which is an expression of molality

Answer:

the process of separating several mixtures of coal with the process of fractional distillation

Explanation:

The mean mass of the given sample is 39.12g

mass of first sample = 39.75g

mass of second sample = 38.91g

mass of third sample = 37.66g

mass of fourth sample = 39.75g

mass of fifth sample= 39.55g

Total mass of the sample = 39.75 g + 38.91 g+ 37.66 +39.75 g + 39.55 g = 195.62 g

Number of samples = 5

Therefore mean mass of the samples = 39.12g

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Answer:

S4O5

Explanation:

Answer:

C) the wave is interfered with

Answer:

46.07

Explanation:

im not 100 sure this is right almost tho

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Answer:

Mercury is useful in lighting because it contributes to the bulbs' efficient operation and life expectancy. Fluorescent and other mercury-added bulbs are generally more energy efficient and last longer than incandescent and other equivalent forms of lighting.

Explanation:

Answer:

A, D

Lower amplitude and Shorter wavelength.

Explanation:

The blue light is having higher frequency and lower wavelength than red light. Red light is the longest wave. Hence, the two terms for blue light compared to red is lower amplitude and shorter wavelength.

Wavelength of an electromagnetic wave is the distance between its two consecutive crest or troughs. The wavelength of a wave is inversely proportional to the frequency of the wave.

Frequency of a wave is the number of wave cycles per unit time. As the frequency of the wave increases, its energy increases. Increment in energy generates higher amplitude waves.

However, the dim light has lower amplitude. Higher amplitude make the light brighter. Violet - blue region are shorter wavelength and towards red, wavelength increases.

Therefore, the dim blue light has shorter wavelength and lower amplitude than bright red light.

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Answer: The pressure required is 0.474 atm

Explanation:

Boyle's Law: This law states that pressure is inversely proportional to the volume of the gas at constant temperature and number of moles.

[tex]P\propto \frac{1}V}[/tex]   (At constant temperature and number of moles)

The equation is,

[tex]{P_1V_1}={P_2V_2}[/tex]

where,

[tex]P_1[/tex] = initial pressure of gas = 1.0 atm

[tex]P_2[/tex] = final pressure of gas = ?

[tex]V_1[/tex] = initial volume of gas = [tex]2000cm^3[/tex]

[tex]V_2[/tex] = final volume of gas = [tex]4.22dm^3=4220cm^3[/tex]    ([tex]1dm^3=1000cm^3)[/tex]

Now put all the given values in the above equation, we get:

[tex]{1.0\times 2000}={P_2\times 4200}[/tex]

[tex]P_2=0.474atm[/tex]

The pressure required is 0.474 atm

Answer:

If this anwser helped you mark it the brainest please

Explanation:

Properties are features, qualities or characteristics of an item. Properties shall be used to classify the components. Properties are the attributes of a material that separates it from another substance. These properties are called physical properties and chemical properties in chemistry.

Answer:

HNO2

Explanation:

It is a pale blue solution and it is only known in solution and gas form.

Answer: A man-made object that has been changed by weathering is the pyramids. The pyramids in Egypt have weathered slowly because of the dryness of the desert, but they have indeed weathered throughout the years.

When 1. 46 g of barium peroxide reacts with 30. 0 ml of nitric acid solution that contains 0. 0754 g of the acid per ml, the mass of the hydrogen peroxide it will produce is 0.293 g.

If the nitric acid solution contains 0.0754g of the acid per ml. then 30 ml of this contains a mass of:

mass of nitric acid = (0.0754g acid/ml) x 30 ml

mass of nitric acid = 2.262 g

Determine the number of moles of each reactant.

barium peroxide : moles = mass/MM = 1.46g/169.33 g/mol = 8.622216973 x 10-3

nitric acid : moles = mass/MM = 2.262g/63.01 g/mol = 0.03589906364

The reaction of barium peroxide with nitric acid follows the balanced chemical reaction below:

BaO2 + 2(HNO3) = H2O2 + Ba(NO3)2

1 mole of Barium peroxide reacts with 2 moles of nitric acid will produce 1 mole of hydrogen peroxide and 1 mole barium nitrate.

Using the stoichiometry, or the relationship between the amounts of substances that are involved in the chemical reaction, we can determine how much hydrogen peroxide will be produced.

If there is 8.622216973 x 10-3 moles barium peroxide, then it needs twice as much nitric acid.

moles nitric acid = 2(8.622216973 x 10-3)

moles of nitric acid = 0.01724443395

Since the amount of nitric acid we have for the reaction is greater than the calculated moles of nitric acid needed, all the barium peroxide will be used.

moles of nitric acid needed < moles of nitric acid we have

0.01724443395 < 0.03589906364

Since the barium peroxide is the limiting reagent, we will use its amount as reference.

8.622216973 x 10-3 moles barium peroxide

reacts with

0.01724443395 moles nitric acid

will produce

8.622216973 x 10-3 moles hydrogen peroxide

and

8.622216973 x 10-3 moles barium nitrate

To solve for the mass of the hydrogen peroxide, multiply its amount to its molar mass.

mass of hydrogen peroxide = 8.622216973 x 10-3 mol(34.0147g/mol)

mass of hydrogen peroxide = 0.2932821237 g

mass of hydrogen peroxide = 0.293 g

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Answer:

Mass # = Protons + Neutrons= 35

The charge is -1 because 17 protons arent equal to the 18 electrons each has a -1 charge

Explanation:

Answer:

1. Ba2+ 2. Sr2+

Explanation:

When a solution contains the Barium ,Ba²⁺ ion or Strontium, Sr²⁺ ion, they reacts with either H₂SO₄(aq) or Na₂SO₄(aq) to produce a white precipitate of BaSO₄(s) and SrSO₄(s) respectively

The chemical reactions are given below

Ba²⁺ +  H₂SO₄(aq) ⇒ BaSO₄(s) + 2H⁺ (aq)

Ba²⁺ +  Na₂SO₄(aq) ⇒ BaSO₄(s) + 2Na⁺ (aq)

Sr²⁺ +  H₂SO₄(aq) ⇒ SrSO₄(s) + 2H⁺ (aq)

Sr²⁺ +  Na₂SO₄(aq) ⇒ SrSO₄(s) + 2Na⁺ (aq)

Explanation:

I'm not sure what it is

To measure out a volume of liquid, start by choosing the appropriate graduated cylinder and moving the ____ Bumper__ to the top ___of the graduated cylinder to protect it from breakage. Then, pour the liquid into the graduated cylinder until the__ bottom___ of the meniscus aligns with the desired volume marking when you look at the graduated cylinder from ___eye level___

Bumper to the top, until the bottom aligns, look from eye level

To measure out a volume of liquid, start by choosing the appropriate graduated cylinder and moving the bumper to the Bumper to the top of the graduated cylinder to protect it from breakage. Then, pour the liquid into the graduated cylinder until the untill the bottom aligns of the meniscus aligns with the desired volume marking when you look at the graduated cylinder from look from eye level

A liquid, solid, or gas's volume is the amount of three-dimensional space it occupies. Although there are many additional units that can be used to indicate volume, the most used ones are litres, cubic metres, gallons, millilitres, teaspoons, and ounces.

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Complete Question

To measure out a volume of liquid, start by choosing the appropriate graduated cylinder and moving the bumper to the ___ of the graduated cylinder to protect it from breakage. Then, pour the liquid into the graduated cylinder until the ___ of the meniscus aligns with the desired volume marking when you look at the graduated cylinder from ____.

In mercuric oxide percent by mass of mercury is 93 %.

The mercuric oxide molecular formula is HgO. When mercury is reacted with oxygen, then it forms the product mercuric oxide. Mercuric oxide has a molecular mass of 216 g/mol. It has a melting point of 500°C.

The balance equation for the reaction of decomposition of mercury oxide into mercury and oxygen is,

[tex]2HgO (s)→ 2Hg (l) + O _{2}(g)[/tex]

Mass of mercury oxide = 28.4 g

Mass of the oxygen = 2 g

In mercuric oxide percent by mass of mercury is,

[tex]Mass ℅= \frac{Mass \: of \: Mercury }{Mass \: of \: Mercury \: oxide} \times 100[/tex]

[tex]= \frac{28.4 - 2}{28.4} \times 100[/tex]

= 93 %

Therefore, in mercuric oxide percent by mass of mercury is 93 %.

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Answer:

A

Explanation:

it can be help to remove mood swing

Answer:

Bipolar disorder

Explanation:

People with bipolar disorder face extreme episodes of different moods, so mood stabilizers help calm those extremes down and allow the person to retain a consistent mood.

Answer:

It sounds like they are studying French phonemes

Explanations:

I just learned this.

The students were most likely studying French phonemes.

Words are distinguished from each other by respective sounds of the vowels in the word. There are open vowels and there are closed vowels. These exist in every language.

The part of language learning that has to do with the differentiation of pronunciation of sounds is called phonemes. This means that the students were most likely studying French phonemes.

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Explanation:

The glucose molecules changes as following:

C6H12O6 —> C2H5OH + CO2

There are 12 atoms of H on the left side and 6 atoms of the right side. It can be balance by putting 2 in front of C2H5OH as shown below:

C6H12O6 —> 2C2H5OH + CO2

There are 6 atoms of C on the left side and 5 atoms on the right side. It can be balance by putting 2 in front of CO2 as shown below:

C6H12O6 —> 2C2H5OH + 2CO2

Answer:

2(KCLO3) - - - - > (2)KCL + (3)O3

Explanation:

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Answer:

2.0×10⁻⁶ mol

Prefix = (2)  

exponent = (-6)

Explanation:

Given data:

Number of molecules of water = 1.23×10¹⁸ molecules

Number of moles of water = ?

Solution:

Avogadro number:

The given problem will solve by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.  The number 6.022 × 10²³ is called Avogadro number.

1 mole = 6.022 × 10²³ molecules of water

1.23×10¹⁸ molecules × 1 mol / 6.022 × 10²³ molecules

0.20×10⁻⁵ mol

2.0×10⁻⁶ mol

Prefix = (2)  

exponent = (-6)

+2 is  the most likely charge for a strontium.

Charge often refers to electric charge in chemistry and physics, which is a conserved feature of some subatomic particles that governs their electromagnetic interaction.

An electromagnetic field exerts a force on matter as a result of the physical attribute of charge.

A strontium cation, a divalent metal cation, and a monoatomic dictation are all parts of strontium(2+). It plays the part of a cofactor.

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Answer:

56) 5,722 mL

57) 750 meters

58) 88 km/hr

59) 88 km/? (I can't give you a complete answer if there's no other unit)

60) 5,169g

61) 53.1m/sec

Explanation:

When you are doing sig figs you do its operations normally. However the way you round depes on the operation;

When you are adding or subtracting sig figs you round to the least number of decimal places. In the case where there is no decimal place keep it the same

When you are multiplying or diving sig figs you round to the least amount of sig figs

The work is in the picture