They help to control for any variation that may occur during sample preparation and analysis. This can be due to factors such as changes in temperature, pressure, or humidity.
Internal standards are compounds that are added to a sample prior to GC analysis. These standards are chosen for their similarity to the analyte of interest and are used to correct for any variability in sample preparation, injection, and analysis. Internal standards provide a reliable way to ensure the accuracy and precision of GC results.
There are several reasons why internal standards are commonly used in GC analysis. Firstly, they help to control for any variation that may occur during sample preparation and analysis. This can be due to factors such as changes in temperature, pressure, or humidity. By adding an internal standard to the sample, it is possible to ensure that any changes in the sample are reflected in the standard. This allows for more accurate and precise measurements of the analyte of interest.
Secondly, internal standards help to correct for any losses or gains that may occur during sample preparation and injection. This can be due to factors such as sample adsorption onto the injection port or column, or changes in the sample volume during injection. By adding an internal standard, it is possible to calculate the amount of analyte that was lost or gained during sample preparation and injection. This allows for more accurate and precise measurements of the analyte of interest.
Finally, internal standards can also be used to monitor the performance of the GC system over time. By analyzing the same internal standard over a period of time, it is possible to detect any changes in the system performance. This can include changes in column performance, injector performance, or detector performance. By monitoring the internal standard, it is possible to ensure that the GC system is operating within acceptable limits and that the results obtained are reliable and accurate.
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the enthalpy and entropy change of a reaction are -3.9 kj/mole and 56.6 j/mole k respectively at 25oc. what is the free energy change in kj/mole? is this reaction always spontaneous, never spontaneous or does it depend on the temperature? g
The free energy change of the reaction is -5.8 kj/mole and at higher temperatures, the reaction may become non-spontaneous.
To calculate the free energy change (ΔG) in kj/mole, we can use the equation ΔG = ΔH - TΔS, where ΔH is the enthalpy change, ΔS is the entropy change, and T is the temperature in Kelvin.
So, substituting the given values, we get:
ΔG = (-3.9 kj/mole) - (298 K) * (56.6 j/mole K) / 1000 = -5.8 kj/mole
Therefore, the free energy change of the reaction is -5.8 kj/mole.
Whether the reaction is spontaneous or not depends on the sign of ΔG. If ΔG is negative, the reaction is spontaneous (i.e., it will occur without any external intervention). If ΔG is positive, the reaction is non-spontaneous (i.e., it will not occur unless energy is supplied to the system). And if ΔG is zero, the reaction is at equilibrium.
In this case, since ΔG is negative, the reaction is spontaneous. However, the spontaneity of the reaction may depend on the temperature, since the value of ΔG depends on temperature through the TΔS term. So, the reaction may become non-spontaneous.
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What Is The IUPAC Name For The Compound Shown? IUPAC Name: C10H22
Answer:
Decane Is the IUPAC name of C10H22
By the IUPAC Naming Convention followed by every chemical standards, the structure shown in the image is named as Decane.
IUPAC Stands for International Union of Pure and Applied Chemistry.This organisation issued some standards for naming any chemical components that is followed world wide.
According to the IUPAC Standards:
First of all we have to identify the longest carbon chain which is [CH3-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3] alkane group according to this image.As a result of 10 carbon linked with single bonds and having hydrogen to balance the electron share it will be named Decane.It is an alkane hydrocarbon with the chemical formula C10H22.
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what are the names given to each part of the picture indicated above
A 10 kg shotgun accelerates 0.025 kg of buckshot from rest to a speed of 100 m/s in a distance of just 0.5 m. How much force is used to accelerate the shot? How much force does the gun recoil with?
Answer:
v'2 is the final velocity of the bullet
Explanation:
I had the question and found it on Chegg so credits to him/her
If a scientist wanted to compare air quality throughout the united states but was unable to test the air in every city, the scientist could compare the air quality in a ______ or subset of cities.
If a scientist wanted to compare air quality throughout the united states but was unable to test the air in every city, the scientist could compare the air quality in a sample or subset of cities.
How to check the air quality?
The Air Quality Index, or AQI, is used to gauge air quality. The AQI functions similarly to a thermometer with a range of 0 to 500 degrees. But the AQI is a technique of displaying variations in the quantity of pollution in the air, not changes in temperature.
How do you sample air quality?
Small volumes of air can be collected through air sampling for testing in laboratories. The majority of air sampling techniques use a suction mechanism to draw complete air samples into a bag or container. After that, the bag or container can be sealed before being sent to a lab for analysis.
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The heat of solution of KI is 20.3 kJ/mol.
This means that when one mole of KI dissolves in water the process will be
PLEASE EXPLAIN ANSWER
a. Exothermic, ΔH is positive
b. Exothermic, ΔH is negative
c. Endothermic, ΔH is negative
d. Endothermic, ΔH is positive
Since the heat of solution of KI is 20.3 kJ/mol, the answer to the question is a. Exothermic, ΔH is positive
There are two types of chemical reactions namely exothermic and endothermic reaction.
For exothermic reactions, heat is released. So, ΔH is positiveFor endothermic reactions, heat is absorbed. So, ΔH is negativeGiven the heat of solution of KI as 20.3 kJ/mol.
Since it is positive, the reaction is exothermic and ΔH is positive
Since the heat of solution of KI is 20.3 kJ/mol, the answer to the question is a. Exothermic, ΔH is positive
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How would different ratios of fuel and oxygen affect the altitude the rocket reaches?
For the rocket engine a lean or excessively rich air-fuel ratio will lead to a compromise in the power output and ultimately the altitude the rocket will reach. Hence which ever the ratio the altitude is greatly affected, unless the ideal ratio is archived.
The air-fuel ratio is the ratio of the amount of air need to burn a part of fuel in a combustion cycle, the ratio is basically a compromise between fuel economy and optimum power output.
For a gasoline engine for example, the ideal air-fuel mixture of 14.7 parts air to 1 part fuel.
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In
________, the units that are a part of the measurements
are used to help solve the problem.
Answer:
metric........................................ system..................................
Why is alchemy no longer accepted
Answer:
Because it was based on mystical belief instead of the scientific method (which had not been codified for most of alchemy's existance). It is completely wrong, even if it stumbled on techniques which are still useful. Also it is NOT real
Explanation:
what is the average speed of a train that covers 40 kilometers (km) in 1 hour, 100 kilometers (km) in 2 hours (hr), and 210 kilometers (km) in 4 hours (hr)?
Answer:
\(40 \times 1 = 40\)
) What is activation energy?(1 point) Responses the energy that must be added to a system to break the bonds of the reactants the energy that must be added to a system to break the bonds of the reactants the energy released when atomic bonds are broken the energy released when atomic bonds are broken the total potential energy of the bonds of the reactants in a system the total potential energy of the bonds of the reactants in a system the kinetic energy of the reactants of a system after the reaction has begun
Answer:
Arrhenius equation
k=Ae^{{\frac {-E_{a}}{RT}}}
Explanation:
k = rate constant
A = pre-expoIn
E_{a} = activation energy (in the same units as R*T)
R = universal gas constant
T = absolute temperature (in Kelvin)
in chemistry and physics, activation energy is the minimum amount of energy that must be provided for compounds to result in a chemical reaction. The activation energy of a reaction is measured in joules per mole, kilojoules per mole or kilocalories per molenential factor
Where do chemosynthetic bacteria get their
energy?.
Answer:
inorganic chemicals
Explanation:
Organisms that use inorganic chemicals as a source of energy and convert them into organic substances are known as Chemosynthetic bacteria. Unlike plants, they obtain their energy from the oxidation of inorganic molecules, rather than photosynthesis. Chemosynthetic bacteria use inorganic molecules, such as ammonia, molecular hydrogen, sulphur, hydrogen sulphide and ferrous iron, to produce the organic compounds needed for their subsistence. Chemosynthetic bacteria are found in deep-sea or in the areas where sunlight does not penetrate.
Consider a 1.0 L solution which is 0.55 M NH4Cl and 0.2 M NH3 (Ka for NH4Cl = 5.6 x 10^-10). Complete the table by calculating the pH of the original solution. Then calculate the pH of the solutions after the indicated additions. Calculate all the pH values to two decimal places. Assume no volume change on addition.
pH
original solution =
0.10 mol of HCl added to the original solution =
0.20 mol of NaOH added to the original solution =
1. The pH value of a 1.0 L solution which is composed of 0.55 M NH₄Cl and 0.2 M NH₃ of the original solution is 8.83.
2. The pH value of 0.10 mol of HCl added to the original solution is 8.61.
3. The pH value of 0.20 mol of NaOH added to the original solution is 9.30.
1. To calculate the pH value of the original solution, we must find the pKa value of NH₄Cl:
pKa = - log Ka = - log (5.6 × 10⁻¹⁰) = 9.25
The concentration of [NH₃] and [NH₄⁺] are given as 0.2 M and 0.55 M respectively. Thus, pH can be calculated by substituting the given values in the above formula:
pH = pKa + log ([NH₃]/[NH₄⁺])
= 9.25 + log (0.2/0.55)
= 9.25 - 0.4202
= 8.83
Thus, the pH value of the original solution is 8.83.
2.. To calculate the pH value of the solution after the addition of 0.10 mol of HCl and 0.20 mol of NaOH to the original solution, we must find the new molar concentrations of NH₄⁺ and NH₃ ions:
a. Initial molar concentration of NH₄⁺ = 0.55 M
The number of moles of H⁺ ion produced by 0.10 mol of HCl = 0.10 mol
The number of moles of NH₄⁺ ion reacted with H+ ion = 0.10 mol
Final molar concentration of NH₄⁺ ion = 0.55 - 0.10 = 0.45 M
b. Initial molar concentration of NH₃ = 0.2 M
The number of moles of NH₃ reacted with H+ ion = 0.10 mol
Final molar concentration of NH₃ ion = 0.2 - 0.10 = 0.1 M
The Ka value of NH₄Cl remains the same in this case. Therefore, pH can be calculated by using the same formula used earlier:
pH = pKa + log ([NH₃]/[NH₄⁺])
= 9.25 + log (0.1/0.45)
= 9.25 - 0.6381
= 8.61
Thus, the pH value of the solution after the addition of 0.10 mol of HCl is 8.61.
3. To calculate the pH value after 0.20 mol of NaOH is added to the original solution, we must find the new molar concentrations of NH₄⁺ and NH₃ ions:
Initial molar concentration of NH₄⁺ = 0.55 MInitial molar concentration of NH₃ = 0.2 MThe number of moles of OH⁻ ion produced by 0.20 mol of NaOH = 0.20 molThe number of moles of NH₄⁺ ion reacted with OH- ion = 0.20 molThe final molar concentration of NH₄⁺ ion = 0.55 - 0.20 = 0.35 MThe final molar concentration of NH₃ ion = 0.2 + 0.20 = 0.4 MThe Ka value of NH₄Cl remains the same in this case. Therefore, pH can be calculated using the same formula:
pH = pKa + log ([NH₃]/[NH₄⁺])
= 9.25 + log (0.4/0.35)
= 9.25 + 0.055
= 9.30
Thus, the pH value of the solution after the addition of 0.20 mol of NaOH is 9.30.
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what effect does the dissociation rate (curve) high
partial pressure of carbon dioxide increasing temperature
decreasing PH acidic and presence of 2,3
Diphosphoglycerate
The dissociation curve of hemoglobin is influenced by various factors, including the partial pressure of carbon dioxide, temperature, pH, and the presence of 2,3-DPG.
High partial pressure of carbon dioxide (CO2): An increase in the partial pressure of carbon dioxide shifts the dissociation curve to the right. This is known as the Bohr effect. Elevated CO2 levels indicate increased metabolic activity or higher levels of carbon dioxide produced during respiration. The shift to the right allows for more efficient release of oxygen from hemoglobin in tissues where oxygen demand is high.
Increasing temperature: An increase in temperature also shifts the dissociation curve to the right. Higher temperatures typically occur in metabolically active tissues, where oxygen demand is increased. The shift to the right enhances the unloading of oxygen from hemoglobin, facilitating oxygen delivery to the tissues.
Decreasing pH (acidic conditions): A decrease in pH, resulting in increased acidity (e.g., during exercise or in tissues with high metabolic rates), causes a rightward shift of the dissociation curve. This phenomenon is also known as the Bohr effect. The decrease in pH decreases the affinity of hemoglobin for oxygen, facilitating oxygen unloading in acidic environments.
Presence of 2,3-Diphosphoglycerate (2,3-DPG): 2,3-DPG is a molecule that is present in red blood cells and helps regulate the affinity of hemoglobin for oxygen. Higher levels of 2,3-DPG, which can occur in conditions such as chronic hypoxia or anemia, shift the dissociation curve to the right. This shift allows for more efficient unloading of oxygen from hemoglobin, ensuring that oxygen is delivered to tissues in need.
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Can someone help me with these three questions? please
Answer:
23 43 45 43
Explanation:
put have has or had where appropriate in the following sentence, Exam malpractices_______become a serious issue
Answer:
has
Explanation:
has
Answer:
has
Explanation:
Ethanol, propanol, and methanol are three simple alcohols. They can be grouped together because they _____.
Ethanol, propanol, and methanol are three simple alcohols. They can be grouped together because they all share the same hydroxyl group.
A hydroxyl group is a functional group consisting of an oxygen atom with two lone pairs covalently bonded to a hydrogen atom. The chemical representation of the hydroxyl group is -OH.
Alcohols, Sugar and carboxylic acids usually contain hydroxyl groups. All the alcohol have the same functional group which is why they are represented by the formula ROH. Here R is an alkyl group and OH is a hydroxyl group.
Alcohols are formed when this group is added to an organic compound.
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At 25 °C only 0.0640 mol of the generic salt AB2 is soluble in 1.00 L of water. What is the Ksp of the salt at 25 °C?
AB2 (s) yields A^2+ (aq) + 2B^- (aq)
At 25 °C only 0.0640 mol of the generic salt AB2 is soluble in 1.00 L of water. 1.049 × 10⁻³ is the Ksp value of the salt at 25 °C.
Given that 0.0640 mol of the generic salt AB2 is soluble in 1.00 L of water at 25°C, we can determine the Ksp value using the dissociation reaction you provided:
Calculating the concentrations of ions in solution and Ksp are both possible using the molar solubility.
AB2 (s) ⇌ A²⁺ (aq) + 2B⁻ (aq)
First, find the molar concentrations of the ions at equilibrium:
[A²⁺] = 0.0640 mol/L
[B⁻] = 2 × 0.0640 mol/L = 0.128 mol/L
Next, write the Ksp expression for the reaction:
\(Ksp=[A^{2+}][B-]^{2}\)
Finally, substitute the concentrations into the Ksp expression and calculate the Ksp value:
Ksp = (0.0640) × (0.128)² = 1.049 × 10⁻³
The Ksp of the generic salt AB2 at 25°C is approximately 1.049 × 10⁻³.
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Which of the following does NOT move thermal energy
through convection currents on Earth?
a the ocean
b the atmosphere
€ molten rock
If you have 60 moles of HCl, what should the volume of solution be to make a 10 M solution?
Answer:10
Explanation:
Multiply the volume by the density to get the mass.
Divide the mass by the molar mass to get the number of moles.
How many moles of Al are necessary to form 35.2 g of AlBr₃ from this reaction: 2 Al(s) + 3 Br₂(l) → 2 AlBr₃(s) ?
Based on the mole ratio, the number of moles of Al required to produce 35.2 g of AlBr₃ is 0.13 moles.
What is the mole ratio of the reaction?The mole ratio of the reaction is the ratio in which moles of reactants combine to form moles of product.
The mole ratio is obtained from the equation of the reaction.
Considering the given reaction equation below:
Al(s) + 3 Br₂(l) → 2 AlBr₃(s)
1 mole of Al produces 2 moles of AlBr₃ when reacted with 3 moles of Br₂
Molar mass of AlBr₃ = 267 g
Molar mass of Al = 27 g
Moles of Al required to produce 35.2 g of AlBr₃ = 35.2 * 27/267 * 1 mole/27
Moles of Al required to produce 35.2 g of AlBr₃ = 0.13 moles of Al
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what does the atomic mass number of each atom represent.
The atomic mass number tells us the number of neutrons and protons in the nucleus of an atom.
3502. (Refer to Figure 17.) Determine the wind and temperature aloft forecast for DEN at 9,000 feet.
A— 230° magnetic at 53 knots, temperature 47°C.
B— 230° true at 53 knots, temperature -47°C.
C— 230° true at 21 knots, temperature -4°C.
The wind and temperature aloft forecast for DEN at 9,000 feet is B— 230° true at 53 knots, temperature -47°C.
It's important to note that the wind direction is given in magnetic heading rather than true heading, which is important for aircraft navigation. The temperature at this altitude is relatively warm, which could have an impact on aircraft performance and fuel consumption. It's also important for pilots to take into consideration any changes in wind and temperature at different altitudes throughout their flight, as this can affect their flight plan and fuel management. Overall, this forecast suggests favorable flying conditions for an aircraft flying at 9,000 feet over the DEN area.
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Can someone pleasee help me with this asap!! Im struggling
4a. D - The last number in the configuration represents the group, in this case 3, and the number of shells represent the period, which is also 3.
4bi. Rubidium metal reacts very rapidly with water to form a colourless solution of rubidium hydroxide (RbOH) and hydrogen gas (H2). The resulting solution is basic because of the dissolved hydroxide. The reaction is very exothermic and explosive.
4bii. Lithium is smaller in size than potassium . so valence electrons are more tightly held in Li than K. Due to larger size of K the valence electrons are loosely held and easy to remove the electron from K. Hence K is more reactive.
An insoluble solid that forms from a chemical reaction is called
Precipitates are insoluble ionic solid products of a reaction, formed when certain cations and anions combine in an aqueous solution. The determining factors of the formation of a precipitate can vary.
How cold does it really get on Pluto's moon, Charon? (I know this is not a Chem question per se, but is there no Earth Science, nor Space, nor Astronomy, nor General Science category on Brainly?)
Answer:
Explanation:
After various studies and experiments conducted on Pluto's moon, Charon it has been determined that it gets to minus 459.67 degrees Fahrenheit which would be equivalent to minus 273.15 degrees Celsius. This is the coldest temperature that scientists have registered for Charon. This temperature is nearing absolute zero and puts it colder than Pluto itself since Pluto's temperature is believed to get to minus 400 degrees Fahrenheit which is equivalent to minus 240 degrees Celcius.
Describe the changes to the coastline pictured above. Look particularly at North and South Monomy Island.
Where is the picture?
During a laboratory activity, a student places 21.0 mL of hydrochloric acid solution, HC1(ag),
of unknown concentration into a flask. The solution is titrated with 0.125 M NaOH(ag) until the
acid is exactly neutralized. The volume of NaH(ag) added is 18.5 milliliters. During this
laboratory activity, appropriate safety equipment is used and safety procedures are followed.
The presence of the ions in the HCl would make the solution to conduct electricity.
Why does HCl solution conduct electricity?Because it separates into ions (H+ and Cl-) when hydrochloric acid is dissolved in water, HCl (hydrochloric acid) solution conducts electricity. The electric charge of the H+ and Cl- ions allows them to travel and convey current across the solution.
The dissociation constant (Ka) of HCl describes how much of the compound separates into ions depending on the concentration of the solution. A higher HCl concentration will produce more ions, which will increase conductivity.
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studocu lab how would you describe the different types of polymerization techniques and how do they produce different properties of polystyrene?
The descrition the different types of polymerization techniques and they produce different properties of polystyrene because the monomers that make up the polymer have different carbon bonds.
Polymerization is a reaction in which small molecules or monomers combine to form large molecules or polymers. A type of synthetic polymer that is widely used as an electrical insulator and food wrapper is polystyrene. A liquid hydrocarbon that is prepared commercially from petroleum and is carried using a coordinating catalyst.
There are two polymerization techniques, the first is addition polymerization where double bonds break down into single bonds and atoms are added to the compounds that are formed. Monomers open double bonds and join with other monomers to form single bonds. While the second is condensation polymerization, which is the accumulation of functional groups between two monomers. Polymers are formed by the reaction of monomers with each other through other molecular processes.
So different polymerization techniques can produce different polystyrene properties because the monomers that make up the polymer have bonds different carbons such as alkenes, sterinas, and haloalkenes.
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What is the best set of reagents to achieve the following transformation? ph-co2h => ph-come
The best set of reagents to achieve the ph-co2h => ph-come will be Br2, CH2N2.
A material or ingredient supplied to a system to trigger a chemical reaction or check to see whether one occurs is known as a reagent as well as an analytical reagent. Reactant refers to a substance that is consumed during a chemical reaction. The phrases reactant and reagent just aren't frequently used interchangeably.
Diazomethane reacts swiftly and extremely effectively, producing just N2 as a byproduct, making it an appealing methylating agent for carboxylic acids including phenols.
Therefore, the best set of reagents to achieve the ph-co2h => ph-come will be Br2, CH2N2.
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