All --- is a good conductor of heat​

Answer:

[tex]n=6\ to\ n=3[/tex]

Explanation:

From the question we are told that:

Wavelength [tex]\lambda=274 *10^{-9}m[/tex]

Bohr's constant [tex]R = 1.097 × 10^7 / m (or m−1)[/tex]

Helium atom [tex]z=2[/tex]

Generally the equation for Wavelength is mathematically given by

 [tex]\frac{1}{\lambda}=Rz^2(\frac{1}{nf^2}-\frac{1}{nf^2})[/tex]

 [tex]0.083=(\frac{1}{nf^2}-\frac{1}{nf^2})[/tex]

Therefore

The Range of n fall at

 [tex]n=6\ to\ n=3[/tex]

Explanation:

In the formula of [tex]CaCl_2[/tex] we can see that there are 2mol Cl in 1 molecule of CaCl2. So, now we can do some math to find out how many mol of Cl there are in 1.9mol CaCl2!

[tex]1.9molCaCl_2*\frac{2molCl}{1molCaCl_2}[/tex]

So, there are 3.8mol Cl

Answer: Moles of hydrogen required are 4.57 moles to make 146.6 grams of methane, [tex]CH_{4}[/tex].

Explanation:

Given: Mass of methane = 146.6 g

As moles is the mass of a substance divided by its molar mass. So, moles of methane (molar mass = 16.04 g/mol) are calculated as follows.

[tex]Moles = \frac{mass}{molar mass}\\= \frac{146.6 g}{16.04 g/mol}\\= 9.14 mol[/tex]

The given reaction equation is as follows.

[tex]C + 2H_{2} \rightarrow CH_{4}[/tex]

This shows that 2 moles of hydrogen gives 1 mole of methane. Hence, moles of hydrogen required to form 9.14 moles of methane is as follows.

[tex]Moles of H_{2} = \frac{9.14}{2}\\= 4.57 mol[/tex]

Thus, we can conclude that moles of hydrogen required are 4.57 moles to make 146.6 grams of methane, [tex]CH_{4}[/tex].

The question is incomplete, the complete question is;

What functional group results when cyclopentanone reacts with ethylamine in the presence of trace acid? A) cyanohydrin B) semicarbazone C) imine D) enamine E) oxime

Answer:

imine

Explanation:

An imine is an unsaturated amine. An imine contains the carbon- nitrogen double bond.

Imines are obtained when a carbonyl compound is condensed with NH3 or an amine. The reaction involves several steps in its mechanism.

Since cyclopentanone is a ketone (carbonyl compound) and ethylamine is an amine,in the presence of trace acid, condensation of the two compounds occur to yield an imine

Answer:

n = 2.23 moles

Explanation:

Given the following data;

Standard temperature = 273 K

Standard pressure = 101.325 kPa

Volume = 50 liter

R = 8.314 J/mol·K  

To find the number of moles, we would use the ideal gas law formula;

PV = nRT

Where;

Making n the subject of formula, we have;

[tex] n = \frac {PV}{RT} [/tex]

Substituting into the formula, we have;

[tex] n = \frac {101.325*50}{8.314*273} [/tex]

[tex] n = \frac {5066.25}{2269.722} [/tex]

n = 2.23 moles

Therefore, 2.23 moles of carbon dioxide at STP will fit in a 50 liter container.

Answer:

the result for the following are (a) P is directly proportional to n

(b) V is directly proportional to T (c) P is directly proportional to T (d) T is inversly proportional to V (e) P is inversely proportional to V

Answer:

so 0.15 moles X 22.4 dm3/mole=3.36 dm3. Next we find the moles of hexane combusted, and then the moles of CO2. Finally, we find the volume of CO2 using the fact that at STP, 1 mole of gas = 22.4 dm3.

The formula that we can use to calculate energy released when a mass of liquid freezes is Grams liquid x mol/g x delta Hfusion.

Stoichiometry deals with the relationship between mass and moles or volume which can be used to make calculations involving chemical reactions. Most chemical calculations involving stoichiometry use the mole concept.

Hence, the formula used to obtain the energy released when a mass of liquid freezes is Grams liquid x mol/g x delta Hfusion.

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Answer:

none All have the same kinetic energy

Explanation:

Answer: The product of the given reaction is [tex]HNO_{3}[/tex] and the solution at equilibrium will be acidic.

Explanation:

When two or more chemical substances react together then it forms new substances and these new substances are called products.

For example, [tex]3N_{2}O_{5} + 3H_{2}O \rightarrow 6HNO_{3}[/tex]

This shows that nitric acid [tex](HNO_{3})[/tex] is the product formed and it is an acidic substance.

Hence, the solution at equilibrium will be acidic in nature.

Thus, we can conclude that the product of the given reaction is [tex]HNO_{3}[/tex] and the solution at equilibrium will be acidic.

Answer:

Tin + silver trioxonitrate V -------->Tin IV nitrate + silver

Explanation:

The term word equation refers to an equation in which the reactants and products are written in words rather than chemical symbols.

Note than tin is above silver in the electrochemical series hence silver will be displaced by tin as follows;

Tin + silver trioxonitrate V -------->Tin IV nitrate + silver

Answer:

0.465

Explanation:

To find the volume of a substance, divide the mass by the density.

M/D = V

10.0 / 21.5 = 0.4651163

Then round to 3 significant figures: and the density is 0.465

Answer:2-chloro-1,3-dimethylcyclopentane

Explanation

Answer:

No mass of HCl could be left over by the chemical reaction because is the limting reactant and it is all consumed.

Explanation:

Our reactants are: HCl and NaOH

Products are: NaCl and H₂O

This is a neutralization reaction that can also be called an acid base reaction, an acid and a base react to produce water and a neutral salt, in this case where we have strong acid and base.

Ratio is 1:1. We convert mass to moles:

35 g . 1 mol / 36.45 g = 0.960 moles of HCl

73 g . 1 mol / 40 g = 1.82 moles of NaOH

As ratio is 1:1, for 0.960 moles of HCl we need 0.960 moles of NaOH and for 1.82 moles of NaOH, we need 1.82 moles of acid.

As we only have 0.960 moles of HCl and we need 1.82 moles, no acid remains after the reaction goes complete. HCl is the limiting reactant, so the acid, it is all consumed.

Answer:

The entropy change of carbon dioxide = 0.719 kJ/k

Explanation:

Given:

1.5 m - 3 insulated rigid tank contains 2.7 kg of carbon dioxide at 100 kPa

The objective is to determine the entropy change of carbon dioxide

Formula used:

ΔS=

Solution:

On considering,

[tex]C_{P} =0.846 kJ/kg K\\C_V=0.657 kJ/kg k\\[/tex]

ΔS=[tex]mc_{v} lu\frac{p_{2} }{P_{1} }[/tex]

On substituting the values,

ΔS=[tex]2.7*0.657lu\frac{150}{100}[/tex]

ΔS=0.719 kJ/k

The entropy change is "0.719 kJ/K".

Given values are:

Mass of tank,

Pressure,

Rised pressure,

Assumption of constant specific heat is,

As we know the formula,

→ [tex]\Delta S = mC_v \ ln(\frac{P_2}{P_1} )[/tex]

         [tex]= (2.7)(0.657) \ ln (\frac{150}{100} )[/tex]

         [tex]= 1.7739\times 0.4055[/tex]

         [tex]= 0.7193 \ kJ/K[/tex]

Thus above answer is right.

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Answer:

The best existing methods of control—artemisinin-based drug treatment and insect control with chemical sprays and treated bednets—can reduce the burden of disease substantially, and can even eliminate the disease in some regions,

hope this will help you more

The question is incomplete, the complete question is;

It takes 412. KJ/mol to break a carbon-hydrogen single bond. Calculate the maximum wavelength of light for which a carbon-hydrogen single bond could be broken by absorbing a single photon. Round your answer to significant digits.

Answer:

289 nm

Explanation:

The energy of the photon = 412 × 10^3/6.02 × 10^23 = 6.84 × 10^-19 J

From;

E = hc/λ

h= Plank's constant

c= speed of light

λ = wavelength

λ = hc/E

λ = 6.6 × 10^-34 × 3 × 10^8/6.84 × 10^-19

λ = 2.89 × 10^-7 m

λ = 289 nm

Answer:

heat rate= 1281W

length = 15.8m

Explanation:

we have this data to answer this question with

Tmi = 85 degrees

Tmo = 35 degrees

Ts = 25 dgrees

flow rate = 25 degrees

using engine oil property from table a-5

Tm = Tmo - TMi/2 = 333k

u =0.522x10⁻²

k = 0.26

pr = 51.3

cp = 2562 J/kg.k

mcp(Tmo-Tmi) =

0.01 x 2562(35-85)

= 1281 W

we find the change in Tim

= [(35-25)-(85-25)]/ln[(35-25)/(85-25)]

= -50/ln0.167

= -50/-1.78976

= 27.9°c

we finf the required reynold number

4x0.01/πx0.003x0.522x10⁻²

= 0.04/0.00004921

= 812.8

= 813

we find approximate correlation

NuD = hd/k

NuD = 3.66

3.66 = 0.003D/0.26

cross multiply

0.003D = 3.66x0.26

D = 3.66x0.26/0.003

= 317.2

As = 1281/317x27.9

= 0.145

As = πDL

L = As/πD

= 0.145/π0.003

= 0.145/0.009429

L = 15.378

Answer:look down below

Explanation:

The statements that are true about hands that are immersed in the water are:

1. The hand that was in hot water would feel cold.

2. The hand that was in cold water would feel hot.

The correct option is B 1. and 2.

Temperature is the measurement of the hotness or coldness of any object. It is measured in Celsius or kelvin. Our body has nerves that feel the different temperatures of any object. The high temperature is called hot and the low temperature is called cold.

When Louis put his hand in the warm water and one hand in the cold water. He feels the temperature of both glasses of water. Then he put both hands in the normal water.

So the hand that is warm would feel the water as cold and the hand with cold water would feel the water as hot.

Thus, the correct option is B. 1. and 2.

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Answer:

Theoretical yield is 138.4 g

Explanation:

In the first step we determine the reaction:

3Mg + N₂ → Mg₃N₂

Mass of reactant is 100 g. We assume the nitrogen is in excess, so we work with Mg. We convert mass to moles:

100 g . 1mol/ 24.3g = 4.11 moles of Mg.

Ratio is 3:1. 3 moles of Mg can produce 1 mol of nitride

Our 4.11 moles, may produce (4.11 . 1)/3 = 1.37 moles of Mg₃N₂

We convert mass to moles, to find the theoretical yield:

1.37 mol . 100.9 g/mol = 138.2 g

This question is incomplete, the complete question is;

A certain liquid X has a normal boiling point of 150.4 °C and a molar boiling point elevation constant kb is 0.60 °Ckgmol⁻¹.

A solution is prepared by dissolving some urea (NH22CO) in 750 g of X. This solution boils at 150.9 °C . Calculate the mass of urea that was dissolved. Round your answer to 3 significant digits.

Answer:

the mass of urea that was dissolved is 37.5 g

Explanation:

Given the data in the question;

normal boiling point of X; Tb⁰ = 150.4 °C

boiling point of solution Tb = 150.9 °C

Change in boiling point Δt = Tb - Tb⁰  = 150.9 °C - 150.4 °C = 0.5 °C

Kb = 0.6 °C.kg.mol⁻¹

V = 750 g

Now, we know that

Δt = Kb × molality

so

0.5 = 0.6 × molality

molality = 0.5 / 0.6

molality = 0.833

we know that molar mass of urea is 60 g/mol

so

molality = mass × 1000 / molar mass × volume( g )

we substitute

0.833 = ( mass × 1000 ) / ( 60 × 750 )

0.833 = ( mass × 1000 ) / 45000

0.833 × 45000 = mass × 1000

mass = ( 0.833 × 45000 ) / 1000

mass = 37485 / 1000

mass = 37.485 ≈ 37.5 g   { 3 significance figure }

Therefore, the mass of urea that was dissolved is 37.5 g

Answer:

15 mL of the solute

Explanation:

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

Solution = 50 mL

Solvent = 35 mL

Solute =?

Solution is simply defined as:

Solution = solute + solvent

With the above formula, we can easily obtain the solute in the solution as follow:

Solution = 50 mL

Solvent = 35 mL

Solute =?

Solution = solute + solvent.

50 = solute + 35

Collect like terms

50 – 35 = solute

15 = solute

Solute = 15 mL

Therefore, 15 mL of the solute is required.

Answer:

[tex]_{19} ^{40} K[/tex] → [tex]_{20} ^{40} Ca[/tex] + [tex]_{-1} ^{0} e[/tex] + ¯v

Explanation:

[tex]_{19} ^{40} K[/tex] is an unstable potassium isotope which has the capacity to undergo beta decay. During the decay process, it transforms to calcium atom with a release of beta particle and an antineutrino.

The required nuclear equation is:

                                              [tex]_{19} ^{40} K[/tex] → [tex]_{20} ^{40} Ca[/tex] + [tex]_{-1} ^{0} e[/tex] + ¯v

The calcium formed due to this process is a stable atom.

Explanation:

Saturated fats are defined as the fat where fatty acid chains contain only single bonds.

For example, stearic acid, palmitic acid etc.

Unsaturated fats are defined as the fat where fatty acids contain one or more number of double bonds on the carbon atoms.

For example, oleic acid, palmitoleic acid etc.

Answer:

Substrate

Explanation:

In biochemical sciences, a substrate is a substance that is acted upon by an enzyme to yield a product. Enzymes are known for catalyzing biochemical reactions. The substances that are usually worked with during this catalytic process are termed as SUBSTRATES.

Substrates, which are usually changed during the process, binds to the active site on the enzyme and form an enzyme-substrate complex.

According to this question, pyruvate is converted to lactate in a reaction that is catalyzed by the enzyme lactate dehydrogenase. This means that the compound on which the enzyme works, pyruvate, is called the SUBSTRATE.

Answer:

all electrons of the atom

Answer:

80.8%

Explanation:

Let's consider the following balanced equation.

4 Al(s) + 3 O₂(g) → 2 Al₂O₃(s)

The mass obtained of Al₂O₃ (experimental yield) is 84.0 g. The theoretical yield of Al₂O₃ is 104 g. We can calculate the percent yield of Al₂O₃ using the following expression.

%yield = (experimental yield / theoretical yield) × 100%

%yield = (84.0 g / 104 g) × 100% = 80.8%

Answer:

Percent Yield = 80.8%

Explanation:

We can find the percent yield of a reaction using the equation:

Percent yield = Actual yield (g) / Theoretical Yield (g) * 100

Where Actual yield is the amount of product produced (84.0g)

And theoretical yield is the mass produced assuming a 100% of product (104.0g)

Replacing the computed values:

Percent yield = 84.0g / 104.0g * 100

Percent Yield = 80.8%

Answer:

Fill in the blanks with each titration term with its definition.

a. Solution of an unknown concentration that has another solution slowly added to it ________________

b. Process of slowly adding a solution to react with another solution and determine the concentration of one of the solutions based on the reaction between them ______________

c. A reagent added to the analyte solution that changes color when the reaction is complete ______________

d. Glassware that allows a solution to be precisely and slowly added to another solution _____________

e. Solution of known concentration that is slowly added to a solution of unknown concentration ________________

f. When the required amount of one solution has been added to the second solution to complete the reaction ____________

Explanation:

a. Solution of an unknown concentration that has another solution slowly added to it is called analyte.

b. Process of slowly adding a solution to react with another solution and determine the concentration of one of the solutions based on the reaction between them is called titration.

c. A reagent added to the analyte solution that changes color when the reaction is complete is called an indicator.

d. Glassware that allows a solution to be precisely and slowly added to another solution is called a pipette.

e. Solution of known concentration that is slowly added to a solution of unknown concentration is called titrant.

f. When the required amount of one solution has been added to the second solution to complete the reaction is called neutralization.

Answer:

[tex]M_{a}[/tex] = 0.104 m

Explanation:

This expression is used to determine either the mass or volume of an acid or a base used during titration process.

So that;

[tex]M_{a}[/tex][tex]V_{a}[/tex] = [tex]M_{b}[/tex][tex]V_{b}[/tex]

[tex]M_{a}[/tex] is the mass of the acid

[tex]V_{a}[/tex] is the volume of the acid

[tex]M_{b}[/tex] is the mass of the base

[tex]V_{b}[/tex] is the volume of the base

Given that:

[tex]M_{a}[/tex] x 5.0 m l = 5.2 ml x 0.10 m

[tex]M_{a}[/tex] x 5.0 = 0.52 m

[tex]M_{a}[/tex] = [tex]\frac{0.52}{5.0}[/tex]

      = 0.104

[tex]M_{a}[/tex] = 0.104 m

The mass of the acid used is 0.104 m.