Answer:
1500kg/m^3
Explanation:
Formula:
d=m/v
Given:
m=1.5kg
v=1000cm^3
(The side length of a cube is always equal to the others)
Required:
d=?
Solution:
d=m/v
d=1.5kg/1000cm^3
d=1.5kg/0.001m^3
d=1500kg/m^3
Hope this helps ;) ❤❤❤
D. Answer these questions.
1. What is chemistry?
2. What is scientific method?
Answer:
1.Chemistry is the scientific discipline involved with elements and compounds composed of atoms, molecules and ions: their composition, structure, properties, behavior and the changes they undergo during a reaction with other substances.
2.The scientific method is an empirical method of acquiring knowledge that has characterized the development of science since at least the 17th century. It involves careful observation, applying rigorous skepticism about what is observed, given that cognitive assumptions can distort how one interprets the observations.
If 25.0 g of carbon monoxide react with 8.50 g of ammonia and 10.0 g of hydrogen to produce water and acetonitrile (CH3CN), what mass of each excess reactant is left over after the reaction is complete?
Answer:
The mass of NH₃ left over = 0.91 g of NH₃
The mass of H₂ left over = 8.2 g of H₂
Explanation:
The given information are;
The mass of the carbon monoxide present in the reaction = 25.0 g
The mass of the ammonia present in the reaction = 8.50 g
The mass of the hydrogen present in the reaction = 10.0 g
The above masses reacts to produce water and acetonitrile (CH₃CN)
The balanced chemical equation for the reaction is given as follows;
2CO + NH₃ + 2H₂ → CH₃CN + 2H₂O
Therefore, two moles of CO reacts with one mole of NH₃ and two moles of H₂ to produce one mole of CH₃CN and two moles of H₂O
The molar mass of CO = 28.01 g/mol
The molar mass of NH₃ = 17.031 g/mol
The molar mass of H₂ = 2.0159 g/mol
The molar mass of H₂O = 18.015 g/mol
The molar mass of CH₃CN = 41.05 g/mol
The number of moles of CO present = 25/28.01 = 0.893 moles
The number of moles of NH₃ present = 8.5/17.031 = 0.5 moles
The number of moles of H₂ present = 10/2.0159 = 4.96 moles
Therefore, 0.893 moles of CO reacts with 0.893/2 mole of NH₃ and 0.893 moles of H₂ to produce 0.893/2 mole of CH₃CN and 0.893 moles of H₂O
The excess reactants left are;
0.5 - 0.893/2 = 0.0535 moles of NH₃ with mass 0.0535 × 17.031 = 0.91 g
4.96 - 0.893 = 4.067 moles of H₂ with mass 4.067 × 2.0159 = 8.2 g
The mass of NH₃ left over = 0.91 g of NH₃
The mass of H₂ left over = 8.2 g of H₂.
what is non lustrous ?
Answer:
materials which do not show the quality of lustre i.e. shiney surface
for eg- non metals except Iodine
Explanation:
hope it helps u plz mark as the brainliest
Answer:
These are materials that don't have lustre
Explanation:
They are not shiny.
They include non-metals but not iodine.
Hope it helps.
0.024 is how many significant figures?
Answer:
24×10^-3Explanation:
[tex]Move \: the\:decimal \:point\:,\\3 \:times\:to\:the \:right = 24\\\\When \:the\:decimal\:point \: moves\\\:to\:the \:right\:it\:becomes\:a \:negative\:power\\\\0.024= 24 \times 10^-^3[/tex]
What is the complete ionic equation for this reaction?
2KOH(aq) + H2SO4(aq) → 2H20(1) + K2SO4(aq)
O A. 2K+ + OH + H2SO4 → OH + 2H+ + K2SO4
B. OH + 2H+ + 2H20()
C. 2KOH + H2SO4 → 2H20 + K2SO4
D. 2K+ + OH + 2H+ + SO42- → 2H20() + 2K+ + SO42-
SUBMIT
Answer:
The answer is "Option D".
Explanation:
The entire ionic equation for all the substances, which are ionic compounds but are available in an aquatic is represented in the form with ions in the full ionic equation.
In the Net ionic equation, it doesn't have the particulate matter throughout the net ionic equations throughout the equations.
In the Spectator ions, it doesn't participate in interactions mostly on reaction and the material hand. From both sides, the very same ions are present.
The evenly balanced chemical formula is,
[tex]2KOH (aq)+ H_2SO_4(aq) \longrightarrow 2H_2O(l) + K_2SO_4[/tex]
It is the separate organic compound that full ion formula will match the choice D.
what is the correct electron configuration for an element with five electrons in the third energy level
[tex]1s^2 2s^2 2p^6 3s^2 3p^3[/tex] is the correct electron configuration for an element with five electrons in the third energy level.
What are elements?Elements are the simplest substances which cannot be broken down using chemical methods.
The shell nearest to the nucleus, 1n, can carry two electrons, while the next shell, 2n, can carry eight, and the third shell, 3n, can carry up to eighteen.
The third shell carries 18 electrons; 2 in a 3s orbital; 6 in three 3p orbitals; and 10 in five 3d orbitals. The fourth shell carries 32 electrons; 2 in a 4s orbital; 6 in three 4p orbitals; 10 in five 4d orbitals; and 14 in seven 4f orbitals.
The element would be phosphorus. Its electron configuration is [tex]1s^2 2s^2 2p^6 3s^2 3p^3[/tex]
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calculate the atomic number of an element whose neutral atom has four electrons in its valence shell and its valence shell is the m shell
Answer:
The atomic number of the atom is 14.
Explanation:
The following data were obtained from the question:
Valence electrons = 4
Atomic number =.?
From the question given, we were told that the valence electron is in the m shell. Thus, we can say:
M shell = 4 electrons
The number of shells of the atom can be written in the order K, L, M with M as the last shell because we were told that the valence electrons i.e electrons in the outer shell is located at the M shell.
From a detailed knowledge of atom,
K shell = 1st shell
L shell = 2nd shell
M shell = 3rd shell
The first shell, K of an atom can only accommodate 2 electrons while others can accommodate a maximum of 8 electrons.
Note: we can only put electrons in another shell if a shell is already having 8 electrons. This rule only applies to the 2nd shell and above.
Thus, the atom in question has the following electrons:
K shell = 1st shell = 2 electrons
L shell = 2nd shell = 8 electrons
M shell = 3rd shell = 4 electrons
To get the atomic number of the atoms, we simply add all the electrons together.
This is illustrated below:
Atomic number = 2 + 8 + 4
Atomic number = 14
Therefore, the atomic number of the atom is 14.
Answer:
The answer on Edge is,
C. the number of valence electrons an atom has
Scientists have changed the model of the atom as they have gathered new evidence. One of the atomic models is shown below. A purple ball in the center surrounded by overlapping concentric black ovals, each with a small green ball on each of the 6 ovals. What experimental evidence led to the development of this atomic model from the one before it? A few of the positive particles aimed at a gold foil seemed to bounce back. The colors of light emitted from heated atoms had very specific energies. Experiments with water vapor showed that elements combine in specific proportions. Cathode rays were bent in the same way whenever a magnet was brought near them.
Answer:
A few of the positive particles aimed at a gold foil seemed to bounce back.
Explanation:
Rutherford's experiment took the search for the structure of the atom a step further. In this experiment, a narrow beam of alpha particles emitted from a source was used to bombard a thin gold foil.
The scattering of the alpha particles was detected by a movable ZnS screen. It was found that most of the alpha particles followed a straight path through the gold foil but some were scattered through large angles and some even scattered backwards.
Following this experiment, Rutherford decided on his planetary model of the atom in which the nucleus is at the core of the atom with electrons moving round the nucleus in orbits. Rutherford was awarded a Nobel prize for this work.
Answer:
a
Explanation:
edge 2020
Consider two bulbs seperated by a valce. Both bulbs are amintained at the same temperature. Assume that when the valve between the two bulbs is closed, the gases are sealed in their respective bulbs. When the valve is closed, the following data apply:
Bulb A Bulb B
Gas Ne CO
V 2.50L 2.00L
P 1.09 atm 0.73 atm
Assuming no temperature change, determine the final pressure inside the system after the valve connecting the two bulbs is opened. Ignore the volume of the tube connecting the two bulbs.
Answer:
The pressure is [tex]P_f = 0.93 \ atm[/tex]
Explanation:
From the question we are told that
The volume of Ne is [tex]V_N = 2.50 \ L[/tex]
The volume of CO is [tex]V_C = 2.00 \ L[/tex]
The pressure of [tex]Ne[/tex] is [tex]P_N = 1.09 \ atm[/tex]
The pressure of CO is [tex]P_C = 0.773 \ atm[/tex]
The number of moles of Ne present is evaluated using the ideal gas equation as
[tex]n_N = \frac{P_N * V_N}{R T}[/tex]
=> [tex]n_N = \frac{1.09 * 2.50 }{R T} = \frac{2.725}{RT}[/tex]
The number of moles of CO present is evaluated using the ideal gas equation as
[tex]n_N = \frac{P_C * V_C}{R T}[/tex]
=> [tex]n_N = \frac{0.73 * 2.00 }{R T} = \frac{1.46}{RT}[/tex]
The total number of moles of gas present is evaluated as
[tex]n_T = n_N + n_C[/tex]
[tex]n_T = \frac{2.725}{RT} + \frac{1.46}{RT}[/tex]
[tex]n_T = \frac{4.185}{RT}[/tex]
The total volume of gas present when valve is opened is mathematically represented as
[tex]V_T = V_N + V_C[/tex]
=> [tex]V_T = 2.50 + 2.00 = 4.50 \ L[/tex]
So
From the ideal gas equation the final pressure inside the system is mathematically represented as
[tex]P_f = \frac{n_T * RT }{ V_T}[/tex]
=> [tex]P_f = \frac{[\frac{4.185}{RT} ] * RT }{ 4.50}[/tex]
=> [tex]P_f = 0.93 \ atm[/tex]
A mixture of reactants and products for the reaction shown below is at
equilibrium in a 2.0 L container. What would most likely happen to the
equilibrium if the volume of the container were increased to 4.0 L?
N.(g) + 3H2(g)
22NH3(g)
Answer:
The system will shift to the left producing more moles of gases trying to maintain the original pressure of the system
Explanation:
Based on LeChatelier's principle, a change in temperature, pressure, volume or concentration on a system result in an opposing change trying to maintain the initial equilibrium conditions.
In the reaction:
N₂(g) + 3H₂(g) ⇄ 2NH₃(g)
4 moles of gas reacts producing 2 moles of gas.
In a gas reaction, the system will try to maintain the total pressure.
If the volume of the container increases, the system will shift to the side of the reaction that has more moles of gases in order to maintain the pressure.
That means if in the reaction the volume of the container increase from 2.0L to 4.0L the system will shift to the left producing more moles of gases trying to maintain the original pressure of the system.
the overall take away of an experiment’s results is the______. A. hypothesis B. introduction C. conclusion
Answer:
conclusion
Explanation:
it can't be a hypothesis since tests are carried out to verify so it is not a theory
an introduction to an experiment only gives the basis of what we are investigating therefore nothing has been proven and the question is still unanswered
The overall takeaway of an experiment’s results is the conclusion. Hence, option C is correct.
What is a hypothesis?A hypothesis is a testable statement about the relationship between two or more variables or a proposed explanation for some observed experiment.
The overall takeaway of an experiment’s results can't be a hypothesis since tests are carried out to verify so it is not a theory
An experiment only gives an idea about the investigation therefore nothing has been proven and the question is still unanswered.
Hence, the overall takeaway of an experiment’s results is the conclusion.
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All carbon ato ms have atomic number 6 but some have mass number 12 and others have mass number 14.what is a) the same b) different about the structure of these two types of carbon atoms
Answer:
a) The similarities in their structure are;
1) The two isotopes have the same number of protons in their nucleus
2) The two isotopes have the same number of electrons in their orbit
3)The basic chemical properties of the two isotopes are the same
b) The differences in their structure are;
1) The number of neutrons in their nucleus are different
6 for carbon 12 and 8 for carbon 14
2) The structure of carbon 12 is stable while the structure of carbon 14 disintegrates
3) The isotopes have different densities, therefore, different packing
Explanation:
The atomic number is the number of protons in the nucleus of an atom
The mass number is the sum or total number of protons and neutrons in an atom
Given that the atomic number of all carbon atoms = 6
The number of protons in all carbon atoms = 6
Given that some of the carbon atoms have a mass number of 12 while others have a mass number 14, we have
Therefore, the number of neutrons in some of the carbon atoms = 12 - 6 = 6
The number of neutrons in the remaining of carbon atoms = 14 - 6 = 8
Therefore the carbon atom has two isotopes including ¹²₆C and ¹⁴₆C.
Select the correct answer. Which state of matter is highly compressible, is made of particles moving independently of each other, and is present in large quantities near Earth's surface? A. solid B. liquid C. gas D. plasma
Se someten a combustion 0,452g de un compuesto de C,H y N de masa molecular 80. Al recoger el CO2 y el H2O producidas obtenemos 0,994 g y 0,203 respectivamente. Determine formula empirica y formula molecular
Answer:
Fórmula empírica: C₂H₂N
Fórmula molecular: C₄H₄N₂
Explanation:
Un compuesto que contiene carbono hidrógeno y nitrógeno con fórmula CₐHₓNₙ es sometido a combustion produciendo:
CₐHₓNₙ + O₂ → aCO₂ + x/2 H₂O + nNO₂
Con la masa de dióxido de carbono y agua podemos encontrar las moles de carbono e hidrógeno y su aporte a los 0.452g de muestra que fueron puestos en combustión, así:
Moles C:
Moles C = Moles CO₂ = 0.994g CO₂ ₓ (1mol / 44g) = 0.0226 moles C
Masa C: 0.0226 moles C ₓ (12.01g / mol) = 0.271g Carbono hay en la muestra
Moles H:
Moles H = 2 Moles H₂O = 0.203g H₂O ₓ (1mol / 18g) = 0.0113 moles H₂O = 0.0226 moles H
Masa H: 0.0226 moles H ₓ (1.01g / mol) = 0.023g Hidrógeno hay en la muestra
Así, la masa de nitrógeno en la muestra y sus moles son:
Masa N = 0.452g - 0.271g C - 0.023g H
Masa N = 0.158g Nitrógeno
Y su moles son:
0.158g ₓ (1 mol / 14.01g) = 0.0113 moles N
Con las moles de C, H y N podemos determinar la formula empírica que se define como: "La relación de números enteros más simple entre la cantidad de átomos presentes en una mólecula. Si usamos como base las moles de nitrógeno (Valor menor):
Relación H/N: 0.0226 mol / 0.0113 mol = 2
Relación C/N: 0.0226 mol / 0.0113 mol = 2
Relación N/N: 0.0113 mol / 0.0113 mol = 1
Así, la fórmula empírica es:
C₂H₂NEsta fórmula empírica tiene una masa molar de:
2C = 2*12 g/mol = 24g/mol
2H = 2*1g/mol = 2g/mol
N = 14g/mol
24+14+2 = 40g/mol
Como la masa molecular del compuesto es 80g/mol (Dos veces la de la fórmula empírica, la fórmula molecular es 2 veces la fórmula empírica:
C₄H₄N₂find the empirical formula of the compound containing 11.3% of carbon, 43.4 % of sodium 45.3 % of oxygen
Answer:
CNa203
Explanation:
thats is method in the picture send
oxidation number of Fe in Fe2(CO3)2
Answer:
+2
Explanation:
Oxidation number of an element, also called its oxidation state, is the number of electrons its atoms lost or gain in the process of forming a chemical compound.
To determine the oxidation state of an element or compound;
- The sum of all the oxidation numbers in a neutral compound must equal zero (0).
In the compound: Fe2(CO3)2
This compound is a neutral one, hence, its oxidation state is equal to zero (0).
It contains a polyatomic ion (carbonate ion) i.e. CO3 2-, whose net charge is -2.
Hence, to find the oxidation number of Iron (Fe), which is represented by X, in the compound, we say;
X(2) + -2(2) = 0
2X + -4 = 0
2X - 4 = 0
2X = 4
X = +2
Therefore, the oxidation number of Fe in Fe2(CO3)2 is (+2)
The compound Fe2(CO3)2 is called Iron (II) carbonate
Oxidation number of Fe in [tex]\rm Fe_2(CO_3)_2[/tex] is 2. An atom's oxidation number is a positive or negative number.
A notion used in chemistry to characterise the relative electron distribution and the level of oxidation or reduction of atoms in a compound or ion is known as the "oxidation number," sometimes known as the "oxidation state." Based on the presumption that electrons in chemical bonds are entirely transmitted to the more electronegative atom, it is a method of bookkeeping that assigns a notional charge to each individual atom in a molecule or ion.
The -4 stands for the overall charge that the carbonate ions provided, and the x is the Fe's oxidation number.
2x + (-4) = 0
2x - 4 = 0
2x = 4
x = 4/2
x = 2
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Can a window pane be considered a mineral?
Answer:
Explanation:
The glass (which does not crystallize even though it is accepted) of a window is NOT a mineral, since it is neither a substance of natural origin (although it is manufactured from natural components) nor does it have a defined crystalline structure, that is, the atoms they are not arranged in an orderly and regular way along axes and planes forming flat faces that keep a symmetry.
Remember that a mineral is defined as a solid, inorganic, homogeneous substance, of natural origin, with a crystalline structure and a determined and well-defined chemical composition within narrow margins and that has regular and characteristic physical properties.
Explanation: No, glass is not a mineral. ... Definable chemical composition: SiO2 *Actually, most industrially-produced glass is not pure silica, but having impurities is still a definable chemical composition so this part of the definition is ok. Orderly arrangement of atoms in a lattice: NO.
In the molecule 4H2O2 the number of hydrogen atoms is what
Answer:
Scientists
Explanation:
Scientists because they are the one who makes hypothesis.
what is an example of mechanical energy converting to heat energy?
Answer:
Rubbing your hands together converts mechanical energy to thermal energy. Turning on a light switch converts mechanical energy to electrical and radiant energy.
Which of the following is not equal to 485 L?
0.485 kL
4.85 x 104 mL
48,500 cL
4.85 x 108 µL
Answer:
[tex]4.85 * 10^4\ mL[/tex]
Explanation:
Given
485 L
Required
Determine the measurement not equal to 485L
[tex]0.485\ kL[/tex]
From standard unit of conversion;
1 KL = 1000 L
Multiply both sides by 485
[tex]485 * 1 KL = 485 * 1000 L[/tex]
[tex]485KL = 485000L[/tex]
Divide both sides by 1000
[tex]\frac{485KL}{1000} = \frac{485000L}{1000}[/tex]
[tex]0.485KL = 485L[/tex] ---- This is equivalent
---------------------------------------------------------------------------------------------
[tex]4.85 * 10^4\ mL[/tex]
From standard unit of conversion;
1000 mL = 1 L
Multiply both sides by 485
[tex]485 * 1000 mL = 1 L * 485[/tex]
[tex]485000\ mL = 485\ L[/tex]
Convert to standard form
[tex]4.85 * 10^5\ mL = 485\ L[/tex]
Hence; [tex]4.85 * 10^4\ mL[/tex] is not equivalent to 485L
---------------------------------------------------------------------------------------------
[tex]48500 \ cL[/tex]
From standard unit of conversion;
100 cL = 1 L
Multiply both sides by 485
[tex]485 * 100 cL = 1 L * 485[/tex]
[tex]48500\ cL = 485\ L[/tex]
Convert to standard form
[tex]4.85 * 10^4\ cL = 485\ L[/tex] ---- This is equivalent
---------------------------------------------------------------------------------------------
[tex]4.85 * 10^8 \[/tex] μL
From standard unit of conversion;
1000000 μL = 1 L
Multiply both sides by 485
[tex]485 * 1000000uL = 1 L * 485[/tex]
[tex]485000000uL = 485\ L[/tex]
Convert to standard form
[tex]4.85 * 10^8\ uL = 485\ L[/tex] ---- This is equivalent
From the list of given options;
[tex]4.85 * 10^4\ mL[/tex] is not equivalent to 485L
what’s the answer to this?
how will you measure the length of a curved line by using a thread?
Si se usa 450 gramos de carbonato de calcio para dicho proceso ¿Qué volumen de CO2 se obtendrá, si la presión es de 8 atm y la temperatura 200°C? R=0,082 atm.L/mol.K
Respuesta:
21.8 L
Explicación:
Paso 1: Escribir la reacción balanceada
CaCO₃ ⇒ CaO + CO₂
Paso 2: Convertir 450 g de CaCO₃ a moles
La masa molar de CaCO₃ es 100.09 g.
450 g × (1 mol/100.09 g) = 4.50 mol
Paso 3: Calcular los moles de CO₂ que se forman a partir de 4.50 moles de CaCO₃
La relación molar de CaCO₃ a CO₂ es 1:1. Los moles de CO₂ formados son 1/1 × 4.50 mol = 4.50 mol.
Paso 4: Convertir la temperatura a Kelvin
Usaremos la siguiente expresión.
K = °C + 273.15 = 200°C + 273.15 = 473 K
Paso 5: Calcular el volumen de CO₂
Usaremos la ecuación del gas ideal.
P × V = n × R × T
V = n × R × T / P
V = 4.50 mol × (0.082 atm.L/mol.K) × 473 K / 8 atm
V = 21.8 L
A wittig reaction occurs when 4-methylbenzaldehyde and benzyltriphenylphosphonium chloride are stirred together at room temperature in the presence of sodium hydroxide base. Draw the major isomer produced by this reaction.
Answer:
See explanation
Explanation:
The wittig reaction is an organic reaction in which an aldehyde or a ketone reacts with a phosphonium ylide to give an alkene. This phoshonium ylide that participates in the reaction is usually generated insitu in the system by reaction of an alky or aryl triphenylphosphonium halide salt with a base(sodium hydroxide is mostly used).
In this particular reaction 4-methylbenzaldehyde and benzyltriphenylphosphonium chloride were reacted together in the presence of sodium hydroxide and the product with the structure shown in the answer was obtained as the major isomer produced in the reaction.
which statement is true about this reaction 14/7n + 1/1h ------> 15/8o
A. it is a practical source of energy on earth
B.it occurs only outside the solar system
C.its product is heavier than each of its reactants
D.it shows the critical mass of an element
Answer: answer is C
Explanation:
Its product is heavier than each of its reactants is true about this ₇N¹⁴ + ₁H¹ → ₈O¹⁵ reaction
What is Nuclear reaction ?A nuclear reaction is a reaction in which one or more than one nuclides are generate and it collides between two atomic nuclei or one atomic nucleus.
The reaction is
₇N¹⁴ + ₁H¹ → ₈O¹⁵
Now equating the mass number of both sides
14 + 1 = 15 + a
a = 0
Equating atomic number of both sides
7 + 1 = 8 + x
x = 0
Thus, we can say that its product is heavier than each of its reactants is true about this reaction
Hence, option C is correct answer.
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can you catch coronavirus from F.A.R.Ts?
Answer:
No
Explanation:
Droplets or aerosols. When an infected person coughs, sneezes, or talks, droplets or tiny particles called aerosols carry the virus into the air from their nose or mouth. Anyone who is within 6 feet of that person can breathe it into their lungs.
Airborne transmission. Research shows that the virus can live in the air for up to 3 hours. It can get into your lungs if someone who has it breathes out and you breathe that air in.
Surface transmission. Another way to catch the new coronavirus is when you touch surfaces that someone who has the virus has coughed or sneezed on. You may touch a countertop or doorknob that's contaminated and then touch your nose, mouth, or eyes. The virus can live on surfaces like plastic and stainless steel for 2 to 3 days. To stop it, clean and disinfect all counters, knobs, and other surfaces you and your family touch several times a day.
Fecal-oral. Studies also suggest that virus particles can be found in infected people's poop. But experts aren't sure whether the infection can spread through contact with an infected person's stool. If that person uses the bathroom and doesn't wash their hands, they could infect things and people that they touch.
Consider the following: Li(s) + ½ I₂(g) --> LiI(s) ΔH = –292 kJ. LiI(s) has a lattice energy of –753 kJ/mol. The ionization energy of Li(g) is 520 kJ/mol, the bond energy of I₂(g) is 151 kJ/mol, and the electron affinity of I(g) is –295 kJ/mol. Use these data to determine the heat of sublimation of Li(s).
Answer:
Heat of sublimation of Li(s) = 160.5 kJ/mol
Explanation:
Given that:
[tex]\mathtt{2Li(s) + \dfrac{1}{2} I_2(g) \to 2LiI(s)}[/tex]
ΔH = –292 kJ
The heat of formation for the above reaction = –292 kJ × 2 = -584 kJ/mol
[tex]\mathtt{Li^+_{(g)} + I^-_{(g)} \to LiI_{(s)}}[/tex]
The lattice energy of LiI(s) = -753 kJ/mol
[tex]\mathtt{Li(g)\to Li^+(g) + e^- }[/tex]
The ionization energy of LiI(s) = +520 kJ/mol
[tex]\mathtt{I_2_{(g)} \to 2I_{(g)} }[/tex]
The Bond Energy of I₂(g) = 151 kJ/mol
[tex]\mathtt{I_{(g)} + e^- \to I^-_{(g)}}[/tex]
The electron affinity of I(g) = -295 kJ/mol
Heat of sublimation: Sublimation is the process of changing of a solid matter into gas without passing through the liquid stage, Now, the molar heat of sublimation is the amount of energy that must be added to a mole of solid to turn it directly into a gas without any interference through the liquid phase provided the pressure is constant.
From the above reactions: The heat of sublimation of Li(s) can be calculated by the sum total of the following.
[tex]\mathtt{Li_{(s)} + \dfrac{1}{2} I_2_{(g)} \to LiI_{(s)} \ \ -292 kJ/mol} \\ \\\mathtt{I_{(g)} \to \dfrac{1}{2} I2(g) \ \ -75.5 kJ/mol} \\ \\ \mathtt{I^-(g) \to I(g) + e^- \ \ +295 kJ/mol} \\ \\ \mathtt{LiI(s) \to Li^+_{(g)} + I^-_{(g)} \ \ +753 kJ/mol} \\ \\ \mathtt{Li^+_{(g)} + e^- \to Li(s) \ \ -520 kJ/mol} \\ \\[/tex]
[tex]\mathtt{Li(s) \to Li(g)}[/tex] = (-292 +(-75.5)+295+753+(-520)) kJ/mol
[tex]\mathtt{Li(s) \to Li(g)}[/tex] = 160.5 kJ/mol
Heat of sublimation of Li(s) = 160.5 kJ/mol
A star is estimated to have a mass of 2.0 x 10 ^36kg. Assuming it to be a sphere of average radius of 7.0 x 10 ^5 km. Calculate the average density of the star in g/cm^3 and in lb/ft^3
Answer:
a) 1.392 x 10^6 g/cm^3
b) 8.69 x 10^7 lb/ft^3
Explanation:
mass of the star m = 2.0 x 10^36 kg
radius of the star (assumed to be spherical) r = 7.0 x 10^5 km = 7.0 x 10^8 m
The density of substance ρ = mass/volume
The volume of the star = volume of a sphere = [tex]\frac{4}{3}\pi r^{3}[/tex]
==> V = [tex]\frac{4}{3}*3.142*(7.0*10^8)^{3}[/tex] = 1.437 x 10^27 m^3
density of the star ρ = (2.0 x 10^36)/(1.437 x 10^27) = 1.392 x 10^9 kg/m^3
in g/cm^3 = (1.392 x 10^9)/1000 = 1.392 x 10^6 g/cm^3
in lb/ft^3 = (1.392 x 10^9)/16.018 = 8.69 x 10^7 lb/ft^3
A gas has a volume of 25.0 mL at 2.50 atm. What is the volume at 457 mmHg if the temperature remains constant?
Answer:
≈ 0.104 liters
Explanation:
We can use Boyle's Law: [tex]P_{1}V_{1} = P_{2}V_{2}[/tex]
P₁ = 2.50 atm
V₁ = 25.0 mL
P₂ = 457 mmHg
V₂ = ?
Because pressure should be in atm we will convert 457 mmHg to units in atm:
1 atm = 760mmHg so we can divide 457 by 760 and we get ≈ 0.601atm
Next we can plug in the units to the equation for Boyle's Law:
(2.50)(25.0) = (0.601)(V₂)
Solve for V₂
V₂ will give you ≈ 104mL or 0.104L
Either is correct depending on which unit they are asking you to use
Metal A reacts with oxygen to form an oxide.The oxide is dissolved in water to form a soluble hydroxide.What is the solution formed called and what is metal A
Answer:
The solution formed is called Barium hydroxide Ba(OH)2 and metal A is Barium
Explanation:
All basic oxides except BaO are insoluble in water
