Respiration occurs in the mitochondria
Answer:
mitochondria
Explanation:
Respiration happens in the cells of plants, animals and humans, mainly inside mitochondria.
A 15.50 gram sample of a gas exerts a pressure of 1.40 atmospheres when held in an 8.00 liter at 22 °C. What is the molar mass (grams/mol) of the gas?
Answer:
33.5 g/mol
Explanation:
PV=nRT
(1.40 atm)(8.00 L)=n(0.08206)(295 K)
n=0.463 mol
15.50 g/0.463 mol=33.5 g/mol
A compound contains 34.5% calcium, 24.1% silicon and 41.4% oxygen by mass. What is its empirical formula?
[tex]empirical \: formula \\ = CaSiO3 \\ please \: see \: the \: attached \: picture \\ hope \: it \: helps[/tex]
Who was the second person to organize the elements on the periodic table and what property did he use to re-organize them?
Answer:
Dmitri Mendeleev
Explanation:
He was a Russian Scientist who decided to reorganize the periodic table after other notable scientists such as Antoine-Laurent Lavoisier had also tried to organize it based on the states of matter of the elements.
Mendeleev reorganized the period in the order of increasing atomic mass although there were some other modifications by modern scientists.
boron has two naturally occurring isotopes .there are 10 b(20%)and 11b(80%).what is the average atomic mass of boron
Answer:
Explanation:
Average Atomic mass of any element =[ ∑ Abundance* mass of element] /100
= 10*20 +11*80 /100
= .........
Hope this helps you
The ____ contains the highest concentration of ozone. (troposphere (exosphere ( stratosphere ( mesosphere
Answer:
the answer is stratosphere.
about 90% of ozone is found in the stratosphere.
Explain why covering something with a blanket can put out a fire
Answer:
No oxygen
Explanation:
when something is covered in a blanket it prevents the fire from being able to have any oxygen
Answer:
Its called smothering the fire
Explanation:
A fire needs three things to burn always: fuel, oxygen, and a heat source. Eventually the heat source will not be an issue, but the oxygen and fuel is. If the fire is small enough throwing a blanket can quite smother it. What happens is it cuts off the oxygen supply the fire needs long enough for it to die out.
(c)
Suggest a reason why substance E does not conduct electricity in both solid and
molten states.
Answer:
Substance E does not conduct electricity in both solid and molten states because of very low melting and boiling points.
In both solid and molten state free electrons are required to conduct electricity. substance E has low boiling and melting point which means substance will have relatively weak bonds. Because of weak bonds substance E might not have much free electron in its outermost shell that can cause the electric current by their coordinated movement.
Hence, substance E is unable to conduct in both melting and molten state.
What is the mass number of an atom that contains 19 protons, 19 electrons, and 20 neutrons?
Answer:
39
Explanation:
Total protons + total neutrons = mass number
A balloon has a volume of 10,500 liters, and the temperature is 15°C. If the temperature were -25°C, what would the volume of the balloon be?
12,194 L
9,042 L
12,194 L is the answer!
Explanation:
Water has the maximum density at the temperature of 4°Celsius. So, it expands at temperatures higher or lower than 4°C, knowing that at the temperature of -25°C the water can't have a lower volume than the one at 15°C.
Answer:
12, 194 L
That's your answer!!!
An acid is added to water, and a new equilibrium is established. What is the system after the acid is added? A. pH w = 1 x 10-14 B. pH w -14 C. pH > pOH and Kw = 1 x 10-14 D. pH > pOH and Kw > 1 x 10-14
Answer:
C. pH > pOH; Kw = 1.0 * 10^-14
Explanation:
The ion product of water, Kw = [H+]*[OH-] = 1.0 * 10^-14. It is a constant.
When an acid or base is added to water, its ion product does not change as it a constant. However, the relative concentrations of H+ ions and OH- ions will change depending on whether an acid or base is added to water.
When an acid is added to water, the concentration of H+ ions increases while that of OH- ions decreases, and vice versa.
Therefore, in the above situation where an acid is added to water, pH > pOH; Kw = 1.0 * 10^-14
1.Mitch weighs out 67 grams of potassium (K) to make a buffer. How many moles of potassium did Dr. Hellman weigh out?
2.Which statement is NOT true about a reaction rate?
Group of answer choices
Increases with increase in reactant concentration
Increases with increasing temperature
Is the speed at which product is formed
Is the rate at which reactant is used up
All of the answers are true
3.Which statement is NOT true about a catalyst?
Group of answer choices
Are not used up during a reaction
Increases the rate of the reaction
Lowers the energy of activation
Biological catalysts are called enzymes
Are used up during a reaction
Answer:
1. 1.72 moles of potassium.
2. All of the answers are true
3. Are used up during a reaction
Explanation:
Recall that the number of moles is obtained from;
Number of moles= Mass of potassium/ molar mass of potassium
Mass of potassium= 67 g
Molar mass of potassium= 39 gmol-1
Number of moles of K= 67 g/ 39 gmol-1
Number of moles = 1.72 moles of potassium.
2. When we look at all the options, we will realize that all the options are true. The rate of reaction doubles for each 10°C rise in temperature, increasing reactant concentration increases particle collision and ultimately increases the rate of reaction. Rate of reaction deals with rate of disappearance of reactants or rate of appearance of products.
3. Catalysts remain unchanged in a chemical reaction because they do not actually participate in the reaction. Hence they are not used up in any chemical reaction.
Why does the presence of lone pairs contribute to the polarity of a water molecule
Explanation:
They allow the bonds between oxygen and hydrogen to be single. They increase the partial positive charge on the oxygen atom. They counter the uneven pull on electrons between the atoms.
A 20 mL volume of a hydrochloric acid solution, HCl (aq), was placed into a beaker containing an appropriate
acid-base indicator. It was titrated with a solution of sodium hydroxide, NaOH (aq), until the endpoint was
reached. If 25 mL of sodium hydroxide solution with a concentration of 0.20 mol/L was used, what is the
concentration of the acid?
Select one:
a. 2.5 mol/L
O
b. 0.20 mol/L
C. 0.25 mol/L
d. 2.0 mol/L
Answer:
C- 0.25mol/L
Explanation:
Hcl+Naoh-Nacl+H2O
Ratio =1:1
0.2moles of Naoh in1000cm3 what about 25=(25×0.2)÷1000=
0.005moles
0.005moles in 20cm³ what about in 1000
(0.005×1000)÷20=0.25mol/L
According to the molar concentration, the concentration of the acid is 2.5 mole/liters.
What is molar concentration?Molar concentration is defined as a measure by which concentration of chemical substances present in a solution are determined. It is defined in particular reference to solute concentration in a solution . Most commonly used unit for molar concentration is moles/liter.
The molar concentration depends on change in volume of the solution which is mainly due to thermal expansion. Molar concentration is calculated by the formula, molar concentration=mass/ molar mass ×1/volume of solution in liters.
In terms of moles, it's formula is given as molar concentration= number of moles /volume of solution in liters.In case of 2 solutions, molar concentration is obtained as M₁V₁=M₂V₂, on substitution of values, M₁=25×0.20/20=2.5 mole/L.
Thus,the concentration of the acid is 2.5 mole/liters.
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The table below shows the similarity of Methane and water in molecular mass. They are also similar in both size and shape. Why does Methane exist in the gas state with a very low boiling point?
Answer:
Explanation:
In case of Water there are strong hydrogen boding excist as result shows high boiling point, wher as in case of methane the there is no hydrogen bond and excist weak vanderwall attraction between the molcuels so the lower boiling point.
Two atoms bonded together will remain some distance apart, minimizing the Question 1 options: A) potential energy of the bond. B) bond distance. C) number of valence electrons in the bond. D) partial charge of the bond. Question 2 (5 points) BeH2 has no lone pairs of electrons. What's the structure of this molecule? Question 2 options: A) Tetrahedral B) Bent C) Octahedral D) Linear Question 3 (5 points) In KCl, how are the valence electrons distributed? Question 3 options: A) The electrons are transferred from K to Cl. B) The electrons are unequally shared between K and Cl, forming a polar covalent bond. C) The electrons are shared between many K and Cl ions, creating a "sea of electrons." D) The electrons are equally shared between K and Cl, forming a covalent bond. Question 4 (5 points) Chlorine can bond with fluorine to form ClF. Chlorine can also bond with lithium to form LiCl. Which compound will have a greater partial charge? Question 4 options: A) Both compounds will have the same partial charge. B) ClF C) LiCl D) Neither compound will have partial charge. Question 5 (5 points) Which of the following elements will not form a polar covalent bond with oxygen? Question 5 options: A) Hydrogen B) Oxygen C) Sodium D) Fluorine Which process is used to produce gases from solutions of salts dissolved in water or another liquid? Question 6 options: A) Electrolysis B) Polar covalent bonding C) Ionic bonding D) Metallic bonding Question 7 (5 points) Saved A chemical reaction has the equation AgNO3 (s) + NaCl (s) → AgCl (s) + NaNO3 (s). What type of reaction occurs between AgNO3 and NaCl? Question 7 options: A) Decomposition B) Double displacement C) Single displacement D) Synthesis
Answer:
1) potential energy of the bond.
2) Linear
3) The electrons are transferred from K to Cl.
4) ClF
5) Oxygen
6) Electrolysis
7) Double displacement
Explanation:
As two atoms approach each other in a bonding situation, the potential energy of the bond is minimized as the internuclear distance of the bonding atoms decreases.
BeH2 has two electron domains and the central beryllium atom is sp2 hybridized. According to valence shell electron pair repulsion theory. A molecule having two regions of electron density will lead to a linear molecule.
KCl is an ionic compound hence there is a transfer of electrons from K(metal) to Cl(nonmetal).
ClF has partial charges because it contains a polar covalent bond. The partial charges arise from the dipole within the molecule. LiF is a pure ionic compound formed by transfer of electrons from Li to F. The species possess full and not partial charges.
When an oxygen atom bonds with another oxygen atom, what has been formed is a homonuclear covalent bond. Since the electro negativity of the both atoms is exactly the same, a pure covalent bond is formed. Recall that polar covalent bonds are formed when there is a significant electro negativity difference between the bonding atoms.
When direct current is passed through certain salt solutions during electrolysis, gases may be evolved and collected at the appropriate electrodes.
A double-replacement reaction is a reaction in which the cations and anions present in two different ionic compounds that are reacting together exchange their positions to form two new compounds on the product side. For instance, look at the reaction shown in question 7 as a typical example of this;
AgNO3 (s) + NaCl (s) → AgCl (s) + NaNO3 (s).
Does the number of ions in solution increase, decrease, or remain constant?
It decreases at first, then increases.
It continuously increases.
It continuously decreases.
It increases at first, then decreases.
Answer:
It continuously decreases.
The oxide of element X is reduced by heating with carbon.Element X does not react with cold water, steam or dilute hydrochloric acid.What is X?
The question is incomplete, the complete question is;
The oxide of element X is reduced by heating with carbon.
Element X does not react with cold water, steam or dilute hydrochloric acid.
What is X?
A copper
B iron
C magnesium
D zinc
Answer:
Copper
Explanation:
Copper is below hydrogen in the activity series of metals. Remember that the activity series of metals is an arrangement of metals in order of decreasing reactivity from most reactive to least reactive. The metals at the head of the series are highly reactive, metals at the middle of the series are moderately reactive while metals below hydrogen in the series are least reactive.
Copper being below hydrogen in the series cannot displace it from water (cold or steam) or from dilute acid solutions. Copper can be reduced by heating it with carbon (thermal reduction).
Which of the following is an example of frontier research?
A. Investigating how organisms are made of cells.
B. Testing the electrical resistance of different materials.
C. Discovering the nature of dark matter.
D. Researching how animals on the Great Plains interact.
Answer:
B. Testing the electrical resistance of different materials.
Explanation:
An example of frontier research is " Testing the electrical resistance of different materials".
What is frontier research?A frontiers Research Topic offers researchers the chance to present various viewpoints, approaches, and findings on a new or developing topic in a forum monitored by experts in the area but also published in a complete open-access journal.
What is electrical resistance?Electrical resistance towards the current stream within an electrical circuit is measured by resistance. The Greek letter omega (ω) stands for ohms, which are used to evaluate resistance.
Therefore, the correct answer will be an option (B).
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Match these people to the discoveries or work that they are known for. Galileo developed geocentric theory Aristotle developed heliocentric theory Celsius founded nursing profession Torricelli invented barometer Copernicus considered "Father of Modern Science" Vesalius developed law of universal gravitation Newton examined the inner workings of the human body Nightingale developed metric temperature scale
Answer:
Galileo: "Father of Modern Science."
Aristotle: Geocentric theory." (The planests revolves around the earth.)
Torricelli: Invented the barometer. (An instrument which measures pressure.)
Copernicus: Heliocentric theory. (Aka, the planets revolves around the sun.)
Vesalius: Examined the inner workings of the human body
Newton: Developed law of universal gravitation.
Nightingale: Founded nursing profession.
Celsius: Developed metric temperature scale
I hope this helps! Thanks:)
This type of substance has a pH of 7. It will not change the color of litmus.
1. Acid
2. Base
3. Neutral
This question was just so some of y'all can get more points lol.
CHEM HELP PLEASE
a reaction that has been calculated to produce 346 g of CH3OH actually produced 312 g of CH3OH. what is it's percent yield?
Answer:
90.2%
Explanation:
% yield = actual yield/ theoretical yield * 100%
% yield = (312/346)*100% = 90.2%
What does the VSEPR theory predict?
A. The chemical formula of a molecule
B. The size of a molecule
C. The shape of a molecule
D. The charge of a molecule
Answer: C
Explanation:
A P E X
The VSEPR theory predicts the shape and molecular geometry of the molecule.
What is molecular geometry?Molecular geometry can be defined as a three -dimensional arrangement of atoms which constitute the molecule.It includes parameters like bond length,bond angle and torsional angles.
It influences many properties of molecules like reactivity,polarity color,magnetism .The molecular geometry can be determined by various spectroscopic methods and diffraction methods , some of which are infrared,microwave and Raman spectroscopy.
They provide information about geometry by taking into considerations the vibrational and rotational absorbance of a substance.Neutron and electron diffraction techniques provide information about the distance between nuclei and electron density.
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HELP!!!!!!!!!!!!!!!! PRETTY PLEASE !!!!!!!!!!!!!!!!
Answer:
B. 75.0 kPa
Explanation:
P1V1/T1=P2V2/T2
(x * 100 L)/(300 K)=(100 kPa * 50.0 L)/(200 K)
x=75.0 kPa
Answer:
24rq3r54
Explanation:
3t5q6tq6tq
Se construye una pila galvánica con una barra de cobre sumergida en una disolución 1M de cationes Fe+2 y una barra de plata sumergida en una disolución 1M de da cationes Ag+ , Calcular el potencial estándar de la celda teniendo en cuenta que a 25°C: Cu+2/Cu = -0.34V Ag+/Ag = 0.80V
Answer:
El potencial celular estándar, [tex]E_{cell}[/tex] is +0.46 V
Explanation:
Las reacciones de media célula son;
Media reacción del ánodo Cu²⁺ + 2e⁻ ↔ Cu, E ° = 0.34 V
Media reacción catódica 2Ag + 2e⁻ ⁻ 2Ag, E ° = 0.80 V
Sin embargo tenemos para hierro Fe²⁺ + 2e⁻ ↔ Fe, E ° -0.44 V
y Fe³⁺ + e⁻ ↔ Fe²⁺, E ° = 0.77 V
que es más alta que la del cobre presente, por lo tanto, el cobre se oxidará en el ánodo
Por lo tanto, en el ánodo, tendremos
Cu → Cu²⁺ + 2e⁻ (E ° = -0.34 V)
En el cátodo
2Ag + 2e⁻ → 2Ag (E ° = 0.80 V)
[tex]E_{cell} = E_c + E_a = -0.34 + 0.8 = +0.46 \, V[/tex]
El potencial celular estándar, [tex]E_{cell}[/tex] = +0.46 V
The reaction 2 NO(g) ⇌ N2(g) + O2(g) has a value of Keq = 2400 at a temperature of 2000 K. If 0.570 mol of NO(g) is initially placed in a 3.0 L container, calculate the equilibrium concentrations of each gas
Answer:
[tex][N_2]_{eq}=0.094M[/tex]
[tex][O_2]_{eq}=0.094M[/tex]
[tex][NO]_{eq}=0.002M[/tex]
Explanation:
Hello,
In this case, for the given chemical reaction, we write the following law of mass action:
[tex]Keq=\frac{[N_2][O_2]}{[NO]^2}[/tex]
That in terms of the change [tex]x[/tex] due to the reaction extent (ICE procedure) we can write:
[tex]Keq=\frac{x*x}{([NO]_0-2x)^2}[/tex]
Thus, the initial concentration of nitrogen monoxide is:
[tex][NO]_0=\frac{0.570mol}{3.0L} =0.19M[/tex]
Thereby, we write:
[tex]2400=\frac{x*x}{(0.19-2x)^2}[/tex]
That we can solve by suing the quadratic equation formula or solver to obtain two roots:
[tex]x_1=0.094M\\x_2=0.096M[/tex]
Nevertheless, the correct answer is 0.094 M since the other root will produce a negative concentration of nitrogen monoxide at equilibrium, therefore, the equilibrium concentrations turn out:
[tex][N_2]_{eq}=x=0.094M[/tex]
[tex][O_2]_{eq}=x=0.094M[/tex]
[tex][NO]_{eq}=0.19M-2x=0.19M-2(0.094M)=0.002M[/tex]
Best regards.
Twenty liters of NO gas react with excess oxygen. How many liters of NO2 gas are produced if the NO gas reacts completely?
Answer:
2O L
Explanation:
The balanced chemical equation is 2NO+O
2
→2NO
2
Thus, 2 moles of NO will produce 2 moles of NO
2
.
Also, the volume is directly proportional to the number of moles.
Therefore, 20 L of NO will produce 20×
2
2
=20 L of NO
2
A simple experiment to demonstrate that NaOH is a stronger alkali than NH3
Answer:
pH value test can be used to demonstrate that NaOH is a stronger alkali than NH3
Explanation:
pH value test can be used to demonstrate that NaOH is a stronger alkali than NH3. This is done by measuring the same volume of equal concentration of hydroxide and ammonia. A glass rod was dipped into 0.2 M of sodium hydroxide and 0.2 M of ammonia, each drop of solution was then placed on a pH paper matched with a color chart and the pH value was recorded.
The result showed that sodium hydroxide being a strong alkali would dissociate completely in aqueous solution thereby having a higher pH while ammonia would dissociate slightly/partially in aqueous solution thereby having a lower pH value
How do greenhouse gases such as CO2 and N2O contribute to an increase in Earth’s atmospheric temperature?
A.
Greenhouse gases interact with infrared photons and reflect them back to Earth’s surface.
B.
Greenhouse gases chemically react with one another, releasing heat in the process.
C.
Greenhouse gases agitate visible light photons, increasing the photons’ temperature and motion energy.
D.
Greenhouse gases generate internal heat through radioactive decay, similar to the core of Earth.
Answer:
The answer is A
Explanation:
The earth naturally maintains the heat energy balance by absorbing a sufficient amount of sunlight energy by the terrestrial land and then reverting back the excess sunlight energy back to the space. The increase in abundance of greenhouse gases in the atmosphere results in absorption of sunlight energy which contains infrared photons this is responsible for increasing the global temperature levels hence, responsible for global warming. These infrared photons are reflected to the earth surface instead of sending back to the space. This is responsible for disturbing the heat balance.
Greenhouse gases interact with infrared photons and reflect them back to earth’s surface, hence option A is correct.
How does greenhouse gases rise in earth’s atmosphere?The burning of fossil fuels, logging of forests, and raising of livestock all have a rising impact on the climate and temperature of the planet.
This increases the greenhouse effect and causes global warming by adding a significant amount of greenhouse gases to those that are already present in the atmosphere.
The earth naturally maintains the balance of heat energy by receiving enough solar energy through the terrestrial land and then returning any excess energy to space.
Therefore, greenhouse gases such as CO₂ and N₂O interact with infrared photons and reflect them back to earth’s surface.
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A.
B.
C.
D.
what’s could be the correct answer?
The three states of matter can be arranged in the increasing order of interparticle forces as 1) gas > liquid >solid 2) solid >liquid > gas 3) liquid > gas > solid pls answer fast
Answer:
OPTION 2 SOLID>LIQUID>GAS
Explanation:
because the inter molecular forces are the strongest in the solid than in liquid and than in gas
