Answer: The energy of a photon with a wavelength of 820 nm is [tex]2.42 \times 10^{-19} m[/tex].
Explanation:
Given : Wavelength = 820 nm
Convert nm into meter as follows.
[tex]1 nm = 10^{-9}\\So, 820 nm = 820 nm \times \frac{10^{-9} nm}{1 nm}\\= 820 \times 10^{-9} m[/tex]
The relation between energy and wavelength is as follows.
[tex]E = \frac{hc}{\lambda}[/tex]
where,
E = energy
h = Planck's constant = [tex]6.63 \times 10^{-34} kg m^{2}/s[/tex]
c = speed of light = [tex]3.0 \times 10^{8} m/s[/tex]
[tex]\lambda[/tex] = wavelength
Substitute the values into above formula as follows.
[tex]E = \frac{hc}{\lambda}\\= \frac{6.63 \times 10^{-34} kg m^{2}/s \times 3.0 \times 10^{8} m/s}{820 \times 10^{-9} m}\\= \frac{1.989 \times 10^{-25}}{820 \times 10^{-9}}\\= 2.42 \times 10^{-19} m[/tex]
Thus, we can conclude that energy of a photon with a wavelength of 820 nm is [tex]2.42 \times 10^{-19} m[/tex].
Identify the acid, base, and salt in the following reaction
HNO3 + KOH —> H2O + KNO3
Explanation:
acid ,HNO3
base,KOH
salt ,KNO3
How many milliliters of a 3.28 M copper (II) nitrate Cu(NO3)2
solution are needed to provide a total of 146.59 g of Cu(NO3)2?
Use 187.56 g/mol as the molar mass of solute. Solve your answer
to two decimal places.
Answer:
237.80mL
Explanation:
Molarity of a solution can be calculated using the formula;
Molarity = number of moles (n) ÷ volume (V)
However, we first need to calculate the number of moles of Cu(NO3)2 by using the formula:
moles = mass/molar mass
Molar mass of Cu(NO3)2 = 187.56 g/mol
moles = 146.59 ÷ 187.56
moles = 0.782moles
Molarity = n/V
3.28 = 0.78/V
V = 0.78/3.28
V = 0.2378L
In milliliters (mL), 0.24 litres = 0.24 × 1000
= 237.80mL
ionic bounds are quite weak and will break easily? T or F
Answer:
False
Explanation:
Ionic bonds are actually strong, but unfortunately can be broken easily
IF the heat involved in a chemical reaction has a positive sign,
Answer: more explaintion
Explanation:
how many grams of chromium are needed to react with of cuso4 to produce 10.2g cu
Answer:
14.7 g of chromium
Explanation:
4 Weathering Assessment
2 of 132 of 13 Items
Question
POSSIBLE POINTS: 5.88
On a hot summer day, you and your friend decide to make a drink by mixing ice cubes, water, sugar, and Kool-Aid mix. Which of the following statements best describes what type of change has occurred?
This is an example of chemical change because the sugar dissolved.
This is an example of chemical change because the sugar dissolved.
This is an example of a physical change because the sugar dissolved
This is an example of a physical change because the sugar dissolved
This is an example of a physical change because the ice cubes began to melt.
This is an example of a physical change because the ice cubes began to melt.
This is an example of a chemical change because the Kool-aid dissolved and turned the water red.
Answer:
This is an example of a physical change because the ice cubes began to melt.
This is an example of a physical change because the ice cubes began to melt.
Explanation:
The above is the right answer to the question about the dissolution of the whole mixture mentioned in the excerpts above.
How does weather impacts our lives
Answer:
Weather affects us in a huge number of ways. Climate influences the growth of crops, thus affecting the availability and kind of food we eat. Fluctuations in weather (e.g. dry spells, wet spells) also affect crops. Weather affects what clothes we wear.
Explanation:
The outermost layers of the Earth are warm compared to the Earth's core.
[ ]False
[ ]True
Answer:
I am not sure this one is False.
Explanation:
Answer:
False
Explanation:
This is false because the outer part of earth is cooler than the inner. For example, the inner is filled with lava, and all kinds of stuff, so this is technically saying that the outer is much cooler, It has dirt, and dirt can be cool.
Phosphoric acid is delivered to a drinks factory in
concentrated form. Why do you think the acid is not
diluted before transporting it?
Answer:
Because it might be reactive or may lose its property in liquid form..
With the dilution of phosphoric acid, its volume will increase. To avoid the transport cost the acid might not be diluted before transporting.
What is the food additive?
Food additives are the chemicals that are used in food products, that prevent food from spoiling due to bacterial growth.
Food additives are a kind of food preservative that is added to food products to prevent spoilage and retain their nutritional value for a long time. These additives inhibit microbial growth in food.
Different types of food additives are preservatives, nutrients, sweeteners, flavoring agents, antioxidants, and colorants.
Phosphoric acid acts as a preservative and prevents the growth of mold and bacteria in foods with sugary solutions. This increases the shelf life of that beverage and improves affordability.
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Please help, I'm so confused!!!!
Answer:
[tex]\boxed {\boxed {\sf N_2}}[/tex]
Explanation:
Let's examine this reaction, especially the coefficients.
[tex]N_2+3H_2 \rightarrow 2NH_3[/tex]
First of all, remember that reactants are used to make the product. They are found on the left of the arrow usually. Therefore, N₂ and H₂ are the reactants, while NH₃ is the product. We can automatically eliminate NH₃ from our answer choices, because it is simply not a reactant.
Next, look at the coefficients.
N₂ has no coefficient, so a 1 is implied. H₂ has a coefficient of 3.Therefore, for the reaction to work, there must be 1 mole of N₂ and 3 moles of H₂.
We have 3.2 moles of N₂ and 5.4 moles of H₂.
Divide each amount given by the required amount for completion.
3.2 mol N₂/ 1 mol N₂= 3.2 times 5.4 mol H₂/ 3 mol H₂=1.8 timesTherefore, there is enough nitrogen to complete the reaction 3.2 times, but only enough hydrogen for 1.8 times. If everything is completely reacted, we will run out of hydrogen and have excess nitrogen.
Which one of the equations below is an exothermic reaction?
A) CO2 (g) - C(s) + O2 (g) AH = 394 kJ/mol
B) CaO (s) + H2O (D = Ca(OH)2 (aq) AH = -64
kJ/mol
C) C (s) + 2 F2 (g) - CF. (9) AH = 141.3
kJ/mol
2 NO (9) AH° = 180.6
D) N2 (g) + O2 (9)
kJ/mol
Answer:
B) CaO(s) + H2O(l) --> Ca(OH)2(aq)
Explanation:
This is the only reaction with a negative enthalpy value. Exothermic reactions have a negative enthalpy.
What final temperature will be attained by a 250. g sample of Cu at 20.0oC if it absorbs 1000 J of heat? Cu 's c = 0.39 J/(g oC
Answer:
30.26 °C
Explanation:
From the question,
Q = cm(t₂-t₁)................ Equation 1
Where Q = Heat, c = specific heat capacity of Cu, m = mass of Cu, t₁ = Initial temperature, t₂ = Final temperature.
Given: Q = 1000 J, c = 0.39 J/g.°C, t₁ = 20°C, m = 250 g
Substitute into equation 1 and solve for t₂
1000 = 250×0.39(t₂-20)
250×0.39(t₂-20) = 1000
97.5(t₂-20) = 1000
(t₂-20) = 1000/97.6
(t₂-20) = 10.26
t₂ = 10.26+20
t₂ = 30.26 °C
Why can water birds drown if they still have detergent on their feathers?
A student transfers a gas at STP from a 11.0 L tank to a 25.0 L tank. If the pressure
remains constant, what is the new temperature?
. Consider a sample of oxygen gas at 27° C with a volume of 9.55L at a pressure
Answer:620 k
Explanation:
Please help!! I have 10 minutes left!!
Explanation:
1 is a process that occurs when gases in earth's atmosphere trap the sun's heat .
2 . heat in the atmosphere to warm the planet .
I only know the first too sorry ✨
How many grams in 4.5 moles of H2O?
the are 18.01528 grams
.....
How many moles are in 3.25 x 1025 molecules of H2O?
Answer:
[tex]27.72 g[/tex]
Explanation:
The relationship between the number of particles and the number of mole of a substance is given by the equation N = n L ; where N is the number of particles, n is the number of mole, and L is Avogadro's constant.
You use 50.00 mL of a 12.0 M solution of HCl solution to make a 500.00 mL solution. What is the concentration of the new solution? *
Answer:
1.2 M
Explanation:
If you use the dilution equation (M1V1=M2V2), you end up with (50)(12)=(500)(M2), and when you solve for M2 you get 1.2 M.
How
many
moles of water are produced from 12.8 moles of oxygen?
with work
Answer:
12.8 moles
Explanation:
The formula for water is H2O, so for every mole of water, there are two moles of hydrogen and one mole of oxygen.
As the ratio of oxygen particles to water particles is one to one, 12.8 moles of oxygen are required to produce 12.8 moles of water.
Therefore, 12.8 moles of water are produced from 12.8 moles of oxygen (assuming hydrogen is available in excess).
10. How many moles of glucose are in 0.5L of a 0.138M solution of glucose in
water?
Answer:
0.069 moles of glucose
Explanation:
(0.138 mol/L)(0.5 L) = 0.069 moles of glucose
Answer:
[tex]\boxed {\boxed {\sf 0.069 \ mol \ C_6H_12O_6}}[/tex]
Explanation:
Molarity is the moles per liter of a solution. It is found by dividing the moles of solute (glucose) by the liters of solution (water).
[tex]M= \frac {moles}{liters}[/tex]
We know the molarity is 0.138 M. 1 M is equal to 1 mole per liter, so we can rewrite the molarity as 0.138 moles per liter.
There are 0.5 liters of solution.
We are solving for the moles, so we can use x.
[tex]0.138 \ mol/L= \frac {x }{0.5 \ L}[/tex]
We must isolate the variable (x) to solve for the moles. It is being divided by 0.5 liters. The inverse operation of division is multiplication. Multiply both sides of the equation by 0.5 L.
[tex]0.5 \ L *0.138 \ mol/L= \frac {x }{0.5 \ L}* 0.5 \ L[/tex]
The liters on both sides cancel.
[tex]0.5 *0.138 \ mol= {x }[/tex]
[tex]0.069 \ mol =x[/tex]
[tex]0.069 \ mol \ C_6H_12O_6[/tex]
Ther are 0.069 moles of glucose in a 0.138 M solution with 0.5 liters of water.
9) What is the density of the gold rock with a mass of 386 grams and has a volume of 20 cubic centimeters?
O 0.193 g/cc
O 193 g/cc
O 1.93 g/cc
19.3 g/cc
Answer:
density= mass/volume
hence density of gold rock
= 386/20
=19.3 g/cc
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Write a scientific explanation that explains how organelles perform specific tasks within cells.
USE CER (Claim Evidence Reasoning)
Answer:
Some of these parts, called organelles, are specialized structures that perform certain tasks within the cell. ... It also provides a track-like system that directs the movement of organelles and other substances within cells. Endoplasmic reticulum (ER) This organelle helps process molecules created by the cell
Organelles perform specific tasks within the cells such as protein synthesis, energy production, etc.
Organelles are specialized structures that perform different functions in the cells. Examples of organelles include lysosome, nucleus, chloroplast, mitochondria, endoplasmic reticulum, etc.
It should be noted that every cell process is done in a particular location in the cell. Some of the functions that are performed by the organelle include processing of food and waste, protein synthesis, energy production, replication, etc.
For example, the nucleus is used for the storage of DNA, mitochondria is vital for energy production, the ribosome is necessary for protein synthesis, etc.
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How many atoms is 500.0 moles of pure gold?
Answer:
2.5385 mol
Explanation:
do a quick conversion : 1 grams gold = 0.0050770041918285 mole using ...powered by AnyClip. 1 ... 500 grams gold to mol = 2.5385 mol
The volume and amount of aflium gas remains constant.
Under these conditions, aflium gas has an initial pressure of
635 torr when it is at 67.0°C. What is the new temperature if
the pressure drops to 250 torr?
Answer:
133.85 K
Explanation:
Initial pressure, P₁ = 635 torr
Initial temperature, T₁ = 67.0°C = 340 K
Final pressure, P₂ = 250 torr
We need to find the new temperature. The relation between temperature and pressure is given by :
[tex]\dfrac{P_1}{T_1}=\dfrac{P_2}{T_2}\\\\T_2=\dfrac{P_2T_1}{P_1}\\\\T_2=\dfrac{250\times 340}{635}\\\\T_2=133.85\ K[/tex]
So, the new temperature is equal to 133.85 K.
Answer all of these questions about the molecule glucose in order
i. the name of the molecule.
ii. the names of the different atoms that make up the molecule, and the color you chose for each of them.
iii. the state of the molecule (i.e., solid, liquid, or gas).
iv. any units of the molecule that repeat.
v. the type of bonds in the molecule, based on the molecule’s chemical formula.
vi. the characteristics of the substance, based on whether it is an ionic compound or a covalent compound (you may need to do additional research to find this information).
What is the specific heat of ethanol if 4650 j are required to raise the temperature of 250.0g of ethanol from 22.0oc to 29.6 degrees Celsius
Answer:
[tex]C=2.45\frac{J}{g\°C}[/tex]
Explanation:
Hello there!
In this case, since the thermodynamic definition of heat in terms of mass, specific heat and temperatures is given by:
[tex]Q=mC(T_2-T_1)[/tex]
We are to calculate the specific heat of the ethanol as shown below:
[tex]C=\frac{Q}{m(T_2-T_1)}[/tex]
Thus, by plugging it the given data we can obtain:
[tex]C=\frac{4650J}{250.0g(29.6-22.00\°C)} \\\\C=2.45\frac{J}{g\°C}[/tex]
Regards!
3. Determine the pH of each of the following solutions. (Hint: See Sample Problem B.) a. 1.0 x 10-2 M HCI c. 1.0 x 10-MHI b. 1.0 x 10-3 M HNO3 d. 1.0 x 10-M HB
Answer:
a. pH = 2 b. pH = 3 c. pH = 1 d. Unanswerable
Explanation:
pH = -log[H+] OR pH = -log{H3O+]
and inversely
pOH = -log[OH-]
1. Determine what substance you are working with, (acid/base)
2. Determine whether or not that acid or base is strong or weak.
a. 1.0 x 10^-2M HCl
HCl is a strong acid, therefore it will dissociate completely into H+ and Cl- with all ions going to the H+, therefore, the concentration of HCl and concentration of H+ are going to be equal, meaning we simply take the negative logarithm of the concentration of HCl and that would equal pH
pH = -log[H+]
pH = -log(1.0x10^-2)
pH = 2
b. 1.0 x 10^-3M HNO3
HNO3 like part a, is a strong acid, therefore it would simply require you to take the negative logarithm of the concentration of the compound itself, to find its pH.
pH = -log[H+]
pH = -log(1.0 x 10^-3)
pH = 3
c. 1.0 x 10^-1M HI
Like the previous parts, HI is a strong acid
pH = -log[H+]
pH = -log(0.10)
pH = 1
d. HB isn't an element, nor is it a compound so that would be unanswerable.
URGENT PLS I NEED THIS OR I WILL FAIL AND HAVE TO DO SUMMER SCHOOL
Carbon monoxide gas and oxygen gas combine to form carbon dioxide
gas in the following equation:
2CO(g) + O2(g) → 2CO2(g)
The enthalpy value for gaseous carbon monoxide is -110.5, and gaseous
carbon dioxide is -393.5, calculate the enthalpy change (AH) for the
reaction.
Answer:
ΔHr = -566kJ/mol
Explanation:
Based on Hess's law, the ΔH of a reaction is the sum of the ΔH's of products times its coefficient subtracting the ΔH of reactants. For the reaction:
2CO(g) + O2(g) → 2CO2(g)
ΔH is:
ΔHr = 2*ΔH CO2 - (2ΔH CO + ΔH O2)
As ΔH CO2 = -393.5kJ/mol; ΔH CO = -110.5kJ/mol and ΔH O2 = 0kJ/mol
ΔHr = 2*-393.5kJ/mol - (2*-110.5kJ/mol)
ΔHr = -566kJ/molThe compound calcium carbonate contains the calcium ion (Ca2+) and the polyatomic carbonate ion (CO32-). Explain why calcium carbonate is considered to be an ionic compound when it contains both ionic and covalent bonds.
Answer:
Because of the electronegativity difference C-O (covalent) and Ca-O (ionic) bonds have.
Explanation:
Hello there!
In this case, in order to understand the polarity of this compound, calcium carbonate, it firstly necessary that it is comes from the definition of electronegativity, as a property defining the capacity to attract electrons from another atom; thus, since the electronegativities of calcium, carbon an oxygen are 1.0, 2.55 and 3.44, it is possible to realize this compound has O-Ca and O-C bonds according to its Lewis dot structure. In such a way, we calculate the difference electronegativity for these two bonds:
[tex]\Delta E_{O-Ca}=3.44-1.0 = 2.44\\\\\Delta E_{O-C}=3.44-2.55=0.89[/tex]
Thus, since 2.44 accounts for an ionic bond and 0.89 for a covalent one, we bear out the given statement in the question.