Answer:
A. Salt, hope its helped
If 45.0 g of O2 are mixed with 45.0 g of H2 and the mixture is ignited, what mass of water is produced?
Group of answer choices
45.0 g
50.7 g
79.9 g
25.3 g
90.0 g
Answer:
45.0gExplanation:
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steel cranes can carry heavy steel beams thousands of feet high
Answer:
yes they were made to carry thousands of lb high up
22.5 ml of a 0.200 m HBr solution was added to a 50.00 ml sample of 0.250 m sodium benzoate (NaC7H5O2). Calculate the pH. Benzoic acid has a Ka 6.30 x 10-5.
In this problem, we need to find the pH of a buffer (pH = 4.45) that is produced by the reaction of strong acids as HBr that reacts with weak bases as NaC₇H₅O₂ producing its weak acid and a salt, as follows:
HBr + NaC₇H₅O₂ → HC₇H₅O₂ + NaBr
If in the reaction, the limiting reactant is the strong acid, we will produce a buffer (The aqueous mixture of a weak acid and its strong base).
Using Henderson-Hasselbalch equation, we can find the pH of this buffer:
[tex]pH = pKa + log \frac{[NaC_7H_5O_2]}{[HC_7H_5O_2]}[/tex]
Where:
pKa is -log Ka = 4.20
[] could be taken as the moles of each species
After the reaction, the moles of HBr = Moles of HC₇H₅O₂ and the remaining moles of NaC₇H₅O₂ = Initial moles of NaC₇H₅O₂ - Moles of HBr.
Moles HBr:
22.5mL = 0.0225L * (0.200mol/L) = 4.5x10⁻³ moles HBr
Moles NaC₇H₅O₂:
50.0mL = 0.0500L * (0.250mol/L) = 0.0125 moles NaC₇H₅O₂
That means the moles after the reaction of the species of the buffer are:
Moles HC₇H₅O₂ = Moles HBr = 4.5x10⁻³ moles
Moles NaC₇H₅O₂ = 0.0125 moles - 4.5x10⁻³ moles = 8.0x10⁻³ moles
Replacing in H-H equation:
[tex]pH = 4.20+ log \frac{[8.0x10^{-3}]}{[4.5x10^{-3}]}[/tex]
pH = 4.45
Learn more about Henderson-Hasselbalch equation in:
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3. How can you decrease the pressure of a gas in a container without changing the volume of the gas?
add more gas particles to the container
move the container to a lower altitude
o o
reduce the temperature of the gas
O
change the shape of the container
Answer:
reduce the temperature of the gas
Explanation:
when you reduce the temperature of the gas the pressure will decrease
As a person BAC level increase it becomes difficult for them to judge their vehicle distances and speed
Answer:
TRUE
Explanation:
The blood alcohol content is also known as the blood alcohol level or the blood alcohol concentration. It is defined as the measurement of the alcohol intoxication in the body and is used for the legal or the medical purposes.
When the BAC increases in the person's body, the person started to loose clear vision, loss of short term memory, poor muscle coordination, impaired perception and face difficulty in concentrating. Thus it becomes very difficult for a person to drive a car or ride a bike whose BAC has increased.
The driver cannot properly judge the distances between the vehicle and the speed of the vehicle.
Hence the answer is TRUE.
3. An atom
OF
elemente A has mass number 39 and 19 protons
Write the electron arrangement of the atom
Answer:
Explanation:
Potassium (K) atom has 19 electrons. The full electron configuration of Potassium (K) is 1s22s22p63s23p64s1
Principal energy level
Quantum number: n
1
2
3
4
5
6
Sublevels
availableQuantum number: l
1s
2s 2p
3s 3p 3d
4s 4p 4d 4f
5s 5p 5d 5f 5g
6s 6p 6d 6f 6g 6h
PLZ HELP ME WITH MY WORK
What is a compound?
A substance that is made from two different metals
B. A substance that cannot be broken into simpler substances
C. A substance that is made using a chemical reaction
D. A substance that can be separated by physical means
Answer:
C.
Explanation:
Answer A is incorrect because a compound doesn't have to be made with only metals.
Answer B is incorrect because that is actually the definition of a pure element.
Answer C is correct because to make a compound, there has to be a chemical reaction where bonds are formed and an entirely new substance is created.
Answer D is incorrect because compounds cannot be separated by physical means.
Hope this helps :D
The addition of solute particles into a solution causes:
A. the solvent particles to be attracted to the solute particles and to have less kinetic energy.
B. the solute particles to bump the solvent particles out of the solution, making it easier to boil.
C. the solute particles to form seed crystals and make the solution freeze more easily.
D. the solvent particles to be spread further out and have more to move, increasing their kinetic energy.
Answer:
D. the solvent particles to be spread further out and have more to move, increasing their kinetic energy.
Explanation:
The addition of solute particles results in an increased boiling point. As the solutes increases so does the energy inside as the solutes add and occupies more space near the surface of the liquid.Chemistry!! Help me! And explain step by step!
1st part is ure answer --> 2M
Given mass -> 58 grams
mass of NaCl -> 58.44 approx -> 58 any
moles given-> 1 moles
[tex]Molarity = \frac{moles}{vol \: in \: lts} [/tex]
[tex]Molarity = \frac{1}{0.5} = \frac{10}{5} \\Molarity = 2M[/tex]
When a compound is added to water only a few of its molecules dissociate to produce hydrogen ions. It is a...
a. strong acid.
b. weak acid.
c. strong base.
d. weak base.
relate the pH of a solution to its hydronium and hydroxyl ion concentration and its acidity or basicity
brain list if your answer is good
when ph decrease that means acidity increase
when ph increase that means basicity increase
describe the location of the Philippines
Answer:
Philippines, island country of Southeast Asia in the western Pacific Ocean. It is an archipelago consisting of more than 7,000 islands and islets lying about 500 miles (800 km) off the coast of Vietnam. Manila is the capital, but nearby Quezon City is the country's most-populous city.
How does adding oxygen (O) to this reaction change the equilibrium?
2s02(g) + O2(g) = 2s03(8)
Answer:
The equilibrium shifts right to produce more SO3 molecules.
Explanation:
The equilibrium law states that when a system encounters a disturbance like a temperature, concentration, or pressure modifications, it will react to restore a new state of equilibrium.
Adding a reactant such as oxygen (O2) will shift the reaction in the direction of the product, on the basis of the equilibrium law. Therefore, the equilibrium will move toward the product side.
Câu 9: 100 g dung dịch MgCl2 9.5 % tác dụng đủ với dung dịch KOH 5,6 % .được dung dịch A và chất rắn B. Lọc rắn B và nung đến khối lượng không đổi được chất C.
a) Viết pt .Tính khối lượng răn C
b) Tính nồng độ phân trăm của dung dịch A.
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Which of the following is an example of a molecule?
A. A sodium atom forms a metallic bond with another sodium atom.
B. A hydrogen atom forms a covalent bond with a chlorine atom.
C. A sodium atom forms an ionic bond with a chlorine atom.
D. A sodium atom forms a metallic bond with another sodium atom.
Answer:
The answer is B. A hydrogen atom forms a convalent bond.........
Suppose you had a valuable collection of small diamonds, which you kept safe from the thieves by mixing them with white sugar crystals. You store the mixture in a jar labeled 'sugar'. Now you want to sell the diamonds. Describe how you would separate all the diamonds from the sugar.
Answer:
Pour the sugar/diamond mixture into a container of water and stir until the sugar is dissolved completely. Then strain the mixture and wash the diamonds with water.
Answer:
Stir with a large enough volume of cold water to dissolve all the sugar. Filter to leave the diamonds on the filter paper. Wash on the filter paper with more water to remove any last traces of sugar solution. Allow to dry.
What is the pH value of lithium chloride?
Answer:
0.0003HERE IS YOUR ANSWER2. A photon of wavelength for 4 x10 -7 m strikes on the metal surface the work
function of the metal being 2.13 eV.Calculate (i)the energy of the photon in
eV(ii) the kinetic energy of the emission(iii) velocity of the photoelectron
[1ev=1.602x10-19 J]
Answer:
See explanation
Explanation:
Energy of the photon;
E = hc/λ
h= Planks constant
c= speed of light
λ = wavelength
E= 6.6 × 10^-34 × 3 × 10^8/4 x10 -7
E = 4.95 × 10^-19 J
If 1ev=1.602x10-19 J
x = 4.95 × 10^-19 J
x= 3.1 ev
From Einstein's photoelectric equation;
KE = E - Wo
Where;
KE = kinetic energy of ejected photoelectron
E= energy of the photon
Wo= work function of the metal
KE = 3.1 eV - 2.13 eV
KE= 0.97 eV
KE = 0.97 eV × 1.602x10-19 J
KE = 1.55 × 10^-19 J
KE = 1/2 mv^2
1.55 × 10^-19= 1/2 × 9.1 × 10^-31 × v^2
v= √2 × 1.55 × 10^-19/9.1 × 10^-31
v= 5.8 × 10^5 m/s
3. What would be the freezing point for a 5.7 molal aqueous sucrose (C12H22O) solution? The freezing
point depression constant for water = 1.86°C/m. Show your work.
Answer:
- 10.6° C
Explanation:
Given that,
In the aqueous sucrose solution,
Molality of the solution (m) = 5.7
Freezing point constant (K) = 1.86
To find,
The freezing point of the solution = ?
Method:
To find its freezing point, we will first find out if the solute demonstrates an electrolyte or not.
In case it is not, the van't Hoff factor i.e. ration of particles' concentration denoted by (i) would be taken as 1. So,
ΔT(change in temperature) = i * m * K (putting the given values)
= 1 * 5.7 * 1.86
= 10.6° C
Thus, the freezing point equals to 0 - 10.6° C = -10.6° C.
A scientist claims that the water molecules that you drink today could be millions of years old. Use evidence from the water cycle to support the scientist’s claim.
Answer:
As water on the surface of lakes, oceans, and rivers warms up, it travels into the sky as very tiny droplets, or vapor. When the water vapor gets colder, it turns back to liquid to help form clouds.
When the liquid gets so heavy it can’t stay in the atmosphere anymore, it falls, or “precipitates,” as rain, snow, sleet, hail, or, my favorite, graupel. Once the precipitation reaches the ground or lands in lakes, oceans, and rivers, the cycle continues.
Explanation:
A scientist claims that the water molecules that you drink today could be millions of years old in the water cycle the new clouds athat re made cannot rain but the clouds which are old do rain.
What is the water cycle?The water cycle or cycle of water is the journey of each and every water molecule by which it is made up of as the clouds in the environment are made up of the evaporation process in the environment.
The vapors of evaporation condense in the environment to form the clouds and these clouds are only responsible for the rain but the old and heavy clouds can only do it.
Therefore, in the water cycle, the new clouds are made cannot rain but the clouds which are old do rain scientist claim that the water molecules that you drink today could be millions of years old.
Learn more about the water cycle, here;
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According to the law of conservation of energy, what will most likely happen in a closed system?
Answer:
It is right or wrong I cannot say if it is wrong forgive me.
Answer:
The energy in the system will likely be exchanged, but the matter will not be exchanged.
Explanation:
According to the first law of thermodynamics, also known as Law of Conservation of Energy, energy can neither be created nor destroyed; energy can only be transferred or changed from one form to another. The law of conservation of mass also states that for any system closed to all transfers of matter and energy, the mass of the system must remain constant over time, as the system's mass cannot change.
Questions: Answer on the following slide.
1. What is needed from adults when conducting experiments at home?
2. Why are chemicals so dangerous?
3. What should always be followed when conducting experiments?
4. What is science?
Which of the following apply to organic compounds. Select all that apply. Organic compounds cannot be synthesized. Organic compounds contain carbon. All organic compounds are products of living things. Organic compounds can be synthesized. All compounds that contain carbon are organic.
Answer:
Organic Compounds CAN BE synthesized
Organic Compounds contain Carbon
Uranium-235 and uranium-238 are different ________ of uranium
(Apx answers please)
Answer:
Isotopes
Explanation:
An isotope are the atoms of an element with similar chemical identity and number of protons but different atomic masses. This means that isotopes of an element differ from one another by their number of NEUTRONS.
For example, the uranium element possesses isotopes as follows: Uranium-235 and uranium-238. This two isotopes have the same chemical identity and number of protons/atomic no., which is 92. However, the atomic masses (235 and 238) are different.
Answer:
Isotopes
Explanation:
please answer this questions soon
i will mark him or her brillient
Answer:
1)Or
d.Sublimation
2)
b.iodine is the solute and alcohol is solvent
3)
a.compostion of solute
Answer:
1) a) centrifugation
OR
b) sublimation
2) a) iodine is the solute and alcohol is solvent
3) a) concentration of soLute
A sample of gas occupies 1.2 L at 12.0oC. Assuming pressure remains the same, what would be the volume (in L) of this gas at 67oC?
A.
1.4
B.
1.0
C.
0.2
D.
5.0
E.
6.7
Answer:
e.
6.7
hope it help
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how many protons electrons and neutrons are present in the following atoms
Answer:the element is potassium
the proton and electron is 19 and the nuetron is 19
Explanation:
Answer:
The atomic number gives the number of protons 19
p = 19
The atomic mass is the sum of the protons and neutrons
p+n = 39 p = 19
Put p into the equation and solve for n the neutrons
19+n = 39
Subtract 19 from both sides
19-19+n = 39-19
n = 20
The number of electons equal the number of protons in a neutral atom. The positive charge equal to the negative charge. The negative charge is the number of electons. This ion has a charge of +1. So solve for the negative charge.
-19+1 = -18
The negative charge is -18 so
e = 18
A new stable element with an atomic number of 120 and an atomic mass of 246 is created in a particle accelerator. Enough of this element is created to determine that it combines with chlorine in a 1:2 ratio. Element 120 should be placed in the same group as _____ on the periodic table.
Answer:
Be,Mg,Ra etc
Explanation:
It should be palced in group 2A because as it reacts with chlorine in ratio of 1:2 . It's valancy is 2 and is metal as it react with non metal donating two electrons .
one more thing it fits there orderly
Balance the following equations
ANSWER
2Ba + 2HBr → 2BaBr + H2
2BiCl3 + 3H2S → Bi2S3 + 6HCl
Br2 + 2KI → I2 + 2KBr
4Fe + 3O2 → 2Fe2O3
I HOPE THIS WILL HELP YOU IF NOT THEN SORRY HAVE A GREAT DAY:)Answer:
[tex]3Mg _{(s)} + N _{2(g)} → Mg_{3} N _{2(s)}[/tex]
[tex]Ba _{(s)} + 2HBr_{(g)} → BaBr _{2(s)} + H _{2(g)}[/tex]
[tex]2BiCl_{3(s)} + 3H_{2} S _{(g)} → Bi _{2} S _{ 3(g)} + 6HCl _{(g)} \\ [/tex]
[tex]Br_{2(g)} + 2KI _{(g)} → I _{2(g)} +2 KBr _{(g)}[/tex]
[tex]4Fe_{(s)}+ 3O_{2(g)} → 2Fe_{2} O _{3(s)} [/tex]
Some species form social groups only with members of the same gender. For example, elephants form groups with
only females and their offspring. Once the male offspring reach a certain age, they leave the group and become
solitary.
Which is a benefit of this type of social group structure?
Explanation:
For example, elephants form groups with only females and their offspring. Once the male offspring reach a certain age, they leave the group and become solitary. Which is a benefit of this type of social group structure? A:Females do not have to compete for a mate.
