Answer:
13.5g
Explanation:
Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 138.8g of aluminium is needed to react with 640g of iron oxide.
What is mole?The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number.
Mathematically, the balanced equation can be written as
3Fe[tex]_2[/tex]O[tex]_3[/tex] + 4Al [tex]\rightarrow[/tex] Al[tex]_2[/tex]O[tex]_3[/tex] + 6Fe
number of moles of iron oxide= 640/159.6
=4.01
number of moles of aluminium =(4/3)×4.01
=5.34moles
mass of aluminium =5.34×26
=138.8g
Therefore, 138.8g of aluminium is needed to react with 640g of iron oxide.
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2. Which is true regarding water? A. Compound of element B. Element of gases C. Mixture of gases D. Substances of gases
D or A im not fully sure about my answer on that
calculate the mass of butane needed to produce 64.1 g of carbon dioxide to three significant figures and appropriate units
Answer:
21.2 gm
Explanation:
calculate the mass of butane needed to produce 64.1 g of carbon dioxide to three significant figures and appropriate units
butane is the hydrocarbon C4H10
in combustion, we react hydrocarbons with O2 to form CO2 and H2O
so
C4H10 + O2----------------> CO2 + H2O
BALANCE
2C4H10 + 1302--------> 8CO2 + 10 H2O
the molar mass of CO2 is 12 + 16X2 = 44
64.1 gm of CO2 is
64.1/44 = 1.46 MOLES OF CO2,
FOR EVERY 8 MOLES OF CO2 WE NEED 2 MOLES OF BUTANE IT IS A
8:2 OR 4:1 RATIO. THE MOLES OF C4H10 ARE 1/4 THE MOLES OF CO2
SO
THE MOLES OF C4H10 H10 ARE 1.46/4 =0.365 MOLES
THE MOLAR MASS OF BUTANE IS 58.12
0.365 MOLES OF C4H10 HAS A MASS OF 0.365 X 58.12 = 21.2 gm
What does the number 84 in the name krypton-84 represent?
the atomic number
the mass number
Answer:
The Atomic number
Explanation:
Mark brainliest please
What is the wavelength, in nm, of the light photon emitted by a hydrogen atom when an electron goes from n
Answer:
Hence, the wavelength of the photon associated is 1282 nm.
Explanation:
Proteins have two main secondary structures: _______, which are spirals formed by hydrogen bonds between amino acids, and _______, which are formed by a bend in the amino acid with alternating hydrogen bonding between amino acids.
Answer:
Explanation:
Proteins have two main secondary structures: alpha helices, which are spirals formed by hydrogen bonds between amino acids, and beta pleated sheets, [ which are formed by a bend in the amino acid with alternating hydrogen bonding between amino acids.
how many electrons need to be lost or gained by Ca to attain noble gas electron configuration?
Answer:
six electrons need to be gained
Explanation:
Calcium has two valence electrons. To have a stable amount of valence electrons, or to attain noble gas electron configuration, an element needs to have eight valence electrons. Now, it's just a simple math problem. How many more valence electrons does calcium need to get to eight? It needs six, since eight minus two is six.
Hopefully that's helpful! :)
A compound contains 9.50 moles of carbon, 9.60 moles of hydrogen and 2.38 moles of sulfur. The molar mass of the compound is 168 grams per mole. What is the empirical and molecular formula of the compound?
Answer :
C4H4S and C8H8S2
What are the 4 properties of substances that contain Hydrogen Bonds?
Answer:
Increase in the melting point, boiling point, solubility, and viscosity of many compounds can be explained by the concept of hydrogen bonding
Explanation:
melting point- when does the solid melt to a liquid
boiling point - a temperature when a liquid will turn into a gas
solubility -solubility is ability of a substance, the solute, to form a solution with another substance
viscosity- Viscosity is a measure of a fluid's resistance to flow. It describes the internal friction of a moving fluid. ( basically how thick it is)
Answer:
Melting point, boiling point, solubillity and viscosity of many substances
Hope this helped you
A 0.100 g sample of phosphoric acid (H3PO4, MW 99.0 g/mol), a tri-protic acid, requires 35.0 mL of a NaOH solution for neutralization. What is the molarity of the NaOH solution
Answer:
0.0866 M
Explanation:
answer key
The molarity of the NaOH solution has been 0.0865 M.
The neutralization reaction of the Phosphoric acid and NaOH results in the formation of sodium phosphate and water.
The balanced chemical equation can be given as;
[tex]\rm H_3PO_4\;+\;3\;NaOH\;\rightarrow\;Na_3PO_4\;+\;3\;H_2O[/tex]
Thus for the neutralization of 1 mole of Phosphoric acid, 3 moles of NaOH has been used.
The moles of phosphoric acid in 0.100 grams sample:
Moles = [tex]\rm \dfrac{weight}{molecular\;weight}[/tex]
Moles of phosphoric acid = [tex]\rm \dfrac{0.100}{99}[/tex]
Moles of phosphoric acid = 0.001 mol
For the neutralization of 0.001 moles of NaOH:
1-mole Phosphoric acid = 3 moles NaOH
0.001-mole Phosphoric acid =0.003 moles of NaOH.
The molarity of the NaOH solution:
Molarity = [tex]\rm \dfrac{moles}{Volume\;(L)}[/tex]
Molarity of NaOH = [tex]\rm \dfrac{0.003}{0.035}[/tex]
Molarity of NaOH = 0.0865 M
The molarity of the NaOH solution has been 0.0865 M.
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Please someone help WHATS the answer
can someone plaexplain to me what is 'first ionisation energy' in simple words coz my small brain can't understand it
[tex] \: \: \: \: \: \: [/tex]
the first ionization energy of an element is the energy needed to remove the outermost, or highest energy, electron from a neutral atom in the gas phase.hope it helps[tex] \: \: \: \: \: [/tex]
Which objects are scratched?
Answer:
We would need a picture to help you out with this.
Explanation:
how does the solubility of oxygen in water affect the value of r you determined?
Answer:
R, the gas law constant, is a constant,
Solubility of gas is inversely proportional to temperature.
Solubility of gas ∝ 1/Temperature
That means as temperature increases the solubility gas goes on decreasing and vice versa.
But R is inversely proportional to temperature .
So Solubility ∝ R. (1/T ∝ R)
That means solubility of gas goes on increasing as R increases.
Step 2: Result
Result:
So from above conclusion the solubility of Oxygen in water increases that result into increasing R value.
Explanation:
A red car and a black car begin to accelerate from rest at the same time. The red car accelerates at a constant rate of 3 meters per square second. The motion of the black car is shown in the graph below.imageWhich of the following statements correctly compares the acceleration of the two cars?A.While the cars are accelerating, the red car accelerates faster than the black car.B.While the cars are accelerating, the black car accelerates faster than the red car.C.The red car only accelerates faster than the black car for the first second of acceleration.D.The black car only accelerates faster than the red car for the first second of acceleration.
That car moves or accelerates faster which has the higher speed.
If the red car accelerate at higher speed than black car then the red car reach first on the destination but if the black car moves with higher speed than red car then the black car reach its destination earlier than the red car.
The conclusion can be drawn when the image is present or any data but there is no data or image present which provides us accurate information so we can conclude logically that car which moves at higher speed will move faster than the other car.
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1. Describe what happens when two substances at different temperatures come into contact. Describe how the
law of conservation of energy applies to this system.
Answer:
Explanation:
When two substances at different temperatures like into contact, the substance that is at higher temperature will transfer energy, in the form of heat, to the substance that is at lower temperature, until their temperatures get equal.
In this case, if the two substances are isolated of the rest of the universe, the law of conservation of energy states that the heat released by the substance initially at higher temperature is the same amount of heat gained by the substance originally at lower temperature.
life situation scenario that portrays the modernization and professionalism of the Philippine National Police Organization as per discussed under RA 6975.
Answer:
members shall perform their duties with integrity, intelligence and competence in the application of specialized skill and technical knowledge with excellence and expertise.
Explanation:
any members on duty should be wiling and ready to help at all times
What is the
name of the
compound
Na2Co3?
Answer:SODIUM CARBONATE
Explanation:
An Oxygen atom Isotope has an overall charge of -1. How many electrons does it have?
Answer:
8 electrons.
Explanation:
Suppose you are planning an afternoon picnic a week in advance. Fair weather is forecast for that day, but a storm is expected that night. What will you do? Explain your reasoning.
I'd schedule the picnic a bit earlier than originally planed. I'd do this because everyone can be home by the time the rain starts.
If you don't want to do that do /weather clear and no more rain.
What is the frequency of radiation whose wavelength is 2.40×10
Answer:
24
Explanation:
2.40*10=24.0
which molecule or ion has a trigonal planar geometry around its central atom?
Answer:
Structure of boron trifluoride, an example of a molecule with trigonal planar geometry.
Explanation:
11) When sodium metal is subjected to violet light, it causes the photoelectric effect. However, red light does not affect
the sodium. Explain this phenomena.
The maximum wavelength for which photoelectric effect occurs in sodium is 400 nm.
Photoelectric effect has to do with the ejection of electrons from a clean metal surface when energy is supplied in the form of light. All wavelengths of light are not capable of achieving photoelectric effect.
There exists a maximum wavelength that the incident rays must posses in order for photoelectric effect to occur. The maximum wavelength for which photoelectric effect occurs in sodium is 400 nm.
The wavelength of red light is around 625 - 740 nm which is far longer than the wavelength of violet light which is around 380 - 425 nm. Hence, when sodium metal is subjected to violet light, it causes the photoelectric effect but red light does not affect the sodium metal.
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the temperature of absolute zero is stated as ___________.
Answer:
-273.15 degrees Celsius
-459.67 degrees Fahrenheit
It is considered to be coldest conceivable temperature and is impossible to reach
Explanation:
If you are looking for degrees it is
-273.15 degrees Celsius
-459.67 degrees Fahrenheit
or just 0 on the keilvin scale
2. For each of the six elements aluminium (Al), boron (B), nitrogen (N), oxygen (O) phosphorus (P), sulfur (S), write down:
a. the period of the periodic table to which it belongs.
b. its group number in the periodic table.
c. its proton number (atomic number).
d. the number of electrons in one atom.
e. its electronic configuration.
f. the number of outer-shell electrons in one atom.
g. Which of the above elements would you expect to have similar properties?
Elements in the same group of the periodic table tend to have similar chemical properties
What is the periodic table?For Al;
a. Period: Period 3
b. Group: Group 13
c. Proton Number (Atomic Number): 13
d. Number of Electrons: 13
e. Electronic Configuration: 1s² 2s² 2p⁶ 3s² 3p¹
f. Number of Outer-Shell Electrons: 3
g. Similar Properties: Boron (B)
For Boron (B):
a. Period: Period 2
b. Group: Group 13
c. Proton Number (Atomic Number): 5
d. Number of Electrons: 5
e. Electronic Configuration: 1s² 2s² 2p¹
f. Number of Outer-Shell Electrons: 3
g. Similar Properties: Aluminium (Al)
For Nitrogen (N):
a. Period: Period 2
b. Group: Group 15
c. Proton Number (Atomic Number): 7
d. Number of Electrons: 7
e. Electronic Configuration: 1s² 2s² 2p³
f. Number of Outer-Shell Electrons: 5
g. Similar Properties: Phosphorus (P)
For Oxygen (O):
a. Period: Period 2
b. Group: Group 16
c. Proton Number (Atomic Number): 8
d. Number of Electrons: 8
e. Electronic Configuration: 1s² 2s² 2p⁴
f. Number of Outer-Shell Electrons: 6
g. Similar Properties: Sulfur (S)
For Phosphorus (P):
a. Period: Period 3
b. Group: Group 15
c. Proton Number (Atomic Number): 15
d. Number of Electrons: 15
e. Electronic Configuration: 1s² 2s² 2p⁶ 3s² 3p³
f. Number of Outer-Shell Electrons: 5
g. Similar Properties: Nitrogen (N)
For Sulfur (S):
a. Period: Period 3
b. Group: Group 16
c. Proton Number (Atomic Number): 16
d. Number of Electrons: 16
e. Electronic Configuration: 1s² 2s² 2p⁶ 3s² 3p⁴
f. Number of Outer-Shell Electrons: 6
g. Similar Properties: Oxygen (O)
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what is the accepted iupac name for the compound mg3p2?
There are two types of chemical compound one is covalent compound and other is ionic compound, covalent compound formed by sharing of electron and ionic compound formed by complete transfer of electron. Therefore, the IUPAC name of the Mg[tex]_3[/tex]P[tex]_2[/tex] is Tri magnesium Di phosphide.
What is chemical Compound?Chemical Compound is a combination of molecule, Molecule forms by combination of element and element forms by combination of atoms in fixed proportion.
An ionic compound is a metal and nonmetal combined compound. Ionic compound are very hard. They have high melting and boiling point because of strong ion bond. The IUPAC name of the Mg[tex]_3[/tex]P[tex]_2[/tex] is Tri magnesium Di phosphide. The oxidation state of phosphide is -3.
Therefore, the IUPAC name of the Mg[tex]_3[/tex]P[tex]_2[/tex] is Tri magnesium Di phosphide.
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[tex]▪▪▪▪▪▪▪▪▪▪▪▪▪ {\huge\mathfrak{Question~}}▪▪▪▪▪▪▪▪▪▪▪▪▪▪[/tex]
Solve this question ~
Find the Hybridization of N in compound " NH3 " and determine its shape ~
Let's check Electronic configuration of N in ground state
[tex]\\ \sf\longmapsto 1s^22s^22p^3[/tex]
In exited state[tex]\\ \sf\longmapsto 1s^22s^22px^12py^12pz^2[/tex]
3 p orbitalsIn hydrogen case
[tex]\\ \sf\longmapsto 1s^1[/tex]
1 s orbitalHence Hybridization
[tex]\\ \sf\longmapsto s-p-p-p[/tex]
[tex]\\ \sf\longmapsto sp^3[/tex]
Structure is tetrahedral .
Spare way:-
Bond pairs==3=>Bonding electrons=6Lone pair=1=>Anti bonding electrons=2Hybridization
[tex]\\ \sf\longmapsto \dfrac{1}{2}[\sigma+\sigma *][/tex]
[tex]\\ \sf\longmapsto \dfrac{1}{2}[6+2][/tex]
[tex]\\ \sf\longmapsto \dfrac{1}{2}[8][/tex]
[tex]\\ \sf\longmapsto 4[/tex]
sp3 HybridizationShape-Tetrahedral .6. A 10.0 g sample of krypton has a temperature
of 25 °C at 575 mmHg. What is the volume, in
milliliters, of the krypton gas?
Considering the definition of ideal gas law, the volume of the Krypton gas is 3840 mL.
An ideal gas is a theoretical gas that is considered to be composed of point particles that move randomly and do not interact with each other. Gases in general are ideal when they are at high temperatures and low pressures.
The pressure, P, the temperature, T, and the volume, V, of an ideal gas, are related by a simple formula called the ideal gas law:
P×V = n×R×T
where P is the gas pressure, V is the volume that occupies, T is its temperature, R is the ideal gas constant, and n is the number of moles of the gas. The universal constant of ideal gases R has the same value for all gaseous substances.
Now, taking into account this law, and isolating the pressure variable (P), you get:
[tex]V=\frac{nxRxT}{P}[/tex]
In this case, you know:
n= [tex]10 gramsx\frac{1 mole}{83.80 grams} =[/tex]0.119 moles, where 83.80[tex]\frac{grams}{mole}[/tex] is the molar mass of Krypton, that is, the amount of mass that a substance contains in one mole.R= 0.082 [tex]\frac{atmL}{moleK}[/tex]T= 25 C=298 kP= 575 mmHg=0.756579 atm (being 1 atm=760 mmHg)Replacing in the ideal gas law:
[tex]V=\frac{0.119 molesx0.082 \frac{atmL}{moleK}x298K}{0.756579 atm}[/tex]
Solving:
V=3.84 L= 3840 mL (being 1 L=1000 mL)
Finally, the volume of the Krypton gas is 3840 mL.
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Does molasses need to be refrigerated after opening?
what happens to the 1s orbitals on the hydrogen atoms as they approach to make a covalent bond?
i dont know im only doing for points
Answer: They begin to overlap
Having studied the data for patterns and trends, you should now be able to draw
some conclusions about how knowing the half-life of the element Lokium would
help you determine the absolute age of rock in which this element is found. In a
paragraph, create an imaginary example of finding a given amount of Lokium and
DOL in a rock, and then determining the absolute age of that rock. Assume that
each trial represents 1,000 years
Answer:
The situation given here is imaginary such that the life of Rock has to be found using the half-life of the element lokium that has been found inside the rock.
Half-life of any material is the amount of time taken by that particular material to decay. Now the amount of lokium found in rock can show after how many half-lives this amount has been left out.
The time elapsed will be log (L) atoms X half-life.
Explanation: