Answer:
The volume of ozone produced is 7.53 L.
Explanation:
The reaction is:
3O₂(g) → 2O₃(g) (1)
0.477 mol V=?
11.3 L
From the reaction (1) we have that 3 moles of O₂ produce 2 moles of O₃ so the volume of the ozone produced can be calculated as follows:
[tex] V_{O_{3}} = V_{O_{2}}*\frac{n_{O_{3}}}{n_{O_{2}}} = 11.3 L*\frac{2}{3} = 7.53 L [/tex]
Therefore, the volume of ozone produced is 7.53 L.
I hope it helps you!
The ozone volume (in liters) is 7.53 L.
The calculation is as follows:
The volume of the ozone in liters should be
[tex]= 11.3 \times 2\div 3[/tex]
= 7.53L
we have that 3 moles of O₂ produce 2 moles of O₃
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When are these words used?
could ,would and should
what's difference between them?
Make 3 sentences using each word
a sentence for 'could': could u pass me the salt?
a sentence for 'would': what would you do if u were the president of usa?
sentence for 'should': you should practise ur spellings before the exam. :)
hope this helps!
What three things are required for a fire to start?
Identify the difference between natural and artificial dyes.
Answer:
Natural dyes, although pure from chemicals, are often times more expensive than chemical dyes.
Answer: natural dyes is dye that it is anything that grow on earth that haven't been possessed and artificial dye mean that it is good for something in your body or something else
Explanation:i search it up
Which one of these is most likely to gain electrons and which one is most likely to lose electrons? (And please explain why)
1. Ra (Radium)
2. In (Indium)
3. P (Phosphorus)
4. Te (Tellurium)
5. Br (Bromine)
6. Rb (Rubidium)
Answer:
(I). The most likely to lose electron is Rubidium
(II). The most likely to lose electron is Bromine
Explanation:
Given that,
Radium, Indium, Phosphorus, Tellurium, Bromine and Rubidium
We know that,
Metal :
They atom which to lose electron these is called metal.
When the atom loses the electron then the positive charge come on the atom.
The most likely to lose electron is Rubidium
Non metal :
They atome which is gains electron. It is called non metal.
So, we can say that, the non metal gains electron.
When the atom gains the electron then the negative charge come on the atom.
The most likely to gain electron is Bromine
Hence, This is required answer.
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
Is this example of a direct proportion or an inverse proportion?
A. Direct proportion
B. inverse proportion
Answer:
Inverse proportion occurs when one value increases and the other decreases. For example, more workers on a job would reduce the time to complete the task. They are inversely proportional.
Answer:
A
Explanation:
The number of ATPs per NADH generated by the electron transport system is higher than the number generated per FADH2 because __________. The number of ATPs per NADH generated by the electron transport system is higher than the number generated per FADH2 because __________. NADH is converted to NAD , which increases the charge gradient for ATP synthesis FADH2 has a higher (more negative) redox potential than NADH does electrons from FADH2 are not oxidized all the way to water FADH2 has a lower (less negative) redox potential than NADH does
Answer:
FADH2 has a lower (less negative) redox potential than NADH does
Explanation:
Flavin Adenine Dinucleotide (FAD) and Nicotinamide Adenine Dinucleotide (NAD) are redox cofactors that play important functions for mitochondrial activity and cellular redox balance. Both coenzymes exist in two forms: an oxidized and a reduced, which are abbreviated as NAD/FAD and NADH/FADH2, respectively. These reduced forms (NADH and FADH2) are produced in the Krebs cycle during respiration. FADH2 has lower redox potential than NADH because FADH2 is only capable of activating 2 proton pumps, while NADH can activate 3 proton pumps during the electron transport chain, thereby FADH2 generates a minor number of ATP molecules than NADH.
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.
If the temperature of a gas increased from 100K to 200K and the volume of a gas decreased from 20L to 10L, what is the new pressure I’d the original pressure was 100 kPa?
Answer:
400 kPa
Explanation:
using General Gas Law
[tex] \frac{100 \times 20}{100} = \frac{p \times 10}{200} [/tex]
[tex]p = 400[/tex]
The concept combined gas law is used here to determine the new pressure of the gas. The pressure of the gas obtained is 400 kPa.
What is combined gas law?The equation connecting the volume, pressure and temperature of a gas can be represented mathematically by an equation called the combined gas law. In this equation the temperature should be always in Kelvin.
The combined gas law is also defined as the ideal gas law without Avogadro's law. It is the combination of Boyle's law, Charles's law and Gay-Lussac's law. The equation is given as:
PV/T = k
Here 'P' is the pressure, 'V' is the volume, 'T' is the temperature and 'k' is a constant. The equation for two gases of different volumes and temperature is:
P₁V₁ / T₁ = P₂V₂ / T₂
Then P₂ = P₁V₁T₂ / T₁V₂
Here the new pressure P₂ is:
P₂ = 100 × 20 × 200 / 100 × 10
P₂ = 400 kPa.
Thus the new pressure is 400 kPa.
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What mass of Fe(OH)3 is produced when 35 mL of 0.250 M Fe(NO3)3 solution is mixed with 55 mL of a 0.180 M
KOH solution? (this is a limiting reactant problem).
Answer:
0.35 g.
Explanation:
We'll begin by calculating the number of mole of Fe(NO3)3 in 35 mL of 0.250 M Fe(NO3)3 solution.
This is illustrated below:
Molarity of Fe(NO3)3 = 0.250 M
Volume = 35 mL = 35/1000 = 0.035 L
Mole of Fe(NO3)3 =?
Molarity = mole /Volume
0.250 = mole of Fe(NO3)3 / 0.035
Cross multiply
Mole of Fe(NO3)3 = 0.25 x 0.035
Mole of Fe(NO3)3 = 8.75×10¯³ mole
Next, we shall determine the number of mole of KOH in 55 mL of 0.180 M
KOH solution. This is illustrated below:
Molarity of KOH = 0.180 M
Volume = 55 mL = 55/1000 = 0.055 L
Mole of KOH =.?
Molarity = mole /Volume
0.180 = mole of KOH /0.055
Cross multiply
Mole of KOH = 0.180 x 0.055
Mole of KOH = 9.9×10¯³ mole.
Next, we shall write the balanced equation for the reaction. This is given below:
3KOH + Fe(NO3)3 —> Fe(OH)3 + 3KNO3
From the balanced equation above,
3 moles of KOH reacted with 1 mole of Fe(NO3)3 to produce 1 mole of Fe(OH)3.
Next, we shall determine the limiting reactant. This can be obtained as follow:
From the balanced equation above,
3 moles of KOH reacted with 1 mole of Fe(NO3)3.
Therefore, 9.9×10¯³ mole of KOH will react with = (9.9×10¯³ x 1)/3 = 3.3×10¯³ mole of Fe(NO3)3.
From the above illustration, we can see that only 3.3×10¯³ mole out of 8.75×10¯³ mole of Fe(NO3)3 given is needed to react completely with 9.9×10¯³ mole of KOH.
Therefore, KOH is the limiting reactant and Fe(NO3)3 is the excess reactant.
Next, we shall determine the number of mole of Fe(OH)3 produced from the reaction.
In this case, we shall use the limiting reactant because it will give the maximum yield of Fe(OH)3 as all of it is consumed in the reaction.
The limiting reactant is KOH and the mole of Fe(OH)3 produce can be obtained as follow:
From the balanced equation above,
3 moles of KOH reacted to produce 1 mole of Fe(OH)3.
Therefore, 9.9×10¯³ mole of KOH will react to produce = (9.9×10¯³ x 1)/3 = 3.3×10¯³ mole of Fe(OH)3.
Finally, we shall convert 3.3×10¯³ mole of Fe(OH)3 to grams. This can be obtained as follow:
Molar mass of Fe(OH)3 = 56 + 3(16 + 1) = 56 + 3(17) = 107 g/mol
Mole of Fe(OH)3 = 3.3×10¯³ mole
Mass of Fe(OH)3 =?
Mole = mass /Molar mass
3.3×10¯³ = Mass of Fe(OH)3 / 107
Cross multiply
Mass of Fe(OH)3 = 3.3×10¯³ x 107
Mass of Fe(OH)3 = 0.3531 ≈ 0.35 g.
Therefore, 0.35 g of Fe(OH)3 was produced from the reaction.
what is the scientific term for salt
Answer:
The scientific term for table salt is Sodium chloride.
Explanation:
The answer is sodium chloride.
It is composed of sodium and chloride. Like,
[tex] {na}^{ + } + {cl}^{ + } = nacl[/tex]
so, it's name is sodium chloride.
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
Which of the following is NOT a product of the electrolysis of NaCl? A. Chlorine gas B. None of these C. Hydrogen gas D. Oxygen gas
Answer:D. Oxygen gas
Explanation: because the experiment showed
how much of the excess reactant remains unchanged?
how much N2 is formed? (in mol)
how much H2O is firmed? (in mol)
Answer:
1. The limiting reactant is H2O2.
2. The amount of excess reactant, N2H4 that remain unchanged is 11.15 moles.
3. 1.65 moles of N2.
4. 6.6 moles of H2O.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
N2H4 + 2H2O2 —> N2 + 4H2O
From the balanced equation above,
1 mole of N2H4 reacted with 2 moles of H2O2 to produce 1 mole of N2 and 4 moles of H2O.
1. Determination of the limiting reactant.
From the balanced equation above,
1 mole of N2H4 reacted with 2 moles of H2O2.
Therefore, 12.8 moles of N2H4 will react with = 12.8 x 2 = 25.6 moles of H2O2.
From the calculations made above, we can see that it will take a higher amount i.e 25.6 moles than what was given i.e 3.3 moles of H2O2 to react completely with 12.8 moles of N2H4.
Therefore, H2O2 is the limiting reactant and N2H4 is the excess reactant.
2. Determination of the excess reactant that remain unchanged.
The excess reactant is N2H4.
First, we shall determine the amount of the excess reactant that reacted. This is illustrated below:
From the balanced equation above,
1 mole of N2H4 reacted with 2 moles of H2O2.
Therefore, Xmol of N2H4 will react with 3.3 moles of H2O2 i.e
Xmol of N2H4 = (1 x 3.3)/2
Xmol of N2H4 = 1.65 moles
Therefore, 1.65 moles of N2H4 reacted.
Now, we shall determine the excess reactant that remain unchanged. This can be obtained as follow:
Amount of N2H4 given = 12.8 moles
Amount of N2H4 that reacted = 1.65 moles.
Amount of N2H4 that remain unchanged =?
Amount of N2H4 that remain unchanged = (Amount of N2H4 given) – (Amount of N2H4 that reacted = 1.65 moles)
Amount of N2H4 that remain unchanged = 12.8 – 1.65
Amount of N2H4 that remain unchanged = 11.15 moles.
3. Determination of the amount of N2 produced.
In this case, the limiting reactant will be used because it will give the maximum yield of N2 as all of it is used up in the reaction.
The limiting reactant is H2O2 and the amount of N2 produced can be obtained as follow:
From the balanced equation above,
2 moles of H2O2 reacted to produce 1 mole of N2.
Therefore, 3.3 moles of H2O2 will react to produce = (3.3 x 1)/2 = 1.65 moles of N2.
Therefore, 1.65 moles of N2 were obtained from the reaction.
4. Determination of the amount of H2O produced.
In this case, the limiting reactant will be used because it will give the maximum yield of H2O as all of it is used up in the reaction.
The limiting reactant is H2O2 and the amount of H2O produced can be obtained as follow:
From the balanced equation above,
2 moles of H2O2 reacted to produce 4 moles of H2O.
Therefore, 3.3 moles of H2O2 will react to produce = (3.3 x 4)/2 = 6.6 moles of H2O.
Therefore, 6.6 moles of H2O were produced from the reaction.
Which statements describe a good hypothesis? Check all that apply.
A good hypothesis is based on one's personal opinion.
A good hypothesis can be tested.
A good hypothesis leads to a test with measureable results.
A good hypothesis does not always have to be based on prior knowledge or research.
A good hypothesis provides a possible explanation to answer a scientific question.
Answer:
- A good hypothesis can be tested.
- A good hypothesis provides a possible explanation to answer a scientific question.
- A good hypothesis does not always have to be based on prior knowledge or research.
Explanation:
The reason being because hypothesis are questions asked before the experiment. They usually involve the testable question and the experiment answers it, but not always. A good hypothesis doesn't need to have accurate results.
Answer:B : A good hypothesis can be tested. C:A good hypothesis leads to a test with measurable results. E: A good hypothesis provides a possible explanation to an answer a scientific question ( B, C, E)
Explanation:Just took the (Assignment) quiz
Which element increases its oxidation number in this reaction? 3KOH + H3PO4 → K3PO4 + 3H2O
Answer:
The answer is "no changes in oxidation number "
Explanation:
Given equation:
[tex]3KOH + H_3PO_4 \longrightarrow K_3PO_4 + 3H_2O[/tex]
In the above-given equation, there are no changes in the oxidation number which can be defined as follows but first we defined the oxidation: In the chemical process, it requires the transfer of ions is oxidation. In particular, it means that products that supply electrodes are oxidized. In the given equation, when 3Potassium hydroxide reacts with phosphoric acid it will produce potassium phosphate and 3 moles of water.
The pOH of a solution is 3.1. Which of the following is true about the solution? (1 point)
It is acidic and has a pH of 10.9.
It is basic and has a pH of 10.9.
It is acidic and has a pH of 6.2.
It is basic and has a pH of 6.2.
Answer:
The answer is option BExplanation:
To solve the question above we must first find the pH of the solution using the formula
pH + pOH = 14
pOH = 3.1
So we have
pH + 3.1 = 14
pH = 14 - 3.1
pH = 10.9
Since it's pH is 10.9 the solution is a basic solution since it's pH lies in the basic region.
Hope this helps you
boron has two naturally occurring isotopes: boron -10 (abundance = 19.8% , mass = 10.013 amu) boron -11 (abundance = 80.2%, mass= 11.009 amu) Calculate th eatomic mass of boron
Explanation:
eam=%abudance×mass+%abudance×mass
eam=19.8%×10.013/100+80.2%×11.009/100
eam=198.2574/100+882.9218/100
eam=1081.1792/100
eam=10.811792
eam=10.812
Choose all the answers that apply
Protons:
Have a positive change
Have no change
Are found in the nucleus
Orbit the nucleus
Have a negative charge
4. (01.05 MC)
Rubbing alcohol evaporates from your arm quickly, leaving a cooling effect on your skin. How do the molecules of gas compare to the molecules as a liquid? (4 points)
The gas particles move faster, have the same molecular composition, and have weaker attractions between them than the liquid particles
The gas particles move faster than the liquid particles, and the bonds of the molecules are broken during evaporation to allow gas atoms to spread apart.
The gas particles move slower but have the same molecular structure and the same attraction between them as the liquid particles.
The gas and liquid particles move at the same speed, but the bonds of the molecules are broken during evaporation to allow the gas atoms to spread apart
Answer:
The correct option is;
The gas particles move faster, have the same molecular composition, and have weaker attractions between them than the liquid particles
Explanation:
The properties of the gas molecules in comparison to liquids are
1) The gas molecules are widely spread out
2) After evaporation and while in conditions favorable to the gaseous state, the kinetic energy of a gas is larger than the inter molecular attractive forces
3) A gas fills the container in which it is placed
For liquids
1) There are strong intermolecular forces holding the molecules together in a liquid
2) Liquid attractive forces in a liquid are strong enough to hold neighboring molecules
3) The volume of a liquid is definite.
What scientific instrument is sensitive enough to detect a planet transiting a star?
Answer:
Photometer
Explanation:
A photometer (photo comes from the Greek for light) measures the light coming from 140,000 stars in Kepler's stationary field of view. If a planet transits (passes in front of) any star the amount of light from the star is reduced enough so that the photometer senses it and relays the information back to the Kepler team.
Scientific instruments are tools used for researching the universe and natural sciences. A Photometer is sensitive enough to detect a planet transiting a star. Thus, option D is correct.
What is a Photometer?A Photometer is a device that converts light energy into electrical voltage by the photoelectric effect given by Einstein. It uses Quantum mechanics to convert the energy possessed by the photons and electrons. It follows Ohm's law to convert energy.
It is used to detect the planets transiting stars as they can detect the light energy as it uses the electromagnetic radiation of various wavelengths to convert them by the photodiode, resistor, and a multiplier.
Therefore, option D. a photometer is used to detect the planets in the universe transiting stars.
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Your question is incomplete, but most probably your full question was, What scientific instrument is sensitive enough to detect a planet transiting a star?
Atomic force microscopeSolar arraysSatellite RadioPhotometerHow does the percentage of monounsaturated and polyunsaturated fatty acids in olive oil compare to that of canola oil? Match the words in the left column to the appropriate blanks in the sentences on the right. Make certain each sentence is complete before submitting your answer. ResetHelp Olive oil has about Olive oil has about blank monounsaturated fats, while canola oil has about blank. monounsaturated fats, while canola oil has about Olive oil has about blank monounsaturated fats, while canola oil has about blank.. Olive oil has about Olive oil has about blank polyunsaturated fats, while canola oil has about blank. polyunsaturated fats, while canola oil has about Olive oil has about blank polyunsaturated fats, while canola oil has about blank..
This question is incomplete, here´s the complete question.
How does the percentage of monounsaturated and polyunsaturated fatty acids in olive oil compare to that of canola oil? Match the words in the left column to the appropriate blanks in the sentences on the right.
Olive oil has about ____ monounsaturated fats, while canola oil has about ___.
Olive oil has about ___ polyunsaturated fats, while canola oil has about ___.
6%
10%
30%
84%
5%
65%
Answer:
Olive oil has about 84% monounsaturated fats, while canola oil has about 65%.
Olive oil has about 5% polyunsaturated fats, while canola oil has about 30%.
Explanation:
Olive and canola oil are the major sources of monounsaturated fatty acids. Although vegetable oils usually have high concentrations of polyunsaturated fatty acids and less monounsaturated fats, olive and canola oils have comparatively less polyunsaturated fatty acids, and more monounsaturated fatty acids.
What does the VSEPR theory describe
Answer:
The shape of a molecule based on the number of electron pairs on the valence shell of its central atom
Explanation:
The improvement of the Sidgwick-Powell theory came to be known as the Valence Shell Electron Pair Repulsion theory (VSEPR). This theory approaches the determination of molecular shape from the perspective of the number of electron pairs on the valence shell of the central atom in the molecule.
Electron pairs on the valence shells of atoms leads to repulsion. Repulsion between two lone pairs is greater than repulsion between a lone pair and a bond pair which is also greater than repulsion between two bond pairs.
Lone pairs cause more repulsion, hence they distort molecules from the ideal shape predicted based on their electron domain geometry.
1.) Given 30 grams of CO2, how many moles of CO2 would you have? How many individual molecules of CO2 is that?
2., Given 22 Grams of NaCl, How many moles of Nacl would you have? How many individual molecules of NaCl is that?
3.) Given 50 grams of ammonia NH3, How many moles of NH3 would you have? How many Molecules of NH3 is that?
Answer:
1a) .68 moles 1b)4.1E-23 molecules.
2a) .37 moles 2b) 2.27E-23 molecules
Explanation:
1a) CO2 is equal to 44 grams (C→12 grams,O→16 grams[·2]) .30g/44g is .68 moles.
1b) multiply 1A by advogadros number (6.022E-23)
2a) NaCl is 58 grams. 22/58 is .37 moles.
2b) multiply 2A by advogadros number.
you'd answer #3 the same way #1 and #2
The branch of science that deals with chemicals and bonds are called chemistry. The moles are units to calculate the quantity required to use the element.
The correct answer is mentioned below.
What are moles?The mole is the base unit of the amount of substance in the International System of Units (SI). It is defined as exactly 6.02214076×10^23 elementary entities which may be atoms, molecules, ions, or electrons.According to the question, the moles to the option is as follows:-
moles of 30 grams of CO2 is[tex]n =\frac{M}{M.M}\\ \\\frac{30}{44} \\\\=0.681\\\\[/tex]
The number of molecules is [tex]0.68 *6022*10^{23} =4.09496*10^{23[/tex].
2. moles of 22 grams of NaCl is
[tex]\frac{22}{44}\\ \\=0.5\\\\[/tex]
Molecules will be [tex]0.5*6.022*10^{23} = 3.011*10^{23}[/tex]
3. moles of 50-gram ammonia
[tex]\frac{50}{17} \\\\2.94\\[/tex]
The number of molecules is [tex]2.94*6.022*10^{23} = 1770*10^{23[/tex]
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plz answer fast i beg u
Which are not particles that enable electrical conductivity?
Select one:
a. delocalised electrons
b. molecules
c. mobile ions
Answer:
The correct option is;
a. Delocalised electrons
Explanation:
The particles that enable electrical conductivity are the delocalised electrons
The metallic structure consists of identically shaped elements having positive ions that have a resultant alignment, surrounded by a vast array of deloclised electrons, which move freely in the metallic structure such that a metallic part usually has a high electrical conductivity.
Therefore, the freely moving delocalised electron in a metal give them the property of good conductors of electricity.
What is the atomic number of copper
Answer:
29
Explanation:
Copper is a chemical element with the symbol Cu and atomic number is 29
Explanation:
What element is depicted by the following electron configuration:
you can determine this by
adding the numbers of the sub-shells, 2+2+6+2+4=16the number on the last sub-shell, 4 means on the 4th main groupthe 3 before 3p4, tells us on the 3rd period, so the answer is Sulphur.A sample of 0.562 g of carbon is burned in oxygen in a bomb calorimeter, producing carbon dioxide. Assume both the reactants and products are under standard state conditions, and that the heat released is directly proportional to the enthalpy of combustion of graphite. The temperature of the calorimeter increases from 26.74 °C to 27.93 °C. What is the heat capacity of the calorimeter and its contents?
Answer:
The correct answer is 15.54 kJ per degree C.
Explanation:
The enthalpy change for one mole of a substance, which combines or burns with the oxygen under the standard conditions, that is, at 25 degree C and 1 bar pressure is known as the standard molar enthalpy of combustion. The amount of heat transferred can be calculated by using the formula, q = mcΔT -------------(i)
Here q is the amount of heat transferred, c is the specific heat, ΔT is the change in temperature, and m is the mass of the substance. As in case of bomb calorimeter, mass if considered constant, thus, for calorimeter the equation mentioned will become, q = cΔT ---- (ii)
The standard molar enthalpy of combustion for carbon is -393.5 kJ/mol, that is, -393.5 kJ per mole of heat is generated by burning one mole of carbon. The molecular mass of carbon is 12 gram per mole.
Thus, the number of moles of carbon equivalent to 0.562 grams of carbon can be determined as,
Number of moles of carbon = mass / molecular mas
= 0.562 grams / 12 gram per mole
= 0.047 mol
The heat generated by burning 0.562 grams or 0.047 mole will be,
q = ΔH° × number of moles
= (-393.51 kJ/mol) × 0.047 mol
= -18.49 kJ, the negative sign shows that the heat is produced.
To find heat capacity of calorimeter, put the value of q as -18.49 kJ, for ΔT as (27.93 °C - 26.74 °C) in the equation (ii)
18.49 kJ = c × (27.93 - 26.74)
c = 18.49 kJ/1.19 °C
c = 15.54 kJ/°C
Lavoisier developed a new theory of combustion that overturned the phlogiston theory. What measurements were central to his theory, and what key discovery did he make?
Answer:
Lavoiser proposed a theory in charge of writing the combustion correctly, denying the phlogiston.
Lavoiser said that combustion is carried out in a medium where there is oxygen, giving as a product water and carbon dioxide.
This combustion results in the decrease in the volume of the material that burns.
Furthermore lavoiser discovered the importance of oxygen in animal respiration.
Explanation:
Lavoisier argued that if or if the presence of oxygen must be present, it is an irreversible and spontaneous process.
• Calculate relative formula masses from formulae and
from balanced equations?
Answer:
Explanation:
Simple molecules have very small masses. Instead of writing their actual masses in grams or kilograms, we usually use their relative formula masses. These are calculated using the chemical formula and the relative atomic masses of the elements in it.
Relative formula mass
Relative atomic mass has the symbol Ar. The Ar for an element is a measure of the mass of its atoms compared to the mass of carbon-12 atoms. The greater the Ar value, the more mass an element's atoms have. The periodic table shows the Ar value for each element. For example, the Ar for carbon is 12, and the Ar for magnesium is 24. This means that a magnesium atom has twice the mass of a carbon atom.
Calculating relative formula mass
Relative formula mass is given the symbol Mr. To calculate the Mr for a substance:
work out how many atoms of each element there are in the chemical formula
add together the Ar values for all the atoms of each element present
For example, the formula for carbon dioxide is CO2. It consists of one carbon atom (Ar = 12) and two oxygen atoms (Ar = 16):
Mr of CO2 = 12 + 16 + 16 = 44
It could also be calculated this way:
Mr of CO2 = (1 × 12) + (2 × 16) = 12 + 32 = 44
Ar and Mr values are just numbers. They have no units because they are relative masses.
Relative formula masses of ionic compounds
Ionic compounds such as sodium chloride do not exist as molecules. However, their relative formula masses are calculated in the same way. The formulae used are their empirical formulae.
