what’s the answer to this question pls help

Answer:

2C8H18 + 25O2 → 16CO2 + 18H2O

Explanation:

1:The energy involved in a phase change depends on two major factors: the number and strength of bonds or force pairs. The number of bonds is proportional to the number of molecules and thus to the mass of the sample. The strength of forces depends on the type of molecules. The heat Q required to change the phase of a sample of mass m is given by

2:According to the law of conservation of energy, energy can neither be created nor destroyed but can be transformed from one form to another. Conversion of electric energy into sound energy is an example of the conservation of energy.

Explanation:

Hope it helps UvU

Answer:

D :)

Explanation:

Cells die and the new cells that are being produced are replaced by new living cells. (If cell division prevented cancer, we'd all be saved by now.)

Cell division is carried to produce new identical cells to during reproduction as well to replace old and diseased cells.  Thus option C is correct.

Cell division is the process of multiplication of a cell into two identical daughter cells. Cell division is taking place in all living organism by which they reproduce and repair cells.

Cell division takes places through several stages namely,  interphase, telophase etc. There are different methods of cell division such as mitosis, meiosis, binary fission etc.

Different level of organisms follows different methods for cell division. In eukaryotes, mitosis takes place where genetically identical daughter cells are produced. It is called vegetative division.

In reproductive cell division the number of chromosomes will be reduced in daughter cell to half or that in parent cells. Thus in a cell cycle , the odl cells are replaced by new cells and identical offsprings are created by cell division. Hence, option C is correct.

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Answer:

Precipitates indication release of gas

Or just vapor-again indictaing release of gas

Change in melting/boiling point, change in pH

Change in temperature

Answer:

Explanation:

these signs show that the chemical reaction has taken place.

Answer:

2.7 moles of Fe₂O₃ is the maximum amount that can be produced. Iron is the limiting reactant.

Explanation:

The balanced reaction is:

4 Fe + 3 O₂ → 2 Fe₂O₃

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of each compound participate in the reaction:

The limiting reagent is one that is consumed first in its entirety, determining the amount of product in the reaction. When the limiting reagent is finished, the chemical reaction will stop.

You can use a simple rule of three as follows: if by stoichiometry 4 moles of Fe reacts with 3 moles of O₂, how much moles of Fe will be needed if 4.7 moles of O₂ react?

[tex]moles of Fe =\frac{4. moles of Fe*4.7 moles of O_{2}}{3 moles of O_{2} }[/tex]

moles of O₂= 6.27

But 6.27 moles of Fe are not available, 5.4 moles are available. Since you have less moles than you need to react with 4.7 moles of O₂, iron Fe will be the limiting reagent.

So you can use a simple rule of three as follows: if by stoichiometry 4 moles of Fe produce 2 moles of Fe₂O₃, how many moles of Fe₂O₃ will be produced if 5.4 moles of Fe react?

[tex]moles of Fe_{2}O_{3}=\frac{5.4 moles of Fe*2 moles of Fe_{2} O_{3} }{4 moles of Fe}[/tex]

moles of Fe₂O₃= 2.7 moles

Then:

2.7 moles of Fe₂O₃ is the maximum amount that can be produced. Iron is the limiting reactant.

Answer:

1) The Difference in water tempture

2) Algae

Explanation:

Have a good day!  ∩__∩

Answer:

question 1. thermocline is caused by a difference in water temperature.

question 2. a kind of phytoplankton is algae

Answer:

The middle hydrogen is bonded to 2

elements.

Each hydrogen must be bonded to one element which is oxygen

Answer:

A, C, and D

Explanation:

Answer:

hardness-Hardness is the ability of a material to resist deformation

luster-the way light interacts with the surface of a crystal

color-the quality of an object or substance with respect to light reflected by the object

streak- the color of the powder produced when it is dragged across an un-weathered surface.

specif gravity-the density of that object divided by the density of water cleavage -the tendency of a mineral to break along smooth planes

fracture-any separation in a geologic formation

tenacity-refers to a mineral's toughness or resistance to breaking or being deformed.

lol sorry that took awhile

Answer:

A. Chemistry can help a chef understand how to combine different ingredients in a recipe.

Explanation:

Knowing the chemical reactions between ingredients used in cooking helps chefs understand how well different ingredients would react to eachother.

*Im pretty sure this is correct.

Answer:  

Mass = 3.24 g

Explanation:

Given data:

Number of atoms of cobalt = 3.31 × 10²² atoms

Mass of cobalt atoms  = ?

Solution:

We will calculate the number of moles of cobalt by using Avogadro number.

1 mole contain 6.022× 10²³ atoms

3.31 × 10²² atoms  × 1 mol / 6.022× 10²³ atoms

0.549 mol × 10⁻¹

0.0549 mol

Mass of cobalt:

Mass = number of moles × molar mass

Mass = 0.0549 mol × 58.93 g/mol

Mass = 3.24 g

Answer:

In general, if the electronegativity difference between two atoms is less than 0.5, the bond is considered nonpolar, even though the only truly nonpolar molecules are those formed with identical atoms. Nonpolar molecules also form when atoms sharing a polar bond arrange such that the electric charges cancel each other out.

Explanation:

sorry if I'm wrong or if this doesn't help you

Answer:

449.5 g

Explanation:

Silver sulfate- Ag2SO4

M(Ag)=107 g/mol => M(Ag2)=214 g/mol

M(S)=32 g/mol

M(O)=16 g/mol => M(O4)=64 g/mol

M(Ag2SO4)=310 g/mol

n=1.45 mol

m(Ag2SO4)=M(Ag2SO4)*n=310 g/mol *1.45 mol= 449.5 g

Answer:

479 grams

Explanation:

5.43 times the molar mass of CaSO4 would give us the answer.

(5.43) * (40.078 + 32.066 + 15.9994) = 478.618662 grams

Significant figures is 3, meaning we need to round it into 3 places, giving us 479 grams.

Answer:

It is 7 g in accordance to the periodic table

The molar concentration of the original HF  solution : 0.342 M

Given

31.2 ml of 0.200 M NaOH

18.2 ml of HF

Required

The molar concentration of HF

Solution

titration formula

M₁V₁n₁=M₂V₂n₂

n=acid/base valence (amount of H⁺/OH⁻, for NaOH and HF n =1)

Input the value :

[tex]\tt 0.2\times 31.2=M_2\times 18.25\\\\M_2=0.342[/tex]

Answer:

Something that is elastic can return to its original shape after being stretched or compressed. As you stretch or compress an elastic material like a bungee cord or a rubber band it resists the change in shape. It exerts a counterforce in the opposite direction. Now if you pull back the rubber band u are using force now if you let go the force that you used to pull back is transferred into the band snapping and bouncing. This force is called an elastic force.

Answer:

it is something that will return back to shape and being stretched or compressed

Answer:

1.14 mol

Explanation:

Given data:

Mass of HNO₃ react = 143.2 g

Moles of Mg(NO₃)₂ produced = ?

Solution:

Chemical equation:

2HNO₃ + Mg(OH)₂   →     Mg(NO₃)₂ + 2H₂O

Number of moles of HNO₃:

Number of moles = mass/molar mass

Number of moles = 143.2 g/ 63.01 g/mol

Number of moles = 2.273 mol

Now we will compare the moles of HNO₃  and Mg(NO₃)₂

                   HNO₃           :          Mg(NO₃)₂

                      2                :            1

                   2.273            :          1/2×2.273 = 1.14 mol

Answer:

1 and 4

Explanation:

Answer:

1 and 4 is correct

Explanation:

(;

Explanation:

1.ca

2.H

3.O

.................

Answer:

it was salt just took it

Explanation:

Halogens are non metals and when a non metals reacts with metals they form an ionic compound by gaining electrons from the metal.

Ionic compounds are formed by electron loss/gain between two atoms. Ionic bond is the strongest type of bond. Ionic bond is formed between metals and nonmetals.

Metals are electron rich and they are electropositive in nature. They lose one more electron when reacted with nonmetals. Nonmetals which are electronegative will gain electron from the metals and form the ionic bond.

Halogens such chlorine, bromine etc are highly electronegative and they form ionic compounds of metals such as sodium, potassium, magnesium etc by losing gaining one electron from the metal. Therefore,  when halogens reacts with metals forming ionic compounds.

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Answer:B is the answer I thinn

Explanation:I think !!

Answer:

d

Explanation:

The statement that is true about the process Austin uses to separate this mixture is that Austin uses neither physical nor chemical changes to separate the mixture's components. The correct option is D.

A laboratory is a place with carefully regulated circumstances where experiments, measurements, and scientific or technological research can be done.

Here, Austin is separating a mixture in the laboratory. Now, iron is attracted to the magnet, and sand and salt are not attracted to the magnet. So these will be separated by the magnetic property of the iron. It is a physical property of a substance that matters in this separation.

Thus, the correct option is D. Austin uses neither physical nor chemical changes to separate the mixture's components.

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Answer:

Mass of ammonia produced= 34 g            

Explanation:

Given data:

Mass of ammonia produced = ?

Number of moles of nitrogen = 1.0 mol

Solution:

Chemical equation:

N₂ + 3H₂       →    2NH₃

Now we will compare the moles of ammonia and nitrogen.

                   N₂          :          NH₃

                    1           :           2

Mass of ammonia:

Mass = number of moles × molar mass

Mass =    2 mol × 17 g/mol

Mass = 34 g                  

Explanation:

Electronic Configuration for Li: 1s²2s¹

Electronic Configuration for Cl: [Ne]3s²3p⁵

When Lithium and Chlorine bonds together, the electron in the Lithium 2s subshell will be transfered to the Chlorine 3p subshell, giving both the Lithium and Chlorine atoms a complete 1st and 3rd energy levels respectively.

Formula for Lithium chloride: LiCl.

Answer:

b

Explanation:

Answer:

3 moles of CO are needed

Explanation:

Given data:

Number of moles of CO used = ?

Mass of Fe produced = 112 g

Solution:

Chemical equation:

Fe₂O₃ + 3CO      →        2Fe + 3CO₂

Number of moles of Fe:

Number of moles = mass/ molar mass

Number of moles = 112 g/ 55.85 g/mol

Number of moles = 2.00 mol

Now we will compare the moles of iron and CO.

                   Fe        :         CO

                   2          :         3

Thus, 3 moles of CO are needed.

Answer:

Explanation:

Rutherford gold experiment gave the explanation to some observations made on atoms.

When he shot the gold foil, most of the [tex]\alpha[/tex]-particles passes through the foil undeflected nor absorbed. This faction of the particles propagated the foil as if there was nothing placed on their path.

The surprising behavior of a few of the [tex]\alpha[/tex]-particles was that they were deflected from their initial path on hitting the gold foil.

This implies that there is a part of the gold foil which has the same charge as the [tex]\alpha[/tex]-particles, and more massive than the particles. Thus, he was able to determine the nucleus of an atom.

Answer:

(a) By the ideal gas law, the temperature of the gas is approximately 423.51129 K

(b) By the Van der Waals equation, the temperature of the gas is approximately 442.00558 K

Explanation:

The given parameters are;

The mass of the methane gas, m = 60 g

The volume of the container in which the gas is placed, V = 1.00-L

The pressure of the gas in the container, P = 130 atm

The molar mass of methane, CH₄ = 16.04 g/mol

The Van der Waals Constant for Methane (CH₄) a = 2.253 atm L²·mole⁻² and b = 0.04278 L·mol⁻¹

The universal gas constant, R = 0.08206 L·atm·mol⁻¹·K⁻¹

The number of moles of methane present, n = 60.0 g/(16.04 g/mol) ≈ 3.7406 48 moles

(a) The ideal gas law is P·V = n·R·T

Where;

P = The pressure of the gas

V = The volume of the gas

R = The universal gas constant

T = The temperature of the gas

n = The number of moles of the gas

Therefore, T = P·V/n·R

By substituting the known values of the variables, we get;

T = 130×1/(3.740648 × 0.08206) ≈ 423.51129 K

The temperature of the gas, T ≈ 423.51129 K

(b) The Van der Waals equation of state;

[tex]n \cdot R \cdot T = \left (P + a \cdot \dfrac{n^2}{V^2} \right) \cdot (V - n\cdot b)[/tex]

Therefore, we have;

[tex]T = \dfrac{ \left (P + a \cdot \dfrac{n^2}{V^2} \right) \cdot (V - n\cdot b)}{n \cdot R}[/tex]

Therefore, we have;

[tex]T = \dfrac{ \left (130 + 2.253 \times \dfrac{3.740648^2}{1^2} \right) \times (1 - 3.740648\cdot 0.04278)}{3.740648 \times 0.08206} = 442.00558 \ K[/tex]

The temperature of the gas, T ≈ 442.00558 K.