Answer:
The temperature finally increased from 20 °C to 38.7 °C
Explanation:
This a problem about calorimetry. Formula to solve it is:
Q = m . C . ΔT
Where ΔT is Final T° - Initial T°
m is the mass
and C, specific heat.
In this situation we are dissolving NaOH where 1 mol requires 44.4 kJ of heat. As we do not have 1 mol, we need to determine the heat that is released.
We convert the mass to moles
14.1 g . 1 mol / 40g = 0.3525 mol
We determine the heat
0.3525 mol . 44400 J/mol = 15651 Joules of heat.
Now we can replace data in the calorimetry formula:
15651 J = 200 g . 4.18 J/g°C (Final T° - 20°C)
15651 J / (200 g . 4.18 J/g°C) = Final T° - 20°C
18.7°C + 20°C = Final T° → 38.7°C
In plants, algae, and some bacteria, energy is produced by the:
A. nucleus
B. chloroplast
C. vacuole
D. mitochondria
Answer: D?
Explanation: The mitochondrion (plural mitochondria) is a membrane-bound organelle found in the cytoplasm of eukaryotic cells. It is the power house of the cell; it is responsible for cellular respiration and production of (most) ATP in the cell.
What is the approximate energy of a photon having a frequency of 4 x 10^7 Hz? (h = 6.6 x 10^-34 J . s)
Answer:
2.64 ×[tex]10^{-26}[/tex] J
Explanation:
I think you should mark it a physics question instead but anyway.
---------------------------------------------------------------------------
The Planck equation should be applied:
E = hv , while E is energy of proton; h is Planck constant; and v is frequency.
E = 6.6 × [tex]10^{-34}[/tex] × 4 × [tex]10^{7}[/tex]
= 6.6 × 4 × [tex]10^{-27}[/tex]
= 2.64 ×[tex]10^{-26}[/tex] J
Contour plowing, conservation plowing and crop rotation are ways to __________ soil. a. prevent c. lose b. conserve d. none of the above
Explanation:
prevent becoz crop rotation means using it by planting the crop according to nuetrients so ur soil is prevented
PLEASE HELP!!!!
it would mean alot !
Answer:
i looked it up its slinky waves
Explanation:
Answer:
diffracted
Explanation:
Sure it might look like a slinky but if you're talking about waves then it's deffinetly diffracted hope this helps
HY
Warm
Cool
Is this a land or a sea breeze?
Answer
Explanation:
Recall that the land surface cools quicker than the water surface at night. Therefore, the warmer air over the ocean is buoyant and is rising. The denser cool air over the land is flowing offshore to replenish the buoyant warm air and is called a land breeze.
What is Newton's First Law known as? The Law of
____
Answer:
inertia
Explanation:
Answer:
Law of inertia, also called Newton's first law, postulate in physics that, if a body is at rest or moving at a constant speed in a straight line, it will remain at rest or keep moving in a straight line at constant speed unless it is acted upon by a force.
Explanation:
hope it helps, please mark brainliest
The structures of three hydrocarbons are given below : a. They have same physical properties. B.They have same structural formula. c.They have same general formula. D.They are isomers of each other.
Answer:
The correct answer is option C "They have same general formula"
Explanation:
Hydrocarbons are any of a class of natural substance intensifies made distinctly out of the components carbon (C) and hydrogen (H). The carbon particles consolidate to shape the structure of the compound, and the hydrogen molecules append to them in various arrangements.
Hydrocarbons are the chief constituents of oil and gaseous petrol. They fill in as powers and ointments just as crude materials for the creation of plastics, strands, rubbers, solvents, explosives, and modern chemical substances.
All of the compounds given are alkanes and they have the same general formula which is represented by CnH2n+2, where ‘n’ is the number of carbon atoms.
what makes electrons jumo to other orbits around the nucleus then fall again?
Answer:
The higher the excitation state, the more energy the electron contains. When an electron absorbs energy, it jumps to a higher orbital. ... An electron in an excited state can release energy and 'fall' to a lower state.
Answer:
the higher the excitation state, the more the energy the electrons contains. when an electrons absorbs energy , it jumps to a higher orbital.
Explanation:
the electrons with its extra packet of energy becomes excited , and promptly moves out of its lower energy level and takes up a position in a higher energy level
How do particles change as the temperature increases in a system? Is this a chemical or physical change?
Answer:
chemical change
Explanation:
particals react to temperature wheteher its cold or warm
The particles begin to move at a higher speed. It is a physical change.
Temperature is defined as the average kinetic energy of the particles of a body. Hence, when a body is heated, the kinetic energy and consequently the speed of its particles increases.
This increase in particle speed is reversed when the system cools down. Recall that a physical change is easily reversible while a chemical change is not easily reversible.
As such, this increase of particle speed with temperature is a physical and not a chemical change.
https://brainly.com/question/11321843
2. Vessels that carry blood back to the heart are called
O a. capillaries
b. arteries
O c. veins
O d. both band c
Answer:
the answer for your question is veins
Answer:
blood vessels aka veins
How does one determine how much of a molecule is produced in a reaction?
O A. Oxidation states are used to calculate the number of product molecules.
B. The molar masses of the molecules tell how many grams of product will form.
O c. The coefficients and molar masses are used to calculate amounts of molecules
D. The mass of the products is determined by adding the mass of the reactants.
Answer:
c
Explanation:
i doubt it
The coefficients and molar masses are used to calculate the amounts of molecules. Hence, option C is correct.
What is a molecule?The smallest particle of a substance has physical and chemical properties of that substance. Molecules are made up of one or more atoms.
A molecule can be determined by how much is produced in a reaction through the coefficients and molar masses are used to calculate the amounts of molecules.
Hence, option C is correct.
Learn more about molecules here:
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Na+ is an ion give reasons
Answer:
Na+ represents a sodium atom that has lost an electron.
Explanation:
An atom that has gained or lost electrons is called an ion.
Answer:
I think because of the positive radical it's carrying
HEEEEeEELP PLEasE! IS SCIENCE
Given the equation representing a reaction: H + H --> H2, explain in terms of energy what is happening as the bond is being formed
Answer:
The formation of the bond releases energy. This is because the individual hydrogen atoms are more unstable than when they are joined together. Stability brings about the release of energy, and this would be an exothermic reaction.
Hey please answer this for me thanks.
Explanation:
Moles of N2 = 84/28 = 3.0mol
Moles of H2 = 29/2 = 14.5mol
Hence amount of ammonia produced = 6.0 * 17 = 102g.
What would red litmus paper be used to determine?
A. If a solution is acidic or neutral
B. If a solution is basic or neutral
C. If a solution is acidic
D. If a solution is supersaturated
Answer:
determines if a solution is acidic.
Explanation:
Nuclear fusion, like the example here, produces huge amounts of energy. Consider the statements below. BUT ONE statement provides more information about nuclear fusion
Answer:
Explanation:
Nuclear fusion of a form of nuclear reaction in which two small atomic nuclei combines to form larger ones with the release of a large amount of energy.
For example;
²₁H + ²₁H → ⁴₂He + Energy
The energy released in a nuclear reaction provides the needed temperature for another set of ²H atoms to fuse. This process in turn yields another ⁴He with the release of a lot of energy. Thus, enormous release of energy accompanies a nuclear reaction.
It is based on this principle that an hydrogen bomb is formed.
Answer:
Where are the answer choices.......
Explanation:
The density of lead is 11.3g/ml. What is the volume in ml of 50.75g of lead?
Answer:
4.49 mLExplanation:
The volume of a substance when given the density and mass can be found by using the formula
[tex]volume = \frac{mass}{density} \\[/tex]
From the question we have
[tex]volume = \frac{50.75}{11.3} \\ = 4.491150...[/tex]
We have the final answer as
4.49 mLHope this helps you
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plant or animal and to explain the reasoning for their conclusion. What is the correct response?
The cell is an animal cell because it has a cell membrane and no cell wall. Cell walls are unique to plant cells.
The cell is a plant cell because it has cytoplasm, which helps the plant make their own food from sunlight.
The cell is a plant cell because it has chloroplast, which helps the plant make its own food from sunlight.
The cell is an animal cell because it has chloroplast used for making useable energy.
Answer:
The cell is a plant cell because it has chloroplast, which helps the plant make its own food from sunlight.
Explanation:
Chloroplasts are organelles found in plant cells and eukaryotic algae that conduct photosynthesis. Chloroplasts absorb sunlight and use it in conjunction with water and carbon dioxide gas to produce food for the plant.
An atom of nitrogen would be stable if it bonded with how many atoms of chlorine?
Base your answers to questions 74 through 76 on the data table below and on your knowledge of Earth
science. The data table shows the mass of a sample of radioactive carbon-14 remaining after each half-life.
Data Table
Number of Half-lives Mass of Carbon-14 (9)
0
64
1
32
2
16
8
3
4
4
5
2
6
1
74 On the grid in your answer booklet, construct a line graph by plotting the data for the mass of carbon-14 in
the sample for each half-life shown on the data table. Connect the plots with a line. [1]
75 Identify the stable disintegration product of the radioactive isotope carbon-14. [1]
76 Determine the number of grams of carbon-14 remaining in this sample at 17,100 years. [1]
Answer:
See explanation
Explanation:
Now we have, the graph attached.the stable disintegration product of C-14 is N-14.
Then;
Since the mass of C-14 originally present is 64g, at a time t= 17100 years, we will have;
N/No = (1/2)^t/t1/2
N = mass of C-14 at time t
No= mass C-14 originally present
t = time taken for N amount of C-14 to remain
No = mass of C-14 originally present
t1/2 = half life of C-14
N/64 = (1/2)^17,100/5730
N/64 = (1/2)^3
N/64 = 1/8
8N = 64
N = 8 g
Is combining baking soda and shaving cream a chemical or physical change? It doesn't have to be for today, but please help!
Answer:
it's chemical
Explanation:
Capture energy from sunlight and use it to produce food for the cell; perform
photosynthesis
O cell membrane
O cell wall
O Mitochondria
O chloroplasts
Answer:
The answer is option 4.
Explanation:
Chloroplast is the place where they absorb sunlight to perform photosynthesis to produce food.
Mg + 2 AgNO₃ → Mg(NO₃)₂ + 2 Ag How many grams of magnesium nitrate, Mg(NO₃)₂, are formed when 9.87 moles of silver nitrate, AgNO₃, react?
Mass of Magnesium nitrate formed : 731.86 g
Further explanationA reaction coefficient is a number in the chemical formula of a substance involved in the reaction equation. The reaction coefficient is useful for equalizing reagents and products.
Reaction
Mg + 2AgNO₃ → Mg(NO₃)₂ + 2 Ag
moles of silver nitrate, AgNO₃ = 9.87
mole ratio AgNO₃ : Mg(NO₃)₂ = 2 : 1, so mol Mg(NO₃)₂ :
[tex]\tt \dfrac{1}{2}\times 9.87=4.935[/tex]
mass of Mg(NO₃)₂(MW=148,3 g/mol) :
[tex]\tt mass=mol\times MW\\\\mass=4.935\times 148,3\\\\mass=731.86~g[/tex]
Rank the electronegativity values of lithium, oxygen, potassium, and selenium from lowest to highest
Answer:
Potassium < lithium < Selenium < Oxygen
Explanation:
Oxygen has the highest electronegativity value from the given choices.
Electronegativity of an element is a property that combines the ability of its atom to lose and gain electrons.
It is a measure of the relative tendency with which atoms of the element attracts valence electrons in a chemical bond.
Down a group, electronegativity reduces and across the period from left to right, it increasesPotassium and lithium are in group 1 , selenium and oxygen are group 7;
So group 1 elements will have lower electronegativity value.
Potassium is below lithium in group 1 and its electronegativity value will be lower.
Selenium is below oxygen and also, its electronegativity value is lesser.
The electronegativity values of lithium, oxygen, potassium, and selenium from lowest to highest is potassium, lithium, selenium and oxygen.
The electronegativity of an element is a measure of the tendency of an atom of element to attract bonding pair of electrons. Electronegative elements have the ability to attract shared electrons of covalent bonds to itself.
The most electronegative element is fluorine. Electronegativity increases across the period in the periodic table .
Electronegativity decreases down the group in the periodic table. Generally metallic elements are have lower electronegativity. This is because they mostly give out there electrons.
Therefore, the electronegativity values of lithium, oxygen, potassium, and selenium from lowest to highest is potassium, lithium, selenium and oxygen.
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How many moles of CO2 are found in 2.5 L of CO2?
Answer: 2.5L x 1mol/22.4 = 0.112 mol
Explanation:
What is the difference between absorption and scattering
Answer:
scattering is the direction of transmission absorption is the particle absorbs the energy of the photon
Explanation:
Help me ASAP !!! Thank youuu
Answer:
uhh the first one is the baby plants are gentically simulator to the parent if its wrong im sorry
Explanation:
Help I’ll give brainlist
Answer:
A, And D
Explanation:
I did this before and i got it right ❤
How did we find out the nitroglycerin would also help people with weak hearts?
Answer:
The physician William Murrell was one of the first physicians to recognize the the clinical benefits of nitroglycerin in the treatment of the heart disease known as angina pectoris, a type of chest pain caused by reduced blood flow to the heart.
Explanation:
The physician William Murrell was one of the first physicians to recognize the the clinical benefits of nitroglycerin in the treatment of the heart disease known as angina pectoris, a type of chest pain caused by reduced blood flow to the heart. He also used nitroglycerin to treat and reduce high blood pressure. He used small diluted doses of nitroglycerin to treat patients with angina pectoris. Murrell published his treatment results in the article "Nitro-glycerine as a remedy for angina pectoris," in the journal The Lancet in 1879. Thereafter, the use of nitroglycerin as treatment procedure for angina pectoris soon became generally adopted by other physicians.
Nitroglycerin is a vasodilator which is a medicine that opens blood vessels in order to improve blood flow. Nitroglycerine acts to improve blood flow to the heart by opening up or dilating the coronary arteries in the heart, thereby reducing how hard the heart has to work in pumping blood round the body. It reduces preload by dilating veins and reduces afterload moderately by dilating arteries.
Nitroglycerin comes in two forms: quick-acting forms and long-acting forms.
The quick-acting forms include tablets or oral sprays.
Long-acting forms include pills, tablets, skin ointment, and skin patches.