True or false: to get 8 valence electrons, oxygen can borrow or share some electrons
Answer:
True
Explanation:
In ionic compounds, oxygen borrows electrons. In covalent compounds, oxygen shares electrons.
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:
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
Indicate whether the following processes are spontaneous or nonspontaneous. (a) Liquid water freezing at a temperature below its freezing point (b) Liquid water freezing at a temperature above its freezing point (c) The combustion of gasoline (d) A ball thrown into the air (e) A raindrop falling to the ground (f) Iron rusting in a moist atmosphere
Answer:
The correct answer is -
(a) spontaneous;
(b) nonspontaneous;
(c) spontaneous;
(d) nonspontaneous;
(e) spontaneous;
(f) spontaneous
Explanation:
(a) Liquid water freezing at a temperature below its freezing point.
in this reaction, there is no requirement of external energy or force to make it possible due to the fact that the temperature of the environment is less than the freezing point of water. So, the water will spontaneously freeze.
(b) Liquid water freezing at a temperature above its freezing point. the melting of ice takes place with the increase or absorbing the heat which is a nonspontaneous,
(c) The combustion of gasoline produces gas molecules, and release energy which means it is an exothermic reaction, the combustion of gasoline is a spontaneous reaction.
(d) A ball is thrown into the air is not a natural process and it requires force or energy to be complete and works against gravity, Therefore, it is a nonspontaneous reaction.
(e) A raindrop falling to the ground is a naturally occurring reaction without any external force and in the direction of gravity, thus it is a spontaneous reaction.
(f) Iron rusting in a moist atmosphere is a spontaneous reaction as it does not require energy to occur and it naturally takes place. It is a redox reaction.
What is 1 x 102 divided by 1 x 10-3?
O 1x 10-6
O 1x 10-1
0 1x 103
O 1 x 105
Answer:
Option (d) is correct.
Explanation:
Let [tex]x=10^2[/tex] and [tex]y=10^{-3}[/tex].
We need to find the value of [tex]\dfrac{x}{y}[/tex].
Put the values of x and y such that,
[tex]\dfrac{x}{y}=\dfrac{10^2}{10^{-3}}\\\\=10^2\times 10^3\ (As\ \dfrac{1}{x^{-a}}=x^a)\\\\=10^5\ (As\ x^a\times x^b=x^{ab})\\\\=1\times 10^5[/tex]
So, the required answer is equal to [tex]1\times 10^5[/tex]. Hence, the correct option is (d).
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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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.
Sruthi accidentally poured salt into the lemonade she was making instead of sugar. Can Sruthi remove all the salt by pouring it through a filter? Explain why or why not. 2 marks need answers ASAP, I'll mark brainliest if correct.
Answer:
Yes you can!
Explanation: Here is one method i did in school you can put a cup of the salted lemonade into a big container seal it off and put plastic inside heat it up and the water will evaporate and leak from the sides while the salt will stay in the cup. Pls give me brainliest
How many molecules are in 0.500 mol of AlBr3
.500 mol ( 6.02x10^23 molecules/1 mol) = 3.01x10^23
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:
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
Which of the following has to remain constant to allow you to use the combined gas law for calculations?
O A pressure
ОВ.
volume
Oc.
temperature
OD.
amount of gas
Answer:
Amount of gas
Explanation:
The combined gas law has to do with pressure, volume, and temperature. All of them can be a variable that you have to solve for. However, amount of gas is not a variable you can solve for, which means it must remain constant.
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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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:
When you draw a bow'across a violin string, which kind of wave is created in
the air surrounding the string?
A. surface
B. electromagnetic
C. longitudinal
D. Transverse
Answer:
C
Explanation:
Answer: C. Longitudinal
Explanation: A P 3 X
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:
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
#1 pls help me complete
Answer:
n = 0.045 mol.
Explanation:
Hello there!
In this case, according to the given problem, we can firstly set up the ideal gas equation as shown below:
[tex]PV=nRT[/tex]
Thus, as we are asked to calculate the moles, we proceed as follows:
[tex]n=\frac{PV}{RT}[/tex]
Therefore, we plug in the given data to obtain:
[tex]n=\frac{760mmHg*\frac{1atm}{760mmHg}*1.0L}{0.08206\frac{atm*L}{mol*K}*273K} \\\\n=0.045mol[/tex]
Best regards!
The petrol additive tetraethyl-lead (IV), Pb(C2H3)4, is now
banned in many countries. When it is completely burned in air,
lead (II) oxide, CO, and H2O are formed. How many moles of
oxygen are required to burn one mole of Pb(C2H5)?
Answer:
9.5 mol
Explanation:
Let's consider the unbalanced equation for the combustion of tetraethyl-lead (IV).
Pb(C₂H₅)₄ + O₂ ⇒ PbO + CO + H₂O
Pb atoms are balanced. We will balance C atoms by multiplying CO by 8.
Pb(C₂H₅)₄ + O₂ ⇒ PbO + 8 CO + H₂O
Then, we will balance H atoms by multiplying H₂O by 10.
Pb(C₂H₅)₄ + O₂ ⇒ PbO + 8 CO + 10 H₂O
Finally, we get the balanced equation by multiplying O₂ by 9.5.
Pb(C₂H₅)₄ + 9.5 O₂ ⇒ PbO + 8 CO + 10 H₂O
All in all, we need 9.5 moles of O₂ to burn 1 mole of Pb(C₂H₅)₄.
Please help me! It’s past due but he giving me 15 mins!
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:
bit.[tex]^{}[/tex]ly/3a8Nt8n
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:
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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When 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
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
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.
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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i If a chemical system is at equilibrium, any change in the system will always result in an increase of which of the following?
1.The reaction that opposes the change
2. The concentration of the product
3. The concentration of the reactants
4. The temperature of the system
Answer:
1.The reaction that opposes the change
Explanation:
Consider the reaction;
A + B ⇄ C + D
If a constraint such as a change in temperature, pressure or volume is imposed on this chemical system in dynamic equilibrium, the equilibrium position will shift so as to annul the constraint.
This shift in the equilibrium position will favour either the forward or reverse reaction depending on the type of constraint imposed on the system.
Hence, If a chemical system is at equilibrium, any change in the system will always result in an increase of the reaction that opposes the change.
If have a volume of 18 L of a gas at a temperature of 272 K and a pressure of 90 atm, what will be the pressure of the gas if raise the temperature to 274 Kand decrease the volume to 12 L?
Answer:
P₂ ≅ 100 atm (1 sig. fig. based on the given value of P₁ = 90 atm)
Explanation:
Given:
P₁ = 90 atm P₂ = ?
V₁ = 18 Liters(L) L₂ = 12 Liters(L)
=> decrease volume => increase pressure
=> volume ratio that will increase 90 atm is (18L/12L)
T₁ = 272 Kelvin(K) T₂ = 274 Kelvin(K)
=> increase temperature => increase pressure
=> temperature ratio that will increase 90 atm is (274K/272K)
n₁ = moles = constant n₂ = n₁ = constant
P₂ = 90 atm x (18L/12L) x (274K/272K) = 135.9926471 atm (calculator)
By rule of sig. figs., the final answer should be rounded to an accuracy equal to the 'measured' data value having the least number of sig. figs. This means P₂ ≅ 100 atm based on the given value of P₁ = 90 atm.
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