Answer:
\(\Delta H_{f,C_3H_4}=276.8kJ/mol\)
Explanation:
Hello!
In this case, since the equation we use to model the heat exchange into the calorimeter and compute the heat of reaction is:
\(\Delta H_{rxn} =- m_wC_w\Delta T\)
We plug in the mass of water, temperature change and specific heat to obtain:
\(\Delta H_{rxn} =- (35000g)(4.184\frac{J}{g\°C} )(2.316\°C)\\\\\Delta H_{rxn}=-339.16kJ\)
Now, this enthalpy of reaction corresponds to the combustion of propyne:
\(C_3H_4+4O_2\rightarrow 3CO_2+2H_2O\)
Whose enthalpy change involves the enthalpies of formation of propyne, carbon dioxide and water, considering that of propyne is the target:
\(\Delta H_{rxn}=3\Delta H_{f,CO_2}+2\Delta H_{f,H_2O}-\Delta H_{f,C_3H_4}\)
However, the enthalpy of reaction should be expressed in kJ per moles of C3H4, so we divide by the appropriate moles in 7.00 g of this compound:
\(\Delta H_{rxn} =-339.16kJ*\frac{1}{7.00g}*\frac{40.06g}{1mol}=-1940.9kJ/mol\)
Now, we solve for the enthalpy of formation of C3H4 as shown below:
\(\Delta H_{f,C_3H_4}=3\Delta H_{f,CO_2}+2\Delta H_{f,H_2O}-\Delta H_{rxn}\)
So we plug in to obtain (enthalpies of formation of CO2 and H2O are found on NIST data base):
\(\Delta H_{f,C_3H_4}=3(-393.5kJ/mol)+2(-241.8kJ/mol)-(-1940.9kJ/mol)\\\\\Delta H_{f,C_3H_4}=276.8kJ/mol\)
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Which of the following ions is formed when a base is dissolved in a solution? (5 points)
H+
O−
OH−
SO42+
Answer:
oH-
Explanation:
is the only negative ion in a base
The reaction of 11.9 g of CHCl3 with excess chlorine produced 11 grams of CCl4, carbon tetrachloride. What is the percent yield
For a reaction, AH = 206 kJ/mol and A SO = 0.215 kJ/(K•mol). At what
temperatures is this reaction spontaneous?
O A. At all temperatures
O B. At temperatures greater than 958 K
C. At no temperature
O D. At temperatures less than 44 K
SUBMIT
Do step 3 as outlined in the lab guide. Record your results in the appropriate blanks.
A =
B =
C =
D =
E =
F =
G =
H =
Some tips to follow when doing lab practical are:
Avoid parallax errorsRecord your observations and data accuratelyUse the appropriate lab equipment.How do we know?From the table, Column 1 represents the time in half-life cycles, ranging from the initial state to 8 cycles. Column 2 shows the predicted number of radioactive atoms at each time point, based on the assumption that the number of atoms reduces by half in each half-life cycle.
Column 3 represents the simulated number of radioactive atoms at each time point and corresponds to the predicted values of the simulation.
In conclusion, the results as outlined in the lab guide are A= 27 B= 16 C= 9 D= 4 E= 2 F= 2 G= 0 H= 0.
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#complete question:
Do step 3 as outlined in the lab guide. Record your results in the appropriate blanks. A = B = C = D = E = F = G = H = A 3-column table with 9 rows. Column 1 is labeled Time half-life cycles, n with entries Initial, 1, 2, 3, 4, 5, 6, 7, 8. Column 2 is labeled Predicted radioactive atoms with entries 100, 50, 25, 13, 6, 3, 2, 1, 0. Column 3 is labeled Simulated radioactive atoms with entries 100, A, B, C, D, E, F, G, H.
How many moles of NaHCO3 are in 2.4 x
1024 molecules of NaHCO:?
4.0 moles NaHCO
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
MolesAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Stoichiometry
Using Dimensional AnalysisExplanation:Step 1: Define
[Given] 2.4 × 10²⁴ molecules NaHCO
[Solve] moles NaHCO
Step 2: Identify Conversion
Avogadro's Number
Step 3: Convert
[DA] Set up: \(\displaystyle 2.4 \cdot 10^{24} \ molecules \ NaHCO(\frac{1 \ mol \ NaHCO}{6.022 \cdot 10^{23} \ molecules \ NaHCO})\)[DA] Divide [Cancel out units]: \(\displaystyle 3.98539 \ moles \ NaHCO\)Step 4: Check
Follow sig fig rules and round. We are given 2 sig figs.
3.98539 moles NaHCO ≈ 4.0 moles NaHCO
What state of matter is every compound in for the chemical reaction? CH4 (g)+2 0₂ (g) -> CO₂(g) + 2 H₂0 (g
Answer:
CH4 (g) and O2 (g) are both in the gaseous state, while CO2 (g) and H2O (g) are also in the gaseous state.
In the above reaction, the reactants are in the gaseous state, and the products formed are also in the gaseous state.
Every compound in a chemical reaction can be in any state of matter like solid, liquid, or gas. In the reaction of methane and oxygen, the initial state of the reactants is in the gaseous form. The chemical reaction of methane and oxygen is given by the equation CH4 (g) + 2 O2 (g) -> CO2 (g) + 2 H2O (g).Here, methane and oxygen are the reactants, and carbon dioxide and water are the products. Methane (CH4) and oxygen (O2) react together in the presence of a spark or heat to produce carbon dioxide (CO2) and water (H2O).In the reaction, the methane gas combines with oxygen gas, which causes the release of heat energy and forms carbon dioxide gas and water vapor. Methane gas is a colorless and odorless gas that burns cleanly and is one of the primary components of natural gas.
The oxygen gas required for the reaction is available in the atmosphere. Carbon dioxide is a colorless gas with a faint odor and taste and is a significant component of the Earth's atmosphere. Water is a colorless, odorless, and tasteless liquid that is essential to life.The state of matter of every compound in a chemical reaction can change depending on the conditions in which the reaction occurs. For instance, a substance that is in the solid state at a lower temperature may melt into a liquid or boil into a gas at a higher temperature. Similarly, a liquid may freeze into a solid or vaporize into a gas under different conditions.
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Question 1 of 10
Which of the following is the best scientific hypothesis?
A. Do rattlesnakes strike when they think they are in danger?
B. Rattlesnake venom can be used to treat some diseases.
C. Snakes make good house pets.
D. Snakes are longer than lizards.
MIT
Answer:
AS THE HYPOTHESIS MEANS THAT OUR THOUGHTS AND FINDINGS SO
PART B .... RATTLESNAKES VENOM CAN BE USED AS TREATMENT
Explanation:
PLEASE MARK AS BRAINLIEST
2. What are the two types of pressure?
O Medium pressure/Extreme pressure
ebo...
Medium pressure/ Low pressure
O High pressure/Low pressure
Medium pressure/ High pressure
Answer:
O High pressure/Low pressure
Explanation:
A low pressure system has lower pressure at its center than the areas around it. Winds blow towards the low pressure, and the air rises in the atmosphere where they meet. ... A high pressure system has higher pressure at its center than the areas around it. Winds blow away from high pressure.
The two types of pressure commonly referred to are high pressure and low pressure. Therefore option 3 is correct.
High pressure/Low pressure: This option correctly identifies the two main types of pressure. High pressure refers to conditions where the pressure is greater than atmospheric pressure, such as in compressed gases or in high-pressure systems.
Low pressure refers to conditions where the pressure is less than atmospheric pressure, such as in a vacuum or in areas of low atmospheric pressure, like the center of a weather system.
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What wavelength of light is emitted in nm from an electron in a hydrogen atom moving from the n=4 to n=1 energy state?
Explanation:
n1 = 1 and n2 = 4
from the formula
let v be walength
1/v = 1.097 x 10^7(1/n1 ^2 - 1/n2^2)= 1.097 x 10^7(1/1 - 1/4^2)
= 1.097 x 10^7 x 0.9375
1/v = 1.0287 x 10^7
to find v
v = 1/1.0287 x 10^7
v = 9.72 x 10 ^-8
Wavelength = 97.2nm
What factors affect the speed of a wave? Check all that apply. the amplitude of the wave the energy of the wave the temperature of the medium the type of wave the type of medium
Answer:
I believe its 1,2, and 5
Explanation:
C D E
temperature of medium
type of wave
type of medium
7. What is the volume of the
composite
solid?
4 in.
3 in.
3 in.
Answer:
The volume of Component 1 is 36 cubic inches.
Explanation:
To calculate the volume of a composite solid, we need to determine the individual volumes of the different components and then add them together.
In this case, the composite solid consists of multiple components with the following dimensions:
Component 1:
Length: 4 inches
Width: 3 inches
Height: 3 inches
To find the volume of Component 1, we multiply the length, width, and height together:
Volume of Component 1 = Length x Width x Height = 4 in x 3 in x 3 in = 36 cubic inches
Therefore, the volume of Component 1 is 36 cubic inches.
Please provide the dimensions of the remaining components of the composite solid, and I will calculate the total volume by summing up the individual volumes.
How many grams of nitrogen are in 1.5 moles of nitrogen atoms
Answer:
42 grams
Explanation:
the conversion between moles and grams is by using the molar mass of the substance.
The molar mass for a nitrogen atom is 14.00 g/mol.
N2 has two nitrogen atoms, so its molar mass is 28.00 g/mol
To find how many grams are in 1.5 moles;
\(28g/mol*1.5mol\)
the units of mols cancels out, leaving one with units of grams of N2
Pewter is a solidified solution of tin and lead or tin and zinc. In both cases, tin is the main component. Which metal would you classify as the solute in each type of pewter?
______ + _______ --> H2O + FrF Complete and balance the equation representing neutralization reaction.
The general form of a neutralization reaction is HF + FrOH → FrF + H₂O
Which of the following is the formula for a neutralisation reaction?We refer to this as a neutralisation reaction. Only this reaction, which produces NaCl and water as products, is a neutralisation reaction since it involves HCl and NaOH. The resulting response is listed below: NaCl(aq) + H₂O = HCl(aq) + NaOH(aq) (l)
Which of these reactions neutralises an effect?The interaction of H⁺ ions and OH⁻ ions produces water in a neutralisation reaction, which occurs when an acid and a base combine to make water and a salt. The neutralisation of a strong acid and strong base yields a pH of 7.
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Hydrogen gas is collected over water at 23°C, 767 torr. At this temperature the vapor pressure of water is 21.0 torr. What is the partial pressure of hydrogen in the collected gas?
The partial pressure of hydrogen gas in the collected gas is 746 torr.
To determine the partial pressure of hydrogen gas in the collected gas, we need to consider the difference between the total pressure of the collected gas and the vapor pressure of water at the given temperature. The partial pressure of hydrogen gas is the pressure exerted by hydrogen alone.
Given information:
Total pressure of the collected gas (Ptotal) = 767 torr
Vapor pressure of water (Pwater) = 21.0 torr
The partial pressure of hydrogen gas (Phydrogen) can be calculated using Dalton's law of partial pressures, which states that the total pressure of a mixture of gases is equal to the sum of the partial pressures of each individual gas.
Phydrogen = Ptotal - Pwater
Plugging in the given values:
Phydrogen = 767 torr - 21.0 torr
Phydrogen = 746 torr
Therefore, the partial pressure of hydrogen gas in the collected gas is 746 torr.
It's important to note that in this calculation, we assume that the water vapor does not react with or dissolve in the hydrogen gas and that the gases behave ideally. Additionally, it's assumed that the collected gas is dry, meaning all the water vapor has been removed or does not significantly contribute to the total pressure.
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How many molecules are in 0.0023 moles of CO2?
Taking into account the definition of Avogadro's Number, 1.38529×10²¹ molecules in 0.0023 mole of CO₂ .
Definition of Avogadro's NumberAvogadro's number is defined as the number of particles (atoms, molecules, ions, electrons) in 12 grams of carbon-12, that is, in one mole of the substance or compound.
Its value is 6.023×10²³ particles per mole and it applies to any substance.
Molecules of CO₂ in this caseConsidering the definition of Avogadro's number, you can apply the following rule of three: If 1 mole of CO₂ contains 6.023×10²³ molecules, 0.0023 mole of CO₂ contains how many molecules?
amount of molecules of CO₂= (0.0023 moles × 6.023×10²³ molecules)÷ 1 mole
amount of molecules of CO₂= 1.38529×10²¹ molecules
Finally, there are 1.38529×10²¹ molecules.
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What is the name of the compound O7I9
Answer:
question not clear can u rewrite
Is magnetism a chemical or physical property and why?
helpppp
Answer:
Magnetism is a physical property
Explanation:
Every substance has physical properties that distinguish it from other substances.
Q2) Describe the position of electrons in a metal
Electrons in metals are delocalised. Electrons in ionic bonds are transferred from a metal to a non-metal. Electrons in a covalent bond are shared between two non-mtal ions.
- Eddie
What is the difference between structure and function in plants and animal cell organelles
Answer:
cell wall
Explanation:
plant cell have cell wall and can go through the process of plasmolysis.
they also contain stoma
animal cell are smaller
What's the molality of a solution with 120 g of NaCl and 30 kg of water?A)0.068B)0.004C)0.25D)6.8
Explanation:
Molality is the ratio of the amount of substance of a solute (in moles – n) to the mass in kilograms of the solvent (m).
The symbol for molality is usually W and it can be calculated by the following formula:
W = n/m
here, we need to calculate n of NaCl using the formula:
n = m/MM
where MM of NaCl is 58.5 g/mol
n = 120/58.5
n = 2.05 moles
W = 2.05/30
W = 0.068 mol/Kg
Answer: A) 0.068
Help with chemistry??
Answer:
The first image = double replacement
Second = single replacement
Third = Decomposition
Fourth = Combination
Explanation:
1. a color from each pair is being swapped and replacing each other so there is a double replacement
2. only the blue and the red are changing places so it is single replacement
3. the pair is being separated (decomposed)
4. the red and green are coming together (combined)
You are in a laboratory creating a new chocolate bar. You want to create the sweetest chocolate bar by maximizing the sugar concentration. You are doing this by adding the sugar to a chocolate mixture. Which would allow you to dissolve more sugar?
The answer: Add the sugar after heating the mixture.
Adding the sugar after heating the mixture would allow you to dissolve more sugar, which would result in a sweeter chocolate bar.
When you dissolve sugar in a liquid, such as in a chocolate mixture, there is a limit to the amount of sugar that can be dissolved at a given temperature. This limit is known as the solubility of the sugar in that liquid. The solubility of sugar in water is higher at higher temperatures, which means that you can dissolve more sugar in hot water than in cold water. The same principle applies to chocolate mixtures.
By heating the chocolate mixture, you increase the temperature of the mixture, which in turn increases the solubility of the sugar in the mixture. This allows you to dissolve more sugar in the mixture than if you were to add the sugar to the mixture at room temperature or when it is cold.
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--The given question is incorrect, the correct question is
"You are in a laboratory creating a new chocolate bar. You want to create the sweetest chocolate bar by maximizing the sugar concentration. You are doing this by adding the sugar to a chocolate mixture. Which would allow you to dissolve more sugar?"--
What is the chemical formula for micas
Answer:
X2Y4–6Z8O20 (OH, F)4
Explanation:
The chemical formula for micas is X2Y4–6Z8O20 (OH, F)4, where X is K, Na, or Ca or less commonly Ba, Rb, or Cs; Y is Al, Mg, or Fe or less commonly Mn, Cr, Ti, Li, etc.; Z is chiefly Si or Al, but also may include Fe3+ or Ti1. Structurally, micas can be classed as dioctahedral (Y = 4) and trioctahedral (Y = 6)1.
The chemical formula for micas varies, but they typically have the general formula:
(K,Na,Ba,Rb,Ca)(Al,Mg,Fe)2(Si3Al)O10(OH,F)2
Where:
K, Na, Ba, Rb, and Ca represent alkali metals and alkaline earth metals that can occupy the interlayer sites. Potassium is the most common.Al and Mg represent aluminum and magnesium that occupy the octahedral sites between the silica tetrahedral sheets.Fe can substitute for Al in the octahedral sites.Si and Al occupy the tetrahedral sites within the silica sheets. The ratio of Si to Al is typically around 3:1.O represents oxygen atomsOH or F can occupy the interlayer sites, with hydroxyl (OH) being more common. Fluorine can substitute for hydroxyl in some micas.So in summary, micas have a layered aluminosilicate structure with interlayer cations that can vary, but they are generally characterized by an approximate 3:1 ratio of silicon to aluminum within the silica tetrahedral sheets. The chemical formula given is the generalized structural formula for micas, but the actual compositions can vary based on the specific mica.
what properties of a natural resource make it useful for humans as a materials or energy source?
The properties of a natural resource that make it useful for humans as a material or energy source is the ability to convert mass into energy and vice versa.
What are natural resources?The expression natural resources make reference to all types of matter and energy extracted from nature that can be used to produce goods and services.
Some examples of natural resources include for example irreversible resources such as fossil fuels (i.e., oil, or coal, gas, minerals such as metals, rocks, etc) as well as those based on the use of reversible energy such as eolic air energy, solar radiation or sunlight, soil and hydric resources or water.
Therefore, with this data, we can see that natural resources can be defined as any material and or energy obtained from nature that may be irreversible or reversibly used to produce goods and services.
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formula de oxido de cloro
Explanation:
Formula for Dichlorine trioxide is: Cl2O3
hope this helps you
have a great day :)
An object becomes positively charged when it loses electrons. O loses protons. O gains electrons. O gains neutrons.
an object becomes positively charged when it LOSES ELECTRONS.
* protons are positive, so losing protons means that it would be negatively charged.
* gaining electrons would make it more negatively charged.
* gaining neutrons changes nothing because neutrons are neutral.
3. Consider the following
energy levels of a hypothetical atom:
E4_-1.0 x 10-19.
-5.0 x 10-19 J
-10 x 10--193
E1
.-15 x 10-19
(a) What is the wavelength of the photon needed to excite an electron from E1 to E4? (b)
What is the energy (in joules) a photon must have in order to excite an
electron from
E2
to E3? (c) When an electron drops from E3 level to the E1, the atom is said tO undergo
emission. Calculate the wavelength of the photon emitted in this process.
a)λ = 1.43 x 10⁻⁷ m, b)λ =5 x 10⁻¹⁹ and, c)λ = 1.99 x 10⁻⁷ m.
What is an atom?A chemical element is uniquely defined by its atoms, which are tiny pieces of substance. A core nucleus, often surrounded by one or more electrons, makes up an atom. The charge of every electron is negative. The positively charged nucleus has one or more protons and neutrons, relatively heavy particles.An atom is referred to any elementary particle of matter with at least one proton. Examples of atoms are neon (N) and hydrogen (H) (Ne).Protons, which have a positive charge, and neutrons, which have no charge, make up its structure. All regular, naturally occurring atoms contain the long-lived particles protons, neutrons, and the electrons that orbit them.It is difficult to appreciate how little they are until you see how many atoms there are in your body. Around 7 octillion atoms make up one adult.a) The wavelength of the photon needed to excite an electron from E1 to E4:
ΔE = hc/λ
(-1 + 15) x 10⁻¹⁹ = 6.63 x 10⁻³⁴ x 3 x 10⁸ / λ
λ = 1.43 x 10⁻⁷ m
b) The energy (in joules) a photon must have in order to excite an electron from E2:
= (-5 + 10) x 10⁻¹⁹
λ = 5 x 10⁻¹⁹
c) An electron drops the E3 level to the E1 level, and the atom is said to undergo emission:
Change in energy = 10 x 10⁻¹⁹ J
10 x 10⁻¹⁹ = 6.63 x 10⁻³⁴ x 3 x 10⁸ / λ
λ = 1.99 x 10⁻⁷ m
The wavelength of the photon needed to excite an electron from E1 to E4 is 1.43 x 10⁻⁷ m.
The energy (in joules) a photon must have in order to excite an electron from E2 is 5 x 10⁻¹⁹.
An electron drops the E3 level to the E1 level, and the atom is said to undergo emission is 1.99 x 10⁻⁷ m.
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Choose all the answers that apply.
The troposphere is _____.
the warmest layer
responsible for weather and clouds
the coldest layer
warmed by the Earth's surface
the lowest layer
Answer:
The lowest layerWarmed by earth surfaceExplanation:
Troposphere is the lowest layer located on atmosphere of earthIt contains all green house gases so it becomes warmed by reflection of heat from earth surfaceAnswer:
warmed by the Earth's surface
the lowest layer
Explanation:
What volume of CO2(g), measured at STP is produced if 15.2 grams of CaCO(s) is heated?
Answer:
Volume = 3.4 L
Explanation:
In order to calculate the volume of CO₂ produced when 15.2 g of CaCO₃ is heated, we need to first write out the balanced equation of the thermal decomposition of CaCO₃:
CaCO₃ (s) + [Heat] ⇒ CaO (s) + CO₂ (g)
Now, let's calculate the number of moles in 15.2 g CaCO₃:
mole no. = \(\mathrm{\frac{mass}{molar \ mass}}\)
= \(\frac{15.2}{40.1 + 12 + (16 \times 3)}\)
= 0.1518 moles
From the balanced equation above, we can see that the stoichiometric molar ratios of CaCO₃ and CO₂ are equal. Therefore, the number of moles of CO₂ produced is also 0.1518 moles.
Hence, from the formula for the number of moles of a gas, we can calculate the volume of CO₂:
mole no. = \(\mathrm{\frac{Volume \ in \ L}{22.4}}\)
⇒ \(0.1518 = \mathrm{\frac{Volume}{22.4}}\)
⇒ Volume = 0.1518 × 22.4
= 3.4 L
Therefore, if 15.2 g of CaCO₃ is heated, 3.4 L of CO₂ is produced at STP.