Answer:
The mouth uses both mechanical and chemical digestion. Mechanical digestion involves physically breaking down the food into smaller pieces (using the jaw/teeth). However, chemical digestion then takes over and starts breaking down the food into simpler nutrients that can be used by the cells using saliva, which is naturally made within the mouth.
Hope this helps you! Have a great day! :D
2-81) When a hydrocarbon fuel is burned, almost all of the carbon in the fuel burns completely to form CO2 (carbon dioxide), which is the principal gas causing the greenhouse effect and thus global climate change. On average, 0.59 kg of CO2 is produced for each kWh of electricity generated from a power plant that burns natural gas. A typical new household refrigerator uses about 700 kWh of electricity per year. Deter- mine the amount of CO2 production that is due to the refrigerators in a city with 300,000 households.
Answer:
12.39 x 10⁷ kg
Explanation:
A typical new household refrigerator uses about 700 kWh of electricity per year.
No of household = 300000
Total energy used up = 300000 x 700 kWh
= 21 x 10⁷ kWh .
Production of each kWh energy produces .59 kg of CO₂
Production of 21 x 10⁷ kWh energy produces .59 x 21 x 10⁷ kg of CO₂
CO₂ produced = .59 x 21 x 10⁷ kg
= 12.39 x 10⁷ kg
Gaseous methane (CH4) reacts with gaseous oxygen gas (O2) to produce gaseous carbon dioxide (CO2) and gaseous water (H2O). If 28.2 g of carbon dioxide is produced from the reaction of 15.1 g of methane and 81.2 g of oxygen gas, Calculate the percent yield of carbon dioxide. Be sure your answer has the correct number of significant digits in it.
Answer:
68.1% is percent yield of the reaction
Explanation:
The reaction of methane with oxygen is:
CH₄ + 2O₂ → CO₂ + 2H₂O
Where 2 moles of oxygen react per mole of CH₄
Percent yield is:
Actual yield (28.2g CO₂) / Theoretical yield * 100
To solve this question we need to find theoretical yield finding limiting reactant :
Moles CH₄:
15.1g CH₄ * (1mol / 16.04g) = 0.9414 moles
Moles O₂:
81.2g * (1mol / 32g) = 2.54 moles
For a complete reaction of 0.9414 moles of CH₄ are needed:
0.9414 moles CH₄ * (2 mol O₂ / 1mol CH₄) = 1.88 moles of O₂. As there are 2.54 moles, O₂ is in excess and CH₄ is limiting reactant
In theoretical yield, the moles of methane added = Moles of CO₂ produced. That is 0.9414 moles CO₂. In grams = Theoretical yield:
0.9414 moles CO₂ * (44.01g / mol) = 41.43g CO₂
Percent yield: 28.2g CO₂ / 41.43g CO₂ * 100=
68.1% is percent yield of the reaction35.2 J of heat is
applied to 16.0 g
of a substance.
Temp rises by 7.2
K. Specific Heat?
The specific heat : c = 0.306 J/g K
Further explanationGiven
Heat = 35.2 J
Mass = 16 g
Temperature difference : 7.2 K =
Required
The specific heat
Solution
Heat can be calculated using the formula:
Q = mc∆T
Q = heat, J
m = mass, g
c = specific heat, joules / g ° C
∆T = temperature difference, ° C / K
Input the value :
c = Q / m.∆T
c = 35.2 / 16 x 7.2
c = 0.306 J/g K
ANSWER ASAP
1. Based on the patterns you observe in the figure, what do you think the number inside each box represents? What do you think the circles and dots represent?
The numbers inside the box represent the number of protons or atomic number while the circles represent the energy levels or shells in the atom. The dots represent the electrons occupying those shells.
The atomic number refers to the number of protons in the nucleus of an atom. It is shown as the number inside the boxes. It serves as the identity of an element.
The electrons occupy shells of particular energy levels according to Bohr model. The circles represent these energy levels. The dots in the circles represent the electrons that occupy those energy levels.
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Each of the following organs had a role in excretion, EXCEPT for the _____?
A. Lungs
B. Kidneys
C. Heart
D. Skin
Each of the following organs had a role in excretion, except for the Heart. Therefore, the correct option is option C.
What is excretion?Excretion seems to be the process throughout which an organism eliminates metabolic waste. In vertebrates, this is largely done by that of the skin, kidneys, especially lungs. When a substance is secreted, this could perform certain roles once it leaves the cell. Excretion is required by all forms of life.
Animals, for example, use the urethra, a member of the excretory, to evacuate urine. In unicellular organisms, waste products are ejected quickly via the cell surface. During biological functions, such as cellular respiration, a variety of chemical changes occur in the body. Each of the following organs had a role in excretion, except for the Heart.
Therefore, the correct option is option C.
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I can ride my bicycle at a velocity of 5.655 X 10° um/sec. Is this fast or slow? Prove your answer by converting into km/hr.
answer ASAP
Answer:
56/hr
Explanation:
Aspirin was formed to reduce the irritation of salicylic acid. However, aspirin can still disturb the stomach. Which functional group in aspirin is responsible for stomach irritation? A. Ketone B. Ester C. Carboxylic acid D. Phenol
Answer:
Carboxylic acid
Explanation:
Asprin is a drug that contains the carboxylic acid functional group (R-COOH), ester functional group (R-O-CO-R') and the aromatic group (benzene ring).
When we take in aspirin, it becomes salicylic acid. This metabolite irreversibly inhibits the enzyme cyclooxygenase. Hence the the production of protective prostaglandins is blocked causing inflammation and pain.
Convert 76.78 g of CO2 to a volume.
What is the difference between the structure of simple and complex carbohydrates?
Answer:
Simple carbs break down easier and contain sugars. Complex carbs contain starch and fiber.
Explanation:
Answer Image result for What is the difference between the structure of simple and complex carbohydrates?
Simple vs Complex Carbs. Carbohydrates are sugars that come in 2 main forms – simple and complex. This is also referred to as simple sugars and starches. The difference between a simple and complex carb is in how quickly it is digested and absorbed – as well as it's chemical structure.
Ultraviolet radiation and radiation of shorter wavelengths can damage biological molecules because they carry enough energy to break bonds within the molecules. A carbon-sulfur bond requires 272 kJ/mol to break. What is the longest wavelength of radiation with enough energy to break carbon-sulfur bonds
Answer:
439.7nm
Explanation:
Energy of a quantum can be calculated using below formula
E=hv...........eqn(1)
But v=λ/ c .........eqn(2)
If we substitute eqn(2) into eqn(1) we have
E= hc/(λ)
Where E= energy
h= Plank's constant= 6.62607004 × 10-34 m2 kg / s
c= speed of light
c= 2.998 × 10^8 m/s
λ= wavelength= ?
But the energy was given in Kj , it must be converted to Kj/ photon for unit consistency.
Energy E= 272 kJ/mol × 1mol/6.02× 10^23
Energy= 451.83× 10^-24 Kj/ photon
E= hc/(λ)...........eqn(1)
If we make λ subject of the formula
λ= hc/E
Then substitute the values we have
λ= [(6.626 × 10^-34) × (2.998 × 10^8)]/451.83× 10^-24
λ=(0.00043965) × (1Kj/1000J) × (10^9nm/1m)
λ=439.7nm
Hence, the longest wavelength of radiation with enough energy to break carbon-sulfur bonds is 439.7nm
A solution is prepared by dissolving 25.0 mL ethanol, CH3CH2OH (d=0.789 g/mL), in enough water to produce 250.0 mL solution. What is the molarity of ethanol in the solution?
The molarity = 1.716 M
Further explanationGiven
25 ml ethanol
d = 0.789 g/ml
250 ml solution
Required
The molarity
Solution
Molarity shows the number of moles of solute in every 1 liter of solute or mmol in each ml of solution
[tex]\large{\boxed {\bold {M ~ = ~ \frac {n} {V}}}[/tex]
mass of ethanol :
= 25 ml x 0.789 g/ml
= 19.725 g
mol ethanol :
= 19.725 g : 46 g/mol
= 0.429
The molarity :
= 0.429 : 0.25 L
= 1.716 M
The molarity of ethanol in the solution is 1.716M
What is the molarity of a solution?Molarity shows the number of moles of solute in every 1 liter of solute or mmol in each ml of solution
Determine the mass of ethanol :
Mass of ethanol = 25 ml x 0.789 g/ml
Mass of ethanol = 19.725 g
Determine the moles of ethanol
Moles = Mass/Molar mass
Moles = 19.725 g/46 g/mol
Moles of ethanol = 0.429moles
Calculate the molarity using the formula below;
Molarity = Moles/Volume
Molarity = 0.429/0.25 L
Molarity = 1.716 M
Hence the molarity of ethanol in the solution is 1.716M
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A banana has 0.42 g of potassium. How many moles of potassium are in a banana ?
Answer:
0.011mole
Explanation:
Given parameters:
Mass of potassium in the banana = 0.42g
Unknown:
Number of moles of potassium in the banana = ?
Solution:
To solve this problem, we use the expression below:
Number of moles = [tex]\frac{mass}{molar mass}[/tex]
Molar mass of K = 39g/mol
Number of moles = [tex]\frac{0.42}{39}[/tex] = 0.011mole
What are the differences between proton, neutron, and electron
What are atoms held together by
Label one of the test tubes Fe2+. Add 4 milliliters of iron(II) sulfate to the test tube.
Label the other test tube Fe3+. Add 4 milliliters of iron(III) nitrate to the test tube.
Add 4 milliliters of potassium thiocyanate to each test tube.
Observe the contents of the test tubes, noting any evidence of a chemical reaction. Record your observations in the table. If there is no evidence of a reaction, write “no reaction.”
Answer: A: Has little to no reaction; might turn slightly red in color. B: The liquid grows darker in color to a more reddish tone.
Explanation: I didn’t have the necessary materials to complete the experiment so the teacher told me and I put it in my own words.
3. A gram food sample is burned completely in a calorimeter that contains 1000. of water The temperature of the water increases 23.65 degrees * C . How many Calories does the food have per gram ?
The food has 23629.64 cal
Further explanationGiven
mass = 1000 g of water
temperature increases 23.65 * C
Required
The energy of the food
Solution
Heat absorbed by water :
Q = m . c . Δt
Q = 1000 g x 4.184 J/g°C x 23.65 °C
Q = 98951.6 J
1 Joules = 0.2388 Calories
98951.6 J = 23629.64 cal
Which of the following explains the difference between speed and velocity?
A. Velocity has motion, and speed does not.
B. Velocity has direction, and speed does not.
C. Speed has motion, and velocity does not.
D. Speed has direction, and velocity does not.
Answer:
B. Velocity has direction, and speed does not.
Explanation:
Velocity is a vector, meaning it has both a magnitude and direction. Speed is a scalar, meaning it only has a magnitude and no direction.
To measure the amount of nickel in some industrial waste fluid, an analytical chemist adds sodium hydroxide solution to a sample of the fluid and collects the solid nickel(II) hydroxide product. When no more is produced, he filters, washes and weighs it, and finds that has been produced. The balanced chemical equation for the reaction is:
Answer:
The final balanced equation is
Ni2+ + 2NaOH --> Ni (OH)2 + 2Na+
Explanation:
It is given that sodium hydroxide is added to collect the solid nickel(II) hydroxide product
The empirical equation for this statement is
Ni2+ + NaOH --> Ni (OH)2 + Na+
We will first balance the hydroxide molecule. On the right side there are two OH molecules.
Thus, on the left side we will take 2 sodium hydroxide
Ni2+ + 2NaOH --> Ni (OH)2 + Na+
Now we will balance the sodium ion which are 2 in numbers on the left side and 1 on the right side
Ni2+ + 2NaOH --> Ni (OH)2 + 2Na+
So, the final balanced equation is
Ni2+ + 2NaOH --> Ni (OH)2 + 2Na+
How is the effect of concentration changes on the reaction rate seen in the
rate law?
A. The effect of concentration changes on the rate constant affects
the reaction rate.
O B. A change in concentration of a reactant would change the
exponent of that reactant.
O C. The rate law does not show how concentration changes would
affect the reaction rate.
D. The exponents determine how much concentration changes affect
the reaction rate.
Answer: D. The exponents determine how much concentration changes affect the reaction rate.
Explanation: This is correct. The exponents in the rate law do determine how much the concentration changes impact the reaction rate.
Option A i.e. The effect of concentration changes on the rate constant affects the reaction rate.
what is rate constant?
The proportionality constant, which explains the link between the molar concentration of the reactants and the pace of a chemical reaction, is known as the rate constant. The rate constant, also known as the reaction rate constant or reaction rate coefficient, is indicated by the letter k. Because reactant concentrations decrease as reactants are transformed to products, reaction speeds typically decrease over time. When reactant concentrations are raised, reaction rates generally increase. The temperature has an impact. The following are two methods for calculating rate constant:
Using the Arrhenius formula.The order of the reaction and the molar concentrations of the reactants are used.To know more about rate constant here
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Calculate the solubility at of in pure water and in a solution. You'll find data in the ALEKS Data tab lead chromate.
Answer:
1.34 * 10^-7 M
Explanation:
The Ksp of lead II chromate is 1.8 x 10^-14
So, we have that;
PbCrO4(s) -----> Pb^2+(aq) + CrO4^2-(aq)
s s
Where s = molar concentration of Pb^2+(aq) and CrO4^2-(aq)
and;
[Pb^2+] = [CrO4^2-]
This implies that Ksp = s^2
s = √Ksp
s = √1.8 x 10^-14
s = 1.34 * 10^-7 M
Which types of lenses are used in glasses for a person who is nearsighted? Why is this type used?
Answer:
Concave Lenses Are for the Nearsighted, Convex for the Farsighted. Concave lenses are used in eyeglasses that correct nearsightedness.
Explanation:
A 5 mL sample of an unknown liquid is placed into a 250 mL flask that has had all of the air removed. The pressure measured in the flask is found to be 34.5kPa. In a seperate trial the student puts 214 mL of the same liquid into the same flask at the same conditions. What will the pressure measure (in kPa) in the second trial
Answer:
See explanation below
Explanation:
In this case, we can use the Boyle's law. Assuming that the temperature of both trial remains constant, then:
P₁V₁ = P₂V₂ (1)
You should note that this expression is usable when you are dealing with gases. However, we can treat this unknown liquid as a gas, because all the air on the flask is removed, and we can assume that the liquid can behave like an ideal gas.
So using the above expression, we can solve for P₂:
P₂ = P₁V₁ / V₂ (2)
In this case, we already have the values of presures and volume, so replacing in this expression:
P₂ = 34.5 * 5 / 214
P₂ = 0.806 kPaThis should be the pressure of the liquid.
Hope this helps
Determine the density (in g/mL) of a substance with a mass of 105 g and a volume of 17.6 mL.
Answer:
Density, d = 5.96 g/mL
Explanation:
Given that,
Mass, m = 105 g
Volume, V = 17.6 mL
We need to find the density of the substance. So,
[tex]d=\dfrac{m}{V}\\\\d=\dfrac{105\ g}{17.6\ mL}\\\\d=5.96\ g/mL[/tex]
So, the density of the substance is 5.96 g/mL.
Which of the following would most likely be caused by a tsunami?
A. reshaping of the shoreline
B. seafloor spreading
C. island formation
D. mountain formation
ASAP please
the answer Is A hope it helps
How much money will it cost you to drive 255 miles if your car gets 25.70 miles per gallon and gas costs $3.309/gallon?
what does the roman numeral stand for in copper(1) oxide should it not be copper(II) oxide
Answer:
The roman numeral in copper(I) oxide indicates that the oxidation number of copper in the compound is 1.
Explanation:
Roman numeral is used to indicate the oxidation number of an element in a compound.
The roman numeral in copper(I) oxide indicates that the oxidation number of copper in the compound is 1.
This can be seen from the following illustration:
copper(I) oxide => Cu₂O
Oxidation number of O = –2
Oxidation number of Cu₂O = 0
Oxidation number of Cu =?
Cu₂O = 0
2Cu + O = 0
2Cu – 2 = 0
Collect like terms
2Cu = 0 + 2
2Cu = 2
Divide both side by 2
Cu = 2/2
Cu = 1
Thus, we can see that the oxidation number of Cu in Cu₂O is 1. Hence the name of Cu₂O is copper(I) oxide indicating that the oxidation number of of copper (Cu) in the compound is 1.
For copper(II) oxide, we shall determine the oxidation number of Cu. This can be obtained as follow:
copper(II) oxide, CuO => CuO
Oxidation number of O = –2
Oxidation number of CuO = 0
Oxidation number of Cu =?
CuO = 0
Cu + O = 0
Cu – 2 = 0
Collect like terms
Cu = 0 + 2
Cu = 2
Thus, the oxidation number of Cu in CuO is 2. Hence the name of CuO is copper(II) oxide indicating that the oxidation number of of copper (Cu) in the compound is 2.
From the above illustrations,
We can see that the roman numeral in both copper(I) oxide, Cu₂O and copper(II) oxide, CuO are different because the oxidation number of Cu in both cases are different.
a rock that is pushed down a hill represents both potential and kinetic energy. which statement best represents the energy transformation involved in this scenario
Explanation:
kinetic energy Increases due to gravity. A rock being pushed down a hill increases in speed, due to gravity, what goes up must come down....
How many molecule are in 1.80mol of water
Answer:
1 molecule of H2O contains 10 electrons. So one mole that is equal to 22.4 L of H2O will contain 6.022 × 10^23 × 10 electrons. So 1.8 ml will have - 6.022×10^23×1.8×10/22.4 ×1000=6.022×10^21×1.8/22.4.
Explanation:
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What happens to bromine on a molecular level when it is a gas but is then cooled to a liquid?
it is cooled to a liquid
List 5 things that were made possible because of the use of microscope
Answer:
the invention of the microscope has made seeing bacteria/cells, examining forensic evidence (such as fingerprints), studying atomic structure, tissue analysis, and the study of our ecosystem possible to the naked eye
Explanation:
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