The data shows the number of years that 30 employees worked for an insurance company before retirement. is the population mean for the number of years worked, and % of the employees worked for the company for at least 10 years. (Round off your answers to the nearest integer.)

Answer: See explanation

Explanation:

The calibration curve is the method used for the determination of the concentration of a substance such that the unknown sample will be compared to some standard samples of the known concentration.

To prepare a standard (calibration) curve for a spectroscopy experiment, start by preparing (multiple solutions) with (different known concentrations). Then, measure the (absorbance) of each solution at (thesame wavelength) and create a plot of (absorbance vs. concentration) for the measured values. Finally, find the best-fit line of the data set.

Answer:

Problem Details

The element europium exists in nature as two isotopes:  151Eu has a mass of 150.9196 amu, and 153Eu has a mass of 152.9209 amu. The average atomic mass of europium is 151.96 amu. Calculate the relative abundance of the two europium isotopes.

answer:

151Eu = 48%, 153Eu = 52%

Answer:

65.5J

Explanation:

ML=Q

ML=MC(change in temperature)

0.75 X 23000 =0.75 X 351 X C

C= 65.5J

The energy supplied to the lead to melt from 21°c to its melting point is 51521 Joules.

Specific heat is the amount of heat energy supplied to change the temperature of one unit mass of a substance by 1 °C. The SI unit of the specific heat capacity of a substance is J/Kg.

The mathematical expression for the specific heat capacity can be written as:

Q = mCΔT      Where C is the specific heat of the substance.

The specific heat capacity depends upon the starting temperature and is an intensive characteristic of the material.

Given, the melting point of the lead T₂ = 327.5° C

The initial temperature of the lead, T₁ = 21° C

The latent heat of the lead given, L = 230000 J/Kg K

The specific heat of the lead, C = 130 J/Kg K

The heat required to melt the lead from 12°C to 327.5 °C is :

Q = m× [C × (T₂ - T₁) + L ]

Q = 0.75 × [0.130 (327.5 - 21)  + 23000]

Q = 51521 J

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Answer:

[tex]\boxed {\boxed {\sf 0.0769 \ M}}[/tex]

Explanation:

We are asked to find the molarity of an acid given the details of a titration experiment. The formula for titration is as follows:

[tex]M_AV_A= M_B V_B[/tex]

In this formula, M is the molarity of the acid or base and V is the volume of the acid or base. The molarity of the hydrochloric acid (HCl) is unknown and the volume is 25.0 milliliters.

[tex]M_A * 25.0 \ mL = M_BV_B[/tex]

The molarity of the sodium hydroxide (NaOH) is 0.108 molar and the volume is 17.80 milliliters.

[tex]M_A * 25.0 \ mL = 0.108 \ M * 17.80 \ mL[/tex]

We are solving for the molarity of the acid and we must isolate the variable [tex]M_A[/tex]. It is being multiplied by 25.0 milliliters. The inverse operation of multiplication is division, so we divide both sides of the equation by 25.0 mL.

[tex]\frac {M_A * 25.0 \ mL }{25.0 \ mL}= \frac{0.108 \ M * 17.80 \ mL }{25.0 \ mL}[/tex]

[tex]M_A= \frac{0.108 \ M * 17.80 \ mL }{25.0 \ mL}[/tex]

The units of milliliters cancel.

[tex]M_A= \frac{0.108 \ M * 17.80 }{25.0 }[/tex]

[tex]M_A= \frac{1.9224}{25.0 } \ M[/tex]

[tex]M_A= 0.076896 \ M[/tex]

The original measurements have 3 and 4 significant figures. We must round our answer to the least number of sig figs, which is 3. For the number we calculated, that is the ten-thousandth place. The 9 to the right of this place tells us to round the 8 up to a 9.

[tex]M_A \approx 0.0769 \ M[/tex]

The molarity of the hydrochloric acid is 0.0769 Molar.

Answer:

25.5mL of 0.100M NaOH are needed to reach buffer capacity.

Explanation:

The buffer capacity is reached when the ratio between moles of conjugate base (Sodium acetate) and moles of weak acid (Acetic acid) is 10:

Moles sodium acetate / Moles Acetic acid = 10

The reaction of acetic acid, HA, with NaOH, to produce sodium acetate, NaA is:

HA + NaOH → H2O + NaA

That means the moles of NaOH added = Moles of HA that are being subtracted and moles of NaA that are been produced.

The initial moles of each species is:

Acetic acid:

23.34mL = 0.02334L * (0.147mol / L) = 0.00343 moles Acetic Acid

Sodium Acetate:

33.66mL = 0.03366L * (0.185mol / L) = 0.00623 moles Sodium Acetate

We can write the moles of each species when NaOH is added as:

Moles sodium acetate / Moles Acetic acid = 10

0.00623 moles + X / 0.00343 moles - X = 10

Where X are moles of NaOH added

Solving for X:

0.00623 moles + X = 0.0343 moles - 10X

11X = 0.0281

X = 0.00255 moles of NaOH are needed

In Liters:

0.0255mol NaOH * (1L / 0.100mol) = 0.0255L of 0.100M NaOH are needed =

Answer:

CO2

Molar mass: 44.01 g/mol

Explanation:

CO2

Answer:

2,3 Dimethyl hexane

Explanation:

First, start the count from which side is given the CH3 smallest number

first; the longest carbon chain in this compound is 6

and you don't have any double and triple bonds or functional groups so it is Hexane

you start to count from the right side to give the branch molecules the smallest number ..

CH3 = methyl

and you have 2 methyl in this compound ..

and 2 mean you must write ( Di )

you write the name in this way

2,3 Dimethyl hexane

hope this helps you.

stay safe ...

Answer:

I think third C12/hv is right answer

Explanation:

Answer

Open in answr app

The initial temperature of the coffee T0=100∘C.

The temperature of the room 15∘C.

Let T be the temperature at time t in minutes.

By Newton's law of cooling,

dtdTα(T−15)

∴dtdT=k(T−15)

⇒T−15dT=kdt

⇒∫T−15dT=∫kdt

⇒log(T−15)=kt+logc

⇒log(cT−15)=kt

⇒T−15=cekt

At t=0,T=100

We have 100−15=ce0⇒85=c

Thus we get T−15=85ekt.

When t=5minutes,T=60

⇒60−15=85e5k.

⇒e

Answer:

% NiCl2 = 24.13%

% water = 78.57%

Explanation:

Mass percentage = mass of solute/mass of solution × 100

According to this question, a solution contains 159 g of NiCl2 in 500 g of water. Hence, mass of the solution is calculated as follows:

Mass of solution = 159g + 500g

Mass of solution = 659g

Therefore;

A) % Mass of NiCl2 in solution = mass of NiCl2/mass of solution × 100

% Mass of NiCl2 in solution = 159/659 × 100

% Mass of NiCl2 in solution = 0.2413 × 100

= 24.13%

B) % Mass of water in solution = mass of water/mass of solution × 100

% Mass of water in solution = 500/659 × 100

% Mass of water in solution = 0.7587 × 100

% Mass of water in solution = 75.87%

Answer:

80.8 g

Explanation:

First, let's write a balanced equation of this reaction

MgO + 2HNO₃ → Mg(NO₃)₂ + H₂O

Now let's convert grams to moles

We gotta find the weight of MgO

24 + 16 = 40 g/mol

12/40 = 0.3 moles of MgO

We can use this to find out how much Magnesium Nitrate will be formed

0.3 x 1 MgO / 1 Mg(NO₃)₂ = 0.3 moles of Magnesium Nitrate formed

Convert moles to grams

Find the weight of Mg(NO₃)₂ but don't forget that 2 subscript acts as a multiplier of whatever is inside that parenthesis.

24 + 14 x 2 + 16 x 3 x 2 = 148 g/mol

148 x 0.3 = 80.8 g

Answer:

Explanation:

H = 0.44/1.01 = 0.4356

O = 6.92/16 = 0.4319

This gives a 1:1 ratio. So the closest thing you could say is the formula is 0H

Going to your chemical storage room, you could justify that it is H2O2 or hydrogen peroxide. The question needs one more fact to make the answer certainty.

Answer:

I don't know sorry yyyyyyy6yyyyyyyyyyyyyyyyyyyyyyyyyyy

Answer:

1 ethanol is right answer

Explanation:

CH3- CH2-OH

C₆H₁₂O₆ is the molecular formula of gulcozo.

Answer:

a

...

........

...........

Answer: True no need for an explanation..

Preganglionic axons are myelinated; postganglionic axons are unmyelinated True

Answer:

A

Explanation:

The iron corrodes so it oxidized

The clumping of magnesium sulfate means that the wrong kind of drying agent have been used for the sample.

A drying agent is also referred to as a desiccant. It is a substance that is used to remove moisture from a sample. We must recall that the drying agent to be used must not react with the sample.

Since the magnesium sulfate was found to clump together at the bottom of the flask, it means that the wrong kind of drying agent have been used for the sample.

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Answer:

Top layer is Organic (CH2Cl2 and product)

Explanation:

In a solvent mixture, there are usually two phases, the organic phase and the aqueous phase.

It is usual that the organic phase is almost always less dense than the aqueous phase hence the organic phase tend to remain on top of the aqueous phase.

Hence, the top layer is expected to be the organic CH2Cl2 and product.

The nuclide represented as X is thorium and this is an alpha decay.

The equation shown represents an alpha decay. In an alpha decay, an alpha particle is given off.

The atomic number of the parent nuclide is greater than that of the daughter nuclide by two units while the mass number of the parent is greater than that of the daughter nuclide by four units.

Hence the equation occurs as follows;

[tex]\frac{232}{92} Th ------> \frac{228}{88} Ra + He[/tex]

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Answer:

The elements toward the bottom left corner of the periodic table are the metals that are the most active in the sense of being the most reactive.

The most highly reactive elements are typically found at the far left (Group 1) and far right (Group 17) of the periodic table.

Group 1 elements, also known as alkali metals, are located on the far left of the periodic table. They have one electron in their outermost energy level and are highly reactive due to their tendency to lose that electron to achieve a stable electron configuration. This makes them very reactive with water and other substances.

Group 17 elements, known as halogens, are located on the far right of the periodic table. They have seven electrons in their outermost energy level and are highly reactive due to their strong tendency to gain one electron to achieve a stable electron configuration. This makes them reactive with metals and other elements.

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The predominant consequence to an individual who is genetically deficient in liver fructose 1,6-bisphosphatase would be failure to resynthesize glucose from lactic acid.​

WHAT IS FRUCTOSE 1,6-BISPHOSPHATASE:

CONSEQUENCES OF DEFICIENCY OF FRUCTOSE 1,6-BISPHOSPHATASE:

Therefore, the predominant consequence to an individual who is genetically deficient in liver fructose 1,6-bisphosphatase would be failure to resynthesize glucose from lactic acid.​

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Answer:

Li^3+

Explanation:

The electronic configuration of lithium is ; 1s2 2s1. This means that lithium has one electron in its outermost shell and two core electrons.

We know that it is difficult to remove these core electrons during ionization. Lithium belongs to group 1 hence Li^+ is formed more easily.

It is very difficult to form Li^3+ because it involves loss of core electrons which requires a lot of energy.

Answer: Options related to your question is missing below are the missing options

a. cytochrome c is a one-electron acceptor, whereas QH2 is a two-electron donor.

b. cytochrome c is a two-electron acceptor, whereas QH2 is a one-electron donor.

c. cytochrome c is water soluble and operates between the inner and outer mitochondrial membranes

d. heart muscle has a high rate of oxidative metabolism, and therefore requires twice as much cytochrome c as QH2 for electron transfer to proceed normally.

e. two molecules of cytochrome c must first combine physically before they are catalytically active.

answer:

cytochrome c is a one-electron acceptor, whereas QH2 is a two-electron donor. ( A )

Explanation:

The overall stoichiometry of the reaction requires 2 mol of cytochrome per mole of QH2 because a cytochrome is simply a one-electron acceptor while QH2 is not a one-electron donor ( i.e. it is a two-electron donor )

An electron donor in a reaction is considered a reducing agent because it donates its electrons to another compound thereby self oxidizing itself in the process.

Answer:

-376 kJ

Explanation:

The first step equation:

[tex]\mathsf{N_{2(g)} + 3H_2{(g)} \to 2NH_3{(g)} \ \ \ \Delta H = -92\ kJ}[/tex]    ---- (1)

The second step equation:

[tex]\mathsf{NH_{3(g)} + 2O_2{(g)} \to HNO_3{(g)} +H_2O_{(g)} \ \ \ \Delta H = -330\ kJ}[/tex]      ---- (2)

To determine the enthalpy of formation for 1 mole of HNO₃ (nitric acid), we have the following.

From the above equations; let multiply equation (1) by 1 and equation (2) by 2.

[tex]\mathsf{N_{2(g)} + 3H_2{(g)} \to 2NH_3{(g)} \ \ \ \Delta H = -92\ kJ}[/tex]     ---- (3)

[tex]\mathsf{2NH_{3(g)} + 4O_2{(g)} \to 2HNO_3{(g)} +2H_2O_{(g)} \ \ \ \Delta H = 2(-330)\ kJ}[/tex]      ----- (4)

adding the above two equations, we have:

[tex]\mathsf{N_{2(g)} + 3H_2{(g)}+ 2NH_{3(g)} + 4O_{2(g)} \to 2HNO_{3(g)} + 2NH_3{(g)} +2H_2O_{(g)} \ \ \ \Delta H = (-660 \ kJ -92\ kJ)}[/tex][tex]\mathsf{N_{2(g)} + 3H_2{(g)} + 4O_{2(g)} \to 2HNO_{3(g)} +2H_2O_{(g)} \ \ \ \Delta H = (-752 \ kJ)}[/tex]

Now, from the recent equation, we have:

2 moles of nitric acid = -752 kJ

∴

1 mole of nitric acid will be: = (1 mole × (-752 kJ)) ÷ 2 moles

1 mole of nitric acid will be: = -376 kJ

Answer:

An atom is the smallest particle of an element that can take part in chemical reaction.

Explanation:

hope it will help u Amri

Answer:

Alphabet C :NADH is oxidized,CO2 is reduced

Answer:

4.54 atm

Explanation:

Step 1: Calculate the total number of gaseous moles

We will calculate the moles of each gas using its molar mass.

He: 5.25 g × 1 mol/4.00 g = 1.31 mol

N₂: 3.25 g × 1 mol/28.01 g = 0.116 mol

The total number of moles is:

n = 1.31 mol + 0.116 mol = 1.43 mol

Step 2: Convert 27 °C to Kelvin

We will use the following expression.

K = °C + 273.15 = 27 + 273.15 = 300 K

Step 3: Calculate the total pressure of the mixture

We will use the ideal gas equation.

P × V = n × R × T

P = n × R × T / V

P = 1.43 mol × (0.0821 atm.L/mol.K) × 300 K / 7.75 L = 4.54 atm