Which process is exothermic?
a) the vaporization of water b) the freezing of water c)the sublimation of dry ice d ) the boiling of liquid nitrogen
Answer:
Freezing of water
Explanation:
When water becomes a solid it releases heat into its surroundings (warming it up).
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Solution A has a pH of 2.0. Solution B has a pH of 5.0. Which solution is more acidic? Based on the H+ ion concentrations in the two solutions, how many times more acidic?
Answer:
Solution A is 1,000 times more acidic than Sol. B
Explanation:
for pH values we use scientific notation:
-log10 c (where c is the hydrogen ion concentration) is used to notate pH value (think of it as a unit)
ie:
10^-2 is sol A 10^-5 is sol B
5-2 is 3
10^-3 = 1000
there's a diff of 1,000 between the solutions.
The acidity or alkalinity of a solution depends on the hydronium ion concentration and hydroxide ion concentration. Here the solution A of pH 2.0 is more acidic than the solution of pH 5.0.
What is pH?The pH of a solution is defined as the negative logarithm to the base 10 of the value of the hydronium ion concentration in moles per litre. When the pH of the solution is less than 7 it is acidic whereas when pH is greater than 7, it will be basic.
The pH of the solution is calculated by the equation:
pH = - log [H₃O⁺]
Then the concentration of H₃O⁺ is:
[H₃O⁺] = 10⁻pH
At pH = 2.0, [H₃O⁺] = 10⁻² = 0.01
At pH = 5.0, [H₃O⁺] = 10⁻⁵ = 0.00001
Thus here the Solution A is 1,000 times more acidic than Solution B.
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What relates moles of 1 substance to another in a chemical reaction?
Answer:
Chemical reactions list reactants and products in molar amounts, not just molecular amounts. We can use the coefficients of a balanced chemical equation to relate moles of one substance in the reaction to moles of other substances
Explanation:
What is the standard cell notation of a galvanic cell made with zinc and gold?
A. Zn2+(aq) | Zn(s) || Au(s) | Au+(aq)
B. Au(s)| Aut(aq) || Zn2+(aq) | Zn(s)
C. Aut (aq)| Au(s) || Zn(s) | Zn2+(aq)
D. Zn(s) | Zn2+ (aq) || Aut(aq) | Au(s)
Answer:
D
Explanation:
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Help me get it right and no links
Answer:
i think the second answer " fish migration might be prevented" might possibly be your answer
During a phase change, such as melting or boiling, the kinetic energy __. Highlight correct answer
Answer: During a phase change, such as melting or boiling, the kinetic energy increases.
Explanation:
Kinetic energy is the energy obtained by the molecules of a substance due to their motion.
When phase change such as melting or boiling takes place then it means heat is absorbed by the substance. As a result, their molecules more even more rapidly from one place to another due to which more number of collisions take place.
Hence, a change in phase of substance occurs as kinetic energy increases in melting or boiling process.
Thus, we can conclude that during a phase change, such as melting or boiling, the kinetic energy increases.
Conservation of matter means that:
55
Matter is never created nor destroyed.
Matter is always created and destroyed.
Matter always turns into energy
Matter is flexible, it can be created destroyed, or turned into energy
Answer:
Matter is never created or destroyed
How much 2 M HBr is needed to neutralize 380 mL of 0.1 M NH4OH?
Answer:
19ml
Explanation:
trust me
Given a gas with an initial volume of 3.0 L and a temperature of 290 K, what is the final volume if the
temperature is 273 K?
Plzzz neeed this really quick
Answer:
2.8l
Explanation:
just make v2 de subject
Which of the following is not a reason for extinction?
a change in climate
a change in predation rate
the ability to breed successfully
loss of habitat
Answer:
the ability to breed successfully
Explanation:
Answer:
the ability to breed successfully
Explanation:
the more offspring's an organism has, the less chance of extinction would happen. I hope that helped bestie
What is the IUPAC name for Ester with 9 carbon atoms ?
Explanation:
[tex]CH _{3}CH _{2}COOCH _{2} CH _{2}CH _{2}CH _{2}CH _{2}CH _{3}[/tex]
NAME: Hexylpropenoate
what do you call the materials in which electricity pass easily?
a. insulator
b. conductors
c. non conductors
d. metallic
Answer:
Conductors
Explanation:
True or False: The moon's gravity affects the oceans nearest the moon because the moon's gravity pulls water into a tidal bulge.
Answer: The moon's gravitational pull generates something called the tidal force. The tidal force causes Earth—and its water—to bulge out on the side closest to the moon and the side farthest from the moon. These bulges of water are high tides
Explanation:
The moon's gravity affects the oceans nearest the moon because the moon's gravity pulls water into a tidal bulge is a true statement.
What is tidal force?The tidal force is the result of the moon's gravitational pull.
The tidal force causes Earth—and its water—to bulge out on its closest and furthest sides from the moon. High tides cause these water bulges.
Thus, the statement is correct.
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How many atoms in 13.88 mole of lead? (Round to 3 sig figs)
Answer:
8.36 x 10^24 atoms/molecules
Explanation:
Avagadro's Number: 6.02214076 × 10^23
Avagadro's Number shows the number of molecules in 1 mole of substance. In this case, if there is 13.88 moles of lead, we multiply 13.88 by Avagadro's number:
(6.02214076 × 10^23)(13.88) = 8.358536 x 10^24 = 8.36 x 10^24
Molecules are always in motion. True False
Answer: FALSE
Explanation:
Which illustration represents a sound wave?
A or B
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2H2 + O2 → 2H2O
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Which of the following statements would be correct if one mole of hydrogen was used in this reaction? (5 points)
One mole of oxygen was used in this reaction.
Two moles of oxygen were used in this reaction.
One mole of water was produced from this reaction.
Two moles of water were produced from this reaction.
Answer:
- One mole of oxygen was used in this reaction.
- Two moles of water were produced from this reaction.
Explanation:
In addition: - Two moles of hydrogen were used.
Given the data from the question, the correct statement is:
One mole of water, H₂O was produced from the reaction Basic conceptTo know which options are correct, we shall determine the number of mole of O₂ used and the number of mole of H₂O produced.
How to determine the mole of O₂ usedBalanced equation
2H₂ + O₂ —> 2H₂O
From the balanced equation above,
2 moles of H₂ required 1 mole of O₂
Therefore,
1 mole of H₂ will require = 1 / 2 = 0.5 mole of O₂
Thus, 0.5 mole of O₂ is needed for the reaction
How to determine the mole of H₂O producedFrom the balanced equation above,
2 moles of H₂ reacted to produce 2 moles of H₂O
Therefore,
1 mole of H₂ will also react to to produce 1 mole of H₂O
Thus, 1 mole of H₂O was produced from the reaction.
SUMMARY
When 1 mole of H₂ was used in the reaction,
0.5 mole of O₂ was used 1 mole of H₂O was producedConsidering the options given in the question above, the correct statement is:
1 mole of H₂O was producedLearn more about stoichiometry:
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. Which of the following is not a product of photosynthesis?
O A. Carbon dioxide
O B. Glucose
O C. Oxygen
Answer:
The answer would be a
Explanation:
That is what goes into the plant and oxygen IS an outcome
The same amount of heat is added to a 10-g sample of each of the following metals. If each metal is initially at 20.0°C, which metal will reach the highest temperature? show your work
A. gold 0.129 J/(g °C)
B. beryllium 1.82 J/(g °C)
C. calcium 0.653 J/(g °C)
D. copper 0.385 J/(g °C)
Answer: A
Explanation:
A
Heat is the product of the mass, specific heat, and delta temperature. The gold metal will reach the highest temperature. Thus, option A is correct.
What is specific heat?Specific heat (c) is the heat required by a substance to get heated a unit mass by a unit of temperature. The specific heat is given as,
[tex]\rm c = \rm \dfrac{Q}{m \times \Delta T}[/tex]
Here, Q is the heat applied, m is the sample's mass and delta T is the change in the temperature.
The value of heat applied is the same for all the metals, so a change in temperature is calculated as,
[tex]\rm \Delta T = \rm \dfrac{Q}{c . m }[/tex]
From this, it can be said that the temperature is inversely related to the specific heat of the metal and hence the metal having the smallest c will have the highest change in the temperature.
Therefore, gold (c = 0.129 J/(g°C)) will reach the highest temperature.
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A cube has a mass of 100g and each side is 5cm. What is its density?
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Answer:
D. The energy level of the electron.
Explanation:
There are four quantum numbers which are used to describe the movement and paths or positon of each electron within an atom. Quantum numbers can be used to determine the electronic configuration of atoms and the most likely location of the atom's electrons. Quantum numbers are also used in determining other characteristics of atoms, such as ionization energy and the atomic radius.
The four quantum numbers are namely, principal, azimuthal, magnetic and spin quantum numbers.
Principal quantum numbers are denoted by the symbol ‘n’. They describe the principal electron shell or energy level the atom.The value of the principal quantum number are positive integer values that is equal to or greater than one. The value n = 1 represents the innermost electron shell of an atom, which corresponds to the lowest energy state of an electron. The larger the values of 'n' the greater the energy level and the farther the electron is from the nucleus.
What is the molecular formula for this molecule? a
Answer:
In a molecular formula, it states the total number of atoms of each element in a molecule.
Explanation:
Which model shows a way that large molecules can enter a cell without using the cell's energy? Outside the cell O A Cell membrane Vacuole 1 2 Inside the cell В.
Answer:
its B
Explanation:
I took the test and its that passage way thing. (tell me if this works for you! it will but just wanna make sure!)
Question 1
A molecule contains carbon, hydrogen and oxygen. For every carbon atom there are
twice as many hydrogen atoms but the same number of oxygen atoms.
What is the formula of the molecule?
А
CH 0
B
C2H4O2
C
C,H,O2
D
C,H,O2
The required molecule is :
=》option B.) C2H4O2
it has 2 carbon atoms, 4 hydrogen atoms which it twice the number of carbon atoms and 2 oxygen atoms same as carbon.
Why are models used to represent atoms?
O A. Atoms are too small to see.
O B. Models are completely accurate.
O C. Models explain new evidence.
O D. Models never change over time.
who discovered electron
Answer: Electricity
Answer:
J.J Thomas in 1897
B) A company president would like to offer a 4.00 L cylinder containing 500 g of chlorine in the new catalog. The cylinders you have on hand have a rupture pressure of 40 atm. Use both the ideal gas law and the van der Waals equation to calculate the pressure in a cylinder at 25°C. Given a = 6.58 L2 atm mol-2 and b = 0.056 L mol-2, Cl =35.5. (5 marks)
Answer:
43.1atm is the pressure using gas law and 27.2atm using Van der Waals Law.
Explanation:
Ideal gas law is:
PV = nRT
Where P is pressure in atm
V is volume = 4.00L
n are moles of the gas (For chlorine Molar Mass: 70.90g/mol):
500g * (1mol / 70.90g) = 7.052 moles
R is gas constant = 0.082atmL/molK
T is absolute temperature = 25°C + 273 = 298K
To solve the pressure, P:
P = nRT/V
P = 7.052mol*0.082atmL/molK*298K / 4.00L
P = 43.1atm is the pressure using gas law.
Van der Waals equation is:
[tex]P + a(\frac{n}{V})^2 * (V-nb) = nRT[/tex]
Where a is 6.58L²atm*mol⁻²
b = 0.056Lmol⁻²
Solving for pressure:
[tex]P + a(\frac{n}{V})^2 = \frac{nRT}{(V-nb)}[/tex]
[tex]P = \frac{nRT}{(V-nb)}-a(\frac{n}{V})^2[/tex]
[tex]P = \frac{7.052mol*0.082atmL/molK*298K}{(4.00L-7.052mol*0.056L*mol)}-6.58L^2mol^{-2}(\frac{7.052mol}{4.00L})^2[/tex]
P = 172.323 / 3.6051 - 20.4866
P = 27.2atm using Van der Waals Law
is the answer A or B?
Answer:
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