Answer:
The specific heat capacity is 0.67 [tex]\frac{J}{g*C}[/tex]
Explanation:
Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.
The amount of heat that a body receives or transmits is determined by the following expression:
Q = c * m * ΔT
Where Q is the heat exchanged by a body of mass m, made up of a specific heat substance c and where ΔT is the temperature variation.
This expression indicates that between heat and temperature there is a direct proportional relationship.
In this case:
Q= 100 Jc= ?m= 5 gΔT= Tfinal - Tinitial= 40 °C - 10 °C= 30 °CReplacing:
100 J= c*5 g* 30°C
Solving:
[tex]c=\frac{100 J}{5 g* 30C}[/tex]
c= 0.67 [tex]\frac{J}{g*C}[/tex]
The specific heat capacity is 0.67 [tex]\frac{J}{g*C}[/tex]
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.
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.
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
Select the correct answer.
Which action reflects irresponsible lab safety behavior?
A.
not wearing goggles when breaking a rock with a hammer
B.
not shaking hands with your lab partner after a successful experiment
C.
not chatting with others while mixing two reactive chemicals
D.
not sharing findings and recordings with the general public
E.
not using scientific tools while making crucial observations
Answer:
A. not wearing goggles when breaking a rock with a hammer
Explanation:
You could get extremely hurt if you are not wearing goggles while doing lab work.
The action that reflects irresponsible lab safety behavior is not wearing goggles when breaking a rock with a hammer. Thus, the correct option for this question is A.
What are Lab safety behaviors?Lab safety behaviors may be defined as those actions and habits that are persistently taken by individuals in order to maintain discipline and safety on their own. Some of the lab safety behaviors are as follows:
Avoid skin and eye contact with all chemicals by wearing gloves and goggles.Follow an accurate protocol during an experiment. Beware of all safety showers, eye washers, and fire extinguishers. Avoid eating, drinking, and unnecessary talking in the lab.Never smell or inhale laboratory chemicals.Some of the lab safety behaviors also include not shaking hands with your lab partner after a successful experiment, not sharing findings and recordings with the general public, etc. This is because these are some private sources of information.
Therefore, the action that reflects irresponsible lab safety behavior is not wearing goggles when breaking a rock with a hammer. Thus, the correct option for this question is A.
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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
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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26.9 g of solid lithium is combined with 20.0 grams of nitrogen gas. .
When the reaction is complete, an actual yield of 32.5 grams of solid product is produced.
Need to know how to do it, please help me soon!
Answer:
The theoretical yield of
Li
3
N
is
20.9 g
.
Explanation:
Balanced Equation
6Li(s)
+
N
2
(
g
)
→
2Li
3
N(s)
In order to determine the theoretical yield, we must first find the limiting reactant (reagent), which will determine the greatest possible amount of product that can be produced.
Molar Masses
Li
:
6.941 g/mol
N
2
:
(
2
×
14.007
g/mol
)
=
28.014 g/mol
Li
3
N
:
(
3
×
6.941
g/mol Li
)
+
(
1
×
14.007
g/mol N
)
=
34.83 g/mol Li
3
N
Limiting Reactant
Divide the mass of each reactant by its molar mass, then multiply times the mole ratio from the balanced equation with the product on top and the reactant on bottom, then multiply times the molar mass of
Li
3
N
.
Lithium
12.5
g Li
×
1
mol Li
6.941
g Li
×
2
mol Li
3
N
6
mol Li
×
34.83
g Li
3
N
1
mol Li
3
N
=
20.9 g Li
3
N
Nitrogen Gas
34.1
g N
2
×
1
mol N
2
28.014
g N
2
×
2
mol Li
3
N
1
mol N
2
×
34.83
g Li
3
N
1
mol Li
3
N
=
84.8 g Li
3
N
Lithium produces less lithium nitride than nitrogen gas. Therefore, the limiting reactant is lithium, and the theoretical yield of lithium nitride is
20.9 g
.
Explanation:
a _____ is substance in which one or more atoms have the same number of protons (I.e. the same atomic number)
Answer: Element
Explanation:
Answer: a proton is substance in which one or more atoms have the same number of protons
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
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]
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
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.
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 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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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:
What is one thing NOT impacted by Acid
Rain.
Granite
Metal
Limestone
CAN SOMEONE HELP PLS!!!
Answer:
Matals tend to LOSE electrons to become POSITIVE ions
Which statements correctly describe the rock cycle? Check all that apply.
Rocks are preserved through the process.
Rocks change from one type to another.
Different rock groups are interrelated.
Rocks change from one type to another in a specific order.
Environmental conditions influence a change in rock type.
Answer: I italicize for checking
Rocks are preserved through the process.Rocks change from one type to another.Different rock groups are interrelated.Rocks change from one type to another in a specific order.Environmental conditions influence a change in rock type.
Explanation:
Rocks are preserved, as in you can't destroy them completely, but no, they don't stay the same they change.
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.
When a substance changes from a liquid to a solid, it has reached its _____ point
Answer:
The temperature at which a substance changes from the liq- uid state to the solid state is called the freezing point. The freez- ing point of the liquid state of a substance is the same temperature as the melting point of the solid state. For example, solid water melts at 0°C and liquid water freezes at 0°C.
Explanation:
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.
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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When an electric circuit operates a buzzard makes a sound what happens to the electric charges in the circuit
Answer:
Explanation:
Khfxgkfxyfkx
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
Students are comparing the physical properties of sugar water, salt water,and plain water,including the affects of thermal energy. What safety equipment is needed?
A-Graduated Cylinder and gloves
B-safety goggles and thermometer
C-thermometer and hot plate
D-safety goggles and gloves
Answer:
D
Explanation:
The safety equipment that is needed when your doing a science experiment you need a safety goggles and gloves.
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
You take a very hot block of metal on top of a cold block of metal. What will
happen to the temperature of both blocks over time?
Answer:
They will both cool down overtime
Explanation:
Once you put something that is hot on something that is cold. They will both be hot, but overtime they will cool down. It can't stay hot forever.
Answer:
Hey!
Your answer is that one block of metal (the cold one) would heat up a bit whilst the other block (the hot one) would cool down...This is because of the metal's CONDUCTIVITY!
Explanation:
Eventually you would measure the temperature of both blocks and they will reach the same temperature. After this they will naturally cool down...
HOPE THIS HELPS!!
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%
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.
