A compound contains 57.2 percent carbon, 6.1 percent hydrogen, 9.5 percent nitrogen, and 27.2 percent oxygen. What the empirical formula of the compound?

Answer:

Hox are transcription factors that are evolutionarily conserved across bilaterians and, therefore, they share sequence homology between paddlefish and humans .

Explanation:

The Hox genes represent a family of homeodomain transcription factors that play roles in the development of the axial and appendicular skeleton, being therefore critical during embryonic development. In this case, the human Hox genes are homologous to homeobox genes found in the paddlefish. These genes have a DNA-binding domain of 60 amino acids which is evolutionarily conserved in bilaterian species including paddlefish and human species.

Answer:Agas loses kinetic energy to become a liquid and then becomes a solid

i believe i had this before but where is the graph

Explanation:

please mark this answer as brainlest

B. A solid gains kinetic energy to become a liquid and then becomes a gas

Moles: 1

Weight, g : 192.3900

Answer:

Moles: 1

Weight, g : 192.3900

Explanation:

Answer:

Theoretical Yield = 0.4882 grams

Explanation:

Potassium Chromate = K2CrO4 Molar mass: 194.1896 g/mol

Silver Nitrate = AgNO3 Molar mass: 169.87 g/mol

Silver(I) Chromate = Ag2CrO4 Molar mass: 331.73 g/mol

Potassium Nitrate = KNO3  Molar mass: 101.1032 g/mol

K2CrO4 + 2AgNO3 = Ag2CrO4 + 2KNO3

Potassium Chromate + Silver Nitrate = Silver(I) Chromate + Potassium Nitrate

Ratio 1:2 = 1:2

0.5g AgNO3

AgNO3 Molar mass: 169.87 g/mol

2AgNO3 = 339.74grams

0.5/339.74 = 0.0014717

Ag2CrO4 Molar mass: 331.73 g/mol

0.4882 grams

Theoretical Yield = 0.4882 grams

Explanation:

Ok so water is H2O and cabon dioxide in the air is CO2, so the water goes through the carbon dioxide and makes acid rain H2SO4.

Now we have our limestone which is CaCO3.

What happens is that the acid breaks apart our limestone into Ca2+ and CO3 2-. This then reforms into Calcium bicarbonate Ca(CO3)2.

Calcium bicarbonate is soluble in water and is hence washed away by the rain eroding the limestone.

Answer:

Fuels made from oil mixtures containing large hydrocarbon molecules are not efficient as they do not flow easily and are difficult to ignite. Crude oil often contains too many large hydrocarbon molecules and not enough small hydrocarbon molecules to meet demand. This is where cracking comes in

Explanation:

The functional group that defines a ketone is =O and the correct option is option 4.

Ketones are a common functional group in organic chemistry. Ketones have important physiological properties. As a result, they are a part of several sugars and compounds involved in medicinal use such as cortisone, an anti-inflammatory.

In ketones, the carbonyl group has 2 hydrocarbon groups attached to it. These can be either the ones containing benzene rings or alkyl groups. Ketone does not have a hydrogen atom attached to the carbonyl group.

Therefore, the functional group that defines a ketone is =O and the correct option is option 4.

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Answer: The molarity of [tex]Br^-[/tex] anions in the chemist's solution is 0.0084 M

Explanation:

Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.

[tex]Molarity=\frac{n\times 1000}{V_s}[/tex]

where,

n = moles of solute

[tex]V_s[/tex] = volume of solution in ml

moles of [tex]FeBr_3[/tex] = [tex]\frac{\text {given mass}}{\text {Molar mass}}=\frac{0.0411g}{295.6g/mol}=0.00014mol[/tex]

Now put all the given values in the formula of molality, we get

[tex]Molarity=\frac{0.00014\times 1000}{50}=0.0028[/tex]

As 1 mole of [tex]FeBr_3[/tex] gives = 3 moles of [tex]Br^-[/tex]

0.0028 moles of [tex]FeBr_3[/tex] gives = [tex]\frac{3}{1}\times 0.0028=0.0084 moles[/tex] of [tex]Br^-[/tex]

Thus the molarity of [tex]Br^-[/tex] anions in the chemist's solution is 0.0084 M

Answer:

22.6881 Grams of CO

Explanation:

Fe2O3 + 3CO = 3CO2 + 2Fe

Ratio

1:3 = 3:2

How many grams of CO are needed to produce 30.2 grams of Fe

Fe2O3 Molar mass: 159.69 g/mol

CO Molar mass: 28.01 g/mol

Fe Atomic mass: 55.845

Ok so our end result is 30.2 Grams of Fe, we have 2 Fe so we have 15.1 Grams per Fe

15.1/55.845 = 0.27

So then we multiply this by 3 as we we know the ratio and get get 0.81 required as this is 3CO.

So we need 0.81 Moles of CO so we need 22.6881 Grams of CO.

Answer:

Intake, compression, power, and exhaust

Explanation:

A four-stroke cycle engine is an internal combustion engine that utilizes four distinct piston strokes (intake, compression, power, and exhaust) to complete one operating cycle. The piston make two complete passes in the cylinder to complete one operating cycle.

The sequence of a single complete engine cycle is Intake, compression, power, exhaust. Therefore option 1 is correct.

1. Intake: In this step, the intake valve opens, allowing a mixture of air and fuel to enter the combustion chamber.

2. Compression: After the intake stroke, the intake valve closes, and the piston moves back up, compressing the air-fuel mixture. This compression increases the pressure and temperature inside the cylinder, preparing it for combustion.

3. Power: Once the air-fuel mixture is compressed, the spark plug ignites it. The burning mixture rapidly expands, generating a high-pressure force that pushes the piston down.

4. Exhaust: After the power stroke, the exhaust valve opens, and the piston moves back up, pushing the burned gases out of the cylinder and into the exhaust system.

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Answer:best

Explanation:

Best

Answer:

From left to right

Neutral

Acid

Base

Explanation:

So using HSAB theory hard and soft (Lewis) acids and bases.

OH - Is a Hard Base

H+ Strong Acid

Answer:

[tex]\large \boxed{\text{-827.4 kJ}}[/tex]

Explanation:

We have three equations:

1. 2H₂S(g)            + O₂(g)   ⟶ 2S(s, rhombic) + 2H₂O(g) ; ∆H = -442.4 kJ

2. S(s, rhombic)  + O₂(g)   ⟶ SO₂(g);                                 ∆H = -296.8 kJ

3. PbO(s)             + H₂S(g) ⟶ PbS(s)               + SO₂(g);    ∆H =  -104.3 kJ

From these, we must devise the target equation:

4. 2PbS(s)            + 3O₂(g) ⟶2PbO(s)             + 2SO₂(g); ΔH = ?

The target equation has PbS(s) on the left, so you reverse Equation 3 and double it.

When you reverse an equation, you reverse the sign of its ΔH.

When you double an equation, you double its ΔH.

5. 2PbS(s) + 2H₂O(g) ⟶ 2PbO(s) + 2H₂S(g); ∆H = 208.6 kJ

Equation 5 has 2H₂O on the left. That is not in the target equation.

You need an equation with 2H₂O on the right, so you copy Equation 1.  

6. 2H₂S(g) + O₂(g) ⟶ 2S(s, rhombic) + 2H₂O(g) ; ∆H = -442.4 kJ  

Equation 6 has 2S(s, rhombic) on the right. That is not in the target equation.

You need an equation with 2S(s, rhombic) on the left, so you double Equation 2.  

7. 2S(s, rhombic)  + 2O₂(g) ⟶ 2SO₂(g); ∆H = -593.6 kJ

Now, you add equations 5, 6, and 7, cancelling species that appear on opposite sides of the reaction arrows.

When you add equations, you add their ΔH values.

You get the target equation 4:

5. 2PbS(s)  + 2H₂O(g)  ⟶ 2PbO(s) + 2H₂S(g);  ∆H =  208.6 kJ

6. 2H₂S(g) + O₂(g)        ⟶ 2S(s)     + 2H₂O(g) ; ∆H = -442.4 kJ

7. 2S(s)      + 2O₂(g)      ⟶ 2SO₂(g);                   ∆H = -593.6 kJ

4 . 2PbS(s) + 3O₂(g)      ⟶ 2PbO(s) + 2SO₂(g); ΔH = -827.4 kJ

[tex]\Delta H \text{ for the reaction is $ \large \boxed{\textbf{-827.4 kJ}}$}[/tex]

Answer:

The substances on the right side of a chemical equation are the products as reactions typically move from left to right.

A chemical equation is a representation of chemical reaction in the form of symbols and formulae where the reactants are on left side and the products on right side.

Eg. CaCO3(s)→CaO(s)+CO2(g

Chemical equation is written "with the reactants on the left side of an arrow and the products of the chemical reaction on the right".

Reactants are "the starting materials in a chemical reaction".

What is a product?

A product is "a chemical species resulting from a chemical reaction".

Hence, the substances on the right side of a chemical equation are products.

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Answer:

CrO

Explanation:

0.765g Cr

0.235g O

O = 16g/mol

Cr = 52g/mol

O     2-

Cr  2+, 3+, 6+

0.765 + 0.235 = 1

so 76.5% Cr

23.5% O

76.5/52 = 1.47/1.47 = 1

23.5/16 = 1.47/1.47 = 1

CrO

Answer:

hydroxide ion / OH-

Explanation:

Basic solutions have a greater concentration of hydroxide ions than hydrogen (H+) ions

Answer : The value of [tex]\Delta H_{rxn}[/tex] for the reaction is, -390.3 kJ

Explanation :

According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.

According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.

The main chemical reaction is:

[tex]CH_4(g)+4Cl_2(g)\rightarrow CCl_4(g)+4HCl(g)[/tex]    [tex]\Delta H_{rxn}=?[/tex]

The intermediate balanced chemical reaction are:

(1) [tex]C(s)+2H_2(g)\rightarrow CH_4(g)[/tex]     [tex]\Delta H_1=-74.6kJ[/tex]

(2) [tex]C(s)+2Cl_2(g)\rightarrow CCl_4(g)[/tex]     [tex]\Delta H_2=-95.7kJ[/tex]

(3) [tex]H_2(g)+Cl_2(g)\rightarrow 2HCl(g)[/tex]     [tex]\Delta H_2=-184.6kJ[/tex]

Now we are reversing reaction 1, multiplying reaction 3 by 2 and then adding all the equations, we get :

(1) [tex]CH_4(g)\rightarrow C(s)+2H_2(g)[/tex]     [tex]\Delta H_1=74.6kJ[/tex]

(2) [tex]C(s)+2Cl_2(g)\rightarrow CCl_4(g)[/tex]     [tex]\Delta H_2=-95.7kJ[/tex]

(3) [tex]2H_2(g)+2Cl_2(g)\rightarrow 4HCl(g)[/tex]     [tex]\Delta H_2=2\times (-184.6kJ)=-369.2kJ[/tex]

The expression for enthalpy change for the reaction will be,

[tex]\Delta H_{rxn}=\Delta H_1+\Delta H_2+\Delta H_3[/tex]

[tex]\Delta H_{rxn}=(74.6kJ)+(-95.7kJ)+(-369.2kJ)[/tex]

[tex]\Delta H_{rxn}=-390.3kJ[/tex]

Therefore, the value of [tex]\Delta H_{rxn}[/tex] for the reaction is, -390.3 kJ

Answer:

60g/mol

Explanation:

By using nucleon numbers given on the periodic table, the mass of 1 mole of each element is:

C= 12g

H= 1g

O= 16g

Since molar mass is the sum of the masses of each element present in the compound,

Molar Mass (Mr) = 12+3(1)+12+16(2)+1 = 60g/mol

Answer: 1500 kg•m/s north

Explanation:

A PE X

Answer: nucleus

Explanation: the bigger the nucleus there more reactive the atom is

Answer:

The larger an atom is, the more reactive it will be.

It helps to think about the size of an atom with the location of the electrons and nucleus in mind. You know that protons are positively charged and electrons are negatively charged, therefore there is a level of attraction between these two oppositely charged subatomic particles. This attraction helps stabilize the atom.

Now, in a larger atom, with more electrons are those electrons (specifically the valence electrons) going to be closer or further from the nucleus than in a smaller atom?

They will of course be further from the nucleus and therefore further from the positively charged nucleus. This makes it easier for the valence electrons to leave the atom and form an ionic bond or to interact with another atom to form a covalent bond.

If electrons can leave more easily, then the atom is more likely to react.

Answer:

C

Explanation:

Oxygen & water form rust

Answer:

d)carbon(iv)oxide/carbon(ii)oxide

e)Calcium,carbon,oxygen

f)carnonhydride

g)Carbonhydrate

h)hydrogen+oxygen

I)Iron sulphide

j)Magnesiumoxide

m)magnesium hydroxide+hydrogen gas

d)carbon dioxide

Answer:

D. Na2CO3

Explanation:

I'm just guessing tbh

Answer:

Check Explanation

Explanation:

In this case the Mushroom would get energy from decomposing dead plants and animals in the soil/ground

The plant would get energy from the sun (simplified)

the rabbit would get energy from eating the plant

in this case the wolf would energy from eating the rabbit but in a normal setting the wolf could get energy from eating any animal

Answer:

Explanation: A wolf gets its energy from food and water

A rabbit gets its energy from food and water too

A plant get it energy from sunlight, rain

A mushroom also get its energy from dead plant/animal’s

If this wasn’t the answer you wanted I’m sorry