Answer:
The work was to demonstrate a repaid, precise and accurate determination method for ten trace elements (Al, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Se and Zn) in periostracum serpentis (PS) and periostracum cicadae (PC) by inductively coupled plasma atomic emission spectrometry (ICP-AES). In order to evaluate the best digestion method, three different sample digestion methods including dry ashing, wet ashing and microwave digestion procedures were compared in this study.
Explanation:
What happens to the conductivity of water when a base is dissolved in it.
Answer:
See Explanation
Explanation:
The conductivity of water refers to how much it conducts electricity. The electrical conductivity of water increases as more ions are dissolved in it.
Hence, increase in concentration of dissolved ions improves the electrical conductivity of water.
Therefore, when a base (which is an ionic substance) is dissolved in water, the concentration of ions present increases and the conductivity of the solution increases accordingly since ions are charge carriers in solution.
The addition of a base to the sample results in an increase in the conductivity of the sample.
Conductivity can be defined as the transfer of charge by the sample. The sample has consisted of the ions that mediate the transfer of charge.
The sample with a high number of ions has consisted of high conductivity and vice versa. The dissolution of acid or base to the solution results in an increase in the number of ions in the solution, and thereby there has been an increase in the charge transfer.
Thus, with the increase in the charge transfer, there has been an increase in the conductivity of the sample.
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Share a family recipe for a cooking class- marking brainliest
Answer:
Sopes
In order to make them you will need
1.flour
2.Cheese
3.Lettuce
4. beans
5.tomatoe
Help please :) I don’t understand
Answer:
#3
Explanation:
What do we call a large group of wind turbines used to generate electricity?
1)Wind Pack
2)Wind Mill
3) Wind Farm
4) Wind Plant
Answer:
your answer is 3 hope this helps you
Answer:
A wind farm
Explanation:
another word is a wind park
balance and find out the coefficients of reactions and products
Answer:
2, 1, 1, 4.
Explanation:
Hello there!
In this case, for the given chemical reaction:
[tex]H_2SO_4+Pb(OH)_4\rightarrow Pb(SO_4)_2+H_2O\\[/tex]
We can see how there is one SO4 on the left and two on the right, thus, we add a 2 in front of H2SO4:
[tex]2H_2SO_4+Pb(OH)_4\rightarrow Pb(SO_4)_2+H_2O\\[/tex]
Next, since there are 8 atoms of hydrogen on the left and two on the right, we add a 4 in front of H2O to obtain:
[tex]2H_2SO_4+Pb(OH)_4\rightarrow Pb(SO_4)_2+4H_2O\\[/tex]
Which is now balanced so the coefficients 2, 1, 1, 4.
Best regards!
What is the ratio by atoms of elements present in hafnium phosphite?
1:3:4
3:6:2
3:4:12
1:6:15
3:6:2 is the correct answer
According to the Kinetic Molecular Theory, which container has helium particles with the greatest average kinetic energy?
Answer:
Explanation:
The correct option would be that the average kinetic energy of the gas particles is greater in container B because it has a higher temperature.
According to the kinetic theory of matter, the temperate of a substance is a measure of the average kinetic energy of the molecules of substance. In other words, the higher the temperature of a substance, the higher the average kinetic energy of the molecules of the substance.
In the illustration, the gas in container B showed a higher temperature than that of container A as indicated on the thermometer, it thus means that the average kinetic energy of the molecules of gas B is higher than those of gas A.
Iron is obtained by reaction of hematite (Fe2O3) with carbon monoxide. From the balanced reaction below, how many grams of iron is produced when 24.6 mol of hematite is used up in the reaction?
Fe2O3 + 3CO ® 2Fe + 3CO2
Answer: 2755.2 g of [tex]Fe[/tex] will be produced from 24.6 mol of haematite.
Explanation:
The balanced chemical equation is:
[tex]Fe_2O_3+3CO\rightarrow 2Fe+3CO_2[/tex]
According to stoichiometry :
1 mole of [tex]Fe_2O_3[/tex] produce = 2 moles of [tex]Fe[/tex]
Thus 24.6 moles of [tex]Fe_2O_3[/tex] will produce=[tex]\frac{2}{1}\times 24.6=49.2moles[/tex] of [tex]Fe[/tex]
Mass of [tex]Fe=moles\times {\text {Molar mass}}=49.2moles\times 56g/mol=2755.2g[/tex]
Thus 2755.2 g of [tex]Fe[/tex] will be produced from 24.6 mol of haematite.
During the Viking landings on Mars, the atmospheric pressure was determined to be on the average about 6.50 millibars (1 bar = 0.987 atm). What is that pressure in torr and kPa?
Answer:
The pressure is equal to 4.87 torr and 0.649 kPa.
Explanation:
The atmospheric pressure was determined to be on the average about 6.50 millibars.
As 1 bar = 0.987 atm
6.5 mbar = 0.0065 bar
So,
0.0065 bar = (0.0065×0.987 ) atm
= 0.0064155 atm
Since, 1 atm = 760 torr
So, 0.0064155 atm = 4.87 torr
Since, 1 torr = 133.322 Pa
4.87 torr = 649.27 pa
or
4.87 torr = 0.649 kPa
Hence, the required pressure is equal to 4.87 torr and 0.649 kPa.
The value of H° for the reaction below is -72 kJ. ________ kJ of heat are released when 5.5 mol of HBr is formed in this reaction.
Answer:
-198 kJ
Explanation:
Hello there!
In this case, as the reaction is not given but we can see that HBr is formed, we can infer that reaction is:
[tex]H_2+Br_2\rightarrow 2HBr[/tex]
Whereas the -72 kJ per moles of HBr are:
[tex]\frac{-72kJ}{2molHBr}[/tex]
Thus, by multiplying by the formed 5.5 moles of HBr, the total energy release is:
[tex]\frac{-72kJ}{2molHBr} *5.5molHBr\\\\=-198kJ[/tex]
Best regards!
How does static electricity forma force field around an object?
Answer:
because its electrified and it like makes it own force feild
PLEASE HELP WILL GIVE 20PTS AND WILL MARK BRAINLIEST FOR RIGHT ANSWER!!!
Water can be formed from the synthesis reaction of hydrogen with oxygen:
2 H2 (g) + O2 (g) → 2 H2O (g)
The complete reaction of 5.12 Liters of O2 with excess hydrogen produces how many moles of H2O?
A) 10.24 moles H2O
B) 114.7 moles H2O
C) 0.457 moles H2O
D) 5.12 moles H2O
Answer:
C) 0.457
Explanation:
The ratio between O2 and H2O is 1:2 according to the balanced equation. You can find how many moles is O2 by : 5.12/22.4 = 0.22857 ( 1 mole = 22.4 litters)
Moles of H2O will be 0.22857 * 2 = 0.457142.
Therefore answer C)
Please help is for today
Answer:
Our bodies are designed to regulate our temperature. When it's cold outside, your body makes sure to keep the blood flowing to your core and vital organs to keep them warm. This can change the amount of blood flow to your hands and feet, making them feel cold
the experimental control is the ?
A. Dependent variable
B. Design of the experiment.
C. Outcome of the experiment
D. the standard against which the results are measured .
Answer:
D. In an experiment, one of the variables will be giving a placebo and the other, a treatment
Explanation:
Photosynthesis, the process by which green plants and certain other organisms transform light energy into chemical energy. During photosynthesis in green plants, light energy is captured and used to convert water, carbon dioxide, and minerals into oxygen and energy-rich organic compounds.
Express each of the following answers in the IUPAC format. Do not include any capitals or spaces in your name. Separate multiple substituent numbers using a comma. Use a hyphen between numbers and names. (ex: 1,2-dichloro-3-methylcyclopentane). Part A Spell out the full name of the molecule. Part B Spell out the full name of the molecule. Part C Spell out the full name of the molecule. Part D Spell out the full name of the molecule.
The full question is shown in the image attached
Answer:
See explanation
Explanation:
In naming an alkane, the first thing we do is to obtain the parent chain by counting the number of carbon atoms in the chain.
When we obtain that, then we identify the substituents and number them in such a way that they have the lowest numbers. The compounds shown have the following names according to the order in which the structures appear in the image attached;
1. 2-methyl propane
2. 2,4-dimethyl heptane
3. 2,2,3,3-tetramethyl butane
4. 5-ethyl-2,4-dimethyl octane
Is it posible Count a grain of sand?explain
Answer:
Yes
Explanation:
As long as its a solid, you can count it. It will be hard, but possible.
Explain why each of these elements occur as diatomic molecules, Match the words in the left column to the appropriate blanks in the sentences on the right.
triple
double
octet
single
duet
When two hydrogen atoms pair together, they form a ____bond to achieve a complete _______which is a stable configuration.
When two halogens poir together,they form a________bond to achieve a complete_______ which is a stable configuration
to achieve a completo
When two oxygen atoma pair together, they form a_________bond to achieve a complete which is a stable configuration
When two nitrogen atomo poir together, they form a_________bond to achieve a complete which is a stable configuration
Answer: When two hydrogen atoms pair together, they form a single bond to achieve a complete duet which is a stable configuration.
When two halogens poir together,they form a single bond to achieve a complete octet which is a stable configuration
When two oxygen atoma pair together, they form a double bond to achieve a complete octet which is a stable configuration
When two nitrogen atoms pair together, they form a triple bond to achieve a complete octet which is a stable configuration
Explanation:
The tendency of atoms to achieve a noble gas configuration that is eight valence electrons is said to be octet rule. This is done to attain noble gas configuration and stability.
In order to attain stability the atoms tends to have eight electrons in its valence shell which can be obtained by either by sharing of electrons or complete transfer of electrons.
Hydrogen [tex](H:1s^1)[/tex] has one valence electron each, so sharing of electrons result in formation of single bond and the same electron configuration as the Helium and thus complete its duet.
Halogens [tex](F:1s^22s^22p^5)[/tex] have 7 valence electron each, so sharing of electrons result in formation of single bond. The stable noble gas configuration is attained and thus complete its octet.
Oxygen [tex](O:1s^22s^22p^4)[/tex] has six valence electrons each, so sharing of two electrons result in a double bond. The stable noble gas configuration is attained and thus complete its octet.
Nitrogen [tex](N:1s^22s^22p^3)[/tex] has 5 valence electrons, so sharing of three electrons result in a triple bond. The stable noble gas configuration is attained and thus complete its duet.
Which of the following statements are true? Select all answers that are true (this might be more than one answer). Select one or more: a. London dispersion forces are the only type of intermolecular forces that nonpolar molecules exhibit. b. Molecules that have only London dispersion forces will always be gases at room temperature (25 oC). c. None of the listed answers are true. d. The molecules in SO2 (g) exhibit dipole-dipole intermolecular interactions. e. CH3CH2CH3 has stronger London dispersion forces than does CH4.
Answer:
London dispersion forces are the only type of intermolecular forces that nonpolar molecules exhibit.
The molecules in SO2 (g) exhibit dipole-dipole intermolecular interactions.
CH3CH2CH3 has stronger London dispersion forces than does CH4.
Explanation:
London forces result from temporary shifts or distortion in the electron cloud of non-polar molecules. London forces occur in all substances; whether polar or non-polar. However, it is the only kind of intermolecular force in non-polar molecules and noble gases.
Polarity in a molecule stems from difference in electronegativity between the atoms in the molecule. SO2 is a polar molecule due to the magnitude of electronegativity difference between sulphur and oxygen. Hence SO2 exhibit dipole-dipole intermolecular interactions since it is a polar molecule.
The magnitude of London dispersion forces depends on the molar mass and surface area of molecules. CH3CH2CH3 has a higher molar mass and larger surface area than CH4 hence CH3CH2CH3 has stronger London dispersion forces than does CH4.
The following statements which are true include
London dispersion forces are the only type of intermolecular forces that nonpolar molecules exhibit.The molecules in SO2 (g) exhibit dipole-dipole intermolecular interactions.CH3CH2CH3 has stronger London dispersion forces than does CH4.London forces are the only type of intermolecular force found in non polar
compounds and they are responsible for their attractive interactions.
The molecules in SO2 (g) exhibit dipole-dipole intermolecular interactions as
a result of it being polar.
CH3CH2CH3 has stronger London dispersion forces than does CH4
because it is more non-polar and it is the characteristic attraction found in
non-polar compounds.
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Explain if the reaction of iron and copper sulfate supports the Law of Conservation of Mass. Use evidence and scientific reasoning to support your answer.
Helen is studying the properties of solids. She is comparing the wooden cube and the steel cube shown in the picture below.
mc065-1
Which property is the same for the two cubes?
color
luster
texture
volume
more reactive material can help to stop iron rusting please answer true or false
Answer:
true
Explanation:
and don't look up the link everyone says it's scam bots
QUESTION 7
When excess magnesium was reacted with dilute sulphuric acid, the reaction was fast at first but
gradually became slower and finally stopped.
Which of the following describe the reaction?
A.
B.
The magnesium was used up.
The sulphuric acid was used up.
The temperature of the mixture decreased.
The magnesium particles became coated with hydrogen gas.
C.
D.
The reactant present in more amounts is called excess reagent. In the reaction between Mg and sulphuric acid, the reaction gradually stopped due to the consumption of the acid. Thus, option B is correct.
What is an excess reagent?An excess reagent is a chemical reactant present in more quantity than the other substance or reactant in the reaction. They are not totally consumed after the reaction ends, unlike the limiting reagent.
In the reaction, magnesium is the excess reagent while dilute sulphuric acid is a limiting reagent that determines the reaction rate and the product formation. At first, the reaction will be fast but gradually will become slow as all dilute sulphuric acid will be consumed slowing downs and stopping the reaction.
Therefore, dilute sulphuric acid will be used up at the end of the reaction.
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Which is least likely to occur after an experiment is conducted to a test a hypothesis?
The data is analyzed to see if it supports or refutes the hypothesis.
• The same experiment is conducted again to see if the data are reliable.
The hypothesis becomes a theory if the results support it.
O A new experiment is designed to provide additional data about the hypothesis.
Answer:
4th one. (A new experiment is designed to provide additional data about the hypothesis.)
Answer:
The correct answer is C)The hypothesis becomes a theory if the results support it.
Explanation:
A 250 mL beaker is submerged in a large container of Liquid X and turned upside down, and another 250 mL beaker is submerged and turned upside down in a large container of Liquid Y. Hydrogen (H2) gas is bubbled into each upside-down beaker until 100 mL of liquid has been displaced. The masses m X and my of hydrogen inside each beaker is then chemically determined.
a. mx will be greater than my
b. m x will be less than my
c. mx will be equal to my
d. It's impossible to predict whether mx or my will be greater without more information.
Answer:
Mx will be less than My.
Explanation:
The correct option is - Mx will be less than My.
Because, liquid X have been higher viscosity and vapor pressure than liquid B.
Vapor pressure of liquid A is greater, so the amount of liquid X will vaporized greater and H2 gas has been displaced greater from the beaker as compared to liquid Y.
The amount of H2 in liquid Y remains greater in beaker as compared to liquid X.
So, Mx will be less than My.
A gas cylinder initially contains 463 L of gas at a pressure of 159 atm. If the final volume of gas is 817 L, what is the final pressure?
Answer:
The final pressure is 90.1 atm.
Explanation:
Assuming constant temperature, we can solve this problem by using Boyle's Law, which states:
P₁V₁=P₂V₂Where in this case:
P₁ = 159 atmV₁ = 463 LP₂ = ?V₂ = 817 LWe input the given data:
159 atm * 463 L = P₂ * 817 LAnd solve for P₂:
P₂ = 90.1 atmThe final pressure is 90.1 atm.
If a gas has a molecular mass of 44.0, the volume of 88.0 grams of the gas at STP would be ..
1) 44.8 L
2) 11.2 L
3) 22.0 L
4) 88.0 L
How are gas giants different from each other
Answer:there different from the rocky like planets gas giants don't have such a firm surface like rocky terrestrial planets
Explanation:
Identify the Lewis base in this balanced equation: 6 upper H subscript 2 upper O plus UPper C r (upper H subscript 2 upper O) subscript 6 superscript 3 plus. H2O Cr3+ Cr(H2O)63+
The Lewis base that we can see in the equation is [tex]H_{2} O[/tex]
What is the Lewis base?We have to bear in mind that the Lewis base is the substance that is able to donate a pair of electrons. The substances that is able to accept the pair of electrons is what we call the Lewis acid.
The Lewis acid must possess a space for the addition of an electron pair while the Lewis base would have to be a specie that has a lone pair of electrons or has a negative charge. Thus the water molecule would serve as a Lewis base in this regard.
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Answer:
6 upper H subscript 2 upper O plus UPper C r (upper H subscript 2 upper O) subscript 6 superscript 3 plus.
✔ H2O or A.)
Cr3+
Cr(H2O)63+
Suggest a possible
reason for the change
in sulfur dioxide levels
in North America and
Europe around
1970-1980.
Answer: a reason for this is fossil fuels
Explanation:
The reduction in SO2 is largely due to the implementation of the Acid Rain Program under the Clean Air Act through a cap and trade program for fossil-fuel powered plants.
Electrolysis is used in the electroplating of metals. The same amount of current is passed through separate aqueous solutions of CuSO4, Sn(SO4)2 and Cr2(SO4)3 in separate electrolytic cells for the same amount of time. State and explain which cell would deposit the greatest amount (in mol) of metal. Identify the electrode at which the metal is deposited.
Answer:
CuSO4 cell will have the greatest amount of deposit among all three. The deposit will occur at the cathode
Explanation:
The valence of the elements in this case is as follows -
Cu - 2e-
Sn - 4e-
Cr - 3e-
CuSO4 cell will have the greatest amount of deposit among all three
The atoms of copper metal will deposit at the cathode. At the cathode, the least number of moles of electrons needed .
Hence, more amount of copper can be extracted out by the electrolyte