Answer:
None of them
Explanation:
The number of moles in 75ml is 0.01875moles while in 25ml is 0.004375 and in 129 ml is 0.018705.
REMEMBER: Molarity is the number of moles per litre so in order to get the number of moles you multiply the molarity of the substance by the quantity of the substance in litres.
129 mL of 0.145 M solution of KCl solution has the same number of moles of KCl as 75.00 mL of 0.250 M solution of KCl. Therefore, option B is correct.
What is molarity ?Molarity is defined as the number of moles of a solute in one liter of solution. A solution's molarity is also known as its molar concentration.
To calculate the molarity of a solution, divide the number of moles of solute by the total volume of solution in liters.
Molarity is a concentration unit that is defined as the number of moles of dissolved solute per liter of solution. Molarity is expressed as the number of millimoles per milliliter of solution when the number of moles and volume are divided by 1000.
Given:
number of mol = M ×V
= 0.250 M × 0.0750 L
= 1.87 × 10^-2 mol
volume, V = 1.29*10^2 mL
= 0.129 L
use:
number of mol,
n = Molarity × Volume
= 0.145 × 0.129
= 1.87 × 10^-2 mol
Thus, option B is correct.
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Explain why caesium is more reactive than sodium.
You should answer in terms of electrons.
In experiment 9, in one operation, we heat up the alcohol with acid and do a concurrent distillation. What was the purpose of doing this
Answer:
we heat up because the component with lower boiling evaporates first,
leaving the other behind
1. If the wavelength is changed, what will happen to the absorbance values?
Answer:
The longer the path length, the more molecules there are in the path of the beam of radiation, therefore the absorbance goes up. As you likely know from other experiences, a particular chemical species absorbs some wavelengths of radiation and not others
The wavelength is used to determine the concentration of a colored solution since at this wavelength a slight change in concentration allows for a significant change in the absorbance of light.
What is Wavelength?Wavelength is the distance between equal points in adjacent cycles of a wave signal that propagates in space. Each wave has a definite shape and length, so the distance between the peaks is called the wavelength.
It can be calculated by this formula-
[tex]\lambda=\frac{v}{f}[/tex]
[tex]where, \lambda =wavelength\\{v} = velocity\\{f} = frequency[/tex]
Absorbance measures the amount of light with a specific wavelength which a given substance prevents from passing through ii.
Thus, the wavelength is used to determine the concentration of a colored solution since at this wavelength a slight change in concentration allows for a significant change in the absorbance of light.
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Question 2
Which of the following models the arrangement of atoms in a gas?
O None of these
PLEASE HELP ASAP
Answer:
The option where the atoms are furthest apart.
Explanation:
Gasses are the most energetic of the three basic states of matter, their atoms have more kinetic energy than either solids or liquids and will therefore also have the most spread out atoms.
Which statement best describes mechanical energy?
A.the energy of heat and magnetism
B.the energy of electricity and motion
C.the energy of moving parts and motion
D.the energy of electricity and heat
Answer:
the answer is B.
Explanation:
your welcome
Answer:
the answer is B
Explanation:
i have the same exact questionn
từ một dung dịch có pH=7 muốn tạo thành dung dịch có pH nhỏ hơn 7 thì cho vào dung dịch
Answer:
you lift my feet off the ground spin me around you make me crazier crazier
The mass of a metal ball was 20.350 g. The volume of the water in a 25 mL graduated cylinder was increased from 16.05 to 17.90 mL when the metal ball was placed in the cylinder. What is the density of the metal ball
Answer:
11000 g/L
Explanation:
Since density is mass divided by volume, find the volume of the metal ball by subtracting the initial volume of water in the graduated cylinder from the ending volume. In this case, the volume would be 17.90 mL - 16.05 mL = 1.85 mL = 0.00185 L. Then using the formula for density, calculate 20.350 g / 0.00185 L = 11000 g/L.
Density is an intensive property as it does not depend on the quantity of the substances Whereas mass and volume are extensive property. Therefore, the density of the metal ball is 11000 g/L.
What is density?Density tells about the compactness of the substances, how much dense is the substances in other words. Object that is more denser than water they just sink in the water.
Mathematically,
Density = Mass of the metal ball ÷volume marked on the graduated cylinder
volume=ending volume- initial volume of water in the graduated cylinder
=17.90 mL - 16.05 mL
= 1.85 mL
= 0.00185 L.
substituting all the given values in the above equation, we get
density= 20.350 g / 0.00185 L
= 11000 g/L.
Therefore, the density of the metal ball is 11000 g/L.
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Electromagnetic waves travel fastest through
A -Solid
B -Liquid
C -Gas
D-Vacuum
Answer:
Gas
Explanation:
Mechanical waves- travel faster in solids & slowest in gases
Electromagnetic waves- travel fastest in empty space and slowest in solids.
Because they are so close, than can collide very quickly, i.e. it takes less time for a molecule of the solid to 'bump' into its neighborough. Solids are packed together tighter than liquids and gases, hence sound travels fastest in solids. The distances in liquids are shorter than in gases, but longer than in solids.
Answer C- Gas
Explanation:
Electromagnetic waves- travel fastest in empty space and slowest in solids.
The strongest intermolecular interactions between propanol (CH3CH2CH2OH) molecules arise from hydrogen bonding
a. True
b. False
The claim that the strongest intermolecular interactions between propanol molecules arises from hydrogen bonding is True.
Intermolecular forces are weaker attraction forces that are utilized to define physical characteristics of molecules such as:
boiling point temperature densitymelting pointsHydrogen bonding is an type of intermolecular forces.
It is a type of dipole-dipole interaction that only happens when a hydrogen atom is connected to the atomic element of oxygen, nitrogen, or fluorine.
From the question given, in the propanol (CH3CH2CH2OH) molecule, the hydrogen usually has a partially positive charge which attracts the partially negative charge of the oxygen.
Therefore, we can conclude that the claim is True.
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which mass movement does this describe?
Answer:
landslide mudflows slump and creep
Explanation:
no explanation
Your skin is an important organ and has several functions. All of the functions below are performed by the skin EXCEPT
A)
makes vitamin D.
B
prevents-dehydration:
C)
maintains body temperature.
D)
works with bones to help you move
Answer:
D. works with bones to help you move
Explanation:
Your muscles and tendons are what help bones move.
How many grams are 0.300 moles of glucose, C6H12O6?
Answer:
Explanation:
Firstly, let us calculate the molar mass of the glucose. To find the molar mass we need to add the masses of individual elements which constitute one glucose molecule.
Now, we know that
Molar mass of Carbon C=12gmol−1
Molar mass of Hydrogen H=1gmol−1
Molar mass of oxygen O=16gmol−1
Therefore, Molar Mass of glucose (C6H12O6) can be calculated as shown below
⇒ 6×12+12×1+6×16
⇒72+12+96⇒180gmol−1
Given mass of glucose = 300g
Now, we can calculate the number of moles in given mass of glucose, using the below formula,
Using the Formula numberofmoles=givenmassmolarmass we get
numberofmoles=300180 = 1.7 moles or 2 moles (approx.)
Hence the number of moles present in 300 g of glucose is 1.7 moles or 2 moles approximately.
1 ton of methanol are accidentally discharged into a lake. By how much is the biological oxygen demand of this water increased
The biological Oxygen demand of the lake is increased by 1.5 ton.
Discussion:
The reaction of methanol with Oxygen is as follows;
2CH3OH + 3O2 ==> 2CO2 + 4H2O.In the reaction above; Since Methanol, CH3OH and Oxygen, O2 have the same molar mass; 32.
Therefore we can say since;
2 moles of CH3OH requires 3 moles of O2.
Therefore, 1 ton of methanol will require 1.5 ton of oxygen.
The biological Oxygen demand of the water is therefore increased by 1.5 ton as this is the amount of Oxygen consumed by the ethanol.
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What is caused by temperature differences in the mantle resulting in plate movement?
Crust
Convection Currents
Lithosphere
Answer:
Convection Currents
Explanation:
What does IUPAC stand for?
Answer: International Union of Pure and Applied Chemistry
The International Union of Pure and Applied Chemistry (IUPAC), established in 1919, is the international body that represents chemistry and related sciences and technologies.
What is the use of GMO?
Some benefits of genetic engineering in agriculture are increased crop yields, reduced costs for food or drug production, reduced need for pesticides, enhanced nutrient composition and food quality, resistance to pests and disease, greater food security, and medical benefits to the world's growing population.
Insect resistance: Corn
Herbicide tolerance: Soybean
HELP ME OUT PLEASE!!
Which model represents the chemical formula NO2, nitrogen dioxide?
A) A.
B) B.
C) C.
D) D.
Answer:
C
Explanation:
The answer is C, because nitrogen is in purple, and oxygen is in blue, and in NO2 you have 2 oxygen atoms.
No one helps me please find an answer to my recent question in chemistry...please!!!
oh so sad for ur msg
if i were science student then absolutely i will help
but i am। computer science student in management faculty so so sry
Explanation:
your answer to the chemistry question is given !
hope that helps you.
How do you convert a temperature from Celsius to kelvin?
Answer:
Kelvin = Celsius + 273.15
Explanation:
Instead of 273.15 you can use just 273 as well
Which of the following is NOT a type of evidence indicating that a chemical change has occurred? *
- fizzing/bubbling
- heat is released
- solubility
- sound is given off
Answer:
sound is given off
Explanation:
due to a number of scientific research sound that is given off of an object is not due to a chemical reaction.
A gas has a pressure of 8.5atm and occupies 24L at 25∘C. What volume (in liters) will the gas occupy if the pressure is increased to 13.5atm and the temperature is decreased to 15∘C? Round to the nearest liter.
The volume (in liters) that the gas will occupy if the pressure is increased to 13.5 atm and the temperature is decreased to 15 °C is 15 L
From the question given above, the following data were obtained:
Initial pressure (P₁) = 8.5 atm
Initial volume (V₁) = 24 L
Initial temperature (T₁) = 25 °C = 25 + 273 = 298 K
Final pressure (P₂) = 13.5 atm
Final temperature (T₂) = 15 °C = 15 + 273 = 288 K
Final volume (V₂) =? The final volume of the gas can be obtained by using the combined gas equation as illustrated below:[tex]\frac{P_{1}V_{1}}{T_{1}} = \frac{P_{2}V_{2}}{T_{2}}\\\\\frac{8.5 * 24}{298} = \frac{13.5 * V_{2}}{288}\\\\ \frac{204}{298} = \frac{13.5 * V_{2}}{288}\\\\[/tex]
Cross multiply
298 × 13.5 × V₂ = 204 × 288
4023 × V₂ = 58752
Divide both side by 4023
[tex]V_{2} = \frac{58752}{4023}\\\\[/tex]
V₂ = 15 LTherefore, the final volume of the gas is 15 L
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Can KI+Cl2 occur or not
Yes according to reliable sources.
A 15.0-L vessel contains 0.50 mol CH4 with a pressure of 1.0 atm. After 0.50 mol C2H6 is added to the vessel, what is the partial pressure of CH4? The temperature remains unchanged throughout the process.
Answer: Hi! The partial pressure of CH4 is
=1 atm
Explanation:
The partial pressure of methane in the mixture of methane and ethane has been 1 atm.
Partial pressure has been the pressure exerted by a gas in the solution or mixture. The partial pressure of each gas has been the total pressure of the gaseous mixture.
The partial pressure of the gas has been dependent on the volume, temperature, and concentration of the gas.
The given methane has a partial pressure of 1 atm in the 15 L vessel. The addition of ethane results in the change in the total pressure of the mixture, as there have been additional moles of solute that contributes to the solution pressure.
However, since there has been no change in the concentration and volume of methane, the pressure exerted by methane has been the same. Thus, the partial pressure of methane has been 1 atm.
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A mixture of methanol and water was distilled using both simple distillation and fractional distillation. Which statement is NOT true
With regard to distilling the mixture of methanol and water using simple
distillation and fractional distillation, a statement that can be made that is
not true is that; Methanol and water form an azeotrope.
Reasons:
Azeotrope are liquid mixtures that have the property of a constant boiling
point due to the contents of the vapor are the same as the mixture.
Water when mixed with methanol form network structures. However,
methanol does not form a binary azeotrope with water.
Therefore, a statement that is not true is that methanol and water form an
azeotrope a mixture that has a constant boiling temperature.
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Disadvantage and advantage of iodine ?
- umoren sŭm..
THE ADVANTAGE OF IODIN
IODINE CAN LEAD TO GOITER AND OTHER THYROID PROBLEMS.THE DISADVANTAGE OF IODIN
IODIN MAY LEAD TO THYROIDITIS AND THYROID PAPILLARY CANCERWhat are the dependent and independent variables in this experiment? How are outside factors being controlled in this experiment to make sure that the results test only the dependent variable?
Answer:
1. An independent variable is manipulated, or changed. The dependent, or responding variable, changes based on the independent variable. The dependent variable is examined.
2. It is a controlled experiment.
Explanation:
In a controlled experiment all variables are kept the same, except for the one being tested, which is called the experimental variable , or independent variable . This group is the experimental group . The group that is not affected by the experimental variable is the control group .
Very often a graph will be used to analyze the results of the experiment. The independent/experimental variable is placed on the x-axis and the dependent variable is placed on the y-axis. The dependent variable is what is measured as a result of the application of the experimental variable.
A variable that is independent is altered. Based on the independent variable, the responding variable, or dependent variable, alters. Examining the dependent variable. The experiment is carefully controlled.
What is an independent variable ?In mathematical modeling, statistical modeling, and experimental sciences, there are dependent and independent variables. Dependent variables get their name because, during an experiment, their values are investigated under the presumption or requirement that they are dependent on the values of other variables due to some law or rule.
A variable that is independent is precisely what it sounds like. It is a stand-alone variable that is unaffected by the other variables you are attempting to assess. Age, for instance, could be an independent variable.
When doing an experiment, the independent variable is what you alter, and the dependent variable is what changes as a result of that change. This is an easy way to conceive of independent and dependent variables.
Thus, based on the independent variable, the responding variable, or dependent variable, alters.
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the bleaching action of sulphur (iv) oxide is by
Answer:
The bleaching action of sulphur di oxide is temporary because it involves the process of reduction. sulphur di oxide removes oxygen from the coloured substance and makes it colourless. Atmospheric oxygen slowly takes place of the removed oxygen and because of which the material regains the co
A 5.35 M sugar solution is diluted from 240.0 mL to 862.5 mL. What is the concentration of the dilute solution
Answer:
1.345.0
Explanation:
Hope this helpssss
cyclopropane is a commonly used anesthetic. If a 2.00 L flask contains 3.11 g of cyclopropane gas at 684 mmHg pressure and 23.0 C, what is the molecular mass of cyclopropane
Answer:
42.0g/mol
Explanation:
The steps for this question is to use the ideal gas law, and then use n=m/M to find molar mass.
PV = nRT
n= PV/RT
Change 23 degrees to 296.15 K and 684mmHg to kpa
n = (91.1925kpa)(2.00L)/(8.314Lkpa/mol K)(296.15K)
n= 0.074mol
n = m/M
M = m/n
M = 41.98489g/mol
You measure the absorbance of your extracted curcumin solution and realize that the solution is too concentrated. What made you realize this
If the absorbance of a solution of curcumin which is too concentrated is measured, the absorbance will be unusually high.
Spectrometry measures the interaction of light with molecules. The absorbance refers to how much light that interacts with molecules of the substance. The more the concentration of the substance the higher the absorbance of the solution.
Hence, if the absorbance of a solution of curcumin which is too concentrated is measured, the absorbance will be unusually high. An unusually high absorbance tells us that the solution is too concentrated.
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