Explanation:
Stars aren't visible during the sunlit hours of daytime because the light-scattering properties of our atmosphere spread sunlight across the sky. Seeing the dim light of a distant star in the blanket of photons from our Sun becomes as difficult as spotting a single snowflake in a blizzard. (put in your own words this is from online)
What mass of Ca(OH)2 will be used to make 45.6g of NaOH?
NaCl + Ca(OH)2 -> NaOH + CaCl2
2 NaOH+ CaCl2-> 2 NaCl+ Ca(OH)2
How many moles of NaPh are produced when 26.9 of NaCl are used?
How many moles of fluorine will be needed to produce 5.6 g of HF?
H2+F2-> HF
Answer is in a photo. I can only upload it to a file hosting service. link below!
bit.[tex]^{}[/tex]ly/3a8Nt8n
easy chem homework i will love u if u do it
Answer:
Explanation:
I don’t have calculator rn. So the answers u need to plug into the calculator by ur self.
7a) Mg has molar mass of 24.30g/mol
H=1.008g/mol
O=16.00g/mol
Total molar mass of Mg(OH)2= 24.30+(1.008+16.00)x2
b)41.3g/(the answer u got in a)
C)use number of moles u got in b times 6.02x10^23
8)got number of ones in 3.2x10^21 atoms of iron. 3.2x10^21/6.02x10^23
Then use mole u got times the molar mass of fe which is 55.45 g/mol to get the final answer
What is the molarity of a Sodium Chloride solution if 86.00g of NaCl was dissolved in enough water to form 1000.mL of solution?
Answer:
1.47 M
Explanation:
First we convert 86.00 g of NaCl into moles of NaCl, using the molar mass of NaCl:
86.00 g ÷ 58.44 g/mol = 1.472 mol NaClThen we convert 1000 mL into liters:
1000 mL / 1000 = 1.0 LFinally we can calculate the molarity of the solution:
Molarity = moles / liters1.472 mol / 1.0 L = 1.472 MWhen 565g of a metal with temperature of 90.00 C added to 200.0 g of water at 25.00 degrees. Assuming all the heat lost by the iron is transferred to the water ( specific heat capacity of water = 4/18 J/(g-C)), and the final temperature of the mixture is 34.40 degree Celsius what is the heat capacity of the metal?
Answer:
The specific heat is 0.25J/g°C
Explanation:
To solve this question we must know that the heat released for the metal is equal to the heat absorbed for the water. The equation is:
S(Metal)*m(Metal)*ΔT(metal) = S(water)*m(water)*ΔT(water)
Where S of metal is our incognite (Specific heat of metal)
m is the mass of the metal = 565g
ΔT is change in heat of the metal = 90.00°C - 34.40°C = 55.60°C
Specific heat of water = 4.18J/g°C
The mass of water = 200.0g
ΔT of water is 34.40°C - 25.00°C = 9.40°C
Replacing:
S(Metal)*565g*55.60°C = 4.18J/g°C*200.0g*9.40°C
S(metal) = 0.25J/g°C
The specific heat is 0.25J/g°C
HELP HELP HELP HELP!!!!!!!
Answer:
About 200 moles water
Explanation:
O2 is the limiting reactant, and it allows for 193.75 moles of water to be produced. Good luck on your assignment!
What is the mass of a 0.5 mol sample of C2H6?
Answer: 30.08 g/mol
Explanation:
C2= 12.01 H6=1.01
12.01(2) + 1.01(6) =
24.02 + 6.06 =
30.08 g/mol
Please help me! It’s past due but he giving me 15 mins!
Ametal added to gold to harden it ?
Answer:
copper
Explanation:
Copper is used as a base metal to mix with gold and to make it stronger, harder and less brittle in nature. It acts as the best alloy to make ornaments. Since the Silver layer gets easily oxidized in nature and gets easily corroded, copper remains the best choice as a metal to mix with Gold.
2NH3(g)+3CuO(s)= + 3H2O(I)+N2(g)
If a sample of 51.0g of ammonia's reacted with excess copper oxide, how many moles of nitrogen would be produced?
Answer:
1.50 mol N₂
Explanation:
Step 1: Write the balanced equation
2 NH₃(g) + 3 CuO(s) ⇒ 3 Cu + 3 H₂O(I) + N₂(g)
Step 2: Calculate the moles corresponding to 51.0 g of NH₃
The molar mass of NH₃ is 17.03 g/mol.
51.0 g × 1 mol/17.03 g = 2.99 mol
Step 3: Calculate the moles of N₂ produced from 2.99 moles of NH₃
The molar ratio of NH₃ to N₂is 2:1. The moles of N₂ produced are:
2.99 mol NH₃ × 1 mol N₂/2 mol NH₃ = 1.50 mol N₂
Consider an atom that has an electron in an excited state. The electron falls to a lower energy level. What effect does that have on the electron?
Answer:
On returning to lowest energy state which is stable, it releases energy in the form of light. Hence, option A that is the electron releases energy in the form of light on falling to lower energy state from excite state.
1)
Steel Wool Experiment
Before
Observations
After
Observations
Appearance
Steel wool dark gray,
Balloon deflated
Appearance
Steel wool dark
brown; Balloon
inflated
Mass (9)
485.68
Mass (9)
The students data can be seen here. A chemical reaction clearly took
place in the flask. One entry is missing: the mass of the system at the
end of the experiment. What amount should be added to the data
table?
Answer:
Chemical reactions, chemistry, science as inquiry and data analysis. ... Students burn steel wool in both an open and closed environment to understand ... The difference in mass for this small sample of steel wool will be very small. ... careful attention to the balloon! 9. When rusting occurs the properties of the metal changes.
Explanation:
As CaCl2 dissolves in water, and warms the solution,
a. delta H is positive, and delta S is negative
b. delta H is negative, and delta S is negative
c. delta H is negative, and delta S is positive
d. delta H is positive, and delta S is positive
As [tex]CaCl_{2}[/tex] dissolves in water, and warms the solution, delta H is negative, and delta S is positive.
What are exothermic and endothermic reactions?Chemical reactions that release energy are called exothermic. In exothermic reactions, more energy is released when the bonds are formed in the products which is used to break the bonds in the reactants. Chemical reactions that absorb (or use) energy are called endothermic.
The dissociation of [tex]CaCl_{2}[/tex] in water is
[tex]CaCl_{2}+H_{2}O(l)=Ca_{++}+2Cl_{-}+H_{2}O(l)[/tex]
As the solution is warm, change in Enthalpy is exothermic ΔH < 0.
(ΔH is negative, so the dissociation is exothermic).
As there are produced 2 ions from 1 solid molecule, the disorder is increasing and ΔS > 0
Hence, option C is correct.
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What is the meaning of a null hypothesis being rejected?
The hypothesis is definitely correct.
The hypothesis might be correct.
The hypothesis is false.
The null hypothesis is correct.
Answer:
the hypothesis is false
Explanation:
it I rejected because the hypothesis has been tested severally and the answer still proves to be wrong
Answer:
probably the third option: The hypothesis is false
Explanation:
What combinations of up and down did quarks combine to make the proton?
A. Down + down + down
B. Up+Up+ down
C. Up+Up+Up
D. Up+down+down
E. Up+down
Answer:
it is b
Explanation:
b is the quarks for a proton
Answer:
B
Explanation:
Oxygen has a total of 8 electrons, does that satisfy the octet rule? Explain why or why not.
Answer:
No
Explanation:
The first 2 electrons are in the inner shell, and the other 6 are valence electrons. Oxygen needs 2 more electrons to fill its valence shell and satisfy the octet rule.
Consider these two entries from a fictional table of standard reduction potentials.
X3++3e−⟶X(s)o=−2.11 V
Y3++3e−⟶Y(s)o=−0.22 V
What is the standard potential of a galvanic (voltaic) cell where X is the anode and Y is the cathode?
ocell=
V
Answer:
1.89 V
Explanation:
To calculate the standard cell potential, subtract the reduction potential of the anode from the reduction potential of the cathode.
So for your calculation,
-0.22 V - (-2.11 V)= 1.89 V
In the voltaic cell, current is produced by a sponteanous chemical reaction. The standard cell potential here is 1.89 V.
What is a voltaic cell?A voltaic cell is a cell that produces current by a sponteanous chemical reaction. We are told here that X is the anode and Y is the cathode.
Now;
E°cell = E°cathode - E°anode
E°cell = (−0.22 V) - (−2.11 V) = 1.89 V
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How much heat will be absorbed when 38.2 g of bromine reacts with 12.4g of hydrogen according to the following equation?
H2 + Br2 + 72.80 = 2HBr
Answer:
17.4 kJ
Explanation:
Pls help :( <3333333
Answer:
Option CExplanation:
Look here,
3CuCl2 + 2Al --> 2AlCl3 + 3Cu
On
LHS = 3Cu , 3 × Cl2 = 6Cl and 2Al
RHS = 2Al , 2 × Cl3 = 6Cl and 3Cu
Hence,
LHS = RHS and the above equation is balanced
1.35 m solution NaOCl in water is prepared. What is the mole fraction of the NaOCl?
Answer:
NaOCl + H2O → HOCl + NaOH
so the mole fraction is = moles of NaOCl/(moles of NaOCl+moles of H2O)
so for 1.35 NaOCl it will require 1.35 moleof H2O
mole fraction = 1.35/(1.35+1.35)
mole fraction = 1/2 =0.5
is it correct i d ek but i tried :)
The mole fraction of the NaOCl is 0.0237
We'll begin by calculating the mole of solute (NaOCl) in the solution.
Molality = 1.35 mMass of water = 1 KgMole of NaOCl =?Mole = Molality x mass (Kg) of water
Mole of NaOCl = 1.35 × 1
Mole of NaOCl = 1.35 mole
Next, we shall determine the mole of water.
Mass of water = 1 Kg = 1000 gMolar mass of water = 18.01 g/mol Mole of water =?Mole = mass / molar mass
Mole of water = 1000 / 18.01
Mole of water = 55.52 moles
Finally, we shall determine the mole fraction of NaOCl.
Mole of NaOCl = 1.35 moleMole of water = 55.52 moles Total mole = 1.35 + 55.52 = 56.87 moles Mole fraction of NaOCl =?Mole fraction = mole / total mole
Mole fraction of NaOCl = 1.35 / 56.87
Mole fraction of NaOCl = 0.0237
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Whose ideas were based on scientifically gathered evidence?
A. Aristotle and alchemists
B. Aristotle and John Dalton
C. John Dalton and Marie Curie
D. Marie Curie and alchemists
Answer:
Maybe c?
Explanation:
John Dalton was an English chemist, and Marie Curie was a physicist and chemist. The ideas of John Dalton and Marie Curie were based on scientifically gathered evidence. Thus, option C is correct.
Who are John Dalton and Marie Curie?John Dalton and Marie Curie are famous physicists and chemists. John Dalton is most known for introducing the theory of the atom and color blindness. He gave the theory of atomism based on the experimental setup.
Marie curie hugely contributed to the discovery of radioactivity and cancer research. She and her husband experimented and searched for the radioactive material.
Aristotle was a philosopher and established the relation between the various fields of sciences. He originated the idea of Alchemy by combining the four elements.
Therefore, John Dalton and Marie Curie proposed ideas based on research.
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Chlorine gas is added to a large flask to a pressure of 1.85 atm, at a temperature of 322 K. Phosphorus is added, and a reaction takes place using all of the Cl2 gas. When the reaction is complete, the yield of PCl5 is measured at 118 grams. Calculate the Volume of the flask (in Liters): g
Answer:
The volume of the flask is 20.245 litres .
Explanation:
We are given with following information-
[tex]PV=nRT[/tex] -------- 1
where R =[tex]0.0821L.atom/mole.K[/tex]
Molar mass of [tex]PCl_5=208.22g/mole[/tex]
The given chemical equation is -
[tex]2P _(_s_)+5Cl_2 _(_g_)\rightarrow2PCl_5 _(_s_)[/tex] --------- 2
Now , calculation -
Mass of [tex]PCl_5[/tex] formed = 118g
Molar mass of [tex]PCl_5[/tex] = [tex]208.22g/mole[/tex]
Mole = [tex]\frac{mass (g)}{molar mass}[/tex]
Therefore , moles of [tex]PCl_5[/tex] formed = [tex]\frac{118}{208.22}[/tex]
From equation 2 , we get to know that ,
2mole [tex]PCl_5[/tex] formed from 5 mole [tex]Cl_2 _(_g_)[/tex]
Therefore , [tex]\frac{118}{208.22}[/tex] mole [tex]PCl_5[/tex] formed from [tex]\frac{5}{2} \times\frac{118}{208.22}[/tex] mole [tex]Cl_2 _(_g_)[/tex]
Moles of [tex]Cl_2 _(_g_)[/tex] used =[tex]\frac{5\times118}{2\times208.22} mole[/tex]
R= [tex]0.0821L.atom/mole.K[/tex]
Pressure (P)= 1.85atm
Temperature (T)= 322K
Moles of [tex]Cl_2 _(_g_)[/tex] (n)= [tex]\frac{5}{2} \times\frac{118}{208.22}[/tex] moles
Applying the formula above in 1 equation , that is
PV = nRT
putting the given values -
[tex]1.85 \times V=\frac{5}{2} \times\frac{118}{208.22}\times0.0821\times322[/tex]
V = 20.245 litres.
Hence , the volume of the flask is 20.245 litres .
help help help help
Answer:
2,4,6–trimethylheptanal
Explanation:
To name the compound given, we must first obtain the following:
1. Determine the functional group of the compound.
2. Determine the longest continuous carbon chain. This gives the parent name of the compound.
3. Identify the substituent group attached to the compound.
4. Locate the position of the substituent group.
5. Combine the above to obtain the name of the compound.
Now, we shall name the compound as follow:
1. The functional group of the compound is –CHO. Thus, the compound is an alkanal.
2. The longest continuous carbon chain is 7. Thus, the parent of the compound is heptanal.
3. The substituent group attached to the compound is methyl (–CH₃).
NOTE: There are 3 methyl groups attached to the compound.
4. The methyl groups attached to compound are located at carbon 2, 4 and 6.
5. Therefore, the name of the compound is:
2,4,6–trimethylheptanal
PLZ HELP I WILL GIVE BRAINLIEST!!!
The light is most intense where it strikes Earth ___________ to its surface.
Answer:
the sun's Rays strike Earth surface most directly at the Equator this focuses the race on a small area because be raised hit more directly the area is heated more
Explanation:
yw
20 POINTS PLEASE ANSWER
In the following reaction, if you wanted to produce more hydrochloric acid (HCl), what should you do? (2 points)
4HCl + O2 ⇄ 2H2O + Cl2
Select one:
a. Add more H2O
b. Add more O2
c. Remove H2O
d. Remove Cl2
Answer:
Add more H2O
Explanation:
Is photosynthesis endothermic or exothermic, why?
A. Endothermoc, energy is needed to oxidize water so it can eventually be stored in sugars. Free energy is temperature dependent.
B. Exothermic, energy is needed to oxide water so it can eventually be stored in sugars. Free energy is not temperature dependent.
C. Endothermic, energy is needed to oxidize water so it can eventually be stored in sugars. Free energy is not temperature dependent.
D. Exothermic, energy is needed to reduce water so it can eventually be stored in sugars.
E. Exothermic, energy is needed to oxidize water so it can eventually be stored in sugars.
F. Exothermic, energy is needed to oxidize water so it can eventually be stored in sugars. Free energy is temperature dependent.
G. Endothermic, energy is needed to reduce water so it can eventually be stored in sugars.
Answer: I think A is right
Explanation: Photosynthesis needs light so it is endothermic,
Oxygen in water is oxidised and Oxygen is released in process.
Free energy is temperature dependent. But also Carbo dioxide
involves reaction. You needs to find out Calvin-Benson cycle
Someone please help !!!!!
Sodium chromate can be prepared by oxidizing a chromium(III) salt with sodium peroxide in alkaline
solution. The chromium(III) ions are oxidized to chromate ions. The peroxide ions are reduced to hydroxide
ions. Write down unbalanced half reaction equations and a balanced overall equation for the reaction.
The physical states of all the reagents and products must be shown throughout.
Here's link to the answer:
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PLEASE HELP !! ILL GIVE BRAINLIEST !! 100 POINTS
IF YOU KNOW CHEMISTRY OR BIOLOGY
An unknown amount of gold was being polished in a hot bath that had an
initial temperature of 471 °C. This caused the gold to absorb 7640 J of
heat. After some time the water temperature was found to be 24 °C. Find
the unknown mass of the gold.Specific heat
Copper. 0.385 J/g x C
Aluminum. 0.902 J/g x C
Iron. 0.450 J/g x C
Gold. 0.129 J/g x C
A.132.5 g
B.2467.7 g
C.125.7 g
D.1725.8 g
what blood vessels and chambers of the heart does a red blood cell pass as it delivers oxygen from the lungs to the brain and return to be oxygenated again.
Answer:
capillaries
Explanation:
hope it helps if I'm not tell me right away.
Answer:
Carotid artery, Jugular veins
The chambers are explained below.
Explanation:
THE BLOOD VESSELS
The carotid artery carries red blood (oxygenated) to the head and the neck region and that obviously include the brain via the aorta. To be precise the internal carotid artery supplies oxygenated red blood cells to brain. The jugular veins carry deoxygenated red blood cells from the head back to the heart via the superior vena cava. The most important function of the jugular vein is to drain deoxygenated blood from brain.
THE CHAMBERS
The left atrium receives oxygenated blood from the lungs and pumps it to the left ventricle which also pumps the same oxygenated blood to the rest of the body through the aortic valve (aorta).
The right atrium receives deoxygenated blood from the body via the vena cava and pumps the deoxygenated blood to the right ventricle which pumps the deoxygenated blood to be oxygenated by the lungs via the pulmonary valve (pulmonary artery).
CONCLUSION
The oxygenated red blood cells from the lung pass through the pulmonary vein through the left atrium to the left ventricle through the carotid artery (internal carotid artery) via the aorta to the brain and
The deoxygenated red blood cells in the brain are drained through the jugular vein via the superior vena cava to the right atrium, which pumps the deoxygenated blood to the right ventricle. From here the deoxygenated blood is pumped to the lungs via the pulmonary artery for oxygenation.
This is my answer, thus if I got your question right.
Which best explains why ionization energy tends to decrease from the top to the bottom of a group? The number of orbitals decreases. The number of neutrons decreases. Electrons get closer to the nucleus. Electrons get farther from the nucleus.
Answer:
Electrons get farther from the nucleus.
Explanation:
By going from the top to the bottom of a group, the atomic number increases. That would mean that:
The number of orbitals increases, as there are more electrons.A higher atomic number implies an increasing number of neutrons.As there are more electrons, they get farther from the nucleus. The farther an electron is from the nucleus, the easier it is for the electron to be removed from the atom.Ionization energy decreases down the group because electrons get farther from the nucleus hence they are easier to remove.
Ionization energy refers to the energy required to remove an electron from an atom. The ionization energy is a periodic trend that decreases down the group but increases across the period.
The ionization energy decreases down the group because electrons get farther from the nucleus hence they are easier to remove.
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