Answer:
1.34 * 10^-7 M
Explanation:
The Ksp of lead II chromate is 1.8 x 10^-14
So, we have that;
PbCrO4(s) -----> Pb^2+(aq) + CrO4^2-(aq)
s s
Where s = molar concentration of Pb^2+(aq) and CrO4^2-(aq)
and;
[Pb^2+] = [CrO4^2-]
This implies that Ksp = s^2
s = √Ksp
s = √1.8 x 10^-14
s = 1.34 * 10^-7 M
________ gas is evolved in cathode during the electrolysis of water. 20 points answer fast
Answer:
hydrogen
Explanation:
In electrolysis of water, gas evolved at cathode is hydrogen
Please help asap! Giving brainliest to correct answer.
Three sections of the periodic table are labeled A, B, and C in the image below.
Which of the following statements is most likely true for an element present in section B?
Select one:
a. It is a highly reactive metal.
b. It is an inert gas at room temperature.
c. It may act as an insulator or a conductor.
d. It is a highly reactive liquid at room temperature.
Answer:
C. It may act as an insulator or a conductor.
Explanation:
Group B are the metalloids, so they have properties of both metals and nonmetals.
The statement which is most likely true for an element present in section B is: C. It may act as an insulator or a conductor.
A periodic table can be defined as an organized tabular array of all the chemical elements, which is typically arranged in order of increasing atomic number or number of protons (in rows).
In this diagram, the chemical element that is present in section B of the periodic table is a metalloid.
A metalloid can be defined as a chemical element that are typically intermediate between those of semiconductors, non-metals and metals.
Thus, a metalloid has both chemical and physical properties that are a combination of metals and non-metals or semiconductors.In this context, the statement which is most likely true for an element present in section B is that it may act as an insulator or a conductor because it is a metalloid.
Read more: https://brainly.com/question/17482288
What element has 12 protons, 12 neutrons and 12 electrons?
Answer:
magnesium atom
The most common and stable type of magnesium atom found in nature has 12 protons, 12 neutrons, and 12 electrons
One way to represent this equilibrium is: 2 Al(s) 3 Br2(l)2 AlBr3(s) We could also write this reaction three other ways, listed below. The equilibrium constants for all of the reactions are related. Write the equilibrium constant for each new reaction in terms of K, the equilibrium constant for the reaction above.
The question is incomplete, the complete question is;
Aluminum metal and bromine liquid (red) react violently to make aluminum bromide (white powder). One way to represent this equilibrium is:
Al(s) + 3/2 Br2(l)AlBr3(s)
We could also write this reaction three other ways, listed below. The equilibrium constants for all of the reactions are related. Write the equilibrium constant for each new reaction in terms of K, the equilibrium constant for the reaction above.
1) 2 AlBr3(s) 2 Al(s) + 3 Br2(l)
2) 2 Al(s) + 3 Br2(l) 2 AlBr3(s)
3) AlBr3(s) Al(s) + 3/2 Br2(l)
Answer:
See explanation
Explanation:
We have that; Al(s) + 3/2 Br2(l)AlBr3(s)
So;
Al(s) + 3/2 Br₂(l) = AlBr₃(s)
K = [ AlBr₃] / [ Al] [ Br₂]³/²
K² = [ AlBr₃]² / [ Al ] ² [ Br₂]³
Now;
1) 2 AlBr₃ = 2 Al(s) + 3 Br₂(l) =
K₁ = [ Al ] ² [ Br₂]³ / [ AlBr₃]²
K₁ = ( 1 / K² ) = K⁻²
For the second reaction;
2 ) 2 Al(s) + 3 Br₂(l) = 2 AlBr₃(s)
K₂ = [ AlBr₃ ]² / [ Al ]² [ Br₂ ]³
K₂ = K²
For the third reaction;
3 )
AlBr₃(s) = Al(s) + 3/2 Br₂(l)
K₃ = [ Al ] [ Br₂ ] ³/² / [ AlBr₃ ]
= ( 1 / K ) = K⁻¹
Please help
15 points
Given
Atomic symbol
RequiredAtomic composition
Solution
Atomic number = number of protons = number of electrons
Mass Number (A) is the sum of protons and neutrons
Number of protons and Number of Neutrons in nucleus
Number of electrons in the shell
From the picture:
protons = 3
neutrons = 4
electrons = 3
atomic number = protons = electrons = 3
mass number = protons + neutrons = 3+4 = 7
Breathing equipment used by rescue workers needs to capture the CO2 the humans breath out and produce O2 for them to breath in, like a plant during photosynthesis. One compound capable of doing this is potassium superoxide (KO2), which produces the salt by-product potassium carbonate. What is the balanced chemical equation for this reaction? Don't include states of matter.
Answer: [tex]4KO_2+2CO_2\rightarrow 2K_2CO_3+3O_2[/tex]
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
The balanced chemical equation for reaction of potassium superoxide with carbon dioxide to produce oxygen and potassium carbonate will be:
[tex]4KO_2+2CO_2\rightarrow 2K_2CO_3+3O_2[/tex]
A chemist carefully measures the amount of heat needed to raise the temperature of a 894.0g sample of a pure substance from to −5.8°C to 17.5°C. The experiment shows that 4.90kJ of heat are needed. What can the chemist report for the specific heat capacity of the substance?
Answer:
C = 0.2349 J/ (g °C)
Explanation:
Mass, m = 894.0g
Initial Temperature = −5.8°C
Final Temperature = 17.5°C
Temperature change = 17.5°C - (−5.8°C) = 23.3
Heat, H = 4.90kJ = 4900 J
Specific heat capacit, C = ?
The relationship between these quantities is given by the equation;
H = mCΔT
C = H / mΔT
C = 4900 / (894)(23.3)
C = 0.2349 J/ (g °C)
Which of the following materials will conduct electricity well?
Cotton
Metal
Rubber
Wood
Answer:
Metal
Explanation:
Rubber and Wood are insulators. and Cotton is neither a insulator nor a conductor. But Metals are conductors
Question asked: Which of the following materials will conduct electricity well?
Answer: Metal
____________________________________________________
I hope this helps!
The acid digestion test left 2.595 g of fiber from a composite specimen weighing 3.697 g. The composite specimen weighs 1.636 g in water. If the specific gravity of the fiber and matrix is 2.5 and 1.2, respectively, find the 1. Theoretical volume fraction of fiber and matrix 2. Theoretical density of composite
Answer:
0.4323 ; 1.5394
Explanation:
Given that :
Specific gravity of Fibre (Sf) = 2.5
Specific gravity of Matrix (Sm) = 1.2
Mass of Fibre, Mf = 2.595g
Weight of composite specimen in water , Wc = 1.636g
Composite weight, Ww = 3.697 g
Weight of Fibre and matrix
Volume fraction of Fibre and matrix :
[(Mf/Sf) ÷ (Mf/Sf + Wc/Sm)] * 100
[(2.595/2.5) ÷ (2.595/2.5 + 1.636/1.2)]
(1.038 ÷ 2.4013333)
= 0.43225986
= 0.4323
2.)
Theoretical density of composite :
Weight of composite / (Mf/Sf + Wc/Sm)
3.697 / (2.595/2.5 + 1.636/1.2)
3.697 / 2.4013333
= 1.5395613
= 1.5394
A given compound has the following solubility properties. At room temperature, it is soluble in diethyl ether but insoluble in both ethanol and water. At higher temperatures, it is soluble in both diethyl ether and ethanol, but insoluble in water. Propose a procedure for purifying this compound by recrystallization.
Answer:
See explanation
Explanation:
If we desire to recrystallize the given compound then we must do the following;
1) Add the compound to ethanol and heat the system
2) As the solute dissolves, the solution is allowed to cool
3) The solution may be seeded or the vessel scratched to aid crystallization.
4) The pure crystals are now filtered out, washed and dried.
Remember that recrystallization has to do with dissolving a solute in a solvent in which it is only soluble at high temperature but insoluble at low temperature.
The solvent dissolves the impure solute while pure crystals emerges as the temperature decreases.
There is a third bromobutene structure that could have been formed in the addition of HBr to butadiene: cis-1-bromor-2-butene (the cis isomer of structure 2). Draw this structure. Would you predict (no calculation) its heat of formation to be more or less negative that the trans isomer? Explain.
Answer:
its less negative hope I helped buster
Because trans isomers are more stable than cis isomers, the cis isomer will have a less negative heat of formation than the trans isomer.
What are cis- and trans- isomers?Cis- and trans isomers are compounds that have different configurations in space because of the presence of a rigid structure or functional groups in their molecule.
Cis atoms have functional groups on the same side.
Trans isomers have functional groups on alternate different.
The structure of cis-1-bromor-2-butene is attached.
Generally, trans isomers are more stable than cis isomers..
Stable compounds have more negative heat of formation while unstable compounds have less negative heat of formation.
Therefore, the cis isomer will have a less negative heat of formation than the trans isomer.
Learn more about cis and trans isomers at: https://brainly.com/question/4625349
A magnetic field protects Earth from the Sun's high-energy particles. What two processes are involved in the formation
of Earth's magnetic field?
the movement of materials in Earth's mantle and Earth's rotation
the movement of metals in Earth's core and Earth's rotation
the movement of solar wind toward Earth and Earth's revolution
the movement of eruptions from the Sun's surface and Earth's revolution
Answer:
B
Explanation:
Answer:
definetly b
Explanation:
Predict the chemical formula of the compound that will form when Li and o interact.
Answer:
[tex]Li_2O[/tex]
Explanation:
Hello!
In this case, when looking over the chemical formula of a compound formed when two elements interact, we need to realize about their location in the periodic table; thus, since lithium is a metal and oxygen a nonmetal, we infer lithium turns out the cation and oxygen the anion. Moreover, as the oxidation state of lithium is 1+ and that of oxygen is 2-, we can set up the chemical formula as follows:
[tex]Li^+O^{2-}\\\\Li_2O[/tex]
Best regards!
(ILL GIVE 100 POINTS AND EDIT IT AND MARK BRAINLIEST) Examine the diagram of the cell cycle. Which label identifies the stage in which the DNA is copied and the cell grows? W X Y Z
Answer:
where is diagram. sorry.
You find yourself in a room with dark gray walls. Medeleev’s image says, “This element is essential for plant life to thrive and is found in heavy clay minerals and the ash from your campfire.” What element are these walls made from?
Answer:
juvn hgf jb ujvi i junk food sux
Explanation:
Part A Indicate whether each statement is true or false. Sort these statements into the proper categories. ResetHelp NaClNaCl dissolves in water but not in benzene because the water-ion interactions are stronger than benzene-ion interactions.NaClNaCl dissolves in water but not in hexane because the enthalpy of mixing NaClNaCl with water is more negative than that of mixing NaClNaCl with hexane.NaClNaCl dissolves in water but not in benzene (C6H6)(C6H6) because there are no hydrogen bonds in benzene. True False
Answer:
Explanation:
NaCl dissolves in water but not in benzene because the water-ion interactions are stronger than benzene-ion interactions.
This statement is true . NaCl is ionic compound . I water is ionises strongly because of strong ion - water interaction . It does not dissolve in benzene because of low ion - benzene interaction .
NaCl dissolves in water but not in hexane because the enthalpy of mixing NaCl with water is more negative than that of mixing NaCl with hexane.
This statement is wrong because enthalpy of mixing NaCl with water is positive and not negative .
NaCl dissolves in water but not in benzene(C6H6) because there are no hydrogen bonds in benzene.
This statement is wrong . NaCl does not make hydrogen bond with water molecule .
NaCl dissolves in water but not in benzene because the water-ion interactions are stronger than benzene-ion interactions.This statement is true .
What is an ion ?The term ion is defined as an ion is an atom or molecule with a net electrical charge. There are two types of ions that are cation and anion.
This statement is true . NaCl is an ionic compound . The water is ionizes strongly because of strong ion - water interaction . It does not dissolve in benzene because of low ion - benzene interaction .
NaCl dissolves in water but not in hexane because the enthalpy of mixing NaCl with water is more negative than that of mixing NaCl with hexane. This statement is wrong because enthalpy of mixing NaCl with water is positive and not negative .
NaCl dissolves in water but not in benzene(C6H6) because there are no hydrogen bonds in benzene. This statement is wrong . Because NaCl does not make hydrogen bond with water molecule .
Thus, NaCl dissolves in water but not in benzene because the water-ion interactions are stronger than benzene-ion interactions.
To learn more about an ion, follow the link;
https://brainly.com/question/14982375
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Pls answer this two ASAP PLSSSSSSSS
Answer:
1. aa
2. They have similar DNA
Explanation:
1. According to the question 1, wrinkled seeds (A) are dominant over round seeds (a) in pea plants. This means that, based on the law of dominance proposed by Mendel, wrinkled seeds will be expressed over round seeds in a heterozygous state (Aa).
However, since the round seed phenotype is a recessive trait, it will only be expressed when the alleles for round seeds (a) are the same in the gene i.e. aa genotype.
2. Based on the information in question 2, Ricky, who is working on a family tree for his school project, realizes that his close relatives all look similar in the pictures he collected. This is possible because of the SIMILARITY OF THEIR DNA (genetic material). Note that, relatives are connected by the genes that are inherited from one another, hence, they possess a similar DNA, which is the most valid reason for the resemblance.
Ok so I don't understand how to do this-
Can someone explain how?
Shanghai, China (31° N, 121° E)
1. 24-hr Average Yearly Temperature in ºC
2. Total Yearly Precipitation in mm
Answer:
Oh, you are supposed to look up the yearly temp, and yearly rain for a certain area. I did this before!
cellular respiration uses glucose and oxygen to make
Answer:
The answer is: ATP
(Im pretty sure)
WORTH 35 POINTS! MY LIFE DEPENDS ON IT HELP!
When naming ionic compounds, always
1. use prefixes
2. write the metal first
3. write the nonmetal first
4. capitalize the metal and nonmetal
Answer
2.Write the metal first ( if I am right) as it is ionised
explain the difference between aldehyde and ketones
Answer:
You will remember that the difference between an aldehyde and a ketone is the presence of a hydrogen atom attached to the carbon-oxygen double bond in the aldehyde. Ketones don't have that hydrogen. ... Aldehydes are easily oxidized by all sorts of different oxidizing agents: ketones are not.
Which refers to any disturbance that carries energy from one place to another?
Answer:
A wave
Explanation:
A wave is a disturbance that carries energy from one place to another. Matter is not carried with the wave but instead a wave can move through matter.
Answer:
A Wave
Explanation:
True or false questions?
Most metal elements are brittle and do not conduct electricity. True or False
Any element can be identified by counting the protons in its neucleus. True or False
All Earths matter is made from the combination of about 100 elements. True or false
Answer:
1. False 2.True3.True? Unsure
Explanation:
How to get the density of this unknown liquid?
Answer:
Measure the volume of water poured into a graduated cylinder, then place the object in the water and remeasure the volume. The difference between the two volume measurements is the volume of the object. Now simply divide the mass by the volume to calculate the density of the object.
How many molecules are in 97.21 grams of Sodium Chloride (NaCl)?
Convert 76.78 g of CO2 to a volume.
What would be the mass of 300 liters of dinitrogen monoxide
at STP?
Answer:589 g
Explanation:just answered the question
how many moles are in a 25.0 grams of carbon dioxide
answer:44.0095
Explanation:
sana makatulong
Answer:
44.0095
Explanation:
We assume you are converting between grams CO2 and mole. You can view more details on each measurement unit: molecular weight of CO2 or mol This compound is also known as Carbon Dioxide. The SI base unit for amount of substance is the mole.
When investigating a factor that effects the rate of photosynthesis, you needed to keep the
plant at a temperature of 250C. How did you do this?
Answer:
Photosynthesis defines the process by which plants and some bacteria manufacture glucose. Scientists summarize the process as follows: using sunlight, carbon dioxide + water = glucose + oxygen. The process occurs within special structures called chloroplasts located in the cells of leaves. Optimum photosynthetic rates lead to the removal of greater amounts of carbon dioxide from the local atmosphere, producing greater amounts of glucose. Since glucose levels within plants are difficult to measure, scientists utilize the amount of carbon dioxide assimilation or its release as a means to measure photosynthetic rates. During the night, for example, or when conditions are not prime, plants release carbon dioxide. Maximum photosynthetic rates vary between plant species, but crops such as maize can achieve carbon dioxide assimilation rates as high as 0.075 ounce per cubic foot per hour, or 100 milligrams per decimeter per hour. To achieve optimum growth of some plants, farmers keep them in greenhouses that regulate conditions such as humidity and temperature. There are three temperature regimes over which the rate of photosynthesis changes.
Low Temperature
Enzymes are protein molecules used by living organisms to carry out biochemical reactions. The proteins are folded into a very particular shape, and this allows them to bind efficiently to the molecules of interest. At low temperatures, between 32 and 50 degrees Fahrenheit – 0 and 10 degrees Celsius – the enzymes that carry out photosynthesis do not work efficiently, and this decreases the photosynthetic rate. This leads to a decrease in glucose production and will result in stunted growth. For plants inside a greenhouse, the installation of a greenhouse heater and thermostat prevents this from occurring.
Explanation:
A first order reaction has a rate constant of 0.924 at 25 oC. Given that the activation energy is 89.8 kJ/mol, calculate the rate constant at 33.3 oC.
Answer:
[tex]k_2=2.46[/tex]
Explanation:
Hello!
In this case, according to the Arrhenius equation for variable temperature:
[tex]ln(\frac{k_2}{k_1} )=-\frac{Ea}{R}(\frac{1}{T_2} -\frac{1}{T_1} )[/tex]
Given the temperatures to be computed in kelvins and the activation energy, we obtain:
[tex]ln(\frac{k_2}{0.924} )=-\frac{89800J/mol}{8.314J/(mol*K)}(\frac{1}{306.45K} -\frac{1}{298.15K} )\\\\ln(\frac{k_2}{0.924} )=0.981\\\\k_2=0.924*exp(0.981)\\\\k_2=2.46[/tex]
Best regards!