Answer:
The male cones appear on the trees in the spring time. The male cones are smaller than the female cones that we typically think of when we think of pine cones. These cones are softer and are only on the trees in the spring. After they release their pollen they die away and disappear.
Explanation:
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For the reaction 2H₂(g) + O₂(g) → 2H₂O(g), what volume of water vapor can be made from 100 grams of oxygen gas and an excess of hydrogen at STP? Please show work.
Answer:
140 L
Explanation:
Step 1: Write the balanced equation
2 H₂(g) + O₂(g) → 2 H₂O(g)
Step 2: Calculate the moles corresponding to 100 g of oxygen
The molar mass of oxygen is 32.00 g/mol.
[tex]100g \times \frac{1mol}{32.00g} =3.13mol[/tex]
Step 3: Calculate the moles of water vapor formed
The molar ratio of oxygen to water vapor is 1:2.
[tex]3.13molO_2 \times \frac{2molH_2O}{1molO_2} =6.26molH_2O[/tex]
Step 4: Calculate the volume corresponding to 6.26 moles of water vapor
1 mole of any ideal gas under STP has a volume of 22.4 L.
[tex]6.26mol \times \frac{22.4L}{mol} =140 L[/tex]
Ultraviolet photoelectron spectroscopy (UPS) is an important analytical tool used to characterize the composition of materials in academic, industrial and national laboratories. The technique relies on the photoelectric effect where-in electrons are emitted from a material when it absorbs ultraviolet photons. Make a plot of the kinetic energy of the photo-emitted electrons versus the frequency of the incident light as the frequency is varied across the transition where photon energy exceeds the ionization energy (IE) of a material being examined by UPS. Label you axes.
Answer:
The equation for the Kinetic Energy, [tex]KE_e[/tex], of the photo-emitted electrons is given as follows;
[tex]KE_e = h\cdot f- BE[/tex]
Please find attached the required plot of the kinetic energy versus the frequency
Explanation:
The equation for the Kinetic Energy, [tex]KE_e[/tex], of the photo-emitted electrons is given as follows;
[tex]KE_e = h\cdot f- BE[/tex]
Where:
h = Planck's constant = 6.63×10⁻³⁴ J·s
f = Frequency
BE = Binding Energy = 2.71 eV for Calcium metal
f₀ = Threshold frequency for the material
The ionization energy is the energy required to free an electron from an isolated atom
Which multimedia does this ad from the Centers for Disease Control’s advertising campaign for the flu vaccine include? (more than one)
A.) animation
B.) image
C.) text
D.) graph
E.) chart
Answer:
Image and text
Explanation:
on edge
Which of the following is an example of acceleration? 88m/s, 15km/hr,14m/s East, 9.8 m/s^2 south
Answer: The answer is 9.8 m/s^2 south
Explanation:
Use one of your experimentally determined values of k, the activation energy you determined, and the Arrhenius equation to calculate the value of the rate constant at 25 °C. Alternatively, you can simply extrapolate the straight-line plot of ln(k) vs. 1/T in your notebook to 1/298, read off the value of ln(k), and determine the value of k. Please put your answer in scientific notation. slope=-12070, Ea=100kJ/mol, k= 0.000717 (45 °C), 0.00284 (55 °C), 0.00492 (65 °C), 0.0165 (75 °C), 0.0396 (85 °C).
Answer:
Explanation:
Use one of your experimentally determined values of k, the activation energy you determined, and the Arrhenius equation to calculate the value of the rate constant at 25 °C. Alternatively, you can simply extrapolate the straight line plot of ln(k) vs. 1/T in your notebook to 1/298 , read off the value of ln(k), and determine the value of k. Please put your answer in scientific notation. slope=-12070, Ea=100kJ/mol, k= 0.000717(45C), 0.00284(55C), 0.00492(65C), 0.0165(75C), 0.0396(85C)
Explanation;
According to Arrhenius equation:
i.e. ln(k2/k1) = -Ea/R (1/T2 - 1/T1)
Where, k1 = 0.000717, T1 = 45 oC = (45+273) K = 318 K
T2 = 25 oC = (25 + 273) K = 298 K
i.e. ln(k2/0.000717) = -12070 (1/298 - 1/318)
i.e. ln(k2/0.000717) = -2.54738
i.e. k2/0.000717 = [tex]e^{-2.54738}[/tex]
= 0.078286
Therefore, the required constant (k2) = 0.078286 * 0.000717 = [tex]5.61*10^-^5[/tex]
which of the following is larger then the atomic radius of phosphorus
Options
a: the ionic radius of phosphorus
b: the atomic radius of argon
c: the atomic radius of nitrogen
d: the ionic radius of chlorine
Answer:
a)the ionic radius of phosphorus
Explanation:
phosphorus=2.8.6
for phosphorus to become stable(2.8.8) it gains two electrons thus the ionic radious increases bcz of the gained electrons
what is the sex-ratio in rajasthan according to 2011 census?
Answer:
Sex ratio of India according 2011 census is 940 females per 1000 males. Sex ratio of Rajasthan is 928 which means there are 928 female present per 1000 males
Explanation:
pls check my answer brain list
A proton is a hydrogen atom without its electron?
True
False
Plants need sunlight, water, and minerals from the soil in order to grow and thrive. These factors
A.
are always abundant, allowing unlimited growth.
B.
limit the number of plant populations that can grow in an ecosystem.
C.
require human intervention to be replenished.
D.
prevent new plant populations from entering the ecosystem.
Answer:
B. limit the number of plant populations that can grow an ecosystem
Answer:
B. limit the number of plant populations that can grow in an ecosystem.
Explanation:
What is the amount of energy needed to heat 2.3 g of aluminum from 6.2oC to 46.9oC in Joules?
Answer:
Heat required = 84.25 Joule
Explanation:
Heat required = mass × specific heat capacity × temperature change
Specific heat capacity of aluminium = 0.90 J/g/K
Heat required = 2.3 × 0.9 × (46.9 -6.2)
= 84.25 Joules
1 point
A container with nitrogen, oxygen, and hydrogen has a pressure of 10.46
atm. If the pressure of nitrogen is 321 kPa and the pressure of oxygen is
74.0 psi, what is the pressure of hydrogen? *
2.25 atm
18.7 atm
4.90 atm
237 atm
Answer:
2.25 atm
Explanation:
Given data
Pressure of N₂: 321 kPaPressure of O₂: 74.0 psiPressure of H₂: ?Total pressure: 10.46 atmStep 1: Convert the pressure of nitrogen to atm
We will use the relationship 1 atm = 101.325 kPa.
[tex]321kPa \times \frac{1atm}{101.325kPa} = 3.17 atm[/tex]
Step 2: Convert the pressure of oxygen to atm
We will use the relationship 1 atm = 14.6959 psi.
[tex]74.0psi \times \frac{1atm}{14.6959psi} =5.04atm[/tex]
Step 3: Calculate the partial pressure of hydrogen
The total pressure is the sum of the partial pressures.
P = pN₂ + pO₂ + pH₂
pH₂ = P - pN₂ - pO₂
pH₂ = 10.46 atm - 3.17 atm - 5.04 atm
pH₂ = 2.25 atm
Answer:
[tex]P_H=2.25atm[/tex]
Explanation:
Hello,
IN this case, we can apply the Dalton's law in order to understand the pressure behavior of a mixture as the summation of all the pressures of the compounds in the mixture, in this case, nitrogen, oxygen and hydrogen:
[tex]P_T=P_O+P_N+P_H[/tex]
So, since we are asked to compute the pressure of hydrogen, we simply solve for it:
[tex]P_H=P_T-P_O-P_N=10.46atm-74.0psi*\frac{1atm}{14.6959psi} -321kPa*\frac{1atm}{101.325kPa} \\\\P_H=2.25atm[/tex]
Best regards.
What happens when you put magnesium carbonate and diluted water
Answer:
Magnesium carbonate doesn't dissolve in water, only acid, where it will effervesce (bubble).
Explanation:
An insoluble metal carbonate reacts with a dilute acid to form a soluble salt. Magnesium carbonate, a white solid, and dilute sulfuric acid react to produce magnesium sulfate. Colourless magnesium sulfate heptahydrate crystals are obtained from this solution.
A 2.7 M solution contains
0 2.7 moles of solute per 1000 g of solvent.
2.7 moles of solute per 1000 mL of solution.
0 2.7 grams of solute per 100 mL of solution.
0 2.7 grams of solute 100 g of solution.
per
Answer:
2.7 moles of solute per 1000 mL of solution.
Explanation:
Hello,
In this case, molarity is defined as the ratio of the moles of the solute to the volume of the solution in litres, thus, for a 2.7-M solution, it is clear that we have 2.7 moles of the solute in 1 L of solution, thus the option having the proper relation is 2.7 moles of solute per 1000 mL of solution as 1 L equals 1000 mL.
Best regards.
How many grams of aluminum would have the same number of atoms as 6.94 g of lithium?
Answer:
26.984g =Al cantain 1.6023x10^27amu
6.94=li cantain 1.6023x10^27amu
thus
mass of aluminium/mass of lithium
26.984/6.94=3.89
a chemical reaction can be represented by
Answer:
A chemical reaction is a rearrangement of atoms which turn one or more compounds into new compounds. Equations and models may describe all of the chemical reactions. ... If atoms detach from each other and recombine into various types of atoms, we conclude that there has been a chemical reaction.
Answer:
equations and models.
Explanation:
All chemical reactions can be represented by equations and models.
A substance is followed by the symbol (1) in a chemical equation. What does the symbol represent?
Answer:
The symbol (l) stands for liquid phase.
Explanation:
In Universe L, recently discovered by an intrepid team of chemists who also happen to have studied interdimensional travel, quantum mechanics works just as it does in our universe, except that there are six d orbitals instead of the usual number we observe here.
Use these facts to write the ground-state electron configurations of the fifth and sixth elements in the first transition series in Universe L.
Note: you may use to stand for the electron configuration of the noble gas at the end of the row before the first transition series.
fifth transition metal:
sixth transition metal:
The electron configuration of the fifth and sixth transition elements in universe L may be slight different than as it is on earth.
The electron configuration shows the distribution of electrons in atoms. In atoms electrons are distributed in orbitals. Different orbitals hold different maximum number of electrons in them.
On earth, the d orbitals are five but in universe L, the d orbitals are six. This implies that d orbitals in universe L can hold a total of twelve electrons.
The fifth transition metal is Manganese. The electron configuration of manganese in universe L is [Ar] 3d6 4s1. The sixth transition element is iron. The electron configuration of iron in universe L is [Ar] 3d6 4s2.
Learn more: https://brainly.com/question/4147359
Which location would be best for solar energy
Answer:
An area that has a lot of sun-light!
Explanation:
Predict the products of the following reactions (assume complete reaction). In your submission include the overall balanced equation, and balanced net ionic equation if applicable:
a. Adding zinc metal to a solution of copper(II) sulfate
b. Dripping silver perchlorate into a solution of sodium carbonate
c. A lump of aluminum metal is dropped into concentrated hydroiodic acid
d. Sucrose is fermented in water by yeast to make ethanol and carbon dioxide (note: water is a reactant)
e. Solid calcium oxide is added to water (careful)
f. A lump of potassium metal is dropped into water (careful)
Answer:
Zn(s) + CuSO4(aq) -----> ZnSO4(aq) + Cu(s)
Na2CO3 (aq)+ 2AgClO4(aq) → 2NaClO4(aq) + Ag2CO3(s)
2Al(s) + 6HI(aq) ------> 2AlI3(aq) + 3H2(g)
C12H22O11(s)+H2O(l)→4C2H5OH(aq)+4CO2(g)
2K(s) + 2H2O(l) ------->2KOH(aq) + H2(g)
Explanation:
In the first reaction, zinc displaces copper from an aqueous copper II salt since zinc is higher than copper in the electrochemical series.
Reaction two leads to the precipitation of silver carbonate. Remember that carbonates are mostly insoluble in water.
Acids are known to displace hydrogen gas from dilute acids. Hence in the third reaction, aluminum displaced hydrogen from aqueous hydroiodic acid.
In the fourth reaction, the action of yeast leads to the fermentation of sucrose yielding ethanol and carbon dioxide in the process.
Metals are known to form aqueous alkaline solutions liberating hydrogen gas when they react with water. Hence potassium metal reacts with water to liberate hydrogen gas and form alkaline potassium hydroxide.
What do you need in order to do a stoichiometric calculation? (Choose
multiple)
Balanced Chemical Equation
Molar masses of compounds involved
The type of reaction taking place
Oxidation Numbers
Three examples of chemical reactions ????? PLEASE HELP
Answer:
Photosynthesis, Respiration, Combustion, Anaerobic Respiration
Explanation:
Im not 100% sure if this is what you are looking for but it should be correct. Hope this helps! :)
It is expected that US forests will
Answer:
be able to meet long term timber needs.
Explanation:
Forest Services has been indicated for a long time the exhaustion of timer in the United States. However, in the recent decade, this trend has shown a reverse. The creation of nuclear energy and other technological developments that bring about drastic changes in our way of life. Gradually, the forest has recovered its trees and plants, and it is anticipated that timber will be available to meet long-term wood needs.
Why would scientists use a control sample that is known to be from a
specific species in an eDNA surveillance for that species?
A. So they can have a negative control against samples
B. So they can cut sample DNA into fragments
C. So they can amplify the DNA in small samples
D. So they can identify samples that contain the target DNA
Answer:
Here is the answer...
Explanation:
Option A is used to control sample that is known to be form.
A chemistry journal requires that all new research papers be peer reviewed by other scientists before they are published. This
allows which of the following?
The reviewers can determine the experiment's feasibility
The reviewers can determine the experiment's validity
The reviewers can include their own findings with the research.
The reviewers can determine if they will help fund the research.
Answer:
I think its number 2
Explanation:
True or false. The kinetic energy of reactant particles has no effect on the reaction rate?
Answer:
false
Explanation:
If 100 ml of a 0.75 m hno3 is required to exactly neutralize 50 ml of naoh what is the concentration of the base?
Answer:
1.5M
Explanation:
M1V1=M2V2
(0.75M)(100ml)=(M2)(50 ml)
M2= 1.5 M
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Imagine designing an experiment in which the presence of a gas is determined by simply listening to the gas with your ear. The human ear can detect pressures as low as 2 x 10^-5 N*m^-2. Assuming that the eardrum has an area of roughly 1 mm^2, what is the minimum collisional rate that can be detected by ear? Assume that the gas of interest is N2 at 298 K.
Answer:
Explanation:
Pressure = Force/Area
so,
Force =Pressure x Area
Force =(2x 10⁻⁵ )N/M² x (1 x (10⁻³)² M²
Force = 2 x 10⁻¹¹N
as we know,
Force= mass x acceleration ( F=m.a)
a = F/m
a =(2 x 10⁻¹¹N)/28
g since 1 N=1.kg.m.s⁻²
a=(2 x 10-11kg.m.s⁻² )/(28 x 10⁻³kg)
a = 5.6 x 10-7 m.s⁻²
thus minimum collision rate that can be detected is 5.6 x 10-7 m.s⁻²At certain times during the process, the temperature increased. During these times, the heat that was absorbed took the form of energy in the water molecules. This process caused the molecules to .
At other times during the process, the temperature didn’t increase. During these times, the heat that was absorbed took the form of energy in the water molecules. This process caused the water molecules to .
Answer: kinetic, move faster, potential, change form
Explanation:
Answer: kinetic, move faster, potential, change state
Explanation: Edmentum
5. Which of the following is NOT a physical change?
nailing together boards of wood
breaking an egg
dying your hair
adding food coloring to water