need it by 4:20 please​

Answer:

The answer is "Option b".

Explanation:

Given equation and value:

[tex]\Rightarrow C_2H_2 \ (g)+ \frac{5}{2}O_2 \ (g) \longrightarrow 2CO_2\ (g)+H_2O\ (g)[/tex]

[tex]\left\begin{array}{ccc}C \equiv C&839\\C-H &413\\O=O &495\\ C=O &799\\ O-H &467 \end{array}\right \\\\[/tex]

calculating equation value:

[tex]\Rightarrow 839 + 2(413) +\frac{5}{2} (495) \longrightarrow 2(2)799+2 \times 467 +E[/tex]

[tex]\Rightarrow 839 + 826 +1237.5 = 3196+934 +E\\\\\Rightarrow 2902.5 =4130 +E\\\\\Rightarrow 2902 = 4130 +E\\\\\Rightarrow 2902 - 4130 +E\\\\\Rightarrow E = -1228 \ KJ \\\\[/tex]

The heat(enthalpy) of combustion of acetylene = -1228 kJ

The heat of combustion refers to the amount of heat released when 1 mole of a substance is burned.

The chemical reaction is given in the equation;

The bond energy of the reactant is:

Following the bond energies given in the question, we have:

= ( 1 × 839) +(5/2 × 495) +(2 × 413)

= 2902.5 kJ

The bond energy of the product is:

= (4× 799) +(2 × 467)

= (3196 + 934) kJ

= 4130 kJ

The heat(enthalpy) of combustion of acetylene = bond energy of reactant - bond energy of the product.

The heat(enthalpy) of combustion of acetylene = 2902.5 kJ - 4130 kJ

The heat(enthalpy) of combustion of acetylene = -1227.5 kJ

≅  -1228 kJ

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Answer:

density = mass ÷ volume

Explanation:

mass = volume × density

       =24.9 cm3 × 2.72 g / cm3

      =67.728 g

Answer:

kindly check the EXPLANATION SECTION

Explanation:

In order to be able to answer this question one has to consider the neutron proton ratio. Considering this ratio will allow us to determine the stability of a nuclei. The most important rule that helps us in determination of stability is that when the Neutron- Proton ratio  of any nuclei ranges from  to 1 to 1.5, then we say the nuclei is STABLE.

Also, we need to understand that when the  Neutron- Proton ratio is LESS THAN 1 or GREATER THYAN 1.5, then we say the nuclei is UNSTABLE.

So, let us check which is stable and which is unstable:

a. 4 protons and 5 neutrons =  Neutron- proton ratio = N/P = 5/4= stable.

b. 7 protons and 7 neutrons  =  Neutron- proton ratio = N/P = 7/7= 1 = stable.

c. 2 protons and 3 neutrons  =  Neutron- proton ratio = N/P = 3/5 =0.6 =unstable.

d. 3 protons and 0 neutrons  =  Neutron- proton ratio = N/P = 0/3= 0= unstable.

e. 6 protons and 5 neutrons  =  Neutron- proton ratio = N/P = 5/6= 0.83 = unstable.

f. 9 protons and 9 neutrons  =  Neutron- proton ratio = N/P = 9/9 = 1 = stable.

g. 8 protons and 7 neutrons  =  Neutron- proton ratio = N/P =  7/8 =0.875 = unstable.

h. 1 proton and 0 neutrons =  Neutron- proton ratio = N/P = 0/1 =0 = unstable

A nucleus is unstable if the neutron - proton ratio is less than 1 or greater than 1.5.

The stability of a nucleus depends on the neutron - proton ratio. We must not that an atom is unstable if the neutron - proton ratio is less than 1 or greater than 1.5. Let us now examine each case.

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Answer:

The different brands of sodas will not spew the same amount when shaken because there are different amounts of sugar in the sodas and that will affect the amount spewing. Pepsi will spew the highest, compared to the other brands of sodas

Explanation:

The amount of fizz that different kinds or brands of soft drinks spew out when shaken up may not be the same.

The fizz that soft drinks produce is due to the carbon dioxide gas that is dissolved in the drink. The amount of fizz that soft drinks produce when shaken up can vary depending on various factors such as the brand of soft drink, the temperature of the drink, and the level of carbonation of the drink. When a soft drink bottle or can is shaken, the carbon dioxide gas gets released from the solution and forms bubbles, which causes the spewing action.

However, the amount of carbon dioxide gas that is dissolved in the drink can vary depending on the brand and the level of carbonation. This means that some soft drinks may produce more fizz than others when shaken up.In summary, the amount of fizz that soft drinks produce when shaken up can vary depending on various factors.

Hence different kinds or brands of soft drinks may not spew you the same amount.

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Answer:

Explanation:

a.) Average or mean value of readings, [tex]x_{o}[/tex] = (0.0044 + 0.0079 + 0.0062) / 3

= [tex]\frac{0.0185}{3}[/tex] = 0.0062 AU

b.) The accuracy of the readings is determined by taking determining the standard deviation (SD) of the readings:

SD = ∑ [tex]\sqrt{x- x_{o}}[/tex]/n

[tex](0.0062 - 0.0044)^{2}[/tex] = 0.0000032

[tex](0.0062 - 0.0079)^{2}[/tex] = 0.00000289

[tex](0.0062 - 0.0062)^{2}[/tex] = 0

SD = [tex]\frac{\sqrt{0.0000032 + 0.00000289 + 0} }{3}[/tex] = 0.00082.

c.) The % accuracy is the distance between the average value and true value

= [tex]\frac{0.0062-0.0030}{0.0030} *100[/tex] = 106.7% error.

Answer:

3

Explanation:

the three elements involved in this compound are Li, S, O.

lithium, sulfur, and oxygen. Which create the ionic compound, "Lithium Sulfate."

7 atoms total, since there are two lithium, four oxygen, and one sulfate atom. this is a white inorganic salt.

There are three different types of elements in LiSO₄ which are lithium (Li), sulfur (S), and oxygen (O).

An element is a pure substance made of only one kind of atom which all have the same number of protons in their nuclei.

The chemical element was first presented by Robert Boyle who defined it as "incapable of decomposition”. Boyle’s this definition lies admirably close to present-day theory.

When different kinds of elements undergo particular chemical reactions then atoms are rearranged into new compounds connected together by chemical bonds.

All other naturally occurring elements occur on the Earth as compounds or mixtures. Air is a mixture of the elements nitrogen (N₂), oxygen (O), and argon (Ar), though it does contain carbon dioxide and water.

Given compound, lithium sulfate is formed of LiSO₄ has elements lithium, sulfur, and oxygen.

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Answer:

Explanation:

The acceleration of an object given it's mass and the force acting on it can be found by using the formula

[tex]a = \frac{f}{m} \\ [/tex]

where

m is the mass

f is the force

a is the acceleration

From the question

f = 25 N

m = 75 kg

We have

[tex]a = \frac{25}{75} = \frac{1}{3} \\ = 0.333333333...[/tex]

We have the final answer as

Hope this helps you

Answer:

22,920 years

Explanation:

Took the quiz on Edge

The time that it will take for 112.5 g of a 120.0-g sample to decay radioactively is about 22,920 years.

The term half life is defined as the time taken for only half of the radioactive sample to remain.

The time that it will take for 112.5 g of a 120.0-g sample to decay radioactively is about 22,920 years.

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Answer:

Radiocarbon measurement or radiocarbon dating is a method that is used to measure the age of the carbon-based material in living organisms.

Radiocarbon dating is able to estimate age of fossils that are younger than 50,000 years and unable to measure things that died longer than 200,000 years ago because fossils that are too old do not contain carbon or carbon get vanished from too old fossils of organisms. Some of the fossils also get contaminated due to environmental conditions and during teh collection or preservation process.

Thus,  radiocarbon measurement is useless when trying to measure most rocks older than 50,000 years.

Answer:

Solid potassium iodide decomposes into solid potassium and iodide gas.

Explanation:

The answer given has a subscript "2" on the iodine at the start of the equation. Why is the 2 there as a subscript?

Answer:

3 small cups

Explanation:

The correct answer would be 3 small cups.

The big cup can hold 9/10 of the total seeds.

The small cup can hold 3/10 of the total seeds.

3 of the small cup would be equivalent to the big cup such that:

  3 x 3/10 = 9/10

Hence, 3 small cups = 1 bigger cup.

Answer:

C, C, A

Explanation:

11.  C

12.  C

13.  A

Answer:

The number of protons in an atom is always equal to the atomic number.

Explanation:

Answer:

C. All sodium chloride will contain 40% sodium by mass.

Explanation:

It is definitely true that all sodium chloride will contain 40% sodium by mass. Table salt is the common name of sodium chloride which is the chemical name.

The formula is designated as NaCl.

According to the Law of constant composition or definite proportions; "all pure samples of the same compound contain the same proportions of the elements by mass".

This implies that every time a particular compound forms, it forms in the same percentage composition. It forms in the same percentage composition.

So, we see that all sodium chloride will contain 40% sodium by mass.

Option A, B and D are in contradiction with the law of constant composition.

Answer:

Flame tests are used to identify the presence of a relatively small number of metal ions in a compound. Not all metal ions give flame colors. For Group 1 compounds, flame tests are usually by far the easiest way of identifying which metal you have got. ... Confirm the colors with the elements on Table 1

Explanation:

Answer:

10 g The change from ice to water is a phase change for the water. A phase change does not change the mass of the water. So if you end up with 10 g of water, and you originally started with ice, then that means you had to start with 10 g of ice. Therefore the best estimate of the mass of the ice cube is 10 g.

Explanation:

Answer:

Nucleic Acids

Explanation:

DNA, Deoxyribonucleic acid, is made up up nucleic acids. These nucleic acids are:

Adenine

Guanine

Cytosine

Thymine

Adenine binds to Thymine and Cytosine binds to Guanine. They are then "twisted" into a double helix.

Answer:

Explanation:

from two to several thousand base pairs and is estimated to constitute about 30% of the genome. Many of these sequences are localized in centromeres and telomeres, but they are also dispersed throughout the genome.

Answer: Solubility

Explanation:

Answer:

Solubility i believe

Explanation:

Answer:

Explanation:

0.000625 cm3  

  0.625 cm3  

  1.60 cm3

Answer: CS and F

Explanation:

...ck-12

The pair of elements that would most likely undergo a violent reaction if combined with each other is; Choice D: Cs and F

According to the question;

Conventionally, alkali metals and halogens react violently.

More specifically; Caesium and Flourine react most violently because they are highly reactive members of the Alkali metals and halogens group respectively.

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Answer:

see the image below

Explanation:

oxidation is losing of electrons

reduction is gaining of electrons

Answer:

150 years i guess so? im nkt sure

Answer:

If a fossil bone is found to contain 1/8th as much Carbon-14 as the bone of a living animal, what is the approximate age of the fossil?(half-life of C-14 = 5800 years)

Explanation:

Answer:

About 14.45 seconds

Explanation:

If a object is going 4.5m/s and its destination is 65m then you need to divide.

65÷4.5 = 14.444444

due to the constant 4 you need to round 14.444 so it would be 14.45 seconds.

Answer:

Artificial Intelligence has helped us find fossils faster than ever. Before this technology, finding fossils was based on luck although scientists could make an educated guess. These robots are called paleobots. These robots use various techniques like scanning the location and some robots can also help with excavation.  

Answer:

NASA technology, Remote Sensing, the search can be narrowed. Remote sensing techniques use satellites to help observe and measure objects from a distance. One part of remote sensing involves taking pictures. With images like the ones from NASA's LandSat Satellites, paleontologists use remote sensing to locate areas in the Gobi where fossils are most likely to be found. LandSat sensors measure different wavelengths of reflected sunlight and emitted thermal radiation. The data are beamed back to Earth, where they can be made into images. Paleontologists analyze these images, looking for rock formations most likely to yield fossils.

Explanation:

Answer:

Ne (Neon)

Explanation:

Since the electrons of the image are 2-8,  totaling 10, with no indication that the atom is charged, the electrons and protrons must cancel out, meaning that the element has  10 protons and is thus neon

Answer:

167.28×10^23

Explanation:

500 ml of water weighs 500 gm.

Molecular weight of water =18 gm

So, number of moles in 500 gm of water=500/18=27.78

Number of molecules= number of moles × Avogadro's number=27.78×6.022×10^23=167.28×10^23

So, there are 167.28×10^23 molecules in 500 ml of water

Answer:

Gallium is NOT a transition metal.

Explanation:

1. Titanium is a Transition metal However Gallium is NOT. Gallium is a main group metal, It belongs to group 3 - Boron Group.

All the remaining statements are correct.

Answer: Antimony pentoxide

Hope this helps :)

Answer:

Explanation:

From the given information:

The density of O₂ gas = [tex]d_{ideal} = \dfrac{P\times M}{RT}[/tex]

here:

P = pressure of the O₂ gas = 310 bar

= [tex]310 \ bar \times \dfrac{0.987 \ atm}{1 \ bar}[/tex]

= 305.97 atm

The temperature T = 415 K

The rate R = 0.0821 L.atm/mol.K

molar mass of O₂  gas = 32 g/mol

∴

[tex]d_{ideal} = \dfrac{305.97 \ \times 32}{0.0821 \times 415}[/tex]

[tex]d_{ideal}[/tex] = 287.37 g/L

To find the density using the Van der Waal equation

Recall that:

the Van der Waal constant for O₂ is:

a = 1.382 bar. L²/mol²    &

b = 0.0319  L/mol

The initial step is to determine the volume = Vm

The Van der Waal equation can be represented as:

[tex]P =\dfrac{RT}{V-b}-\dfrac{a}{V^2}[/tex]

where;

R = gas constant (in bar) = 8.314 × 10⁻² L.bar/ K.mol

Replacing our values into the above equation, we have:

[tex]310 =\dfrac{0.08314\times 415}{V-0.0319}-\dfrac{1.382}{V^2}[/tex]

[tex]310 =\dfrac{34.5031}{V-0.0319}-\dfrac{1.382}{V^2}[/tex]

[tex]310V^3 -44.389V^2+1.382V-0.044=0[/tex]

After solving;

V = 0.1152 L

∴

[tex]d_{Van \ der \ Waal} = \dfrac{32}{0.1152}[/tex]

[tex]d_{Van \ der \ Waal}[/tex] = 277.77  g/L

We say that the repulsive part of the interaction potential dominates because the results showcase that the density of the Van der Waals is lesser than the density of ideal gas.

Answer:

1,4,6,7

Explanation:

Electrons have a negitive charge and are outside of the nucleus and have the same atomic number and have the same number os nutrons.