Answer:
Explanation:
mass of the solution m = 1.6 + 75 = 76.6 g
fall in temperature = 25 - 23.34 = 1.66°C
heat absorbed = mass x specific heat x fall in temperature
= 76.6 x 1.66 x 4.18
= 531.5 J .
= .5315 kJ .
mol weight of ammonium nitrate = 80 g
heat absorbed by 1.6 g = .5315 kJ
heat absorbed by 80 g or one mole = 26.575 kJ
enthalpy change ΔH = +26.575 kJ
b )
enthalpy of hydration = 2630 kJ / mol
lattice energy = enthalpy of hydration + enthalpy change
= 2630 + 26.575
= 2656.575 kJ .
22. The metal roof of a building has turned a light green colour. The metal roof is most likely
How much 1.50M KBr can be made from 15.6 mL of concentrated KBr with a molarity of 9.65 M?
Answer: 234.8 M
Explanation:
7.46 - A 0.0500-mol sample of a nutrient substance is burned in a bomb calorimeter containing 2.00 x 10g H20. If the formula weight of this nutrient substance is 114 g/mol, what is the fuel value (in nutritional Cal) if the temperature of the water increased 5.70C?
Answer:
[tex]200\frac{kcal}{g}[/tex]
Explanation:
Hello!
In this case, for this calorimetry problem, since the combustion 0.0500 mol of the nutrient increase the temperature of water by 5.70 °C, we can notice that the heat lost by the nutrient is gained by water in order to write:
[tex]Q_{nutrient}=-Q_{water}[/tex]
Which can be also written as:
[tex]Q_{nutrient}=-m_{water}C_{water}\Delta T_{water}\\\\Q_{nutrient}=-200 g*4.184\frac{J}{g\°C}*5.70\°C\\\\Q_{nutrient}=4769.8 J[/tex]
Thus, in terms of the grams of the nutrient:
[tex]m_{nutrient}=0.0500mol*\frac{114g}{1mol}=5.70g[/tex]
The fuel value in nutritional Cal (kcal/g) turns out:
[tex]Fuel \ Value=\frac{-4.7698kJ}{5.70g}*\frac{1kcal}{4.184kJ}=200\frac{kcal}{g}[/tex]
Best regards!
is the center of an atom is called the nucleus?
Answer:
The center of the atom contains the nucleus so yes
Explanation:
In case of accidental contact with chemicals, how long should the eyes be flushed at the eyewash station
Answer:
See the answer below
Explanation:
The duration of flushing the eyes at the eyewash station in case of accidental contact with chemicals depends of the nature of the chemical.
If the chemical is known to be a non-irritant or mild-irritant one, a 5-minute washing time is recommended as the first aid. before seeking the help of a physician,
For moderate to severe irritant chemicals, an immediate 15-20 minutes washing period is recommended before seeking further medical help.
For corrosive and strong alkalis chemicals, 30 and 60 minutes washing are recommended respectively before seeking the attention of a physician.
However, if the nature of the chemical is unknown, a minimum of 20-minutes washing is generally recommended as first aid before seeking immediate medical help.
The duration of flushing the eyes at the eyewash station in case of accidental contact with chemicals depends on the nature of the chemical.
If the chemical is known to be a non-irritant or mild-irritant one, a 5-minute washing time is recommended as the first aid. before seeking the help of a physician,For moderate to severe irritant chemicals, an immediate 15-20 minutes of washing is recommended before seeking further medical help.For corrosive chemicals, 30 and 60 minutes of washing are recommended respectively before seeking the attention of a physician.If the nature of the chemical is not known, a minimum of 20-minutes of washing is generally recommended as first aid before seeking immediate medical help.
To know more about:-
brainly.com/question/18668750
In the nucleus of an atom, there are 17 protons and 18 neutrons. What is the atomic number? What is the atomic mass? How many electrons are there?
Answer:
atomic number =17
mass number = 17+18= 35
These questions are from an experiment where we had a mixture of Ferrocene, acetylferrocene and diacetyl ferrocene and we separated each by using column chromatography. Before doing the column chromatography we did TLC analysis to ensure that we did, in fact, have a mixture of these 3 compounds.
During the column chromatography we first eluted the ferrocene using pure hexane. Then we eluted the acetylferrocene using a 1:1 mixture of hexane and methylene chloride. Then we eluted the diacetylferrocene using a 9:1 mixture of hexane and methylene chloride.
1. Rank ferrocene, acetylferrocene, and diacetylferrocene in order of increasing polarity. Do the TLC results from your fractions support this ranking? Explain.
2. Rank the solvents used in the experiment in order of increasing polarity.
3. Why do you start with the least polar solvent/solvent mixture and progress to increasing polar solvent/solvent mixtures when eluting the ferrocene compounds from the column rather than starting with more polar solvent system and progressing to less polar solvents?
4. How do the thin layer and column chromatography for this experiment compare in regard to stationary and mobile phases?
5. What key feature in the IR spectrum of acetylferrocene distinguishes it from the spectrum of ferrocene?
Answer:
Explanation:
The polarity of the 3 compounds would be in the order of
Ferrocene < Acetylferrocene < Diacetylferrocene
Your TLC data has to also support this observation . This can be checked by measuring the values of Rf ( Retention factor = distance travelled by solute/solvent ) .The Rf values also has to follow this particular order: -
Ferrocene > acetylferrocene > diacetylferrocene
2) Hexane happens to be a non-polar solvent. The polarity of hexane can be increased if some polar solvents for example, ethyl and methylene chloride etc are added
Therefore, in the increasing order of solvents polarity, we have
Hexane < 1:1 mixture of hexane: methylene chloride < 9:1 mixture of methylene chloride:
3) Chromatographic techniques all have a stationary phase in addition to a mobile phase. In the case of column chromatography, the silica gel will be the stationary phase and the solvent that will be poured will be the mobile phase.
4) The TLC and column chromatography both happen to have the same stationary phase which is the silica gel. Also, the same solvent mixture is used in both the techniques. This makes the result of the 2 to be almost the same. The difference seen between them is that, TLC works against the gravity while on the other hand column chromatography works in the direction of the gravity.
5) The key feature in the IR spectra of the acetylferrocene that will be absent in the spectra of ferrocene is the presence of carbonyl stretching frequency at close to 1700 per cm(cm-1). This peak is easily differentiated between both acetyl ferrocene and ferrocene.
I NEED HELP ASAP PLEASE I BEG
with what?..................
Ultraviolet light A (UVA) can penetrate deeper layers of skin than UVB. If UVA has a wavelength of 400 nm, how much energy would be in this wave? 2 x 10-17)
Answer:
E = 5×10⁻¹⁹ J
Explanation:
Given data:
Wavelength = 400 nm (400×10⁻⁹ m)
Energy of wave = ?
Solution:
Formula:
E = h c/λ
c = 3×10⁸ m/s
h = 6.63×10⁻³⁴ Js
Now we will put the values in formula.
E = 6.63×10⁻³⁴ Js × 3×10⁸ m/s /400×10⁻⁹ m
E = 19.89×10⁻²⁶ J.m / 400×10⁻⁹ m
E = 0.05×10⁻¹⁷ J
E = 5×10⁻¹⁹ J
Decide which of the following statements are true and which are false, concerning the kinetic molecular theory.
1. The particles are in constant motion. The collisions of the particles with the walls of the container are the cause of the pressure exerted by the gas.
A. True
B. False
2. The particles are assumed to exert no forces on each other; they are assumed neither to attract nor to repel each other.
A. TrueB. False
3. The particles are so small compared with the distances between them that the volume of the individual particles can be assumed to be about 1 mL.
A. TrueB. False
4. The molecules in a real gas have finite volumes and do exert forces on each other, thus real gases do not conform to some of the assumptions of an ideal gas as stated by the kinetic molecular theory.
A. TrueB. False
5. The average kinetic energy of a collection of gas particles is assumed to be inversely proportional to the Kelvin temperature of the gas.
A. TrueB. False
Answer:
1. A. True
2. A. True
3. B. False
4. A. True
5. B. False
Explanation:
1. The particles are in constant motion. The collisions of the particles with the walls of the container are the cause of the pressure exerted by the gas. A. True. The pressure of an ideal gas is higher than the one that would exert a real gas.
2. The particles are assumed to exert no forces on each other; they are assumed neither to attract nor to repel each other. A. True. The intermolecular forces are negligible.
3. The particles are so small compared with the distances between them that the volume of the individual particles can be assumed to be about 1 mL. B. False. The volume of the gas particles is negligible.
4. The molecules in a real gas have finite volumes and do exert forces on each other, thus real gases do not conform to some of the assumptions of an ideal gas as stated by the kinetic molecular theory. A. True. We cannot apply ideal gas laws to real gases.
5. The average kinetic energy of a collection of gas particles is assumed to be inversely proportional to the Kelvin temperature of the gas. B. False. The average kinetic energy of a collection of gas particles is assumed to be directly proportional to the Kelvin temperature of the gas.
The given statement, "if the particles are in constant motion and there are collisions of the particles with the walls of the container, then they are the cause of the pressure exerted by the gas." is:
TrueThe given statement "The particles are assumed to exert no forces on each other; they are assumed neither to attract nor to repel each other" is:
True
The given statement, "The particles are so small compared with the distances between them that the volume of the individual particles can be assumed to be about 1 mL" is:
False
The given statement ,"The molecules in a real gas have finite volumes and do exert forces on each other, thus real gases do not conform to some of the assumptions of an ideal gas as stated by the kinetic molecular theory" is:
True
The given statement, "The average kinetic energy of a collection of gas particles is assumed to be inversely proportional to the Kelvin temperature of the gas" is:
FalseRead more here:
https://brainly.com/question/24760728
Which of the following molecules has a covalent bond?
A) H-F
B) H-Cl
C) H-Br
What is the molality of 6 grams of salt in 10 grams of solution?
Answer:
maalat ang salt
Explanation:
Calculate pCl for the titration of 100.0mL of 0.1000 MCI with 0.1000 M
AgNO3 for the addition of 0.00 and 20.00 mL AgNO3.
the titration is the most important part in determining whether
Which unit of measurement would best be used to measure the volume of a points a DROP of water? .
Answer:
milliliter
Explanation:
smallest form of measuring volume from all the available choices
What kind of mixture is sometimes difficult to distinguish form a compound? Why?
Answer:
In a heterogeneous mixture, the parts of the mixture are noticeably different from one another. In a homogeneous mixture, the substances are so evenly distributed that it is difficult to distinguish one substance in the mixture from another.
What is the reason for the trend in lonization Energy? Select all that apply.
A. larger atomic mass number
B. number of energy levels around the nucleus C. number of valence electrons.
D. number of protons in the nucleus
E. number of neutrons in the nucleus
Answer:
Explanation:
A, D,E and B i think is the correct answers
In ethane, C2H6, ethene (ethylene), C2H4, and ethine (acetylene), C2H2, there are direct carbon-carbon bonds. Which one is the shortest?
a. The carbon-carbon bond in ethane's the longest!)
b. The carbon-carbon bond in ethene is the longest
c. The carbon-carbon bond in ethyne is the longest.
d. All of the carbon-carbon bonds have the same length.
Answer:
a. The carbon-carbon bond in ethane's the longest!)
Explanation:
Ethane is a chemical compound that is organic in nature. Its chemical formula is [tex]$C_2H_6$[/tex]. It has two carbon atoms and six of hydrogen atoms that is connected to the carbon atoms.
Ethane is odorless and colorless at the standard temperature and standard pressure.
The carbon to carbon atoms in ethane is connected by a single bond.
The length of single carbon-carbon bond is greater than carbon-carbon double bond and triple bond.
Thus, carbon-carbon bond length in ethane is the longest.
4)
Fluorine and element Z have similar chemical properties. Element Z could have an electron
configuration of
A)
2-2
B)
2-8-1
C)
2-8-8
D)
2-8-18-7
Answer:
D) 2.8.18.7
Explanation:
because it has 7 valence electron that occupied by shells
Is adding food coloring to frosting a chemical reaction?
Answer:
no
Explanation:
Answer:
Yes
Explanation:
Adding food coloring to batter or to your icing involves a chemical reaction of the two products bonding together. This bonding process starts when you add the color and mix it in, but it doesn't end straight away as the color needs some time to fully integrate and settle.
How many oxygen atoms will there be in the balanced equation of Al+O2-Al2O3
Answer: 10
Explanation:
4Al + 2O2 --> 2Al2O3
This is the balanced equation so there are 2*2 +2*3 = 4+6 =10
Which is a chemical property of soda ash?
Explanation:
A chemical property of soda ash is, it is a alkaline compound
If the temperature of the water inside of the
pressure cooker is greater than 104'C, and the
water is still a liquid, then the pressure inside of the
pressure cooker must be
less than 1 atm
equal to 1 atm
c.
greater than 1 atm
Answer:
(C). Greater than 1atm
Explanation:
We are aware that water boils at 100 degree Celsius. Water can change its phase and become vapor at 100degree Celsius and at normal pressure which is 1atm.
In the given scenario we have enough temperature to convert water into vapor phase but we don't want it rather we want it to remain in liquid state. This can be achieved by increasing the pressure which was earlier required for vapor phase conversion. So the pressure should be greater than 1atm.
When we increase the temperature the molecules will get enough energy to escape into vapor phase, but when we will increase the pressure, it will provide hindrance to those molecules and will maintain them into Liquid state.
In the US, nutritional energy is reported in Calories (Cal). One nutritional Calorie is equal to one kilocalorie (kcal). If a food package reports 250.0 Calories (Cal) per serving, how many calories (cal) are in each serving?
Answer:
2.500 × 10⁵ cal
Explanation:
1kcal= 1000 cal
From the analysis, the number of calories in each serving of a food with 250 Calories would be 250,000 calories.
According to the illustration:
1 Calories = 1 kilocalories
The food package reports 250 Calories
Hence, 250 Calories = 1 x 250 kilocalories
= 250 kilocalories
According to metrics, 1 kilocalories = 1,000 calories
Thus, 250 kilocalories = 250 x 1000 calories
= 250,000 calories
More on unit conversion can be found here: https://brainly.com/question/19420601
is a salt water solution saturated when there is undissolved salt at the bottom of the bottle?
Answer:
Yes
Explanation:
Ammonium phosphate NH43PO4 is an important ingredient in many solid fertilizers. It can be made by reacting aqueous phosphoric acid H3PO4 with liquid ammonia. Calculate the moles of ammonium phosphate produced by the reaction of 2.3mol of ammonia. Be sure your answer has a unit symbol, if necessary, and round it to the correct number of significant digits.
Answer:
0.767 moles of ammonium phosphate are produced
Explanation:
The reaction of ammona (NH3), with phosphoric acid is:
3 NH3 + H3PO4 → (NH4)3PO4
Where 3 moles of ammonia reacts per mole of H3PO4 to produce 1 mole of ammonium phosphate.
If 2.3 moles of ammonia reacts, the moles of ammonium phosphate produced if phosphoric acid is in excess are:
2.3 moles NH3 * (1 mole (NH4)3PO4 / 3 moles NH3) =
0.767 moles of ammonium phosphate are produced
The brain combines the electrical signals sent from the what? I NEED THIS ASAP PLEASE!!
Determine the number of Au atoms found in 5.18 grams of gold.
A.1.02x1022 atoms
B. 3.84 x 1022 atoms
C.2.13 x 1022 atoms
D.4.58x1022 atoms
1.58 x 1022. atoms
Please let me know
Answer:
1.58× 10²² atoms of Au
Explanation:
Given data:
Mass of gold = 5.18 g
Number of atoms of gold = ?
Solution:
First of all we will calculate the number of moles of gold.
Number of moles = mass/molar mass
Number of moles = 5.18 g/196.96 g/mol
Number of moles = 0.0263 mol
Number of atoms:
Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ atoms of Au
0.0263 mol × 6.022 × 10²³ atoms of Au / 1mol
0.158× 10²³ atoms of Au
1.58× 10²² atoms of Au
What determines the speed at which a particle of matter moves
Answer:
The force exerted on it.
Explanation:
As the law of motion states, an object at rest will remain at rest an object in motion will remain in motion unless acted upon by another force.
How many different principal quantum numbers can be found in the ground-state electron configuration of nickel?A) 2.B) 3.C) 4.D) 5.E) 6.
Answer:
C) 4.
Explanation:
Hello!
In this case, since the electron configuration of nickel at its ground-state, considering 28 as its atomic number and the number of electrons it has in one atom, is:
[tex]Ni^{28}:1s^2,2s^2,2p^6,3s^2,3p^6,4s^2,3d^8[/tex]
We can see it has four energy levels, 1, 2, 3 and 4, which are related to the following principal quantum number, that describes the energy of an electron in the atom and its most probable distance with respect to the nucleus.
Therefore, nickel has C) 4 different principal quantum numbers.
Best regards!
Arrange in order of decreasing atomic radii: Kr, K, Ge, Ca
Answer:
K > Ca > Ge > Kr
Explanation:
The elements given are all in the 4th period on the periodic table.
Kr, k, Ge, Ca;
Arranging their order from left to right;
K, Ca, Ge, Kr
Atomic radius is taken as half the of the inter-nuclear distance (d) between two covalently bonded atoms of non-metallic elements or half the distance between two nuclei in the solid state of metals.
Across the periodic table atomic radii decreases progressively from left to right. This is due to progressive increase in the nuclear charge (number of protons in the nucleus) without an attendant increase in the number of electronic shells.
From the left to right; decreasing radii;
K > Ca > Ge > Kr