]\approx[/tex]1000 J.

Speed of boy just before hitting the ground is 7.67 m/s

or 17.16 mi/hr.

Explanation:

Given that:

Mass of boy = 75lb = 34 kg

Height, h = 10ft = 3m

To find:

Kinetic energy of boy when he hits the ground.

As per law of conservation of energy The potential energy gets converted to kinetic energy.

[tex]\therefore[/tex] Kinetic energy at the time boy hits the ground = Initial potential energy of the boy when he was at the Height 'h'

The formula for potential energy is given as:

[tex]PE = mgh[/tex]

Where m is the mass

g is the acceleration due to gravity, g = 9.8 [tex]m/s^2[/tex]

h is the height of object

Putting all the values:

PE = [tex]34 \times 9.8 \times 3 \approx 1000\ J[/tex]

Hence, Kinetic energy is [tex]\approx[/tex]1000 J.

Formula for Kinetic energy is:

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

where m is the mass and

v is the speed

Putting the values and finding v:

[tex]1000 = \dfrac{1}{2}\times 34 \times v^2\\\Rightarrow v^2 = 58.82\\\Rightarrow v = 7.67\ m/s[/tex]

Given that:

1 m = 1.094 yd and 1 mi = 1760 yd

[tex]\Rightarrow 1609\ m = 1\ mi[/tex]

Converting 7.67 m/s to miles/hour:

[tex]\dfrac{7.67 \times 3600}{1609}=17.16\ mi/h[/tex]

Answer:

See Explanaton

Explanation:

The law of multiple proportions states that when two same elements form more than a compound, the different masses of one element that combine with the same mass of the other element are in the ratio of small whole numbers.

Oxide A

3.50g of sulphur combined with 6.00g of oxygen

Oxygen:Sulphur = 6 : 3.5

Oxide B

2.80g of sulphur combined with 9.55g

Oxygen : Sulphur = 9.55 : 2.8

Therefore:

The ratio of Oxygen to Sulphur in Oxides A and B is:

[tex]\dfrac{\text{Oxygen}}{\text{Sulphur}} \implies \dfrac{6}{3.5}:\dfrac{9.55}{2.8} = \dfrac{1.7}{1}:\dfrac{3.4}{1}=1:2[/tex]

Ratio of Oxygen=1:2

There is exactly twice in Oxide B as in Oxide A.

This result illustrates the law of multiple proportions.

Explanation:

I think Low melting point

because NaCl (salt has mp 801 degC)

Water has mp 0 degC

Answer:

Explanation:

1).  Ca(NO₃)₂ + KI → CaI + K(NO₃)₂

    This equation is incorrect.

    When Ca⁺⁺ reacts with I⁻, final product is CaI₂

    And when K⁺ react with NO₃⁻, final product is KNO₃

    Hence the equation will be,

    Ca(NO₃)₂ + KI → CaI₂ + KNO₃

    Now we have to balance this equation.

     Ca(NO₃)₂ + 2KI → CaI₂ + KNO₃

                          ↓

     Ca(NO₃)₂ + 2KI → CaI₂ + 2KNO₃

2). Ca(NO₃)₂ + KOH → CaOH + K(NO₃)₂

    This equation is incorrect,

    Since the reaction of Ca⁺⁺ with OH⁻ gives the final product     Ca(OH)₂

    And final product of K⁺ and NO₃⁻ is KNO₃

    Therefore, the equation will be,

    Ca(NO₃)₂ + KOH → Ca(OH)₂ + KNO₃

    Now we will balance this equation by changing the coefficients of the      molecules until the number of atoms on both the sides become equal.

    Ca(NO₃)₂ + KOH → Ca(OH)₂ + 2KNO₃

                                ↓

     Ca(NO₃)₂ + 2KOH → Ca(OH)₂ + 2KNO₃

3). Ca(NO₃)₂ + Na₂C₂O₄ → CaC₂O₄ + 2Na(NO₃)₂

    This equation is incorrect,

    Since the reaction of Na⁺ and NO₃⁻ gives the final product    NaNO₃.

    Therefore, the correct equation will be,

    Ca(NO₃)₂ + Na₂C₂O₄ → CaC₂O₄ + 2NaNO₃

     This equation is in the balanced form.

Answer:

B.

Explanation:

A weak bond forms from a smaller change in energy compared to a strong bond.

Answer:

it is when a state in which opposing forces or influences are balanced.

A example of equilibrium is in economics  supply and demand are equal.

Explanation:

Answer:

Compromise of 1850

Explanation:

Answer:B. A liquid changes to a solid.

Explanation:

A Liquid changes to solid when pressure

increases from 1 atm to 10 atm at -40°C

So, given at -40°C

CO2 will be in liquid state and as per the concept explained above by increasing the pressure on liquid we get the solid state

Thus , With CO2 a liquid phase change to a solid

phase when pressure increases 1 atm to 10atm at -40°C

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Answer:

D)It will lead to forced migration.

Explanation:

Forced migration is an involuntary, sudden movement of organisms from one geographical location to another. This is often in response to short term environmental changes such as drought, famine, etc

When an ecosystem suddenly comes under stress due to these short term environmental changes, organisms may not be left with any other choice but to move or go to new locations in the quest for survival. The organisms may not have left the ecosystem in the absence of such short term ecological stress. This is what is meant by forced migration.

Answer:

D forced migration

Explanation:

Answer:

2 moles

Explanation:

Answer:

The correct option is;

Scientists can drill deep into the ice to collect ice cores which contain trapped atmospheric gases

Explanation:

The study of past climates also known as paleoclimatology, is accomplished by acquiring information from proxy data sources which are physical environment characteristics that are preserved through time to remake the conditions of past climate

Past physical environmental characteristics, from which information about ancient climate can be gained are stored in nature's climate variability records including, ice cores, rings in tree stems, fossil pollen, sediments found in the waters of the ocean

The proxy sources provide a means of understanding the conditions of ancient climate before advent of climate measurement.

Therefore, one way that analyzing ice benefits scientists who study ancient climates is that scientists can drill deep into the ice to collect ice cores which contain trapped atmospheric gases from past climates.

Answer: B: Scientists can study the layers of ice cores to gather information about past atmospheric composition.

Explanation: Got it right on a test!

Answer:

20.76 L OF CO2 WILL BE PRODUCED BY 45 G OF METHANE.

Explanation:

Equation of the reaction:

CH4 + 02 --------> CO2 + 2H20

Molar mass of methane = ( 12+ 1*4) g/mol = 16 g/mol

Calculate the number of moles present in 45 g of methane

1 mole of methane = 16 g / mol of methane

(45 / 16) mole of methane = 45 g of methane

= 2.8125 moles

Using the ideal gas equation:

PV = nRT

P = 1 atm

n = 2.812 moles

T = 90 C

R = 0.082 L atm/ mol C

V = unknown

So we have:

V = nRT / P

V = 2.8125 * 0.082 * 90 / 1

V = 20.756 L

In the production of CO2 by 45 g of methane, 20.756 L of methane was used.

Then, the volume of CO2 produced by this volume will be 20.756 L since 1 mole of methane produces 1 mole of CO2.

In other words;

1 mole of CH4 = 1 mole of CO2

22.4 dm3 of CH4 = 22.4 dm3 of CO2

20.76 DM3 = 20.76 dm3

The volume of CO2 produced will therefore be 20.76 L

Answer:

It’s D

Explanation:

Answer:

D Rocks change from one type to another in a specific order.

Explanation:

Answer:

Carbon has 4 electrons in its outermost shell. ... Therefore, carbon completes its octet by sharing its 4 electrons with other carbon atoms or with atoms of other elements and forms covalent bond. It forms strong covalent bonds because of its small size.

Explanation:

Answer:

2.01 A

Explanation:

Para esta pregunta debemos empezar por la semi-reaccion del plomo:

[tex]Pb^+^2~_(_a_q_)~+~2e^-~->~Pb_(_s_)[/tex]

Se intercambian dos electrones en la semi-reacción del plomo. Si tenemos en cuenta la ecuación:

[tex]n=\frac{I*t}{z*F}[/tex]

Donde:

n= Moles depositados

I= Intensidad de corriente (en Amperios)

z= Numero de electrones intercambiados

F= Constante de faraday = 96484 C/mol

t=tiempo (en segundos)

Que conocemos de esta ecuación?

Los moles (se pueden calcular a partir de la masa atómica del plomo, 207.2 g/mol)

[tex]2.6~g~Pb\frac{1~mol~Pb}{207.2~g~Pb}=0.0125~mol~Pb[/tex]

El tiempo (hay que convertirlo a segundos):

[tex]20~min\frac{60~s}{1~min}=1200~s[/tex]

Z (Numero de electrones)

De acuerdo a la semi-reacción son intercambiados 2 electrones.

Por lo tanto podemos resolver para "I":

[tex]I=\frac{n*z*F}{t}=\frac{0.0125~mol*2*96484\frac{C}{mol}}{1200~s}[/tex]

[tex]I~=~2.01~\frac{C}{s}=2.01~A[/tex]

Espero que sea de ayuda!

Answer:

Temperature is not a chemical change because when a substance changes in temperature, its chemical makeup is not changing.

Answer:

the molarity of cobalt(II) fluoride in the resulting solution is = 0.137  M

Explanation:

Given that :

a student dissolves 6.64 g of CoF₂  into 500 mL of water

volume of the solution(water) = 500 mL = 0.50 L

The standard  molar mass of CoF₂ is 96.93 g/mol

number of moles of CoF₂ = mass of CoF₂/molar mass of CoF₂

number of moles of CoF₂ = 6.64 g/96.93 g/mol

number of moles of CoF₂ = 0.0685 mol

The molarity of any given substance is known to be as the number of moles of solute dissolved in one litre of solution.

Thus ;

Molarity of  cobalt(II) fluoride CoF₂ in the resulting solution is = number of moles / Volume in (L)

Molarity of  cobalt(II) fluoride CoF₂  = 0.0685 mol/ 0.50 L

= 0.137  M

Thus ; the molarity of cobalt(II) fluoride in the resulting solution is = 0.137  M