2. Which of the following could the flame test be used for?

Answer:

Follows are the solution to this question:

Explanation:

Please find the complete solution in the attached file.

Answer:

a. During incomplete metamorphosis, the nymph molts its exoskeleton. During complete metamorphosis, the larva forms a chrysalis or cocoon.

Explanation:

The first stage of incomplete metamorphosis is the egg. During this time, the insect will hatch into a form called a nymph. The nymph is basically a small version of the adult insect. This is very similar to how a child looks like his or her parents.

The correct statement that describes components of complete and incomplete metamorphosis is: d. Incomplete and complete metamorphosis both have three major stages.

Metamorphosis is a biological process that some animals undergo to transform from one developmental stage to another, typically from a juvenile form to an adult form. This process involves a series of physical and physiological changes that can be dramatic and even complete.

Incomplete metamorphosis consists of three stages: egg, nymph, and adult. The nymph hatches from the egg and looks similar to the adult but lacks wings and reproductive organs. The nymph molts its exoskeleton several times and gradually develops into an adult.

Complete metamorphosis also consists of three stages: egg, larva, pupa, and adult. The larva hatches from the egg and looks completely different from the adult, often worm-like in appearance. The larva undergoes a series of molts and grows larger, then forms a pupa or chrysalis. Inside the pupa or chrysalis, the larva undergoes a complete transformation and emerges as an adult.

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Answer:

23.6 moles

Explanation:

From the question given above, the following data were obtained:

Mass of air = 3.6 Kg

Mass percentage of O₂ = 21%

Number of mole of O₂ =?

Next, we shall convert 3.6 Kg of air to grams (g). This can be obtained as follow:

1 kg = 1000 g

Therefore,

3.6 Kg = 3.6 Kg × 1000 / 1 kg

3.6 Kg = 3600 g

Next, we shall determine the mass of O₂ in the air. This can be obtained as follow:

Mass of air = 3600 g

Mass percentage of O₂ = 21%

Mass of O₂ =?

Mass of O₂ = 21% × 3600

Mass of O₂ = 21/100 × 3600

Mass of O₂ = 756 g

Finally, we shall determine the number of mole of O₂ in the sample of air. This can be obtained as follow:

Mass of O₂ = 756 g

Molar mass of O₂ = 2 × 16 = 32 g/mol

Number of mole of O₂ =?

Mole = mass /Molar mass

Number of mole of O₂ = 756 / 32

Number of mole of O₂ = 23.6 moles

Thus, the number of mole of O₂ in the

sample of air is 23.6 moles

Answer:

0.156 M

Explanation:

The neutralization reaction between hydrobromic acid (HBr) and sodium hydroxide (NaOH) is the following:

HBr(ac) + NaOH(aq) → NaBr(aq) + H₂O(l)

As we can see, 1 mol of HBr reacts with 1 mol NaOH. During a titration, at the equivalence point, the number of moles of NaOH added reacts completely with the number of moles of HBr:

moles of NaOH = moles of HBr

The moles of each reactant is calculated as the product of the molarity (M) and the volume (V):

M(NaOH) x V(NaOH) = M(HBr) x V(HBr)

We have the following data:

base: V(NaOH) = 13.5 mL

acid: M(HBr) = 0.104 M;  V(HBr) = 20.2 mL

Thus, we calculate M(NaOH) from the equivalent point equation:

M(NaOH) = (M(HBr) x V(HBr))/(V(NaOH) = (0.104 M x 20.2 mL)/(13.5 mL) = 0.1556 M ≅ 0.156 M

Answer:

Conduction  

Conduction moves heat through direct sub-atomic crash. A region of more prominent dynamic energy will move nuclear power to a region with lower active energy. Higher-speed particles will crash into more slow speed particles. The more slow speed particles will increment in motor energy subsequently. Conduction is the most widely recognized type of warmth move and happens through actual contact. Models is place your hand against a window or spot metal into an open fire.  

The interaction of warmth conduction relies upon the accompanying components: temperature slope, cross-segment of the material, length of the movement was, and actual material properties. The temperature inclination is the actual amount that portrays the bearing and pace of warmth travel. Temperature stream will consistently happen from most sultry to coldest or, as expressed previously, higher to bring down active energy. Once there's warm harmony between the two temperature contrasts, the warm exchange stops.

Convection  

At the point when a liquid, like air or a fluid, is warmed and afterward ventures from the source, it conveys the nuclear power along. This sort of warmth move is called convection. The liquid over a hot surface grows, turns out to be less thick, and rises.

Radiation

Thermal radiation generates from the emission of electromagnetic waves. These waves carry the energy away from the emitting object. Radiation occurs through a vacuum or any transparent medium (either solid or fluid). Thermal radiation is the direct result of random movements of atoms and molecules in matter. Movement of the charged protons and electrons results in the emission of electromagnetic radiation.

Answer:

119 g.

Explanation:

Answer: The formic acid is 3.5 times stronger than acetic acid.

Explanation:

The strength of an acid depends on its acid dissociation constant.

For a hypothetical monoprotic acid HA, the dissociation equilibrium is:

[tex]HA\rightleftharpoons H^++A^-[/tex]

[tex]K_a=\frac{[H^+][A^-]}{[HA]}[/tex]

More is the value of [tex]K_a[/tex] , greater is the dissociation and stronger is the acid.

[tex]\frac{Strength_{\text {formic acid}}}{Strength_{\text {acetic acid}}}=\sqrt{\frac{2.14\times 10^{-4}}{1.81\times 10^{-5}}}=3.5[/tex]

Thus formic acid is 3.5 times stronger than acetic acid.

Answer:

table A

Explanation:

its table A because it requires less force push. the less force used the less friction there is.

the less friction there is the more smooth a surface is.

Answer:

The limiting reagent is the reactant that is used up completely. This stops the reaction and no further products are made. ... The limiting reagent can also be derived by comparing the amount of products that can be formed from each reactant.

Answer:

The limiting reagent is the reactant that is used up completely. This stops the reaction and no further products are made. ... The limiting reagent can also be derived by comparing the amount of products that can be formed from each reactant.

Explanation:

Disclaimer not my answer I looked it up

Answer:

Volume = 19.68 ml

Explanation:

The equation of the reaction is given as;

HNO3 + KOH ---> KNO3 + H2O

1 mol of HNO3 reacts 1 mol of KOH

Converting 0.276 g of KOH to mol;

Number of moles = Mass / Molar mass

Number of moles = 0.276g / 56.1056 g/mol

Number of moles = 0.00492

Since the mole relationship is 1 = 1;

This means 0.00492 mol of HNO3 reacts with 0.00492 mol of KOH

The relationship between molarity and volume id given as;

Molarity = Number of moles / Volume

Volume = Number of moles / Molarity = 0.00492 mol / 0.250 M

Volume = 0.01968 L

Volume = 19.68 ml

Answer: 90.04°C

Explanation: Calorimeter is a device measures the amount of heat of a chemical or physical process. An ideal calorimeter is one that is well-insulated, i.e., prevent the transfer  of heat between the calorimeter and its surroundings. So, the net heat change inside the calorimeter is zero:

[tex]q_{1}+q_{2}=0[/tex]

Rearraging, it can be written as

[tex]q_{1}=-q_{2}[/tex]

showing that the heat gained by Substance 1 is equal to the energy lost by Substance 2.

In our case, water is gaining heat, because its temperature has risen and so, brass is losing energy:

[tex]q_{water}=-q_{brass}[/tex]

Calculating:

[tex]m_{w}.c_{w}.\Delta T=-[m_{b}.c_{b}.\Delta T][/tex]

[tex]100.4.18.(18.4-15)=-[52.9.0.375.(18.4-T)][/tex]

Note: final temperature is the same as the substances are in thermal equilibrium.

Solving:

418(3.4)= - 365.01 + 19.8375T

19.8375T = 1786.21

T = 90.04

The initial temperature for the sample of brass was 90.04°.

Answer:

665.22

Explanation:

you see wich numbers after the decimal points have the least numbers, the one with the least u have to round your answer to that

After performing the required mathematical operation (addition), the answer is equal to 665.22.

In Mathematics, significant figures can be defined as the number of single digits or numerical values in the coefficient of a mathematical expression that are important and meaningful.

Since "653.12" has two (2) significant figures, we must ensure that 12.10247 also has two (2) significant figures as follows:

12.10247 to 2 S.F = 12.10.

Next, we would perform the required mathematical operation (addition):

653.12 + 12.10 = 665.22.

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Answer:

a) Xac = 0.39

b) Xac = 0.58

c) There would be a difference in the two values of the equilibrium conversion because in constant pressure condition it would take longer time to reach the same conversion rate ( higher conversion equilibrium ) and this because the volume increase with the reaction at constant pressure

Explanation:

From elementary gas phase reaction

Cao = Po / RT

Po = 10

R = 82.06

T = 400 K

Cao = 3.05 * 10^-4  mol/cm^3 ≈ 0.305 mol/dm^3

Kc = 0.25 (mol/dm^3 )^2

Calculate the equilibrium conversion for each of the following situations

a) The gas-phase reaction is carried out in a constant-volume batch reactor

Xac = 0.39

b) The gas-phase reaction is carried out in a constant-pressure batch reactor

Xac = 0.58

c) There would be a difference in the two values of the equilibrium conversion because in constant pressure condition it would take longer time to reach the same conversion rate ( higher conversion equilibrium ) and this because the volume increase with the reaction at constant pressure

Attached below is a detailed solution as regards the question above

Answer:

1

Explanation seems right

The magma and sediments formed in the great plains are came from the rocks of the rocky mountains. Therefore, claim 1 is correct.

Sedimentation is the geographical process of accumulation or deposition of the minerals and organic particles from the earth's surface is called sedimentation. This process results in the formation of sedimentary rocks.

Weathering or erosion of rocks by wind, water or other chemicals leads to the geological debris which then move to other places  deposits somewhere.

Rocks in the rocky mountains undergo erosion and the mass movements created by wind or water leads to the sedimentation of these rocky solids to other places. The rocks in the Great planes are reached there by the mass movement of the rocks of rocky mountains. Hence, claim 1 is correct.

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Answer:

ΔS°reaction = 100.9 J K⁻¹ (mol C₃H₈)⁻¹

Explanation:

The equation for the reaction is given as;

C₃H₈(g) + 5O₂(g) → 4H₂O(g) + 3CO₂(g)

In order to determine the entropy change, we have to use the entropy valuues for the species in the reaction. This is given as;

S°[C₃H₈(g)] = 269.9 J K⁻¹ mol⁻¹

S°[O₂(g)] = 205.1 J K⁻¹ mol⁻¹

S°[H₂O(g)] = 188.8 J K⁻¹ mol⁻¹

S°[CO₂(g)] = 213.7 J K⁻¹ mol⁻¹

The unit of entropy is J K⁻¹ mol⁻¹

Entropy change for the reaction is given as;

ΔS°reaction = ΔS°product - ΔS°reactant

ΔS°reaction = [(4 * 188.8) + (3 * 213.7)] - [269.9 + (5 * 205.1)]

ΔS°reaction = 100.9 J K⁻¹ (mol C₃H₈)⁻¹

The entropy change for the combustion of gaseous propane, under standard state conditions  100.9 J K⁻¹.

The equation for the combustion of gaseous propane is given as follows:-

C₃H₈(g) + 5O₂(g) → 4H₂O(g) + 3CO₂(g)

In order to determine the entropy change, we have to use the entropy values for the species in the reaction. This is as follows:-

S°[C₃H₈(g)] = 269.9 J K⁻¹ mol⁻¹

S°[O₂(g)] = 205.1 J K⁻¹ mol⁻¹

S°[H₂O(g)] = 188.8 J K⁻¹ mol⁻¹

S°[CO₂(g)] = 213.7 J K⁻¹ mol⁻¹

The unit of entropy is J K⁻¹ mol⁻¹

Entropy change for the reaction is given as;

ΔS°reaction =nproduct ΔS°product - nreactantΔS°reactant

ΔS°reaction = [(4mol * 188.8 J K⁻¹ mol⁻¹) + (3 mol * 213.7 J K⁻¹ mol⁻¹)] - [(1 mol*269.9J K⁻¹ mol⁻¹ )+ (5 mol* 205.1  J K⁻¹ mol⁻¹)]

ΔS°reaction = 100.9 J K⁻¹

So, the entropy change for the combustion of gaseous propane is 100.9 J K⁻¹ .

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Answer:

Ca, Zn, Ni, Al, Fe

Explanation:

The activity series is an arrangement of metals in order of decreasing reactivity.

Metals that are high up in the activity series are very reactive. They displace metals that are lower in the activity series from an aqueous solution of their salts.

The metals; Ca, Zn, Ni, Al, Fe are all above Pb in the activity series hence they will cause Pb2+ ions to come out of solution as solid Pb.

A more reactive metal displaces the less reactive metals in the solution.  Ca, Al, Zn, and Fe can be accomplished to take out the [tex]\bold{ Pb^2^+}[/tex] from the solution as solid Pb.

Metal displacement Reaction:

In this type of reaction a more reactive metal displaces the less reactive metals in the solution.

The metal reactivity series

Ca > Al > Zn > Fe > Ni > Pb > Ag > Au

The lead ( Pb) is less reactive than the Ca, Al, Zn, and Fe.

Therefore,  Ca, Al, Zn, and Fe can be accomplished to take out the [tex]\bold{ Pb^2^+}[/tex] from the solution as solid Pb.

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Answer:

depends on what molecule you are looking for

Explanation:

In one mole of stuff (atoms, molecules, eggses), there are NA individual items of that stuff. So, there are 4.5 × NA BCl3 molecules; i.e. 4.5 × 6.022×1023 ≅ 27×1023 individual molecules of BCl3

Answer:

See explanation and image attached

Explanation:

The mechanism for both the hydroboration of 2-methyl-1-pentene and acid-catalyzed hydration are shown i the image attached to this answer.

The both processes involve addition reaction. Hydroboration  is similar to hydration but the orientation of addition is anti - Markovnikov in nature.

The acid-catalyzed hydration of  2-methyl-1-pentene yields a minor product and a major product. The major product is  an accordance with Markovnikov  rule as shown by the reaction mechanism. The minor product is anti - Markovnikov.

Answer:

B, C, D, E

Explanation:

According to Henry's law, as the pressure is increased, the solubility of a given gas increases. So, solubility is directly proportional to pressure.

Thus, the following statements are correct:

B. More gas molecules are soluble as pressure is increased.

Is correct because as the pressure is increased, the solubility increases.

C. The solubility of a gas decreases with a decrease in pressure.

Is correct because solubility and pressure are directly proportional: if the pressure is decreased, the solubility will be decreased.

D. The solubility of nitrogen gas at 2.00 atm is twice the solubility of the gas at 1.00 atm.

Is correct because 2.00 atm is twice 1.00 atm, so if the pressure is increased twice, the solubility is increased twice.

E. The concentration of gas particles in the solution is higher at 4.25 atm than at 1.00 atm.

Is correct because 4.25 atm>1.00 atm (the higher the pressure, the higher the solubility, and therefore the concentration of gas particles in solution).

The remaining options (A, G) are incorrect. They contradict Henry's law.

Answer:

A-B) 94 %.

C) 17.9 %.

D) 35.8 %.

Explanation:

Hello!

A-B) In this case, since the total mass of the mixture is 3.02 g and 1.43g+1.41g=2.84 g are recovered in total, we can compute the percent recovery as shown below:

[tex]\%rec=\frac{2.84g}{3.02g}*100\%\\\\\%rec=94\%[/tex]

C) Here, since the solution is made up of NaCl and water, we can say that the mass of the solution is 15g+69g=84g; thus, the percent by mass would be:

[tex]\%=\frac{15g}{84g}*100\%\\\\\%=17.9\%[/tex]

D) In this case, we simply divide 26.1 g by 73.0 g in order to obtain the percent:

[tex]\%=\frac{26.1g}{73.0g}*100\%\\\\\%=35.8\%[/tex]

Best regards!

The percentage in the cases are as follows;

Questions A and B are similar and can be solved as follows;

Question C can be solved as follows;

Question D can be solved as follows;

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Answer:

Turning off the water while brushing teeth, watching shower time.

Explanation:

Answer:

Take shorter showers.

Install water-saving shower heads or flow restrictors.

Turn off the water while brushing your teeth.

Turn off the water while shaving.

Explanation:

have a nice day

This question is incomplete, the complete question is;

The enthalpy change for the reaction between two molecules of carbon oxysulfide (COS) to form one molecule of CO₂ and one molecule of CS₂, as shown below, is -3.2 x 10⁻²⁴ kJ per molecule of COS.

The bond energy for the C-S bond in C=S has been determined to be 552 kJ/mol.

What is the apparent bond energy of a carbon-sulfur bond in COS?

NOTE: A C=O bond adjacent to another double bond is not the same as a C=O bond that is not adjacent to another double bond.  

Answer:

The apparent bond energy of a carbon–sulfur bond is 550.1 kJ/mole

Explanation:

Given the data in the question and the figure 8.122 in the image below;

the given reaction can be written as follows;

2COS -----→ CO₂ + CS₂

Δ[tex]H_{rxn}[/tex] = ∑ Bond Energy ( reactants) - ∑ Bond Energy (products)

= [ (2 × C=O) + (2 × C=S) ] - [ (2 × C=O) + ( 2 × C=S) ]

we know that;

Δ[tex]H_{rxn}[/tex]  = -3.2 x 10⁻²⁴ kJ per molecule

= -3.2 x 10⁻²⁴ kJ × 2 × 6.023 × 10²³ kJ/mole

= -3.85 kJ/mole

Hence;

-3.85 kJ/mole = (2 × C=S)[tex]_{reactant}[/tex] - ( 2 × C=S)[tex]_{product}[/tex]

-3.85 kJ/mole = (2 × C=S)[tex]_{reactant}[/tex] - ( 2 × 552 kJ/mole)

(2 × C=S)[tex]_{reactant}[/tex] = -3.85 kJ/mole + 1104 kJ /mole

(2 × C=S)[tex]_{reactant}[/tex]  = 1100.15 kJ/mole

2 × ( C=S)[tex]_{reactant}[/tex] = 1100.15 kJ/mole

( C=S)[tex]_{reactant}[/tex] = 1100.15 kJ/mole / 2

( C=S)[tex]_{reactant}[/tex] = 550.1 kJ/mole

Therefore, the apparent bond energy of a carbon–sulfur bond is 550.1 kJ/mole

The apparent bond energy of a carbon-sulfur bond in COS is equal to 550.08 kJ/mol.

Given the following data:

Scientific data:

To determine the apparent bond energy of a carbon-sulfur bond in COS:

First of all, we would write a balanced chemical equation for the chemical reaction as follows:

                                   [tex]2COS \rightarrow CO_2 + CS_2[/tex]

The enthalpy change of two (2) moles of COS is:

[tex]\Delta H_{rxn} = -3.2 \times 10^{-24}\times 2 \times 6.02 \times 10^{23}\\\\\Delta H_{rxn} =-3.85\;kJ/mol.[/tex]

Mathematically, the enthalpy change of a chemical reaction is given by this equation:

[tex]\Delta H_{rxn} = \sum Bond\;Energy_{(reactansts)} - \sum Bond\;Energy_{(products)}\\\\\Delta H_{rxn} = [(2\times C=O)+ (2\times C=S)]- [(2\times C=O)+ (2\times C=S)][/tex]

Substituting the parameters into the equation, we have;

[tex]-3.85 = (2\times C=S)- [2\times 552]\\\\(2\times C=S)=1104-3.85\\\\(2\times C=S)=1100.15\\\\(C=S)=\frac{1100.15}{2} \\\\(C=S)=550.08\;kJ/mol[/tex]

Therefore, the apparent bond energy of a carbon-sulfur bond in COS is equal to 550.08 kJ/mol.

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Complete Question:

The enthalpy change for the reaction between two molecules of carbon oxysulfide (COS) to form one molecule of [tex]CO_2[/tex] and one molecule of [tex]CS_2[/tex], as shown below, is [tex]-3.2 \times 10^{-24}[/tex] kJ per molecule of COS.  The bond energy for the C-S bond in C=S has been determined to be 552 kJ/mol. What is the apparent bond energy of a carbon-sulfur bond in COS?

[Note: A C=O bond adjacent to another double bond is not the same as a C=O bond that is not adjacent to another double bond.]

Answer:

Future tense.

Explanation:

The different tenses in grammar are used to denote the time or condition of when the action occurs. This means that tenses tell us the form or condition of the verbs.

The present tense tells us about a present scene while the past tense tells us about an action that happened in the past. Likewise, the future tense tells us about an event that will happen in the future. This means that future tenses are used to describe events that have not taken place, and are yet to happen.

Answer:

20 atoms

Explanation:

n=3

H =12

p=1

O=4

3+12+1+4=20

Answer:

ex.1

1.The water in the test tube expands as it is heated. There is only one direction to expand in, the glass tube. This glass tube is narrow so that a small change in volume will result in a considerable change in height; your signal is amplified. This is the same phenomenon as in thermometers with a glass bulb on the lower end.

2. there will be a thermal expansion will happened.

Answer:

240 g/mol

Explanation:

We'll begin by writing the chemical formula of Disodium sulfide nonahydrate. This is illustrated below:

The molecular formula of disodium sulfide nonahydrate is Na₂S.9H₂O

Finally, we shall determine the molar mass of disodium sulfide nonahydrate, Na₂S.9H₂O. This can be obtained by adding the individual molar mass of the element present in the compound as illustrated below:

Molar mass of Na₂S.9H₂O = (23×2) + 32 + 9[(2×1) + 16]

= 46 + 32 + 9[2 + 16]

= 46 + 32 + 9[18]

= 46 + 32 + 162

= 240 g/mol

Thus, the molar mass of disodium sulfide nonahydrate, Na₂S.9H₂O is 240 g/mol

Answer:

Forgive me if im wrong but i am pretty sure the answer is C

Explanation: