Four different methods are described for validating the results of a particular analysis. Indicate for each whether the method primarily checks the accuracy of the analysis or the precision of the analysis. Method 1: Five aliquots of the same sample are injected for a gas-chromatographic analysis by one person on the same day. a. precision.b. accuracy.Method 2: A known amount of analyte is added to an aliquot of the sample and analyzed with the sample. a. precision.b. accuracy. Method 3: Aliquots from a blood sample are sent to three separate laboratories for analysis using the same method. a. precision.b. accuracy. Method 4: Identical standards are analyzed by two different methods. a. accuracy.b. precision.

Answers

Answer 1

Answer:

Method 1 - precision

Method 2 - accuracy

Method 3 - precision

Method 4 - accuracy

Explanation:

The accuracy of a method refers to how close the experimental result is to the accepted value. Accuracy could be checked by carrying out the required test on the standard and not on the sample or by adding a known amount of analyte to the sample so that the results obtained can be carefully compared.

Precision on the other hand, refers to how close the results of a replicate analysis are to each other. In testing for precision, the analysis must be carried out several times, in order to check how close the results are to each other.


Related Questions

The net ionic equation for the reaction between aqueous nitric acid and aqueous sodium hydroxide is ________. The net ionic equation for the reaction between aqueous nitric acid and aqueous sodium hydroxide is ________. H+ (aq) + Na+ (aq) + OH- (aq) → H2O (l) + Na+ (aq) HNO3 (aq) + OH- (aq) → NO3- (aq) + H2O (l) H+ (aq) + HNO3 (aq) + 2OH- (aq) → 2H2O (l) + NO3- (aq) H+ (aq) + OH- (aq) → H2O (l) HNO3 (aq) + NaOH (aq) → NaNO3 (aq) + H2O (l)

Answers

Answer:

H+ (aq) + OH- (aq) → H2O (l)

Explanation:

The net ionic equation is the main reaction going on in the system. The reaction between nitric acid and sodium hydroxide is a neutralization reaction.

In a neutralization reaction, the main reaction is the combination of hydrogen ions and hydroxide ions to form water. This reaction has been shown in the answer box.

If the heat of fusion for water is 334 j/g, how many Jules are needed to melt 45.0 g of ice at 0.0°c?

Answers

Given parameters:

Heat of fusion of water  = 334j/g

Mass of ice  = 45g

Temperature of ice =  0.0°c

Unknown:

Amount of heat needed to melt = ?

Solution:

This is simply a phase change and a latent heat is required in this process.

  To solve this problem; use the mathematical expression below;

             H  = mL

where m is the mass

            L is the heat of fusion of water;

              H  = 45 x 334  = 15030J

Materials with air pockets that decrease their density and prevent energy transfer are called:
A. Insulators
B. Thermometers
C. Conductors
D. Compressors

Answers

d. compressors because it decreases density and compresses it. that makes it prevent energy transfer

Complete and balance each of the following equations for acid-base reactions.
H3PO4(aq) + Sr(OH)2(aq) →

Answers

Explanation:

Sr(OH)2 + H3PO4 = Sr3(PO4)2 + H2O - Chemical Equation Balancer.

Answer:

3Sr(OH)2 + 2H3PO4 → Sr3(PO4)2 + 6H2O

Explanation:

please check the image for accurate answer

The abiotic factor is primary source of energy for all organisms.

Answers

Answer:

True, abiotic factors are the primary resources.

Answer: The abiotic factor sunlight is the primary source of energy for living organisms.

Explanation: edmentum/plato

Suppose during volleyball practice, you drank 900 grams of water. If your body released 800 calories of energy into the water, what would be the temperature change of the water?

Answers

Answer:

75 degrees

Explanation:

12. What is the frequency of a photon with an energy of 3.03 x 10-19 J?
(Planck's constant: h=6.63x 10-34 J·s) (E =hu)
a. 1.98x10^-18 Hz
b. 4.58x10^14 Hz
c. 2.16x10^14 Hz
d. 4.39x10^-19 Hz

Answers

Answer:

[tex]u=4.57x10^5GHz[/tex]

Explanation:

Hello.

In this case, given the formula:

[tex]E=h*u[/tex]

Whereas E is the energy, h the Planck's constant and u the frequency of the photon. Thus, solving for it, we obtain:

[tex]u=\frac{E}{h}=\frac{3.03x10^{-19}J}{6.63x10^{-34}J*s}\\ \\u=4.57x10^{14}s^{-1}[/tex]

Or also:

[tex]u=4.57x10^{14}Hz*\frac{1GHz}{1x10^9Hz}\\ \\u=4.57x10^5GHz[/tex]

Best regards.

how many protons electrons and nuetrons does as have​

Answers

As (Arsenic) has 33 protons as it is the atomic # on the periodic table and 33 electrons and 42 neutrons.

The isotopes K-37 and K-42 have the same

Answers

They have the same number of protons

A tree burns down and forms ashes

Physical or
Chemical

Answers

Answer:

It is a chemical change.

Explanation:

A tree burning down would be a chemical change because the composition of the tree is what changes, not just the physical characteristics.

In a chemistry laboratory, a student filled a 10.0 L container with two (2) different gases. The
gases are nitrogen gas taken from 24.0 L container at 2.00 atm and 12.0 L container of
oxygen at 2.00 atm. If the temperature of the gases is 273 K, calculate the partial pressure
of both gases in the resulting mixture and the total pressure.​

Answers

Answer:

[tex]P_N=1.33atm\\\\P_O=0.67atm[/tex]

[tex]P_T=2.00 atm[/tex]

Explanation:

Hello.

In this case, the first step is to compute the moles of nitrogen and oxygen given their initial P, T and V conditions via the ideal gas equation:

[tex]n_{N}=\frac{P_{N}V_{N}}{RT} =\frac{2.00atm*24.0L}{0.082\frac{atm*L}{mol*K}*273K}\\ \\n_{N}=2.144molN\\\\n_{O}=\frac{P_{O}V_{O}}{RT} =\frac{2.00atm*12.0L}{0.082\frac{atm*L}{mol*K}*273K}\\ \\n_{O}=1.072molO[/tex]

After that, since the total volume now, once the mixture is formed is the addition between the initial volumes (12.0 L + 24.0 L) is 36.0 L, the partial pressure of each gas turns out:

[tex]P_N=\frac{2.144mol*0.082\frac{atm*L}{mol*K}*273K}{36.0L}\\\\P_N=1.33atm\\\\P_O=\frac{1.072mol*0.082\frac{atm*L}{mol*K}*273K}{36.0L}\\\\P_O=0.67atm[/tex]

Thus, the final total pressure is:

[tex]P_T= P_N+P_O=1.33atm+0.67atm\\\\P_T=2.00 atm[/tex]

Best regards.

What is the independent variable?​

Answers

Answer:

An independent variable is defines as the variable that is changed or controlled in a scientific experiment. It represents the cause or reason for an outcome. Independent variables are the variables that the experimenter changes to test their dependent variable.

Explanation:

:)

Heres some defs-    a variable (often denoted by x ) whose variation does not depend on that of another. The independent variable is the variable the experimenter changes or controls and is assumed to have a direct effect on the dependent variable. ... The dependent variable is the variable being tested and measured in an experiment, and is 'dependent' on the independent variable.

0
Chem
Equations
Balance and Classify each of the following equations into:
Combination reaction, Decomposition Reaction, Single
Replacement reaction, Combustion reaction Double
Replacement reaction
A)
KBr(aq) + Cl2(g) → _ KCl(aq) + Br2(1)
B)
CaBr2(aq)
+ H2SO4(aq) - CaSO4(s) +_HBr(g)
N2(g) + H2(g) + NH3(g)
Grading: Each Equation Balanced --2 points, Classification --
1 point each
Ontime submission ---1 point
DUE: Oct 9, 2020 at 11:00 AM

Answers

Answer :

(A) The balanced chemical reaction will be:

[tex]2KBr(aq)+Cl_2(g)\rightarrow 2KCl(aq)+Br_2(l)[/tex]

This reaction is a single replacement reaction.

(B) The balanced chemical reaction will be:

This reaction is a double displacement reaction.

(C) The balanced chemical reaction will be:

[tex]N_2(g)+3H_2(g)\rightarrow 2NH_3(g)[/tex]

This reaction is a combination reaction.

Explanation :

Balanced chemical reaction : It is defined as the reaction in which the number of atoms of an element present on reactant side must be equal to the product side.

Part (A):

The balanced chemical reaction will be:

[tex]2KBr(aq)+Cl_2(g)\rightarrow 2KCl(aq)+Br_2(l)[/tex]

This reaction is a single replacement reaction in which the most reactive element displaces the least reactive element from its solution.

Part (B):

The balanced chemical reaction will be:

[tex]CaBr_2(aq) +H_2SO_4(aq)\rightarrow  CaSO_4(s)+2HBr(g)[/tex]

This reaction is a double displacement reaction in which a positive cation and a negative anion of two reactants exchange their places to form two new products.

Part (C):

The balanced chemical reaction will be:

[tex]N_2(g)+3H_2(g)\rightarrow 2NH_3(g)[/tex]

This reaction is a combination reaction in which the two atoms combine to form a larger molecule.

Compare Solution X to Solution A, Solution B, and Solution C. Beaker with a zoom view showing eight shperes, four groups of particles each consisting of two differently colored spheres. Beaker with a zoom view showing four spheres of a single color Beaker with a zoom view showing eight spheres of a single color Beaker with a zoom view showing eight shperes, two groups of particles each consisting of four spheres, three of one color and one of a different color. Which of the solutions have the same molar concentration as Solution X? C

Answers

Answer:

SOLUTION A

Explanation:

Molarity is one of the most common measure of concentration

The correct option that gives the solution that has the same molar concentration as solution X is the option;

Solution A

Reason:

The descriptions of the content or each beaker are;

Content of beaker X = Eight spheres of four groups of two differently colored spheres

Content of beaker with solution A = Four spheres of a single color

Content of beaker with solution B = Eight spheres of a single color

Content of beaker with solution C = Eight spheres in two groups of four having three spheres of one color and one sphere of a different color

The concentration of a solution given by the molarity is defined as the    number of moles per liter of the solution

A mole is a quantity of matter that contains 6.023 × 10²² elementary particles

Considering each group of spheres as representing one mole of a substance, we have;

Beaker with solution X contains, Four moles containing two elements each, per volume of the solution, such as HClBeaker with solution A contains, four moles of a single (one) element compound per volume of the solutionBeaker with solution B contains, eight moles of a compound having one element eachBeaker with solution C contains, two moles having four elements each, three of one type and one of another element, such as CH₃

Therefore, the solution that has the same molar concentration, (the same number of moles per volume of the solution) is solution A

 

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the sun warming the surface of a rock is
conduction
convection
radiation

Answers

Radiation..................
Radiation is your answer...

what is the formula for sodium hydrogen phosphate

Answers

Answer: Na2HPO4

Explanation: this is the formula

Answer:

Na3PO4

Explanation:.

Test (Speed, Velocity and Acceleration)
A dog can run as fast as 15 miles per hour for a short distance. If a dog ran at this speed 0.10 of an hour, how far would it run?

Answers

Answer:

1.5 miles

Explanation:

Given that,

Speed of dog, v = 15 mph

Time taken by the dog, t = 0.1 h

We need to find the distance travelled by the dog. We know that, distance is the product of speed and time. So,

d=vt

[tex]d=15\times 0.1\\\\d=1.5\ \text{miles}[/tex]

Hence, the dog will cover a distance of 1.5 miles.

The greater the amount of mass an object has, the more force is needed to move it.

Answers

Answer: Newtons Second Law states that acceleration is produced when a force acts on a mass. The greater the mass (of the object being accelerated), the greater the amount of force needed to accelerate the object (bullet in our case). Everyone inherently knows that heavier objects require more force to move the same distance as lighter objects.

Explanation:

PLEASEEEEEEEEEEEEEEEEEEEE im slow i'll give you brainliest if you answer idkk what to do

Answers

Answer:Molecule:

a group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction.

Compound:

A compound is a material formed by chemically bonding two or more chemical elements. The type of bond keeping elements in a compound together may vary: covalent bonds and ionic bonds are two common types. The elements are always present in fixed ratios in any compound.

Element:

Chemical element, also called element, any substance that cannot be decomposed into simpler substances by ordinary chemical processes. Elements are the fundamental materials of which all matter is composed.

Mixture:

is a material made up of two or more different substances which are physically combined.

Chemical Formula:

A chemical formula identifies each constituent element by its chemical symbol and indicates the proportionate number of atoms of each element. I

Pure substance:

A substance that has a fixed chemical composition throughout is called a pure substance such as water, air, and nitrogen.

hope this help!

Answer:

Here are the definitions of all of them.

Explanation:

Molecule:

a group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction.

Compound:

A compound is a material formed by chemically bonding two or more chemical elements. The type of bond keeping elements in a compound together may vary: covalent bonds and ionic bonds are two common types. The elements are always present in fixed ratios in any compound.

Element:

Chemical element, also called element, any substance that cannot be decomposed into simpler substances by ordinary chemical processes. Elements are the fundamental materials of which all matter is composed.

Mixture:

is a material made up of two or more different substances which are physically combined.

Chemical Formula:

A chemical formula identifies each constituent element by its chemical symbol and indicates the proportionate number of atoms of each element. I

Pure substance:

A substance that has a fixed chemical composition throughout is called a pure substance such as water, air, and nitrogen.

A container of hydrogen at 172 kPa was decreased to 85.0 kPa producing a new volume of 3L. What was the original volume?

Answers

Answer:

The answer is 1.48 L

Explanation:

In order to find the original volume we use the same for Boyle's law which is

[tex]P_1V_1 = P_2V_2[/tex]

where

P1 is the initial pressure

P2 is the final pressure

V1 is the initial volume

V2 is the final volume

Since we are finding the original volume

[tex]V_1 = \frac{P_2V_2}{P_1} \\[/tex]

From the question

P1 = 172 kPa = 172000 Pa

P2 = 85 kPa = 85000 Pa

V2 = 3 L

We have

[tex]V_1 = \frac{85000 \times 3}{172000} = \frac{255000}{172000} = \frac{255}{172} \\ = 1.482558139...[/tex]

We have the final answer as

1.48 L

Hope this helps you

Are strong acids more readily attracted to strong bases than to weak bases?

Answers

A stronger base has a larger ionization constant than does a weaker base

1. 500 grams of sugar occupies a volume of 315 ml. What is the density of the sugar in g/mL? Show
your work.


Answers

Answer:

The answer is 1.59 g/mL

Explanation:

The density of a substance can be found by using the formula

[tex]density = \frac{mass}{volume} \\[/tex]

From the question

mass = 500 g

volume = 315 mL

We have

[tex]density = \frac{500}{315} = \frac{100}{63} \\ = 1.587301...[/tex]

We have the final answer as

1.59 g/mL

Hope this helps you

How does a scientist make two solutions with the same molarity? A By dissolving the maximum amount of each substance in the B. By dissolving the same number of grams of each substance in the OC. By dissolving 1 mole of each substance in enough water to make same volume of water same volume of water sure dissolving is complete By dissolving the same number of nmoles of each substance in the same volume of water OD.​

Answers

Answer: The answer is “ By dissolving the same number of nmoles of each substance in the same volume of water ”

Explanation:

By dissolving the same number of moles of each substance in the same volume of water. Hence, option D is correct.

Define the molarity of a solution.

Molarity (M) is the amount of a substance in a certain volume of solution. Molarity is defined as the moles of a solute per litres of a solution.

Adding water to a solution and the number of moles of the solvent stay the same while the volume increases.

If there is no flow of solute into or out of the volume during the addition of the solvent, the number of moles of solute remains the same.

Hence, option D is correct.

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do it if u trust urself

Which statement provides the complete explanation of how renewable and nonrenewable resources differ?

They differ in the amount they are found in nature.
They differ in the rate they are replaced.
They differ in the available amount and rate they are used and replaced.
They differ in the rate they are used.

Answers

Answer:

They differ in the available amount and rate they are used and replaced.

Explanation:

If one material is replaceable, then it's renewable. If it's not replaceable, then it's non-renewable.

The statement 'they differ in the available amount and rate they are used/replaced' provides an explanation of how renewable and nonrenewable resources differ.

What are renewable resources?

Renewable resources can be defined can natural resources that can be renowned in nature in a given period of time.

These renewable resources include biomass and different types of energies (geothermal, wind, solar, etc).  

Conversely, non-renewable resources are specific resources from nature that cannot be replaced (e.g., coal).

In conclusion, the statement 'they differ in the available amount and rate they are used/replaced' provides an explanation of how renewable and nonrenewable resources differ.

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ILL IBE BRAINLY Asian Tsunami 2004:
2. In decomposition, how are other parts of the ecosystem affected?





3. Under which type of change would more organisms be able to survive? Why?





4. What are some positive effects of a rapid change to an ecosystem?





5. What are some positive effects of a slow change to an ecosystem?

Answers

2. In many ways, one being everything is destroyed. All of the trees, plants, everything. It wouldn’t be a safe place to stay either.

3. A few ecosystems that live in the ocean. Because, they would still be in the ocean.

i’m sorry i don’t know the other answers best of luck tho!

2. What is the pH of the following solutions?
2.1. 50 mmol.dm solution of Ba(OH)2

Answers


i hope this helps (please mark brainliest)

Group the elements into pairs that would most likely exhibit similar chemical properties. It does not matter which pair of elements is pair 1, pair 2, or pair 3, so long as the correct elements are paired. elements are N, As, Br, Mg, Sr, F

Answers

The elements in a group containing similar physical properties are

Pair 1 -- K and Li

Pair 2 -- S and Te

Pair 3 -- Br and F

Those elements which belong to the same group in the periodic table have similar number of valence electrons in the last shell and such elements exhibit similar properties.Potassium(K) and Lithium(Li) belong to a similar group i.e group 1.Sulfur (S) and Tellurium (Te) belong to a similar group i.e. group 16.Bromine(Br) and Flourine (F) belong to a similar group i.e. group 17Elements in a group exhibit similar periodic properties be it physical or chemical.It is in accordance with the periodic rules.

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If I initially have a gas at a pressure of 10.0 atm, a volume of 24.0 liters, and a temperature
of 200. K, and then I raise the pressure to 14.0 atm and increase the temperature to 300. K,
what is the new volume of the gas?

Answers

Answer:

The new volume of gas is 25.7 L.

Explanation:

Given data:

Initial volume = 24.0 L

Initial pressure = 10.0 atm

Initial temperature = 200 K

Final temperature = 300 K

Final volume = ?

Final pressure = 14.0 atm

Formula:  

P₁V₁/T₁ = P₂V₂/T₂  

P₁ = Initial pressure

V₁ = Initial volume

T₁ = Initial temperature

P₂ = Final pressure

V₂ = Final volume

T₂ = Final temperature

Solution:

V₂ = P₁V₁ T₂/ T₁ P₂  

V₂ = 10.0 atm × 24.0 L × 300K / 200 K × 14.0 atm

V₂ = 72000 atm .L. K / 2800 K.atm

V₂ = 25.7 L

The new volume of gas is 25.7 L.

Ammonium cyanate (NH4CNO) reacts to form urea (NH2CONH2). at 65 degrees celsius, the rate constant, K is 3.60 L mol^-1 s^-1. what is the rate law for this reaction

Answers

Answer:

v = 3.60Lmol⁻¹s⁻¹ [NH₄CNO]²

Explanation:

The reaction at 65°C of ammonium cyanate to produce urea is:

NH₄CNO → NH₂CONH₂

The general rate law is:

v = K  [NH₄CNO]ˣ

Where v is rate of the reaction, K is rate constant and x represents the order of reaction

Based on the units of the rate constant (Lmol⁻¹s⁻¹ = M⁻¹s⁻¹) the reaction must be order 2 and the rate law:

v = K  [NH₄CNO]²

v = 3.60Lmol⁻¹s⁻¹ [NH₄CNO]²

A student trying to determine if a liquid was a mixture or a pure substance made several following observations. Which observation would best support the conclusion that the liquid was a mixture?​

Answers

Answer:

Distillation

Explanation:

By using the method of distillation we'll identify if there is other properties of liquid by looking the temperatures,the ordor or the boiling point.

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