Explanation:
Isopropyl alcohol is the solvent used in whiteboard markers. When it comes into contact with the permanent marker, the solvent breaks the cohesive force between the ink molecules and the whiteboard by solubilising them (i.e. returning them to solution).
Radioactive radon-222, found in many homes, is a potential health hazard. The half-life of radon-222 is 3.82 days. If you begin with 35.3 mg of this isotope, what mass remains after 10.1 days have passed
Answer:
5.65mg of the isotope remains
Explanation:
The radioactive decay follows the equation:
Ln[A] = -kt + ln[A]₀
Where [A] is amount of the isotope after time t, k is decay constant, and [A]₀ is initial amount of the isotope.
k = ln 2 / Half-life
k = ln 2 / 3.82 days
k = 0.18145days⁻¹
Replacing:
Ln[A] = -0.18145days⁻¹*10.1days + ln[35.3mg]
ln[A] = 1.7312
[A] = 5.65mg of the isotope remains
g The activation energy for diffusion depends on the strength of atomic bonds. Higher strength bonds result in higher activation energies. How do you predict the activation energy for self diffusion will be related to melting temperature
Answer:
Yes, the activation energy for self diffusion is related to melting temperature.
Explanation:
The activation energy for self diffusion is related to melting temperature because bonds result due to activation energies and we know that bonds are break down when the temperature is increases and as a result the solid substance melts and change into liquid state. When the bonds between atoms are broken down with the use of heat energy the state of matter changes so we can say that activation energy is related to temperature.
in
What are common features in
relation to electron arrangement
across a period and down a group
Igor s elements on the periodic
table.
Answer:
The order of sub-energy levels ( s » p » d » f )
The number of orbitals ( s » 2 ), ( p » 6), ( d» 10), ( f » 14 )
An example of competition between members of two different species is
A) mold growing on a dead tree that has fallen in the forest
B) purple loosestrife plants growing in the same wet areas as cattail plants
C) a coyote feeding on the remains of a deer that died of starvation
D) two male turkeys displaying mating behaviors to attract a female turkey
Pls help
Answer:
B) purple loosestrife plants growing in the same wet areas as cattail plants
Explanation:
Competition between members of two species means that two different species are "fighting for" or desire the same resource. This resource could be shelter, food, territory, etc.
An organism cannot compete if it is already dead, so that eliminates answer choices A and C. Answer choice D is wrong because these are two organisms of the same species.
Answer choice B is correct because there are two different species competing for one area of land.
El agua del mar contiene aproximadamente un 3,0 % m/v de sal (NaCl, 58,44 g/mol), (asuma que es la única fuente de cloruros) si una fábrica de baterías para carro provoca un derrame de material con plomo(II). La concentración máxima (en g/L) de plomo(II) que puede contener el agua marina es:_______________
Kps=1,6x10^5
Answer:
s = 4.41 g/L.
Explanation:
¡Hola!
En este caso, considerando el escenario dado, se hace necesario para nosotros saber que la posible reacción de disociación la experimenta el cloruro de plomo (II) como se muestra a continuación:
[tex]PbCl_2(s)\rightleftharpoons 2Cl^-(aq)+Pb^{2+}(aq)[/tex]
Lo cual hace que la expresión de equilibrio se calcule como:
[tex]Ksp=[Pb^{2+}][Cl^-]^2[/tex]
Y que en términos de la solubilidad molar, s, se resuelve como:
[tex]1.6x10^{-5}=s(2s)^2\\\\1.6x10^{-5}=4s^3\\\\s=\sqrt[3]{\frac{1.6x10^{-5}}{4} } \\\\s=0.0159molPbCl_2/L[/tex]
Ahora, convertimos este valor a g/L al multiplicarlo por la masa molar del cloruro de plomo (II):
[tex]s=0.0159molPbCl_2/L*\frac{278.1gmolPbCl_2}{1molmolPbCl_2} \\\\s=4.41g/L[/tex]
¡Saludos!
HELP WITH MY 2 QUESTION
1-What type of packaging is used for milk?
2-How do the physical and chemical properties (material, reactivity, shape, hardness, color)
of each packaging type help create new and better product?
Answer:
1. Milk comes in a range of sizes and forms, and is packaged in a range of materials. Glass bottles, plastic coated paper board, blow mold nonreturnable polyethylene containers, plastic pouches, and returnable rigid polycarbonate containers are among the commercial containers available.
Dont know the answer to the second one sorry :(
The reduction of carbon dioxide by hydrogen gas takes place at 420°C to produce water vapor and carbon monoxide. The equation for
this reaction at equilibrium is shown below.
H2(g) + CO2(g) = H2O(g) + CO(g)
Which of the following changes in concentration occur when more water vapor is added to the system under equilibrium conditions?
O A [Hz] decreases, [CO] decreases, [CO] increases
OB (H) increases, (CO2) increases, [CO] decreases
OC [Hz, increases, [CO2, increases, [CO] increases
D. [H2, decreases, [CO] decreases, [CO] decreases
why Hydroxide ion is less strong base than hydride ion
Answer:
The hydride ion,H−is a stronger base, so it will abstract a proton from the water. As the water will give protons, so water will work as an acid and an acid-base reaction will take place. Hydride ions get protons from water and form hydrogen gas and hydroxide ions.
Sodium hydride is the chemical compound with the empirical formula NaH. This alkali metal hydride is primarily used as a strong yet combustible base in organic synthesis. NaH is a saline (salt-like) hydride, composed of Na+ and H− ions, in contrast to molecular hydrides such as borane, methane, ammonia, and water.
A solution made by dissolving 9.81 g of a nonvolatile, nonelectrolyte in 90.0 g of water boiled at 100.37 °C at 760 mm Hg. What is the molar mass of the substance? [kp = 0.51 °c/m]
Answer:
151 g/mol
Explanation:
In order to solve this problem we need to keep in mind the formula for the boiling point elevation:
ΔT = Kb * m * iWhere:
ΔT is the temperature difference between the boiling point of the solution and that of pure water. 100.37 °C - 100.00 °C = 0.37 °C.m is the molarity of the solutioni is the van't Hoff factor. As the solute is a nonelectrolyte, the factor is 1.Input the data and calculate m:
0.37 °C = 0.51 °C/m * m * 1 m =0.72 mWe now can calculate the number of moles of the substance, using the definition of molarity:
molarity = moles of solute / kg of solventIn this case kg of solvent = 90.0 g / 1000 = 0.090 kg
0.72 m = moles / 0.090 kgmoles = 0.065 molFinally we calculate the molar mass, using the number of moles and the mass:
9.81 g / 0.065 mol = 151 g/molA molecule or ion that donates the hydrogen in a hydrogen bond is a hydrogen bond donor
a. True
b. False
Answer:
True
Explanation:
Hydrogen bonding is a type of intermolecular interaction that occurs when hydrogen is bonded to a highly electronegative atom.
We define the term ''hydrogen bond donor'' as the molecule that supplies the hydrogen atom in the hydrogen bond.
Hence, it is true that the molecule or ion that donates the hydrogen in a hydrogen bond is a hydrogen bond donor
Choose the substance with the highest viscosity. Choose the substance with the highest viscosity. CF4 C7H16 C2H4I2 HOCH2CH2CH2CH2OH (CH3CH2)2CO
Answer:
C2H4I2
Explanation:
Viscosity of a fluid has to do with the internal friction between the internal layers of the fluid.
Molecular weight is found to be related to the viscosity of a fluid even though the relationship may not be strictly linear.
However, the greater the molecular weight of a substance, the greater the viscosity of the material.
Since C2H4I2 has the greatest molecular weight (281.86 g/mol), it is also expected to display the greatest viscosity among all the compounds listed in the question.
A 29.00 mL sample of an H2SO4 solution of unknown concentration is titrated with a 0.1122 M KOH solution. A volume of 43.22 mL of KOH was required to reach the equivalence point.
What is the concentration of the unknown H2SO4 solution? Express your answer using four significant figures.
Answer: The concentration of the unknown [tex]H_{2}SO_{4}[/tex] solution is 0.167 M.
Explanation:
Given: [tex]V_{1}[/tex] = 29.00 mL, [tex]M_{1}[/tex] = ?
[tex]V_{2}[/tex] = 43.22 mL, [tex]M_{2}[/tex] = 0.1122 M
Formula used to calculate concentration of the unknown [tex]H_{2}SO_{4}[/tex] solution is as follows.
[tex]M_{1}V_{1} = M_{2}V_{2}[/tex]
Substitute the values into above formula as follows.
[tex]M_{1}V_{1} = M_{2}V_{2}\\M_{1} \times 29.00 mL = 0.1122 M \times 43.22 mL\\M_{1} = 0.167 M[/tex]
Thus, we can conclude that concentration of the unknown [tex]H_{2}SO_{4}[/tex] solution is 0.167 M.
A typical dollar bill is 15.50 cm by 6.50 cm.
Calculate the surface area in square meters, square centimeters and square nanometers
Answer:
0.010075 m²100.75 cm²1.0075x10¹⁶ nm²Explanation:
As the measurements are given to us in centimeters, let's start by calculating the surface area in square centimeters:
Area = 15.50 cm * 6.50 cm = 100.75 cm²Now we convert 100.75 cm² to m², as follows:
100.75 cm² * [tex](\frac{1m}{100cm}) ^2[/tex] = 0.010075 m²Finally we convert 0.010075 m² to nm², as follows:
0.010075 m² * [tex](\frac{1nm}{1x10^{-9}m}) ^2[/tex] = 1.0075x10¹⁶ nm²what is the enthalpy of the overall chemical reaction
Answer:
For a chemical reaction, the enthalpy of reaction (ΔHrxn) is the difference in enthalpy between products and reactants; the units of ΔHrxn are kilojoules per mole
What is leukemia
A
B
C
D
C. Cancer that affects the blood
Hope I could help!
For the reaction...
H2 (g) + Cl2 (g) <=> 2HCl (g) + heat
If the pressure in the system is increased, the equilibrium position will _______.
a)shift to the left
b)shift to the right
c)not shift position at all as 2 mol gas <=> 2 mol gas
Answer:
A: Shift to the left
Explanation:
The reaction would try to use up the added heat by making more H 2 and Cl 2.
Based on your knowledge of factors affecting the rate of reaction, why is there a danger of explosions in places such as flour mills and coal mines where there are large quantities of powdered, combustible materials? 
For an aqueous solution of sucrose (C12H22O11), determine:
the number of moles of sucrose in 1.50 L of this solution
Answer:WHAT GRADE WORK IS THIS ?
Explanation:
Consider the dehydration of 2-propanol in sulfuric acid: There is a scheme of a reaction where CH3 CH CH3 with an OH group attached to the second carbon atom dehydrated in the presence of H2SO4. Draw the structure for the product of the dehydration of 2-propanol.
Answer:
CH2=CH-CH3
Explanation:
One of the ways of preparing alkenes is by dehydration of alcohols using sulphuric acid. The sulphuric acid merely acts as a catalyst in the process.
It begins with the protonation of the -OH group. This is followed by loss of water molecule since water is a good leaving group.
Loss of a proton now completes the mechanism and regenerates the acid catalyst.
The mechanism of dehydration of 2-propanol as well as the product formed in the process is shown in the image attached to this answer.
what are the most common measurements used to describe gases in chemistry
Four quantities must be known for a complete physical description of a sample of a gas: temperature, volume, amount, and pressure. ... The height of the mercury column is proportional to barometric pressure, which is often reported in units of millimeters of mercury (mmHg), also called torr.
NO2 (nitrogen dioxide) is a Greenhouse Gas that can be produced in car engines. The average diesel truck produces 80g of NO2 for every 1000 kilometers it drives. How many moles of NO2 are in 80g of NO2?
Answer:
[tex]1.74molNO_2[/tex]
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to perform mole-mass relationships by using the molar mass of the involved substance, in this case NO2, which is 46.0 g/mol; then we just set up a conversion factor like the one shown below:
[tex]80g*\frac{1mol}{46g}\\\\1.74molNO_2[/tex]
Regards!
Which is most likely the reason the U.S government made such an investment
Answer:
The U.S government made such an investment because they're most likely to reduce harmful emissions.
The pH for several solutions is given below. After filling in each blank with the correct number, arrange the substances mentioned at the beginning of each sentence in order from most acidic to most alkaline.
a. Black coffee has a pH of 5, therefore its H+ concentration is __________times greater than a solution with a pH of 10
b. Urine has a pH of 6, therefore its H+ concentration is ________times greater than a solution with a pH of 9.
c. Household ammonia has a pH of 11, therefore its H+ concentration is__________ times less than a solution with a pH of 7 .
d.Grapefruit juice has a pH of 3, therefore its H+ concentration is_______ times greater than a solution with a pH of 5 .
2
100
1000000
4
100000
10
3
100,000
1000
5
how
the
Way
of
it's
the Base
Question 8 (5 points)
(08.02 MC)
A 10 M concentrated stock solution of NaCl was used to prepare 5 liters of diluted 1 M solution. Which of the following statements is true about
the
process used to achieve this required dilution? (5 points)
O a
The volume of stock solution used was less than 0.4 liters.
Oь
The volume of stock solution used was more than 5 liters.
Ос
The volume of the solvent used was less than 0.4 liters.
Od
The volume of the solvent used was less than 5 liters.
Answer:
d . The volume of the solvent used was less than 5 liters.
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to calculate the volume of the stock (initial) solution by using the following equation:
[tex]M_1V_1=M_2V_2[/tex]
Thus, we solve for, V1, which stands for the aforementioned volume of stock solution:
[tex]V_1=\frac{M_2V_2}{M_1}[/tex]
Then, we plug in to obtain:
[tex]V_1=\frac{5L*1M}{10M}\\\\V_1=0.5L[/tex]
Now, since the final volume was 5 L, we can infer that the volume of solvent is 4.5 L and that of the stock solution 0.5 L for a total of 5 L of diluted solution; therefore, the correct reasoning is d . The volume of the solvent used was less than 5 liters.
Regards!
Answer:
The volume of the solvent is less than 5
Explanation:
aluminum chloride and bubbles of hydrogen gas are produced when metallic aluminum is placed in hydrochloride acid. what is a balanced equation for this reaction?
Answer:
AlCl3 + HCl ===> AlCl4 +H-
Look at the equation CO2 + H2 = CO + H20.
CO is a ________
reactant and a product
reactant
product
Answer:
CO is considered as a product.
Explanation:
A general chemical equation for a combination reaction follows:
To write a chemical equation, we must follow some of the rules:
The reactants must be written on the left side of the direction arrow.
A '+' sign is written between the reactants, when more than one reactants are present.
An arrow is added after all the reactants are written in the direction where reaction is taking place. Here, the reaction is taking place in forward direction.
The products must be written on the right side of the direction arrow.
A '+' sign is written between the products, when more than one products are present.
For the given chemical equation:
are the reactants in the reaction and are the products in the reaction.
Hence, CO is considered as a product.
With the temperature held constant at 300 K, use the Select mass slider to place weights on the lid. Record the pressure and volume of the gas for each added mass.
Added mass on the lid Total mass Pressure Volume
(Lid + added mass)
0 kg 10 kg
10 kg 20 kg
20 kg 30 kg
30 kg 40 kg
Solution :
When the temperature is held constant at 300 K, we can use the Select mass slider in order to place the weights on the lid. And we record the pressure and also the volume of the gas for each of the added mass.
Added mass on the lid Total mass Pressure Volume
0 kg 10 kg 98.1 [tex]N/m^2[/tex] [tex]2.54 \ m^3[/tex]
10 kg 20 kg [tex]196.2 \ N/ m^2[/tex] [tex]1.27 \ m^3[/tex]
20 kg 30 kg [tex]294.3 \ N/ m^2[/tex] [tex]0.85 \ m^3[/tex]
30 kg 40 kg [tex]392.4 \ N/ m^2[/tex] [tex]0.43 \ m^3[/tex]
As the pressure increases at a constant temperature, the volume of the gas decreases.
Thus we can see that the pressure is inversely proportional to the volume.
For a phase change, H0 = 2 kJ/mol and A S0 = 0.017 kJ/(K•mol). What are
AG and the spontaneity of the phase change at 500 K?
Answer:
ΔG = -6.5kJ/mol at 500K
Explanation:
We can find ΔG of a reaction using ΔH, ΔS and absolute temperature with the equation:
ΔG = ΔH - TΔS
Computing the values in the problem:
ΔG = ?
ΔH = 2kJ/mol
T = 500K
And ΔS = 0.017kJ/(K•mol)
Replacing:
ΔG = 2kJ/mol - 500K*0.017kJ/(K•mol)
ΔG = 2kJ/mol - 8.5kJ/mol
ΔG = -6.5kJ/mol at 500KUse the drop-down menus to classify each of the following as an addition, substitution, elimination, or
condensation reaction.
CH3CHO+H2O → CH3OCH3
CH,CICH CI + Zn → C2H4 + ZnCl2
CH3CH3Br + OH – CH3CH3OH + Br
2CH2COOH
>>
(CH3CO)20 + H20
Answer:
CH3CHO+H2O → CH3OCH3 - addition
CH,CICH CI + Zn → C2H4 + ZnCl2 - elimination
CH3CH3Br + OH – CH3CH3OH + Br - substitution
2CH2COOH >>(CH3CO)20 + H20 - condensation
Explanation:
An addition reaction is a reaction in which a specie is added across the double bond as we can see in CH3CHO+H2O → CH3OCH3.
In an elimination reaction, a small molecule is lost from a saturated compound to form the corresponding unsaturated compound as in CH,CICH CI + Zn → C2H4 + ZnCl2
In a substitution reaction, a chemical moiety replaces another in a molecule as in; CH3CH3Br + OH – CH3CH3OH + Br .
A condensation reaction is in which two molecules are joined together to form a bigger molecule as in; 2CH2COOH >>(CH3CO)20 + H20.
Answer:
addition
elimination
substitution
condensation
Which of the following compounds is composed of Al,Si,O and H
A.Epsom salt
B.Limestone
C.Clay
D.Urea
Explanation:
the answer is clay as seen from the picture