Answer:
Reliability. When a scientist repeats an experiment with a different group of people or a different batch of the same chemicals and gets very similar results then those results are said to be reliable. Reliability is measured by a percentage – if you get exactly the same results every time then they are 100% reliable.
Explanation:
Sorry, I only got one way.
Body systems such as the nervous and digestive systems work together and help the body
maintain homeostasis. Which of the following correctly describes one way that the nervous
system and the digestive system work together?
Lungs contract during chewing so that food won't be inhaled.
Blood flow to the stomach and intestines decreases during eating.
The involuntary muscles in the jaw stimulate spinal cord neurons to initiate chewing.
Neurons in the brain stimulate smooth muscles in the intestines to move food through the body.
What name is given to any chemical which increase the rate of a chemical reaction
Answer:
It is called catalyst.
Answer:
A catalyst
Explanation:
is a substance that can alter the rate of a chemical reaction. Catalysts can be successfully used to increase the rate of a chemical reaction.
The strong nuclear force is always smaller than the electrostatic force true or false
Answer:
False
Explanation:
The Strong Nuclear Force is defined as an attractive force between neutrons and protons which is responsible to hold the nucleus together.
Electrostatic force is the repulsive or attractive force between two electrically charged objects.
Strong nuclear force is always greater than electrostatic force but changes with the distance. Strong nuclear attraction keeps the nucleus of an atom together in a small space as well which is stronger than their electrostatic repulsion.
it is said that, the strong nuclear force is the strongest force in the universe.
Hence, the given statement is false.
Answer:
False
Explanation:
Strong nuclear forces are much higher than the electrostatic repulsive force. In case if these strong nuclear forces would have not been there, then the nucleus would have disintegrated. This is so because only gravity cannot keep hold on these particles. The nuclear force varies with the size of nucleus. As the size of nucleus increases, the electrostatic repulsion becomes greater
Hence, the given statement is false
In which two ways can the timber industry help prevent loss of forest cover and animal habitats?
Answer:
Cut trees at a sustainable rate
and
Plant one tree for every tree that is cut.
hope i helped, if i could get brainliest that would be great
If the temperature of a gas decreases at constant volume which of the following would occur
Answer:
I need the things after "which of the following would occur".
Explanation:
If you were to maintain a constant volume while decreasing pressure, the temperature would also have to decrease. This is Boyle's law.
11. Calculate the energy required to produce 12.00 mol of CI207 on the basis of the
following balanced equation.
2012(g) + 702(g) + 130 kcal yields 201207(9)
Answer: 780 kcal are required to produce 12.00 mol of [tex]Cl_2O_7[/tex]
Explanation:
Endothermic reactions are defined as the reactions in which energy of the product is greater than the energy of the reactants. The total energy is absorbed in the form of heat and written along with reactants.
The balanced chemical reaction is:
[tex]2Cl_2(g)+7O_2(g)+130kcal\rightarrow 2Cl_2O_7(g)[/tex]
According to stoichiometry :
2 moles of [tex]Cl_2O_7[/tex] are produced by absorption of energy = 130 kcal
Thus 12.00 moles of [tex]Cl_2O_7[/tex] are produced by absorption of energy = [tex]\frac{130}{2}\times 12.00=780kcal[/tex]
Thus 780 kcal are required to produce 12.00 mol of [tex]Cl_2O_7[/tex]
A gas occupies a volume of 2.45 L at a pressure of 1.03 atm. What volume will the
gas occupy if the pressure changes to 0.980 atm and the temperature remains
unchanged? Show your work in the space below. *
Answer:
2.58 L
Explanation:
Please see the step-by-step solution in the picture attached below.
Hope this answer can help you. Have a nice day!
At constant temperature, if the pressure of the gas decreases to the given value, the volume increases to 2.58L.
What is Boyle's law?Boyle's law simply states that "the volume of any given quantity of gas is inversely proportional to its pressure as long as temperature remains constant.
Boyle's law is expressed as;
P₁V₁ = P₂V₂
Where P₁ is Initial Pressure, V₁ is Initial volume, P₂ is Final Pressure and V₂ is Final volume.
Given the data in the question
Initial volume V₁ = 2.45LInitial pressure P₁ = 1.03atmFinal pressure P₂ = 0.980 atmFinal volume V₂ = ?P₁V₁ = P₂V₂
V₂ = P₁V₁ / P₂
V₂ = ( 1.03atm × 2.45L ) / 0.980atm
V₂ = 2.5235Latm / 0.980atm
V₂ = 2.58L
Therefore, at constant temperature, if the pressure of the gas decreases to the given value, the volume increases to 2.58L.
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What happens when light passes from air into water?
A) The light speeds up
B) The light continues at the same speed
C) The light slows down
D) The light forms a mirage
What was the purpose of the Apollo space missions?
to collect rock samples from Mars
to land on Saturn
to collect rock samples from the moon
to land on Jupiter
Answer:
i agree with the above to collect rock samples
Explanation:
took test got 100 best of luck
The purpose of the Apollo space missions was to to collect rock samples from the moon.
What is moon?
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of Australia).The Moon is a planetary-mass object with a differentiated rocky body, making it a satellite planet under the geophysical definitions of the term and larger than all known dwarf planets of the Solar System.
It lacks any significant atmosphere, hydrosphere, or magnetic field. Its surface gravity is about one-sixth of Earth's at 0.1654 g, with Jupiter's moon Io being the only satellite in the Solar System known to have a higher surface gravity and density.
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Do metals or nonmetals have the greatest tendency to lose electrons and become positive ions?
Answer:
The metals have the tedency to lose electrons and become positive ions
Explanation:
In order to attain noble gases electronic configuration, metals of group I A lose one electron and II A lose 2 electrons with ionization energy.
If the mole fraction of sulfuric acid H2SO4 is 0.432 what is the percent by mass of H2SO4.
Answer:
19.47%
Explanation:
The percentage by mass of [tex]H_2SO_4[/tex] would be 19.47%.
The percentage by mass of a substance in solution is calculated as:
[tex]\frac{mass of substance}{mass of substance + water} * 100%[/tex]
Given that the mole fraction of [tex]H_2SO_4[/tex] = 0.432
The total number of mole fraction of a solution = 1
Hence, mole fraction of water = 1 - 0.432 = 0.568
Mass of water = molar mass x mole
= 98.079 x 0.432 = 42.37 g
Mass of [tex]H_2SO_4[/tex] = molar mass x mole
= 18.02 x 0.568 = 10.24 g
Hence,
%mass of [tex]H_2SO_4[/tex] = [tex]\frac{10.24}{10.24 + 42.37} * 100[/tex]
= 19.47%
CAN SOMEONE HELP PLS!!!
Answer:
Matals tend to LOSE electrons to become POSITIVE ions
What are all of the possible products of the electrolysis of Sodium Chloride in aqueous solution of water when the electrodes are made of copper?
A photo has been provided to show what is happening
Answer:
HDHERFEHFFFHRF
Explanation:
Which of the following is the energy that comes from changes in an atom’s nucleus?
a. thermal energy
b. nuclear energy
c. light energy
d. electrical
The mole concept will most likely be used in
calculating the average height of a mountain range.
measuring how many liters of gasoline are poured into a tank.
determining how many ozone molecules are lost in the atmosphere.
finding the mass of a piece of steak in a butcher shop.
Answer:
determining how many ozone molecules are lost in the atmosphere
Pls Mark as Brainliest!!! if this helps...
The mole concept The mole concept can be used to determine the number of ozone molecules are lost in the atmosphere.
The mole concept was introduced by Avogadro. The mole is the SI unit of amount of substance. According to Avogadro, one mole of a substance contains 6.02 × 10^23 atoms, ions, molecules etc.
The mole concept is important in many chemical calculations. The mole concept can be used to determine the number of ozone molecules are lost in the atmosphere. (option C)
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How does activation energy affect the progress of a reaction?
O A. The reaction will not occur unless the activation energy is met.
B. The activation energy decreases the energy needed for a reaction
to progress.
C. The activation energy increases how quickly the reaction will
progress.
D. The activation energy determines equilibrium concentrations of
products.
Answer:
The reaction will not occur unless the activation energy is met.
Explanation
Answer:
A. The reaction will not occur unless the activation energy is met.
Explanation:
a.p.e.x
The volume of an air bubble at the bottom of a lake is 1.35 mL. If the pressure at the bottom of the lake is 125 kPa and the air pressure at the top of the lake is 105 kPa, what will the volume of the bubble be when it rises to the surface?
Answer:
1.61 mL
Explanation:
Step 1:
Data obtained from the question. This includes the following:
Initial volume (V1) = 1.35 mL
Initial pressure (P1) = 125 kPa
Final pressure (P2) = 105 kPa
Final volume (V2) =..?
Step 2:
Determination of the volume of the air bubble at the surface of the lake.
This can be obtained by use the Boyle's law equation as follow:
P1V1 = P2V2
125 x 1.35 = 105 x V2
Divide both side by 105
V2 = (125 x 1.35)/105
V2 = 1.61 mL
Therefore, the volume of the air bubble at the surface of the lake is 1.61 mL
Explain the different principles that allow roller coasters to rip and roar around the tracks. In your response, include how energy is transferred back and forth between kinetic and potential.
Answer:
In the roller coasters the potential energy that is given is the gravitational potential energy, which this energy increases its value as the object moves away from the earth, that is to say, the more height the roller coaster acquires the more gravitational potential energy it will have, and Said train where people usually get on the roller coaster will descend or descend with greater acceleration.
This gravitational potential energy once the mountain begins to descend or descend is converted into kinetic energy
Explanation:
This that we wrote above is considering that the roller coaster does not have curved routes but rectilinear, in the case that it had curved routes, a force would be added in addition to those written that is the centripetal force, it is the same force that appears in the centrifuges or dryers of clothes or the same washing machine. This force, the centripetal force is the force that draws a moving object, in a curvilinear path, towards the center of the curvature.
Blast furnaces extra pure iron from the Iron(IIl)oxide in iron ore in a two step sequence. In the first step, carbon and oxygen react to form carbon monoxide:
2C(s)+O2(g) arrow 2CO(g)
In the second step, iron(lll) oxide and carbon monoxide react to form Iron and carbon dioxide:
Fe203(s) + 3CO(g) arrow 2Fe(s)+ 3CO2(g)
Suppose the yield of the first step is 71.% and the yield of the second step is 72.%. Calculate the mass of oxygen required to make 7.0 kg of iron.
Be sure your answer has a unit symbol, if needed, and is rounded to 2 significant digits.
Answer:
5.9 kg
Explanation:
We must work backwards from the second step to work out the mass of oxygen.
1. Second step
Mᵣ: 55.84
Fe₂O₃ + 3CO ⟶ 2Fe + 3CO₂
m/kg: 7.0
(a) Moles of Fe
[tex]\text{Moles of FeO} = \text{7000 g Fe} \times \dfrac{\text{1 mol Fe}}{\text{55.84 g Fe}} = \text{125 mol Fe}[/tex]
(b) Moles of CO
[tex]\text{Moles of CO} = \text{125 mol Fe} \times \dfrac{\text{3 mol CO}}{\text{2 mol Fe}} = \text{188 mol CO}[/tex]
However, this is the theoretical yield.
The actual yield is 72. %.
We need more CO and Fe₂O₃ to get the theoretical yield of Fe.
(c) Percent yield
[tex]\begin{array}{rcl}\text{Percent yield} &=& \dfrac{\text{ actual yield}}{\text{ theoretical yield}} \times 100 \, \%\\\\ 72. \, \% & = & \dfrac{\text{188 mol}}{\text{actual yield}} \times 100 \,\%\\\\0.72 &= &\dfrac{\text{188 mol}}{\text{actual yield}}\\\\\text{Actual yield} & = & \dfrac{\text{188 mol}}{0.72}\\& = & \textbf{261 mol}\\\\\end{array}[/tex]
We must use 261 mol of CO to get 7.0 kg of Fe.
2. First step
Mᵣ: 32.00
2C + O₂ ⟶ 2CO
n/mol: 261
(a) Moles of O₂
[tex]\text{Moles of O}_{2} = \text{261 mol CO} \times \dfrac{\text{1 mol O}_{2}}{\text{2 mol CO}} = \text{131 mol O}_{2}[/tex]
(b) Mass of O₂
[tex]\text{Mass of O}_{2}= \text{131 mol O }_{2} \times \dfrac{\text{32.00 g O}_{2}}{\text{1 mol O}_{2}} = \text{4180 g O}_{2}[/tex]
However, this is the theoretical yield.
The actual yield is 71. %.
We need more C and O₂ to get the theoretical yield of CO.
(c) Percent yield
[tex]\begin{array}{rcl}71. \, \% & = & \dfrac{\text{188 mol}}{\text{actual yield}} \times 100 \,\%\\\\0.71 &= &\dfrac{\text{4180 g}}{\text{actual yield}}\\\\\text{Actual yield} & = & \dfrac{\text{4180 g}}{0.71}\\\\& = & \text{5900 g}\\& = & \textbf{5.9 kg}\\\end{array}[/tex]
We need 5.9 kg of O₂ to produce 7.0 kg of Fe.
In the following reaction, will the [H2] increase or decrease when equilibrium is reestablished after these stresses are applied?
N2 (g) + 3 H2 (g) ←--> 2 NH3 (g) + 22 kJ
NH3(g) is added ________
N2(g) is removed ________
2. Note reaction: 2 NO (g) + H2 (g)<---->N2 O (g) + H2 O (g) + 36 kJ
In which direction, left or right, will the equilibrium shift if the following changes are made?
NO is added ________
H2 is removed ________
N2O is added ________
H2 is removed ________
3. In this reaction: CO2 (g) + H2 (g) + heat ←-->CO (g) + H2 O (g)
In which direction will the equilibrium shift if these changes are made?
CO is added ________
CO2 is added ________
H2 is removed ________
4. In this reaction: 2 NO (g) + H2 (g) ←--->N2 O (g) + H2 O (g) + heat
What will happen to the [H2O] when equilibrium is reestablished after these stresses are applied?
NO is added ________
N2O is removed _________
Answer:
1. (i) H₂ will decrease
(ii) H₂ will increase
2. (i) Shift right
(ii) Shift left
(iii) Shift left
(iv) Shift left
3. (i) Shift left
(ii) Shift right
(iii) Shift left
4. (i) H₂O will increase
(ii) H₂O will increase
Explanation:
1. For the reaction, N₂ (g) + 3H₂ (g) ↔ 2NH₃ (g) + 22 kJ
(i) When the NH₃ is removed, the concentration of the products is reduced favoring the consumption of further reactants hence the H₂ will decrease
(ii) When N₂ is removed, N₂ will become the limiting reactant resulting in the presence of excess H₂, hence H₂ will increase
2. 2NO (g) + H₂ (g) ↔ N₂O (g) + H₂O (g) 36 kJ
(i) When NO is added, it will favor the increase of the reaction and the equilibrium will shift to the right
(ii) H₂ is removed, it will favor the decomposition of the products hence the equilibrium will shift to the left
(iii) When N₂O is added, it will cause the increase in the partial pressure of the products which will result in the increase in the partial pressures of the reactants to compensate, hence the equilibrium will shift to the left
(iv) When H₂ is removed it will cause the equilibrium to shift left as more products will decompose to form the balance H₂
3. For the reaction;
CO₂ (g) + H₂ (g) + heat ↔ CO (g) + H₂O (g)
(i) When CO is added, there will be an excess partial pressure of the products and the equilibrium will shift left
(ii) When CO₂ is added, there will be an excess partial pressure of the reactants which will favor the formation of the products and the equilibrium will shift right
(iii) When H₂ is removed, there will be an decrease in the partial pressure and concentration of the reactants which will favor the decomposition of the products to balance up the partial pressures of the reactant and the equilibrium will shift left
4. In the reaction 2NO (g) + H₂ (g) ↔ N₂O (g) + H₂O (g) + heat
(i) When NO is added, the concentration of the reactants will increase, hence increasing the likelihood of the formation of more products and the equilibrium will shift to the right and H₂O will increase
(ii) When N₂O is removed, the partial pressure and concentration of the products will reduce hence to balance up the partial pressures of the reacting mixture, more products will be formed and H₂O will increase.
Which of these is a conversion from chemical energy to mechanical energy?
A. A dark light bulb starting to glow
B. A ball rolling down a hill
C. A person lifting a weight
D. A potato being heated in an oven
Answer:
C . A person lifting a weight
What is one thing NOT impacted by Acid
Rain.
Granite
Metal
Limestone
I WILL GIVE BRAINLIEST PLEASE HELP
How many moles of NH₃ are needed to react in order to form 660. g (NH₄)₂SO₄ according to the following balanced equation: 2 NH₃ + H₂SO₄ --> (NH₄)₂SO₄ *
Answer:
10moles of NH₃ will produce 660g of (NH₄)₂SO₄
Explanation:
Equation of reaction:
2NH₃ + H₂SO₄ → (NH₄)₂SO₄
2 mole of NH₃ = 1 Mole of (NH₄)₂SO₄
Molar mass of NH₃ = [14 + (3*1)] = 17g/mol
Number of moles = mass / molarmass
Mass = number of mole * molarmass
Mass = 2 * 17 = 34g
Molar mass of (NH₄)₂SO₄ = [(14 + 4)*2 + (32 + 64)
Molar mass of (NH₄)₂SO₄ = 132g/mol
Mass = molar mass * number of moles
Mass = 132 * 1 = 132g
From the equation of reaction,
34g of NH₃ will produce 132g of (NH₄)₂SO₄
34g of NH₃ = 132g of (NH₄)₂SO₄
X g of NH₃ = 660g of (NH₄)₂SO₄
X = (34*660) / 132
X = 170g of NH₃
170g of NH₃ will produce 660g of (NH₄)₂SO₄
Number of moles = mass / molarmass
Molar mass of NH₃ = 17g/mol
Number of moles = 170 / 17
Number of moles = 10moles
Therefore 10moles of NH₃ will produce 660g of (NH₄)₂SO₄
Compare and contrast the dynamics of energy transfer between the Eocene Period and the Cryogenian Period. In which period would you say that Earth's system is experiencing a net gain in energy and in which period would you say that Earth's system is experiencing a net loss in energy
Answer:
The Eocene Period is experiencing net gain in energy while Cryogenian Period is experiencing a net loss in energy.
Explanation:
In Eocene Period, the population of mammals such as horses , whales and bats etc were high due to the presence of high amount of food and good atmospheric condition such as high temperature while the population of animals were low in Cryogenian Period due to the presence of very low temperature which experiencing loss of energy. Most of area of the earth consist of icy desert.
When an electric circuit operates a buzzard makes a sound what happens to the electric charges in the circuit
Answer:
Explanation:
Khfxgkfxyfkx
A student investigates a pure metal, X. The student takes a 100.0 g piece of metal X, heats it
to 500.0°C, then places it on a 1000.0 g block of ice at 0.0°C. The ice partially melts, and
the final temperature of the metal, ice, and melted water is 0.0°C. The student calculates the
experimental value of the specific heat capacity of metal X and records it as
0.90 J/(g • °C).
(C) Calculate the magnitude of the energy change of metal X during the experiment.
(d) Calculate the mass of ice melted by metal X. (The enthalpy of fusion of ice is 330J/g.
(e) A student claims that the energy transferred to the ice breaks the polar-covalent O-H
bonds found between atoms within water molecules. Do you agree or disagree with this
claim? Justify your answer.
Answer: The answer would be D
Explanation:
The magnitude of the energy change of metal X during the experiment is 6500 J, and the mass of ice melted by metal X is 19.7 g and the claim of the student is correct.
What are changes in ice?The magnitude of energy change of metal is equal to the mass of metal x specific heat capacity of metal x temp. difference
= 100 g x 0.13 J / ( g- oC) x (500 - 0) oC
= 6500 J
According to the question, the enthalpy of the fusion of ice is 330 J / g
Thus 330 J heat is used to melt 1 g of ice
So 6500 J heat is used to melt = 1 x (6500 / 330) = 19.7 g ice
Although hydrogen bonds can form in both a solid and a liquid state, they are more stronger in the solid state. In order to partially dissolve its hydrogen bonds and turn solid ice into liquid water, whatever heat is applied to it is therefore used.
Therefore, the student's assertion is true.
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0.450 moles of K2SO4 are dissolved in 195.0 mL of water. Calculate the molarity of the solution.
Answer:
2.31M
Explanation:
The following data were obtained from the question:
Mole of K2SO4 = 0.450 mole
Volume of water = 195.0 mL = 195/1000 = 0.195L
Molarity =...?
Molarity is defined as the mole of solute per unit litre of the solution. This can be expressed as:
Molarity = mole /Volume
With the above formula we can calculate the molarity of the K2SO4 solution as follow:
Molarity = mole /Volume
Molarity = 0.450/0.195
Molarity = 2.31M
A 52-gram sample of water that has an initial temperature of 10.0 °C absorbs 4,130 joules. If the specific heat of water is 4.184 J/(g °C), what is the final temperature of the water? (4 points) Group of answer choices 11 °C 19 °C 29 °C 51 °C
Answer:
28.98°C
Explanation:
Mass = 52g
Initial temperature (T1) = 10°C
Final temperature (T2) = ?
Heat energy (Q) = 4130J
Specific heat capacity of water = 4.184J/g°C
Heat energy (Q) = mc∇T
Q = heat energy
M = mass of the substance
C = specific heat capacity of the substance
∇T = change in temperature (T2 - T1)
Q = mc∇T
4130 = 52 * 4.184 * (T2 - 10)
4130 = 217.568 * ( T2 - 10)
4130 = 217.568T2 - 2175.68
217.568T2 = 4130 + 2175.68
217.57T2 = 6305.68
T2 = 6305.68 / 217.57
T2 = 28.98°C
Final temperature is 28.98°C
A student observes the chemical process described by this equation:
4Al + 3O2 → 2Al2O3
How does the mass of the new substance compare to the total mass of the starting materials?
Answer:
Both are equal
Explanation:
Mass of starting material i.e Aluminium is [tex]4.480 * 10^{-23}[/tex] grams
The weight of oxygen is [tex]2.65 * 10^{-23}[/tex]
There are 4 atoms of aluminium and 3 atoms of oxygen
Thus, the total mass of starting material is
[tex]4 *[/tex] mass of one atom of aluminium [tex]+ 6 *[/tex] mass of one atom of oxygen
[tex]4 * 4.480 * 10^{-23} + 6* 2.65 * 10^{-23}[/tex]
[tex]35.1 * 10^{-23}[/tex] grams
Mass of new substance is also equal to
[tex]4 *[/tex] mass of one atom of aluminium [tex]+ 6 *[/tex] mass of one atom of oxygen
[tex]4 * 4.480 * 10^{-23} + 6* 2.65 * 10^{-23}[/tex]
[tex]35.1 * 10^{-23}[/tex] grams
If is known how deep the water table in an area is, it is known how deep to dig to reach
Pores
The unsaturated zone
Solid rock
Groundwater
Answer:
grond water
Explanation:
