1. How many grams are there in 1.5 x 10^25 molecules of CO2?

Answer:

2914 J

Explanation:

Step 1: Given data

Step 2: Calculate the temperature change

ΔT = 27.09 °C - 15.71 °C = 11.38 °C

Step 3: Calculate the energy required (Q)

We will use the following expression.

Q = c × m × ΔT

Q = 0.3850 J/g.°C × 665.0 g × 11.38 °C

Q = 2914 J

Answer:

d. Mass is the measure of the earth’s gravitational attraction of a body

This is FALSE. Mass is the measure of matter than an object contains.

Explanation:

b. An atom is the smallest particle of an element that still contains properties of the original element.

This is True

c. Gases can be colorless or colored

This is True

d. Mass is the measure of the earth’s gravitational attraction of a body

This is FALSE. Mass is the measure of matter than an object contains.

e. A pure substance has a fixed composition.

This is True.

Answer: Octane will be used completely.

Explanation:

To calculate the moles :

[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]    

[tex]\text{Moles of octane}=\frac{2.3g}{114g/mol}=0.0202moles[/tex]

[tex]\text{Moles of oxygen}=\frac{12.4g}{32g/mol}=0.388moles[/tex]

The balanced chemical reaction will be

[tex]2C_8H_{18}+25O_2(g)\rightarrow 16CO_2(g)+18H_2O(g)[/tex]  

According to stoichiometry :

2 moles of octane require = 25 moles of [tex]O_2[/tex]

Thus 0.0202 moles of octane will require=[tex]\frac{25}{2}\times 0.0202=0.2525moles[/tex]  of [tex]O_2[/tex]

Thus octane is the limiting reagent as it limits the formation of product and [tex]O_2[/tex] is the excess reagent.  

Thus octane will be used completely.

Answer:

The conditions are

1) Small enough

2) Electronegative atom

3) highly electronegative

4) lone pair of electrons

The correct statement therefore is

It needs to be small enough not to bump into other atoms when approaching the 1s orbital of the hydrogen, it needs to carry at least one electronegative atom, it needs to be highly electronegative enough to create a delta on the connected hydrogen, and it needs to have at least one lone pair of electrons.

Explanation:

Hydrogen bonding is a type of intermolecular bond that occurs between the partial positive charge (delta) on a hydrogen atom bonded to a small highly electronegative element (like nitrogen, oxygen or fluorine) and the free electrons on another electronegative element of another molecule.

The hydrogen atom with the partial positive charge (delta) is known as the hydrogen bond donor, while the electronegative element, carrying lone electrons is called the hydrogen bond acceptor.

Let's take a deeper look at these terms:

1) Hydrogen bond donor

Using water (H₂O) as an example, the high electronegativity of the oxygen atom covalently bonded to the hydrogen atom draws the lone electron in the 1s orbital of the hydrogen atom, creating a partial positive charge (d⁺) on the hydrogen atom. This is what happens within one water molecule

2) Hydrogen bond acceptor

When two or more molecules of water interact, the partial positive charge (d⁺) on the hydrogen atom of one molecule, is attracted to the valence or free electrons on the oxygen atom of a nearby molecule of water thus creating a dipole-dipole intermolecular bond known as a hydrogen bond.

For the hydrogen bond to be effective, the electronegative atom bonded to the hydrogen acting as the hydrogen bond donor in the first water molecule needs to be small enough so as not to disrupt the 1s orbital of the hydrogen atom. The smaller the size of the electronegative atom, the stronger the partial negative charge created on the hydrogen atom.

The valence or free pair of electrons on the electronegative (oxygen) atom of the second molecule of water (hydrogen bond acceptor) is what attracts the partial positive charge on the hydrogen atom to create the hydrogen bond

Answer:

the scientific definition of work

Explanation:

In physics, work is defined as the use of force to move an object. For work to be done, the force must be applied in the same direction that the object moves.

I hope it helps! ^^

☁️☁️☁️☁️☁️☁️☁️

Answer: i think its A diatomic compound..

Explanation: hope i helped! sorry if im wrong!

Answer: The mowed lawn is the one from where the grasses are removed by using the machines or tools.

Explanation:

The mowed lawn is expected to have low number of species as the grasses may be few or scanty thus can support the population of few species like insects, mice, birds, and small number of grazing animals. On the other hand the weedy field can be hub of insects, reptiles like snakes, small mammals, and large mammals. Large weed field can provide food, and habitat to the large number of species. This will support the increase in biodiversity as compared to the mowed lawn.

Mass of iron(ll) oxide= 616.608 g

Given

Reaction

2Fe+O2 -->2FeO

479.6 grams of iron

Required

mass of iron(ll) oxide

Solution

mol of iron :

= mass : Ar Fe

= 479.6 g : 56 g/mol

= 8.564

From the equation, mol FeO :

= 2/2 x mol Fe

= 2/2 x 8.564

= 8.564 moles

Mass of iron(ll) oxide :

= mol x MW

= 8.564 x 72 g/mol

= 616.608 g

Answer: B) Electronegativity is the attraction an element's nucleus has for the electrons in a chemical bond

Explanation:

Electronegativity is defined as the property of an element to attract a shared pair of electron towards itself.

When the size of an atom decreases as we move across the period, as the electrons get added to the same shell and the nuclear charge keeps on increasing. Thus the electrons get more tightly held by the nucleus.

As, the size of an element decreases, the valence electrons come near to the nucleus. So, the attraction between the nucleus and the shared pair of electrons increases and thus the electronegativity increases.

Answer:

C8H16O4

Explanation:

C2H4O= 24+4+16

44

n=molar mass/empirical formula

n=176.21/44

=4

Therefore

Molar Formula= (C2H4O)4=C8H16O4

The mass allowance of Vitamin C for children aged 4-8 years is equal to 0.025 grams.

A mole can be defined as a standard unit that can be utilized to evaluate the number of entities such as atoms, molecules, ions, or other particular particles in a particular amount of the substance.

The number of elementary entities present in one mole of any chemical substance was found to be equal to 6.023 × 10²³ which is also known as the Avogadro number.

Given, the number of moles of vitamin C = 0.000142 moles

Given, the molecular formula of Vitamin C is C₆H₈O₆.

The mass of one mole of C₆H₈O₆ = 176 g

One mole of Vitamin C has mass = 176 g

0.000142 mol of Vitamin C has mass  = 0.000142×176 = 0.025 g

Therefore, the mass of 0.000142 mol of Vitamin C is 0.025 g.

Learn more about the mole, here:

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Answer:

50 g of S are needed

Explanation:

To star this, we begin from the reaction:

S(s) + O₂ (g) →  SO₂ (g)

If we burn 1 mol of sulfur with 1 mol of oxygen, we can produce 1 mol of sulfur dioxide. In conclussion, ratio is 1:1.

According to stoichiometry, we can determine the moles of sulfur dioxide produced.

100 g. 1mol / 64.06g = 1.56 moles

This 1.56 moles were orginated by the same amount of S, according to stoichiometry.

Let's convert the moles to mass

1.56 mol . 32.06g / mol = 50 g

Answer:

increase the chemical rate

Answer:

the answer p+n

Explanation:

Answer:

[tex]\frac{3}{2}He[/tex]

[tex]\frac{6}{2} He[/tex]

[tex]\frac{7}{4}Be[/tex]

[tex]\frac{3}{1} H[/tex]

[tex]\frac{6}{4}Be[/tex]

[tex]\frac{7}{3} Li[/tex]

Explanation:

In the first nucleus we are told that there are two protons and one neutron. Let us remember that the mass number = number of protons + number of neutrons.

This implies that, for the first specie the mass number is 3, for the second specie the mass number is 6 and the third specie has a mass number of 7 and so on. The mass number is indicated as a superscript.

The atomic number is the number of protons in the nucleus of the atom and helps us to identify the atom. It is always written as a subscript as shown.

Answer:

Explanation:

mass fraction N₂ : He : CH₄ : C₂H₆ : : 15 : 5 : 60 : 20

mole fraction  N₂ : He : CH₄ : C₂H₆ : : 15/28 : 5/4 : 60/16 : 20/30

mole fraction  N₂ : He : CH₄ : C₂H₆ : : .5357  : 1.25 : 3.75 : .67

Total mole fractions = .5357 + 1.25 + 3.75 + 0.67 = 6.2057

mole fraction of N₂ =  .5357 / 6.2057 = .0877

mole fraction of He = 1.25 / 6.2057 = .20

mole fraction of CH₄ = 3.75 / 6.2057 = .6043

mole fraction of C₂H₆ = .67 / 6.2057 = .108

Partial pressure = total pressure x mole fraction

Partial pressure of N₂ = 1200 kPa  x .0877 = 105.24 kPa

Partial pressure of He = 1200 kPa  x .20  = 240 kPa

Partial pressure of CH₄ = 1200 kPa  x  .6043  = 725.16 kPa

Partial pressure of C₂H₆ = 1200 kPa  x .108    = 129.6 kPa

This question is incomplete, the complete question is;

A reaction that proceeds by first-order irreversible kinetics is oxidizing chemical A in a wastewater treatment basin with a mean residence time of 1.5 hours. The reaction rate constant is 2.0 Hr-1.The basin is unbaffled and may be characterized as two completely mixed tanks in series.  If the steady-state influent concentration is 30 mg/l, find the effluent concentration.

If baffles are placed in the basin so that the basin may be characterized as four completely mixed tanks in series, and the mean residence time remains constant, find the effluent concentration.

Answer:

a) (two completely mixed tanks in series) the find the effluent concentration is 4.8 [tex]\frac{mg}{l}[/tex]

b) (four completely mixed tanks in series) find the effluent concentration is 3.2 [tex]\frac{mg}{l}[/tex]

Explanation:

Given the data in the question;

we can determine the effluent concentration of two completely mixed tanks in series for first order irreversible reaction using the following equation;

C = Co ( 1 / ( 1 + K[tex]\frac{t}{n}[/tex] )ⁿ

t is the mean hydraulic residence time for two completely mixed tanks in series ( 1.5 hr)

Co is initial concentration of the influent ( 30 [tex]\frac{mg}{l}[/tex] )

C is final concentration of effluent,

n is the number of tanks series ( 2)

k is rate constant for the given first order reaction( 2[tex]\frac{1}{hour}[/tex] )

so we substitute

C = 30 [tex]\frac{mg}{l}[/tex]  ( 1 / ( 1 + 2[tex]\frac{1}{hour}[/tex] . [tex]\frac{1.5}{2}[/tex] )²

C = 30 [tex]\frac{mg}{l}[/tex]  × ( 1/2.5)²

C = 30 [tex]\frac{mg}{l}[/tex] × 0.16

C = 4.8 [tex]\frac{mg}{l}[/tex]

Therefore, (two completely mixed tanks in series) the find the effluent concentration is 4.8 [tex]\frac{mg}{l}[/tex]

b)

using;

C = Co ( 1 / ( 1 + K[tex]\frac{t}{n}[/tex] )ⁿ

t is the mean hydraulic residence time for two completely mixed tanks in series ( 1.5 hr)

Co is initial concentration of the influent ( 30 [tex]\frac{mg}{l}[/tex] )

C is final concentration of effluent,

n is the number of tanks series ( 4)

k is rate constant for the given first order reaction( 2[tex]\frac{1}{hour}[/tex] )

so we substitute

C = 30 [tex]\frac{mg}{l}[/tex]  ( 1 / ( 1 + 2[tex]\frac{1}{hour}[/tex] . [tex]\frac{1.5}{4}[/tex] )⁴

C = 30 [tex]\frac{mg}{l}[/tex] × ( 1/1.75)²

C = 30 [tex]\frac{mg}{l}[/tex] × 0.107

C = 3.2 [tex]\frac{mg}{l}[/tex]

Therefore, (four completely mixed tanks in series) find the effluent concentration is 3.2 [tex]\frac{mg}{l}[/tex]

Answer:

% = 33.83%

Explanation:

To do a better understanding of this, we can treat the mixture of the combustion as two separate reactions, in that way, we can have an idea of what is happening and how to calculate the mass percent.

So the combustion reactions in this mixture are:

2C₂H₆ + 7O₂ ---------> 4CO₂ + 6H₂O

C₃H₈ + 5O₂ ----------> 3CO₂ + 4H₂O

Now that we have both reactions (And balanced) we can hace an idea of the mole ratio between every compound in the mix.

For practical purposes, let's call "a" the mass of ethane, and "b" the mass of propane. The innitial mix have 9.725 g, so this means that:

a + b = 9.725 g    (1)

Now that we have this, we can write a relation between the moles of oxygen and the moles of the gases. If we have 1.115 moles of oxygen, and also know the mole ratio of oxygen to "a" and "b", so:

moles O₂ = moles a (moles O₂/moles a) + moles b (moles O₂/moles b)   (2)

And we know that moles a and moles b are:

moles a = a / MW

moles b = b / MW

The MW of a is 30 g/mol and the MW of b is 44 g/mol

Replacing the given data we have:

1.115 moles O₂ = (a/30)(7 moles O₂/2 moles a) + (b/44)(5 moles O₂/1 mole b)

1.115 moles O₂ = (0.1167a) moles O₂ + (0.1136b) moles O₂

To keep solving this, we can use expression (1) to solve for b, and then, replace here and have only one equation with 1 incognite:

a + b = 9.725 g  

b = 9.725 - a   (3)

Replacing above we have:

1.115 = 0.1167a + 0.1136(9.725 - a)

1.115 = 0.1167a + (1.1048 - 0.1136a)

1.115 - 1.1048 = 0.1167a - 0.1136a

0.0102 = 0.0031a

a = 3.29 g

Now, that we have the mass of the ethane, we can calculate the mass percent:

% = (3.29 / 9.725) * 100

Hope this helps

Answer:

The answer is "[tex]= 0.078 \ kg \ H_2[/tex]".

Explanation:

calculating the moles in [tex]CH_4 =\frac{PV}{RT}[/tex]

                                                [tex]=\frac{(0.58 \ atm) \times (923 \ L) }{ (0.0821 \frac{L \cdot atm}{K \cdot mol})(232^{\circ} C +273)}\\\\=\frac{(535.34 \ atm \cdot \ L) }{ (0.0821 \frac{L \cdot atm}{K \cdot mol})(505)K}\\\\=\frac{(535.34 \ atm \cdot \ L) }{ (41.4605 \frac{L \cdot atm}{mol})}\\\\= 12.9 \ mol[/tex]

Eqution:

[tex]CH_4 +H_2O \to 3H_2+ CO \ (g)[/tex]

Calculating the amount of [tex]H_2[/tex] produced:

[tex]= 12.9 \ mol CH_4 \times \frac{3 \ mol \ H_2 }{1 \ mol \ CH_4}\times \frac{2.016 g H_2}{1 \ mol \ H_2}\\\\= 78 \ g \ H_2 \\\\= 0.078 \ kg \ H_2[/tex]

So, the amount of dihydrogen produced = [tex]0.078 \frac{kg}{s}[/tex]

91.2 g Mn

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Stoichiometry

Step 1: Define

[Given] 1.00 × 10²⁴ atoms Mn

Step 2: Identify Conversions

Avogadro's Numer

[PT] Molar Mass of Mn - 54.94 g/mol

Step 3: Convert

Step 4: Check

Follow sig fig rules and round. We are given 3 sig figs.

91.2321 g Mn ≈ 91.2 g Mn

Answer:

5.80200 Kg / L

Explanation:

Answer:

298. 7 K.

Explanation:

Hello!

In this case, since equation we use to compute the heat in a cooling or heating process is:

[tex]Q=mC(T_f-T_i)[/tex]

Whereas we are given the heat, mass, specific heat and initial temperature. Thus, we infer that we need to solve for the final temperature just as shown below:

[tex]T_f=T_i+\frac{Q}{mC}\\\\T_f=1000 K+\frac{-270000J}{1000g*0.385\frac{J}{g*K} } \\\\T_f=298.7 K[/tex]

It is important to notice that the iron release heat as water absorbs it, that is why it is taken negative.

Best regards!

Answer: The molar mass of menthol is 156.15 g/mol

Explanation:

Depression in freezing point is given by:

[tex]\Delta T_f=K_f\times m[/tex]

[tex]\Delta T_f=T_f^0-T_f=2.84^0C[/tex] = Depression in freezing point

[tex]K_f[/tex] = freezing point constant = [tex]20.8^0C/m[/tex]

m= molality

[tex]\Delta T_f=K_f\times \frac{\text{mass of solute}}{\text{molar mass of solute}\times \text{weight of solvent in kg}}[/tex]

Weight of solvent (cyclohexane)= 25.0 g = 0.025 kg  

Molar mass of solute (menthol) = ?

Mass of solute (menthol) = 0.533 g

[tex]2.84^0C=20.8\times \frac{0.533}{xg/mol\times 0.025}[/tex]

[tex]x=156.15g/mol[/tex]

The molar mass of menthol is 156.15 g/mol

Answer:

[tex]atoms= 1.204x10^{24}atoms[/tex]

Explanation:

Hello!

In this case, according to the Avogadro's number, it is possible to compute the atoms of Kr in 2.00 moles as shown below:

[tex]atoms=2.00mol*\frac{6.022x10^{23}atoms}{1mol} \\\\atoms= 1.204x10^{24}atoms[/tex]

Best regards!

Answer:

2.68 cm^3

Explanation:

Density= Mass/Volume

so...

8.96 g/cm^3 = 24.01 g/ V

and then u solve so it would be 2.68 cm ^3

((: