why the table perdioc has 3 columns in its group 8 ,
i need reference about that please
Answer: It just haven’t been discovered yet
Explanation:
Because the periodic table was discovered long ago some elements haven’t been discovered thats why it maybe has 3 columns
To determine the heat of neutralisation, Chelsea placed 50 cm' of sodium hydroxide
solution of concentration 1.0 mol dm- in a polystyrene cup and recorded its
temperature. She then recorded the temperature of 50 cm of sulfuric acid, added it
to the cup, stirred the solution and recorded its maximum temperature, as follows:
. initial temperature of NaOH(aq) = 29.5 °C
. initial temperature of H.SO, (aq) = 29.9 °C
• maximum temperature of the solution = 35.8 °C
Calculate the increase in temperature
2 solutions of NaOH and H₂SO₄ at 29.5 °C are mixed in a coffee-cup calorimeter and after the reaction is completed the temperature is 35.8 °C. The increase in the temperature is 6.3 °C.
To determine the heat of neutralization, Chelsea used a coffee-cup calorimeter.
Initially, she had 2 solutions, NaOH and H₂SO₄, both at 29.5 °C. Upon mixing, the heat was evolved and the final temperature of the solution was 35.8 °C. The neutralization reaction was:
NaOH + H₂SO₄ ⇒ Na₂SO₄ + H₂O
The increase in temperature (ΔT) is equal to the difference between the final temperature and the initial temperature.
[tex]\Delta T = 35.8 \° C - 29.5 \° C = 6.3 \° C[/tex]
This data can be used to calculate the heat of neutralization (q) using the following expression.
[tex]q = c \times m \times \Delta T[/tex]
where,
c is the specific heat capacity of the solutionm is the mass of the solution2 solutions of NaOH and H₂SO₄ at 29.5 °C are mixed in a coffee-cup calorimeter and after the reaction is completed the temperature is 35.8 °C. The increase in the temperature is 6.3 °C.
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What is an example of microorganisms acting in a harmful way?
Answer:
Mark me as brainlest
Explanation:
Microorganisms present in our body Re viruses, bacteria, fungi, algae, and protozoa among which most of them cause immense benefits to the body. There are some harmful microorganisms too known as pathogens which cause disease and cause a threat to all existing life forms of the earth which can result in death at times.
Answer:
An example of microorganisms acting in a harmful way is a bacteria spoiling food.
does SO3 2- show delocalized bonding
Answer:
YES
Explanation:
SO3 2-DOES show delocalized bonding
delocalized bonding occurs when there is a resonance structure and the electronic bonds are a delocalised "cloud" around the species
The resonance effect of the sulfite sructures ithe folowing link:
https://www.chemistryscl.com/general/lewis-resonance-structure-of-SO32-/index.php
Ions can be made by single element or covalently bonded group of elements. The covalently bonded group of elements is called polyatomic ions or polyatomic atoms. Therefore SO₃²⁻ show delocalized bonding.
What is Ions?Any species that contain charge whether it is positive charge or negative charge is called ions. The example of polyatomic ions are sulfate, phosphate, nitrate etc.
Cation is the species that loose electron and attain positive charge while anion is a species which gain electron and attains negative charge so when anion and cation combine in fixed ration the the overall charge of the molecule is zero that is molecule is neutral, the charge over cation and anion is also called oxidation state.
SO₃²⁻ show delocalized bonding as there is a resonance structure and the electronic bonds are a delocalized "cloud" around the species
Therefore SO₃²⁻ show delocalized bonding.
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Giving brainly for correct answer! :)
Answer: I think its in order, not really sure. First answer on top. Next answer on the left and the Last answer on the right.
Which of the following statements about mass is true? (1 point)
A. A truck has a mass of 2,500 kilograms in the United States. If it goes to Canada, the mass will be converted to weight.
B. A truck has a mass of 2,500 kilograms in the United States. If it goes to Canada, the mass will be less.
C. A truck has a mass of 2,500 kilograms in the United States. If it goes to Canada, its mass will still be 2,500 kg.
D. A truck has a mass of 2,500 kilograms in the United States. If it goes to Canada, its mass will be more.
Answer:
a because mass is converted into weight
Name the element in the second period of the periodic table with 6 valence electrons.
Answer:
Sulfur
Explanation:
Using this to make the answer 20 characters long
A cars is moving at 12 m/s and has a mass of 600 kg. What is the kinetic energy for the car? (Formula:KE= 1/2 MV2) 36,300J 43,200J 72,600J 86,400J
Explanation:
ano po topic nyo para maayos sagut
how many chemical bonds are formed in CH4 molecule
Answer:
4 covalent bonds
What best describes the transition from gas to liquid
It's condensation in which gas particles have a higher kinetic energy..
Using the bond energies provided, calculate the enthalpy of the reaction (∆Hrxn, in kJ) for the hydrogenation of propene to propane, shown below?
CH₂CHCH₃(g) + H₂(g) → CH₃CH₂CH₃(g)
The enthalpy of reaction for the hydrogenation of propene to propane is -926 kJ/mol.
The bond energy of a molecule is obtained as the sum of the bond energies of all the bonds between atoms in the molecule. The heat of reaction can be obtained using the relation;
∆Hrxn = ∑Bonds being broken - ∑Bonds being formed
Hence, we have;
Where all the energies are quoted in KJ/mol
C=C = 598
C - C = 346
H - H = 436
C - H = 416
For the reaction;
CH₂CHCH₃(g) + H₂(g) → CH₃CH₂CH₃(g)
∆Hrxn = ∑[6(C - H) + 1(C=C) + 1(C - C)] - ∑[3(C - C) + 8(C - H)
∆Hrxn = [6(416) + 1(598) + 1(346)] - [3(346) + 8(416)]
∆Hrxn =3440 - 4366 = -926 kJ/mol
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are ions always smaller than their neutral atoms
Answer:
The negative ion is larger than the original atom. but the same number of positive protons, the size of the ionic radius will increase. When an atom has its electrons attracted to another atom it becomes a positive ion. The positive ion is smaller than the original atom.
What is happening when scientists use their five senses to learn new
information?
A. Drawing a conclusion
B. Forming a hypothesis
C. Making observations
C
D. Making predictions
VIOUS
Answer:
A, drawing a conclusion
Explanation:
Which statement correctly explains how matter is conserved in chemical reactions? (1 point)
Answer:
can you include the choices?
Explanation:
Answer:
Answer b: The law of conservation of matter says that in chemical reactions, the total mass of the products must equal the total mass of the reactants.
Explanation:
hope this helps
N2(g) + 3H2(g) ⟶ 2NH3(g)
The equation above is the equation for the Haber process.
If 2.0 moles of nitrogen are available for a reaction, what amount of hydrogen represents the correct stoichiometric ratio?
Which is most likely part of a healthy heart and lung system?
A. daily exercise
B. carbohydrate-rich diet
C. maintaining a high body mass index
D. diet low in vegetables and lean proteins
Which is not an example of vaporization?
Answer:
boi i need the choices idiot
Explanation:
Nobody can add an answer without context.
But if this helps,
"Vaporization of an element or compound is a phase transition from the liquid phase to vapour. There are two types of vaporization: evaporation and boiling. Evaporation is a surface phenomenon, whereas boiling is a bulk phenomenon." - Wikipedia
https://en.wikipedia.org/wiki/Vaporization
PLSS CAN ANYONE HELP ME..
Answer:
there is two mixture homogeneous and heterogeneous mixture
ok
The specific heat of a certain type of cooking oil is 1.75J(g. °C). How much heat energy is needed to raise the temperature of 2.44 kg of this oil from 23. °C to 191 °C?
Answer:
The amount of heat needed is 593.88 kJ.
What is the numerical value of the standard entropy change of formation, delta S degree, for BrCl(g) at 298 K
Answer:
B)
Explanation:
Lead (II) nitrate is reacted with sodium chloride to form a precipitate. What volume (in mL) of 0.666 M lead (II) nitrate is required to react with 517 mL of 2.27 M sodium chloride solution
Answer:
Explanation:
lead 3 is correct!!!!!
Cần bao nhiêu gam KMnO4 và bao nhiêu mililit dung dịch axit clohiddric 1M để điều chế đủ khí clo tác dụng với sắt , tạo nên 16,25 G FeCl3
Answer:
I don't know what you're saying cuz give me the brainless answer please
Can all alkyl halides react with water to give alcohols?
Not all acid-catalyzed conversions of alcohols to alkyl halides proceed through the formation of carbocations. Primary alcohols and methanol react to form alkyl halides under acidic conditions by an SN2 mechanism.
Not all acid-catalyzed conversions of alcohols to alkyl halides proceed through the formation of carbocations. Primary alcohols and methanol react to form alkyl halides under acidic conditions by an SN2 mechanism.
In these reactions the function of the acid is to produce a protonated alcohol. The halide ion then displaces a molecule of water (a good leaving group) from carbon; this produces an alkyl halide:
Again, acid is required. Although halide ions (particularly iodide and bromide ions) are strong nucleophiles, they are not strong enough to carry out substitution reactions with alcohols themselves. Direct displacement of the hydroxyl group does not occur because the leaving group would have to be a strongly basic hydroxide ion:
We can see now why the reactions of alcohols with hydrogen halides are acid-promoted.
Carbocation rearrangements are extremely common in organic chemistry reactions are are defined as the movement of a carbocation from an unstable state to a more stable state through the use of various structural reorganizational "shifts" within the molecule. Once the carbocation has shifted over to a different carbon, we can say that there is a structural isomer of the initial molecule. However, this phenomenon is not as simple as it sounds.
- BRAINLIEST answerer
How is melting simillar evaporation
Answer:
Melting and evaporation both represent changes in matter that involve behavior at the molecular level.
Answer:
well both disappear over time
Explanation:
how many atoms of carbon atoms are in the reactant
Answer:
8
Explanation:
There are 8 carbon atoms in the reactants' side, because you multiply the 2 in front of C4H10 and the 4 under the C atom, and that gives you 8. So, 8 carbon atoms.
0.500 mol aluminium hydroxide, Al(OH)3 reacts with 0.500 mol sulphuric acid, H2SO4 to produce aluminium sulphate and water.
a) Write the balanced equation for the reaction.
b) Which reactant is limiting reactant?
c) How many moles of excess reactant is used in the experiment?
d)Determine how many moles of aluminium sulphates was obtained if the percentage yield of aluminium sulphate during the experiment is 77%.
[9 marks]
a) The balanced equation for the reaction would be as follows:
[tex]2 Al(OH)_3 + 3 H_2SO_4 ---> Al_2(SO_4)_3 + 6 H_2O[/tex]
b) The mole ratio of aluminum hydroxide to sulfuric acid is 2:3. This means that every 1 mole of the aluminum hydroxide would require 1.5 moles of sulfuric acid.
0.5 mole aluminum hydroxide would require:
0.5 x 3/2 = 0.75 moles of sulfuric acid.
But only 0.500 moles of sulfuric acid is present. Thus, the limiting reagent is sulfuric acid.
c) With 0.5 moles sulfuric acid, the mole of aluminum hydroxide required would be:
0.5 x 2/3 = 0.33
Excess moles of aluminum hydroxide = 0.5 - 0.33
= 0.17 moles
d) The mole ratio of sulfuric acid to aluminum sulfate produced is 3:1. With 0.5 moles sulfuric acid, the mole of aluminum sulfate produced would be:
0.5 x 1/3 = 0.17 moles
But the percentage yield is 77%
77/100 x 0.17 = 0.13 moles
Thus, the moles of aluminum sulfate that would be obtained with a percentage yield of 77% would be 0.13 moles.
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What mass of LiOH would need to be dissolved in 500.0 mL of water to produce a solution with a pH of 12.40
Taking into account the definition of pH and pOH, the mass of LiOH needed to be dissolved in 500.0 mL of water to produce a solution with a pH of 12.40 is 0.299375 grams.
First of all, pH is a measure of acidity or alkalinity that indicates the amount of hydrogen ions present in a solution or substance.
The pH is defined as the negative base 10 logarithm of the activity of hydrogen ions, that is, the concentration of hydrogen ions or H₃O⁺:
pH= - log [H⁺]= - log [H₃O⁺]
Similarly, pOH is a measure of hydroxyl ions in a solution and is expressed as the logarithm of the concentration of OH⁻ ions, with the sign changed:
pOH= - log [OH⁻]
The following relationship can be established between pH and pOH:
pOH + pH= 14
In this case, being pH= 12.40, pOH is calculated as:
pOH + 12.40= 14
pOH= 14 - 12.40
pOH= 1.60
Replacing in the definition of pOH the concentration of OH⁻ ions is obtained:
- log [OH⁻]= 1.60
Solving:
[OH⁻]= 10⁻¹ ⁶
[OH⁻]= 0.025 M
Then, the [OH⁻] is 0.025 M.
Strong bases are bases that completely dissociate in water into the cation and OH - (hydroxide ion). LiOH is a strong base, so the OH- concentration is equal to the LiOH concentration:
[OH⁻]= [LiOH]= 0.025 M
Finally, Molarity or Molar Concentration is the number of moles of solute that are dissolved in a certain volume:
[tex]Molarity=\frac{number of moles}{volume}[/tex]
In this case, knowing that molarity is 0.025 M and the volume is 500 mL= 0.5 L, you can replace in the expression for molarity:
[tex]0.025 M=\frac{number of moles}{0.5 L}[/tex]
Solving:
number of moles= 0.025 M× 0.5 L
number of moles= 0.0125 moles
Finally, since the molar mass of LiOH is 23.95 [tex]\frac{g}{mol}[/tex], that is, the amount of mass that the substance contains in one mole, the mass of LiOH that 0.0125 mol contains can be calculated as:
0.0125 mol×23.95 [tex]\frac{g}{mol}[/tex]= 0.299375 g
The mass of LiOH needed to be dissolved in 500.0 mL of water to produce a solution with a pH of 12.40 is 0.299375 grams.
Learn more:
https://brainly.com/question/12200689brainly.com/question/16032912?referrer=searchResultsbrainly.com/question/13557815?referrer=searchResultsChoose the best description that matches the following equation:
2K3PO4 + 3MgSO4 --> Mg3(PO4)2 + 3K2SO4
a) Redox, decomposition
b) Non-redox, synthesis
c) Redox, single displacement
d) Non-redox, double displacement
e) Redox, combustion
Answer:
Non-redox, double displacement
Explanation:
it's the only answer that have double displacement
tell me if it was right
What is the density of an object that has a mass of 1.08 kg and displaces 50.50 cm3 of water? (Please report your answer in g/cm3 ) Please report your answer in decimal notation not scientific notation the computer will mark it incorrect.
Answer:
Explanation:
1.08kg/50.5 cm^3(1000g/kg)=21.386 g/cm^3
Answer:
[tex]\boxed {\boxed {\sf 21.4 \ g/cm^3}}[/tex]
Explanation:
We are asked to find the density of an object.
The density of a substance is its mass per unit volume. It is calculated by dividing the mass by the volume.
[tex]\rho= \frac{m}{v}[/tex]
The mass of the object is 1.08 kilograms. The object displaced 50.50 cubic centimeters of water, so this value is its volume.
We are asked to give the density in grams per cubic centimeter, so we must convert the mass. There are 1000 grams in 1 kilogram. Set up a conversion factor.
[tex]\frac {1000 \ g}{1 \ kg}[/tex]
Multiply by the given mass: 1.08 kg
[tex]1.08\ kg *\frac{1000 \ g }{ 1\ kg}[/tex]
The units of kilograms cancel.
[tex]1.08*\frac{1000 \ g }{1}[/tex]
[tex]1.08*{1000 \ g } = 1080 \ g[/tex]
Now we know the mass in grams and the volume:
m= 1080 g v= 50.50 cm³Substitute the values into the density formula.
[tex]\rho= \frac{1080 \ g }{50.50 \ cm^3}[/tex]
Divide.
[tex]\rho= 21.3861386 \ g/cm^3[/tex]
The original measurements of mass and density have 3 and 4 significant figures. Our answer must have the least number of significant figures, or 3.
For the number we found, that is the tenths place. The 8 in the hundredth place tells us to round the 3 in the tenths place up to a 4.
[tex]\rho \approx 21.4 \ g/cm^3[/tex]
The density of the object is approximately 21.4 grams per cubic centimeter.
Which candle burned the longest time why
Answer:
The one that burned longer because it burned longer
Explanation: