Answer:
B
Explanation:
energy needed to get a reaction started
hope this helps. good luck :)
How many grams of H2S is needed to produce 18.00g of PbS if the H2S is reacted with an excess (unlimited) supply of Pb(CH3COO)2?
Answer:
2.56g of H₂S
Explanation:
The reaction of H₂S with Pb(CH₃COO)₂ is:
H₂S + Pb(CH₃COO)₂ → 2 CH₃COOH + PbS
Where 1 mole of H₂S produce 1 mole of PbS
18.00g of PbS (Molar mass: 239.3g/mol):
18.00g of PbS ₓ (1mol / 239.3g) = 0.0752 moles of PbS
As 1 mole of PbS is produced from 1 mole of H₂S, moles needed of H₂S are 0.0752
As molar mass of H₂S is 34.1g/mol, mass in 0.0752moles is:
0.0752 mol H₂S ₓ (34.1g / mol) = 2.56g of H₂S
Please help, and solve the problem in kJ
Answer:
1. Exothermic.
2. Yes, released.
3. 38.65KJ of heat is released.
Explanation:
The equation for the reaction is given below:
2NO2 —> N2O4...... ΔH = –55.3KJ
1. The sign of the enthalpy change, ΔH tells whether the reaction is endothermic or exothermic. Since the sign of the enthalpy change, ΔH is negative, the reaction is exothermic.
2. The negative sign indicate that heat is released to the surrounding. Since the reaction is generally an exothermic reaction, 64.3g of NO2 will also release heat to the surroundings.
3. Molar mass of NO2 = 14 + (16x2) = 46g/mol
Mass of NO2 from the balanced equation = 2 x 46 = 92g.
From the balanced equation above:
92g of NO2 reacted to release –55.3KJ of heat.
Therefore, 64.3g of NO2 will react to release = (64.3 x –55.3)/92 = 38.65KJ of heat.
Therefore, 38.65KJ of heat is released.
What are the key characteristics of a combustion and redox reactions?
Answer:
Redox reactions have a reducing agent and a oxidizing agent
Explanation:the reducing agent is more reactive than the oxidizing agent
A student caries out an experiment and dissolves 10.0 g of sodium bromide. NaBr, in 200g of water. What is the molality of the solution?
Answer:
0.485mol/kg
Explanation:
Molality is defined as the ratio of the number of moles of a solute to the kilogram of a solvent which is usually water.
Mass of NaBr = 10g
Molar mass of NaBr= 23+80=103g/mol
Mole of NaBr = mass / molar mass=10g/103g/mol= 0.097mol
Molality= Mole of a solute/ mass of solvent in kg
Mole of a solute( NaBr)= 0.097mol; mass of solvent( water in kg)= 200g. To convert to kg: 200g/1000g= 0.2kg
Molality = 0.097mol/0.2kg = 0.485mol/kg
What mass of hydrogen is produced from the reaction of 50.0 g of Mg and 75.0 g of HCl? How much of the excess reagent is left over?
Mg + 2HCl → MgCl2 + H2
if the ph of a solution is 9 then its pOH will be
Answer:
5.
Explanation:
The pOH is found by subtracting the pH by 14, because the pH and the pOH always add up to 14. So the pOH of a solution with the pH of 9 would be 5.
Hope this helps you out. :)
Explain whether a red apple is opaque or transparent and
why it appears red.
Sample Response: An apple is an opaque object because no light can pass through. The red apple reflects red light and absorbs all the other colors
On which side of the periodic table are there alkaline metals?
Please help! I will give brainliest!
Answer:
left/center
Explanation:
Metals including, alkali metals, alkaline earth metals, and transition metals are all located on the left/center.
hope I helped!
Cellular respiration occurs? (2 points)
only in plant cells
only in animal cells
only in chlorophyll
in plant and animal cells
Answer:
in plant and animal cells
Explanation:
It happens in both and occurs in the mitochondria.
If you spilled nails in a sand box what separation tool/method could you use to clean out the sandbox so it would be safe for children to play with it's:filter,screen,magnet,Evaporation
Answer: Magnet
Explanation:Using a magnet is the best separating technique to be deployed in this case. The nails are easily picked out by just holding a magnet over the sandbox.
If I were to draw an electron configuration for a bromine (Br) atom, what is the highest energy level I would reach?
3s
3p
4s
4p
Answer:
4p
Explanation:
3s < 3p < 4s < 4p
This arrangement is in order of increasing energy.
This explains that, 4p is the highest energy level you can reach.
If everyone on the planet used the same amount of resources as an average American, what percent of the Earth would need to be used to support everyone?
Answer:
540% according to an article I read on BBC
Explanation:
3) List two other names for P-waves and for S-waves.
4) How many earthquake recording stations are needed to locate an earthquake
epicenter? What would happen if you only had two stations? Explain and
illustrate the difference.
The atomic mass of iron is 55.85, and oxygen is 16.0. What is the mass of 6.02 × 1023 molecules of Fe2O3?
Answer:159.7grams
Explanation:
(55.85)2+(16)3
159.7grams
Answer:
The correct answer for plato/edmentum is C (159.7g)
What is the name for a nuclear particle that has about the same mass as a neutron, but with a positive charge?
nuclide
proton
electron
isotope.
proton is the name for a nuclear particle that has about the same mass as a neutron, but with a positive charge.
Please answer question 2.
1. What happens when you stir a spoonful of sugar into hot water?
2. When sugar or another substance is dissolved in water, it disappears from view and forms a homogeneous mixture with the water, also called a solution.
If you can’t see the sugar, how can you tell that it is there?
Answer:
The water tastes sweet, and it usually appears to be cloudy or not clear.
Explanation:
If nothing dissolves into the water, then it should be clear.
Answer:You can tell if the sugar is still there by boiling off the water and leaving the sugar behind in the container. Sugar is a solid, and therefore cannot evaporate, so when the water reaches boiling point, it will evaporate at a quicker rate than before (water evaporates at any temperature in liquid form; just not enough to be noticeable) and leave the container to become water vapour
Explanation: If you stir a spoonful of sugar into hot water, the sugar will dissolve in the hot water. When sugar or another substance is dissolved in water, it disappears from view and forms a homogeneous mixture with the water, also called a solution.
Which of the following statements is true about cellular respiration?
It converts energy into food,
It breaks down food to release energy,
It turns carbon dioxide into water.
It tums water into carbon dioxide.
Answer:
It breaks down food to create energy
The parts that are either directly or indirectly related to each other in a system are known as what?
A) the flow
B) the boundary
C) the components
D) the input
Answer:
C) the components
Explanation:
The term component is referred to as the distinctively recognizable part, piece, of a system that is required to complete a function, in that particular system. Moreover, it carries out a distinguishable and necessary function in the operation of a specific system. For example, a computer has a number of components that make it whole, and the most essential of them is the Central Processing Unit.
Answer:
c) the components
Explanation:
I took the quiz
Which hydrocarbon has more than one possible structural formula?
Answer:
An alkane is a hydrocarbon in which there are only single covalent bonds. The simplest alkane is methane, with the molecular formula CH4.
Explanation:
Alkanes.
Name Heptane
Molecular Formula C7H16
Condensed Structural Formula CH3CH2CH2CH2CH2CH2CH3
Boiling Point (°C) 98.5
Hydrocarbons which are alkanes with 4 or more than 4 carbon atoms have more than one possible structural formula which is a type of chemical formula.
What is structural formula?Structural formula helps in identifying location of chemical bonds which are present between atoms in a molecule.It consists of symbols of elements for the atoms which are connected by short lines which actually represent the chemical bonds.
Structural formulae can be deduced from molecular formulae the fragment ions are studied in the mass spectrum.It is concerned with the valency which helps in determination of of how atoms a combine in a definite ratio.
Properties of molecules are much related with their structures. It helps in showing the arrangement of atoms in a three-dimensional space.
Learn more about structural formula,here:
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Genetic material is carried the ______________ of a cell
1.vacuoles
2.cytoplasm
3.nucleus
4.cell membrane
Answer:
3. nucleus
Explanation:
The nucleus contains all the genetic information.
Consider the nuclear equation below. 239/94 Pu—-> X+ 4/2 He. What is X?
Answer:
X = U (Uranium)
Explanation:
Pu-->235/92 U + 4/2 He
The element X which is involved in the given nuclear reaction is ²³⁵₉₂U.
What is radio active decay?Radio active decay is a process in which an unstable nuclei will emit some particles from the nuclei in the form of energy to get stability.
In the given chemical reaction, parent nuclei (²³⁹₉₄Pu) will emit the alpha particle (⁴₂He) which has a atomic number 2 and atomic mass of 4 as a result of which we get a daughter nuclei Uranium which will get the atomic number 92 and atomic mass of 235.
²³⁹₉₄Pu → ⁴₂He + ²³⁵₉₂U
Hence the element X is uranium (²³⁵₉₂U).
To know more about radioactive decay, visit the below link:
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PLEASE HELP!!
Describe the specific numbers measured and calculated. Restate the hypothesis and explain whether it was supported by
the data. Provide an example from the lab.
Answer:
To get from DNA, written in one chemical language, to protein, written in another, requires two major stages, transcription and translation.
Explanation:
I hope This Helps ^^!!! あなたの歓迎
which statement explains the energy term in this reaction
Answer:
Mass is lost due to the conversion of mass to energy
Explanation:
The question is not complete, the complete question is given as:
[tex]^{235}_{72}U +^{1}_{0}n[/tex] ⇒ [tex]^{140}_{56}Ba+^{93}_{36}Kr+3^{1}_{0}n+energy[/tex]
total mass equals 236.053 u total mass equals 235.868 u
Which statement explains the energy term in this reaction? (1) Mass is gained due to the conversion of mass to energy. (2) Mass is gained due to the conversion of energy to mass. (3) Mass is lost due to the conversion of mass to energy. (4) Mass is lost due to the conversion of energy to mass.
Answer: From Einstein’s equation E = mc², when a radioisotope element undergoes fission or fusion in a nuclear reaction, it loses a tiny amount of mass.This mass lost is converted to energy.
The law of conservation of energy holds for this type of reaction (i.e the sum of mass and energy is remains the same in a nuclear reaction). Mass changes to energy, but the total amount of mass and energy combined remains the same before and after a nuclear reaction.
From the reaction above, the total decrease in mass = 236.053 - 235.868 = 0.185 u
colloidal solution show tyndall effect but true solution do not explain
Answer:
Scattering of light through a solution when light passes through it is called Tyndall effect.
In a colloidal solution, the particle size is between 1 nm to 100 nm, when light rays fall on colloidal solution, these particles sizes allow scattering of light ray.
But in true solution the size of particles is smaller than 1nm and unable to scatter the light and do not show tyndall effect.
Hence, colloidal solution shows tyndall effect but true solution do not.
The number of particles in a mole is known as
How many particles can be stored in a 4.0 L container at room temperature (23 C) and standard atmospheric pressure
(101.3 kPa)?
Answer: 9.91×10²³ particles
Explanation:
To find the amount of particles, you will need to use the Ideal Gas Law with what we are given.
Ideal Gas Law: PV=nRT
After we find moles, we can use Avogadro's number to convert to particles.
[tex]n=\frac{PV}{RT}[/tex]
P=101.3kPa=1.00 atm
V=4.0 L
T=23°C+273.15=296.15 K
R=0.08206 Latm/Kmol
[tex]n=\frac{(1.00 atm)(4.0 L)}{(0.08206Latm/Kmol)(296.15K)}[/tex]
[tex]n=0.164595 mol[/tex]
Now that we have moles, we can convert to particles.
[tex]0.164595mol*\frac{6.022*10^2^3 particles}{mol} =9.91*10^2^2 particles[/tex]
Existe una especie de pájaro en las islas Galápagos que puede ejercer una fuerza de 205N (Newton) con un pico para romper una semilla. Si su pico se desplazó 0,004m durante esta operación, ¿cuánto trabajo realiza el pájaro para conseguir la semilla? Ayuda por favor
Answer:
In order to calculate the work that the spike did, you have to respect the following equation:
WORK = FORCE X DISPLACEMENT X COS (0)
Explanation:
Work is measured in joules, and is the amount of energy a body needs to make a certain force over a certain distance.
In the case of this bird we would be calculating with the equation written up in the previous item the work that said animal would do to grind a seed.
Which of the following samples contains the greatest number of atoms?
a. 9 mole of CO2 b. 10 moles of Xe
c. 11 moles of N2O d. 12 moles of CO
Answer:
12 moles of CO
Explanation:
According to Avogadro, one mole of a substance, contains the same number of elementary entities as 12g of carbon-12. Now the number of elementary entities (atoms, molecules, ions, particles etc) in any substance is given by the Avogadro's constant.
Now since 1 mole of a substance contains Avogadro's number of atoms, it means that the substance with the highest number of moles will have the highest number of atoms.
With this in mind we can see that 12 moles of CO is expected to contain 72.24 ×10^23 atoms of CO. Hence the answer.
Answer:
c. 11 moles of N2O.
Explanation:
Hello,
In this case, for each substance, we use the Avogadro's number to compute the number of atoms in the given sample:
a.
[tex]atoms \ C=9molCO_2*\frac{1molC}{1molCO_2} *\frac{6.022x10^{23}atoms\ C}{1molC} =5.4x10^{24}atoms\ C[/tex]
[tex]atoms \ O=9molCO_2*\frac{2molO}{1molCO_2} *\frac{6.022x10^{23}atoms\ O}{1molO} =1.1x10^{25}atoms\ O[/tex]
[tex]Total\ atoms=1.1x10^{25}+5.4x10^{24}=1.64x10^{25}atoms[/tex]
b.
[tex]atoms \ Xe=10molXe *\frac{6.022x10^{23}atoms\ Xe}{1molXe} =6.022x10^{24}atoms[/tex]
c.
[tex]atoms \ N=11molN_2O*\frac{2molN}{1molN_2O} *\frac{6.022x10^{23}atoms\ N}{1molN} =1.3x10^{25}atoms\ N[/tex]
[tex]atoms \ O=11molN_2O*\frac{1molO}{1molN_2O} *\frac{6.022x10^{23}atoms\ O}{1molO} =6.6x10^{24}atoms\ O[/tex]
[tex]Total\ atoms=1.3x10^{25}+6.6x10^{24}=2.0x10^{25}atoms[/tex]
d.
[tex]atoms \ C=12molCO_2*\frac{1molC}{1molCO_2} *\frac{6.022x10^{23}atoms\ C}{1molC} =7.2x10^{24}atoms\ C[/tex]
[tex]atoms \ O=12molCO_2*\frac{1molO}{1molCO_2} *\frac{6.022x10^{23}atoms\ O}{1molO} =7.2x10^{24}atoms\ O[/tex]
[tex]Total\ atoms=7.2x10^{24}+7.2x10^{24}=1.44x10^{25}atoms[/tex]
Thus, we notice 11 moles of N2O have the greatest number of atoms.
Best regards.
Which sentence describes energy?
O A. It measures changes in the temperature of an object.
B. It measures the speed at which an object is moving.
O C. It measures the capacity to do work.
D. It measures the amount of mass an object has.
Answer:
C
Explanation:
energy is measures the capacity to do work.
Answer:
C
Explanation:
APEX
Where is aggregate generally found?
Answer:
They are generally found in mines