Answer:
For a chemical reaction, the enthalpy of reaction (ΔHrxn) is the difference in enthalpy between products and reactants; the units of ΔHrxn are kilojoules per mole
7.A sample of oxygen gas, O2 weighs 28.4 grams. How many molecules of O2 and how
many atoms of O are present in this sample?
Answer:
5.34275*10²³
Explanation:
Molar mass of O2 is 32g/mol
mass of the sample is 28.4g
number of moles = (mass of the sample) / (molar mass of O2)
=28.5g / 32g/mol
=0.8875mol
number of molecules = number of moles * Avogadro's Constant
= 0.8875 * (6.02*10²³)
= 5.34275 molecules
Learning Task 1. Read each item carefully. Choose the letter of your answer.
1. Which type of soil is characterized as having the finest particles holding greater amount of water?
A. Loam
B. Clay
C. Sand
2. Which type of soil is best for planting?
A. Loam
B. Clay
C. Sand
3. How does each soil types differ?
A. Texture
B. Color
C. Both A & B
4. Which type of soil do you usually expect if the community is along the seashore?
A. Loam
B. Clay
C. Sand
5. Why is soil important to living things?
A. Forms part of the earth where animals live
B. Provides the necessary nutrients needed by plants
C. Serves as a place where people live
D. All of the above
Answer:
1. B
2. A
3. C
4. C
5. D
Explanation:
Soil is regarded as the solid unconsolidated material of the earth crust. Soil is of three different types namely: Sandy soil, clay soil and loamy soil. These three different soil types possess different properties that distinguish them. Some of them are:
- CLAY soil is characterized as having the finest particles and can hold greater amount of water i.e. have a high water holding capacity.
- LOAMY SOIL is the best soil type for planting agricultural crops because it has the highest concentration of nutrients that suited for plant growth.
- loamy, Sandy and clay differ in how we feel when touched i.e. texture, and colour.
- SANDY soils are the kind of soils that are found in Sea shores and beaches.
- Soil is important to living things as it forms part of the earth where animals live, provides the necessary nutrients needed by plants, serves as a place where people live.
How much water, in grams, can be made from
2.44 × 10^24 hydrogen molecules?
Answer in units of g.
Answer:
[tex]m_{H_2O}=73.0gH_2O[/tex]
Explanation:
Hello there!
In this case, since the formation of water from hydrogen and oxygen is:
[tex]2H_2+O_2\rightarrow 2H_2O[/tex]
Whereas we find a 2:2 mole ratio of hydrogen to water. In such a way, by using the Avogadro's number, the aforementioned mole ratio and the molar mass of water (18.02 g/mol), we obtain the following grams of water product:
[tex]m_{H_2O}=2.44x10^{24}molec*\frac{1molH_2}{6.022x10^{23}molec}*\frac{2molH_2O}{2molH_2}*\frac{18.02gH_2O}{1molH_2O}\\\\ m_{H_2O}=73.0gH_2O[/tex]
Regards!
2. Energy cycles through ecosystems because it returns to the sun.
True or false
Please help I will give 50 points
Answer:
false
Explanation:
energy does not return to the sun, it returns to the plants or producers. if energy were to return to the sun, it would have to travel though space.
True or false? All producers are at the top of the food web
Answer:
false all producers are at the top of food web
iodide (KI). Identify the correct products of this
reaction. (Note that NO3? is the nitrate ion, a
polyatomic ion.)
AgNO3 + KI – ?
AgK + INO3
✓
Agl + KNO3
Ag + K + I + NO3
COMPLETE
What type of reaction is this?
Answer:
AgNO3 + KI → Agl + KNO3. Double-replacement reaction
Explanation:
Based on solubility rules, Silver, Ag produce an insoluble salt in presence of halides (Fluorides F-, Chlorides Cl-, Iodides, I-, and bromides Br-). That means the mixture of AgNO3 (Ag⁺ ions) with KI (I- ions) produce AgI as insoluble salt.
The reaction is:
AgNO3 + KI → Agl + KNO3And this is a double-replacement reaction where the cations exchange of anion to produce 2 new compounds.
Answer:
AgI + KNO3
Explanation:
double replacement
Identify each of the following as endothermic or exothermic.
a. Water in a pond evaporates.
b. Methane gas burns on a stove top.
c. Water freezes to form ice.
d. Energy flows from the system to the surroundings.
e. Energy flows from the surroundings to the system.
Answer:
Identify each of the following as endothermic or exothermic.
a. Water in a pond evaporates.
b. Methane gas burns on a stovetop.
c. Water freezes to form ice.
d. Energy flows from the system to the surroundings.
e. Energy flows from the surroundings to the system.
Explanation:
An exothermic reaction is the one in which heat energy is released.
An endothermic reaction is one in which heat energy is absorbed.
a. Water in a pond evaporates.
This process absorbs heat energy.
Hence, this is an example of an endothermic process.
b. Methane gas burns on a stovetop and release heat energy and hence this is an example of an exothermic reaction.
c. Water freezes to form ice.
In this process heat energy is released.So this is an example of exothermic reaction.
d. Energy flows from the system to the surroundings.
That means heat energy is released into the surroundings.
So, this is an example of exothermic process.
e. Energy flows from the surroundings to the system.
That means energy is absorbed by the system.
So, it is an endothermic process.
Methanol and butanol are alcohols. Alcohols have the same_______________ as alkanes and the __________ identifies the compound as an alcohol.
Answer:
Methanol and butanol are alcohols. Alcohols have the same_______________ as alkanes and the __________ identifies the compound as an alcohol.
Explanation:
Alcohols belong to a group of organic compounds which contain -OH group as the functional group.
So alcohols have the same carbon -hydrogen bonds as alkanes and the -OH functional group identifies the compound as an alcohol.
all first level consumers are carnivore: True or false?
An alkyl groyp has a formula of CxH6, determine the value of x
Answer:
i didnt understand
Explanation:
Answer:
x = 2 (C₂H₆)
Explanation:
The general formula for alkanes is CₓH₂ₓ₊₂
2x + 2 = 6
Simply solve for n:
2x = 4
x = 2
I NEED THIS NOW NO LINKS OR ILL REPORT
What is a substance that has multiple elements in one area but are not
chemically combined; such as air? *
atom
element
compound
mixture
The correct answer is mixture
g Suppose you are titrating an acid of unknown concentration with a standardized base. At the beginning of the titration, you read the base titrant volume as 1.84 mL. After running the titration and reaching the endpoint, you read the base titrant volume as 27.30 mL. What volume, in mL, of base was required for the titration?
Answer:
25.46 mL
Explanation:
In a titration we use the volume and concentration of a solution to determine the previously unknown concentration of other solution. Let's consider the titration of an acid of unknown concentration with a standardized base (a base whose concentration we know). The generic neutralization reaction is:
HA + BOH ⇒ BA + H₂O
The base is in the buret and we will add it to the acid until the equivalence point is reached. The volume of base used is equal to the difference between the final reading of the buret and the initial reading of the buret.
V = 27.30 mL - 1.84 mL = 25.46 mL
Calculate the amount of heat required to completely sublime 55.0 g of solid dry ice CO2 at its sublimation temperature. The heat of sublimation for carbon dioxide is 32.3 kj mol
Answer:
40.4 kJ
Explanation:
Step 1: Given data
Mass of CO₂ (m): 55.0 gHeat of sublimation of CO₂ (ΔH°sub): 32.3 kJ/molStep 2: Calculate the moles corresponding to 55.0 g of CO₂
The molar mass of CO₂ is 44.01 g/mol.
n = 55.0 g × 1 mol/44.01 g = 1.25 mol
Step 3: Calculate the heat (Q) required to sublimate 1.25 moles of CO₂
We will use the following expression.
Q = n × ΔH°sub
Q = 1.25 mol × 32.3 kJ/mol = 40.4 kJ
Calculate the energy of the orange light emitted, per photon, by a neon sign with a frequency of 4.78 × 1014 Hz.
Answer:
Explanation:
[tex]E=h\nu=6.62606957 *10^{-34}\frac{Kg~m^2}{s}4.78*10^{14}\frac{1}{s}=316.7261*10^{-21}J[/tex]
Which hydrocarbon is saturated?
A)
heptyne
B)
butane
C)
propene
D)
ethyne
HELPPPPPPPPPPPPMEEEEEEEEEE
Answer:
25%
Explanation:
Cystic fibrosis is a recessive allele, meaning that the child must be aa to suffer the symptoms. Only 1/4 of the paired alleles is aa, so the probability of getting cystic fibrosis would be 25%.
The combination of isotopes of hydrogen characterized by emmision of radiation is believed to take place in the
a. sun
b. galaxy
c. moon
d. star
All forms of energy can exist as either ________ or ________ energy.
Answer:
potentiol or kenetic
Explanation:
Zinc sulfate is a 2-ion electrolyte,
dissociating 40% in a
certain concentration. Calculate its
dissociation (i) factor.
On the basis of 40% dissociation, 100
particles of zinc sulfate
will yield:
40zinc ions
40 sulfate ions
60undissociated particles
Jo 11:03
Answer: The value of i is 1.4 and 40% dissociation of 100 particles of zinc sulfate will yield 60 undissociated particles.
Explanation:
The equation used to calculate the Vant' Hoff factor in dissociation follows:
[tex]\alpha =\frac{i-1}{n-1}[/tex]
where,
[tex]\alpha [/tex] = degree of dissociation = 40% = 0.40
i = Vant' Hoff factor
n = number of ions dissociated = 2
Putting values in above equation, we get:
[tex]0.40=\frac{i-1}{2-1}\\\\0.40=i-1\\\\i=1.4[/tex]
The equation used to calculate the degee of dissociation follows:
[tex]\alpha =\frac{\text{Number of particles dissociated}}{\text{Total number of particles taken}}[/tex]
Total number of particles taken = 100
Degree of dissociation = 40% = 0.40
Putting values in above equation, we get:
[tex]0.40=\frac{\text{Number of particles dissociated}}{100}\\\\\text{Number of particles dissociated}=(0.40\times 100)=40[/tex]
This means that 40 particles are dissociated and 60 particles remain undissociated in the solution.
Hence, 40% dissociation of 100 particles of zinc sulfate will yield 60 undissociated particles.
Compound X has the formula C8H14.
X reacts with one molar equivalent of hydrogen in the presence of a palladium catalyst to form a mixture of cis- and trans-1,2-dimethylcyclohexane. Treatment of X with ozone follwed by zinc in aqueous acid gives a ketone plus formaldehyde (CH2=O). What is the structure of X?
Answer:
Compound X has the formula C8H14.
X reacts with one molar equivalent of hydrogen in the presence of a palladium catalyst to form a mixture of cis- and trans-1,2-dimethyl cyclohexane. Treatment of X with ozone followed by zinc in aqueous acid gives a ketone plus formaldehyde (CH2=O). What is the structure of X?
Explanation:
The degree of unsaturation in the given molecule C8H14 is:
DU=(Cn+1)-Hn/2-Xn/2+Nn/2
where,
Cn=number of carbon atoms
Hn=number of hydrogen atoms
Xn=number of halogen atoms
Nn=number of nitrogen atoms
C8H14:
DU=(8+1)-14/2
=>DU=9-7 =2
Hence, the given molecule will have either two double bonds or one double bond and one ring or two rings.
X reacts with one molar equivalent of hydrogen in the presence of a palladium catalyst to form a mixture of cis- and trans-1,2-dimethylcyclohexane.
This indicates that the molecule X has one double bond and one ring that is cyclohexane ring.
Treatment of X with ozone follwed by zinc in aqueous acid gives a ketone plus formaldehyde (CH2=O).
So, the molecule has a ring and double bond CH2.
Based on the given data the structure of compound X is shown below:
The reaction sequence is shown below:
Is benzene a solute or solvent
Doc. No.
QMS
Rev. Date
1. In the reaction
P
> M + N
a) The reactants are:
b) The products are:
Answer: In the reaction:
a) The reactants are: P
b) The products are: M and N
Explanation:
The given reaction equation is as follows.
[tex]P \rightarrow M + N[/tex]
Reactants are the species present on the left side on an arrow in a chemical reaction equation.
On the other hand, products are the species which are present on the right side of an arrow in a chemical reaction equation.
Hence, in the given reaction equation P is the reactant. Whereas M and N are the products.
Thus, we can conclude that in the reaction:
a) The reactants are: P
b) The products are: M and N
anuvia, the trade name for sitagliptin, was introduced in 2006 for the treatment of type 2 diabetes. In what type of orbital does the lone pair on each N atom reside.
Answer: hello your question is poorly written below is the complete question
answer:
For N1 : sp³ orbital
For N2: p orbital
For N3 : p orbital
For N4 : sp² orbital
For N5 : sp² orbital
Explanation:
Determining the type of orbital in which the lone pair on each N atom will reside.
From the configuration attached below we can determine the type of orbital and they are ;
For N1 : sp³ orbital
For N2: p orbital
For N3 : p orbital
For N4 : sp² orbital
For N5 : sp² orbital
The value of ΔH° for the reaction below is -6535 kJ. ________ kJ of heat are released in the combustion of 16.0 g of C6H6 (l)?
2C6H6 (l) + 15O2 (g) → 12CO2 (g) + 6H2O (l)
Answer:
the value of H° is below -6535 kj. +6H2O
Explanation:
6H2O answer solved
For the given reaction, 2 moles of C₆H₆ the heat energy released is - 6535 KJ. Then, for 16 g of the compound or 0.205 moles needs 669.83 KJ of heat released in combustion.
What is combustion ?Combustion is a chemical reaction that occurs between a fuel and an oxidizing agent, typically oxygen, resulting in the release of heat, light, and various combustion products, such as carbon dioxide and water vapor.
The process of combustion involves a rapid and exothermic (heat-releasing) oxidation reaction that produces a flame, which is visible in many cases.
Here, 2 moles of the hydrocarbon releases - 6535 KJ of energy.
molar mass of C₆H₆ = 78 g/mol
then no.of moles in 16 g = 16 /78 = 0.205 moles.
then energy released by 0.205 moles = 0.205 moles × 6535 KJ /2 moles = 669.83 kJ
Therefore, the heat energy released by 16 g of the compound in combustion is 669.83 kJ.
Find more on combustion :
https://brainly.com/question/13153771
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What element provides strength to the exoskeleton of Clams and oysters
Which is most likely the reason the U.S government made such an investment
Answer:
The U.S government made such an investment because they're most likely to reduce harmful emissions.
describe how you would test your indicator to check that it works
Answer:
If the colour of the indicator changes blue when a base is there and when it changes to red or pink or scarlet when it is acid. Then we can say that the indicator is working
Determine the number of significant digits in each number and list the specific significant digits. 1. 306,000 2. 0.0073 3. 39.9999 4. 25.00 5. 40,000,021 6. 45,250.0 7. 0.00011 8. 420.030700
Answer:
1. 306,000: three significant figures because the last three zeros are not preceded by a decimal point.
2. 0.0073: two significant figures because the the leftmost zeros are not significant.
3. 39.9999: six significant figures because all these numbers are nonzero digits.
4. 25.00: four significant figures because right-handed zeros, after a decimal point, are significant.
5. 40,000,021: eight significant figures because intermediate zeros are significant.
6. 45,250.0: six significant figures because al the zeros are to the right of the nonzero digits.
7. 0.00011: two significant figures as well as #2.
8. 420.030700: nine significant figures because all the zeros are to the right of the first nonzero digits and after the decimal point.
Explanation:
Hello there!
In this case, by considering the given numbers, we can proceed as follows, by keeping in mind the rules for assigning significant figures:
1. 306,000: three significant figures because the last three zeros are not preceded by a decimal point.
2. 0.0073: two significant figures because the the leftmost zeros are not significant.
3. 39.9999: six significant figures because all these numbers are nonzero digits.
4. 25.00: four significant figures because right-handed zeros, after a decimal point, are significant.
5. 40,000,021: eight significant figures because intermediate zeros are significant.
6. 45,250.0: six significant figures because al the zeros are to the right of the nonzero digits.
7. 0.00011: two significant figures as well as #2.
8. 420.030700: nine significant figures because all the zeros are to the right of the first nonzero digits and after the decimal point.
Regards!
28) Which of the following is true about the modern model of the atom?
A) Electrons orbit the nucleus in shells at fixed distances
B) Protons, neutrons, and electrons are located in the nucleus.
C)Atoms are hard, indivisible spheres.
D)A positive nucleus is surrounded by negative electrons.
Answer:
A) Electrons orbit the nucleus in shells at fixed distances
Answer:
the answer is A
Explanation:
Fire a single electron towards the hydrogen atom. Describe what happens in a step by step fashion. [N.B. - It may be helpful to utilize the Run in Slow Motion option for this part.]
Answer:
The electrons will be added by the hydrogen.
Explanation:
If we fire a single electron towards the hydrogen atom, the hydrogen atoms added the electron to its shell by applying force of attraction and becomes stable as well as non reactive in nature because the hydrogen attains the electronic configuration of helium which is a noble gas and have completed its outermost shell. The proton that is present in the nucleus attracts this electron and compel it to add in the electron.
