What would be the most effective way for a scientist to get an idea of the actual age of a rock?
Answer:
Radiometric dating
Explanation:
Radiometric dating would be the most effective way since it is a technique that can establish the age of objects older than a few thousand years.
Predict whether the entropy change for this process is positive or negative and explain your answer. Then, predict whether the free energy change for the process is positive or negative and explain your answer.
The given question is incomplete. The complete question is:
Consider the spontaneous dissolution of NaCl in water: NaCl(s) → Na+(aq) + Cl −(aq) Predict whether the entropy change for this process is positive or negative and explain your answer. Then, predict whether the free energy change for the process is positive or negative and explain your answer.
Answer: The entropy change is positive. The free energy change for the process is negative and reaction is spontaneous.
Explanation:
Entropy is defined as the degree of randomness of a system. For a system in which randomness increses , the enetropy is said to increase and [tex]\Delta S[/tex] is positive.
As in the given reaction : [tex]NaCl(s)\rightarrow Na^+(aq)+Cl^-(aq)[/tex] , the solid is dissociating to give ions , randomness increases and thus entropy is positive.
Also the dissociation of a molecule requires energy , thus the enthalpy [tex]\Delta H[/tex] is also positive as heat is absorbed by the system.
[tex]\Delta G=\Delta H-T\Delta S[/tex]
[tex]\Delta G=(+ve)-T(+ve)[/tex]
[tex]\Delta G=-ve[/tex] when Temperature is high.
Consider the spontaneous dissolution of NaCl in water: NaCl(s) → Na+(aq) + Cl −(aq)
Predict whether the entropy change for this process is positive or negative and explain your answer. Then, predict whether the free energy change for the process is positive or negative and explain your answer.
The given question is incomplete. The complete question is:
Consider the spontaneous dissolution of NaCl in water: NaCl(s) → Na(aq) Cl −(aq) Predict whether the entropy change for this process is positive or negative and explain your answer. Then, predict whether the free energy change for the process is positive or negative and explain your answer.
Answer: The entropy change is positive. The free energy change for the process is negative and reaction is spontaneous.
Explanation:
Entropy is defined as the degree of randomness of a system. For a system in which randomness increses , the enetropy is said to increase and is positive.
As in the given reaction : , the solid is dissociating to give ions , randomness increases and thus entropy is positive.
Also the dissociation of a molecule requires energy , thus the enthalpy is also positive as heat is absorbed by the system.
when Temperature is high.
Which of these ideas did you include in your answer?
✔️ When a crystalline solid dissolves, it becomes more disordered.✔️ When disorder increases, ΔG is positive.✔️ This process probably has a positive ΔS .✔️ The process is spontaneous.✔️ Spontaneous processes have ΔG < 0; the process has a negative ΔG .
Have a Nice Day .
What is the formula mass of the fictitious compound: AB2?
What is a buffer used for?
A. To limit the pH change in a solution
B. To prevent an acid from dissociating
C. To neutralize the pH of a solution
D. To prevent a salt from dissolving
A buffer is primarily used to limit the pH change in a solution. Option A is correct.
A buffer is the solution which contains the weak acid and its conjugate base or weak base and its conjugate acid. It is designed to resist changes in pH when small amounts of acid or base are added to it.
When an acid or base is added to a buffer solution, the buffer components react with the added ions to minimize the impact on the solution's pH. If an acid is added, the buffer will react with the acid by accepting the H⁺ ions. If a base is added, the buffer will react with the base by donating H⁺ ions. In both cases, the buffer helps maintain the pH at a relatively stable level.
To prevent an acid from dissociating, is not accurate. A buffer does not prevent an acid from dissociating. In fact, the acid in a buffer solution is necessary to provide the conjugate base and maintain the buffer's pH buffering capacity.
To neutralize the pH of a solution, is also not accurate. A buffer does not neutralize the pH of a solution to a particular value. Instead, it resists significant changes in pH when small amounts of acid or base are added.
To prevent a salt from dissolving, is unrelated to the purpose of a buffer. A buffer is not used to prevent the dissolution of salts.
Hence, A. is the correct option.
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If the temperature remains constant and pressure is INCREASED on gas, what will happen to the volume?
The volume will increase.
The volume will decrease.
The volume will not change.
The volume will randomly increase and decrease, and keep doing this.
Answer:
I believe the volume should increase.
What is the process of old crust sinking back into a mantle?
how do hydrogen fuel cells and fossil fuels produce energy?
Answer:
The hydrogen reacts with oxygen across an electrochemical cell
Explanation:
25) Which of the following would exert the most pressure on the ground? 3 points
A woman standing in running shoes
O A Woman standing in high heels
A woman sitting on the ground
O It doesn't make any difference as long as the weight is the same.
C
ادا آمد
collina abinet avontually
Answer:
a women standing in high heels
Explanation:
Answer:
A woman standing in high heels
the formula equation of Acetylene + oxygen ----> carbon dioxide + water
Answer:
The final balanced equation is : 2C2H2+5O2→4CO2+2H2O.
Determinar el volumen de una solución en mililitros cuya concentración es 0,3 M en ácido sulfúrico y que contiene 1,5 moles del ácido
Answer:
V = 5000 mL
Explanation:
¡Hola!
En este caso, dado que la molaridad de una solution se calcula al dividir las moles por el volume de solución en litros, es posible calcular el volumen cuando se dividen las moles por la molaridad, tal y como se muestra a continuación:
[tex]M=\frac{n}{V}\\\\V=\frac{n}{M}[/tex]
Así, podemos reemplazar la molaridad y moles dadas para obtener:
[tex]V=\frac{1.5mol}{0.3mol/L}=5L[/tex]
Que en mililitros sería:
[tex]V=5L*\frac{1000mL}{1L}\\\\V=5000mL[/tex]
¡Saludos!
HCl (aq) + NaOH (aq) = NaCl (aq) + H2O (l)
What type of reaction is the above?
Answer:
Neutralization reaction
Explanation:
It is a reaction between an acid and a base
How is thermal energy transferred between two objects that are at different temperatures?
Group of answer choices
Heat flows from the object that has more thermal energy to the object with less thermal energy.
The object at a lower temperature pulls heat from the warmer object.
Heat flows from the warmer object to the cooler object until they reach the same temperature.
Heat flows back and forth between the two objects untl they reach the same temperature.
Answer:
heat flows from the object that has more thermal more energy to the object with less thermal energy
helppppp will mark brainlest
Answer:
if you will decrease the HCO3- so the less H+ ion will be form and reaction will more likely shift to product and when HCO3- decreases pH value increases and vica versa for the increasing HCO3 the more H+ ion will be form and reaction will shift to product and the pH value will decreases!!
I've doubt in reaction shift coz whatever is the amount of HCO3- this is completely gonna form number of H+ so reaction shift may or may not be same!!
Benadryl, C17H21NO, is an over-the-counter drug used to treat allergy symptoms. If each dose of Benadryl contains 5.89 x 10^19molecules of Benadryl, how many moles is this equal to?
Answer:
9.78x10^(-5) mol
Explanation:
To convert molecules to moles, divide the # of molecules by 6.02x10^23.
5.89x10^19 / 6.02x10^23 = 9.78x10^(-5) mol
A reaction yields 6.26 grams of a CuCl2. What is the percent yield of CuCl2 if the theoretical yield is 18.81g?
% Yield = (Actual Yield/Theoretical Yield) x 100
Answer:
33% yield
Explanation:
6.26/18.81 =0.33280170122 = 33%
What is responsible for moving the water to the ground?
Answer:
Water applied to the surface of a relatively dry soil infiltrates quickly due to the affinity of the soil particles for water. As time passes and the soil becomes wet, the force of gravity becomes the dominant force causing water to move.
Explanation:
Answer:
Gravity
Explanation:
Water applied to the surface of a relatively dry soil infiltrates quickly due to the affinity of the soil particles for water. As time passes and the soil becomes wet, the force of gravity becomes the dominant force causing water to move.
A piece of metal of mass 23 g at 100 ◦C is
placed in a calorimeter containing 55.4 g of
water at 25◦C. The final temperature of the
mixture is 63.4
◦C. What is the specific heat
capacity of the metal? Assume that there is
no energy lost to the surroundings.
Answer in units of J
g ·
◦ C
.
Answer:
10.58 J/g-°C
Explanation:
To find the specific heat capacity of the metal, you need to know how much heat was lost when it reacted with water.
You know that there are 55.4 g of water, the initial temp. of water is 25°C, and the final temp. (the mixture's temp.) is 63.4°C.
You should also know that the specific heat capacity of water is 4.186 J/g-°C.
Plug this into the equation the q=mcΔT.
q = (55.4 g)(4.186 J/g-°C)(63.4°C - 25°C)
q = 8905.12896 J
If 8905.12896 J was gained by the water, then 8905.12896 J must have been lost from the metal.
You know that there are 23 g of the metal and that its initial temp. is 100°C.
Plug this information into q=mcΔT.
8905.12896 J = (23 g)(C)(63.4°C - 100°C)
C = 10.58 J/g-°C
*When you plug all of this into the calculator, it will result in a negative number but keep in mind that heat was LOST by the metal so 8905.12896 J is essentially negative. So the negative cancels out.*
(Please help 15 points the assignment is late) (multiple questions) (everything is virtual task )
Part 1 What do you think will happen when an effervescent tablet is placed in the water under each inverted glass?
Part 2 Note the changes in the water level and the air space in both glasses, and write down your observations.
Part 3 Did your prediction match your observation?
Part 4. When a substance easily dissolves in a liquid, it has high solubility in that liquid. When a substance does not easily dissolve in a liquid, it has low solubility in that liquid. Solubility of a gas in water describes how well the liquid can “hang on” to gas, instead of releasing it into the air. Based on the results of your experiment, do you think that CO2 has a higher solubility in hot water or cold water? Why?
Part 5 Soda pop is carbonated with CO2. Mark puts one bottle of soda pop in the refrigerator and leaves the other out in the hot sunlight. After one hour, he opens both bottles. Which bottle will likely have more fizzing and bubbles? Why?
Part 6 One result of climate change is that ocean temperatures are increasing. If the temperatures continue to rise, what effect will that have on the oceans’ ability to retain CO2? How might this change affect the atmosphere?
The dissolution of gases in water is exothermic therefore oceans will dissolve less CO2 as their temperatures rise.
What is effervescence?
The term effervescence refers to the rise of a gas in a system or simply put, it is the evolution of gas. When an effervescent tablet is placed in the water under each inverted glass, a gas will rise in each glass.
The air space in the hot glass is greater than the air space in the cold glass We can see that the gas has a lower solubility in hot water than in cold water. This is because, solubility of gases is exothermic.
The bottle that is left in the hot sun will have more fizzing because the CO2 does not dissolve owing to the higher temperature.
The rise in ocean temperature means that the oceans will dissolve less CO2 in the future and reduce the CO2 holding capacity of the oceans.
Learn more about CO2: https://brainly.com/question/867804?
what is the difference between an enzyme and an inhibitor?
When a small piece of sodium metal is dropped into a beaker of water, hydrogen gas (H2) and a solution of sodium hydroxide (NaOH) are products. The solution becomes warm.
Answer:
The reaction is exothermic as the solution becomes warm.
Explanation:
Hello there!
In this case according to the described reaction between sodium metal and water, we can write up the chemical equation whereas the products turn out to be sodium hydroxide and hydrogen gas:
[tex]2Na+2H_2O\rightarrow 2NaOH+H_2[/tex]
Moreover, these reactions are known to be highly exothermic, for that reason the solution becomes warm as the reaction releases heat as it goes to completion.
Best regards!
Complete the following statements of Dalton's atomic model: a) Elements are composed of minute, particles called atoms. b) Atoms of the same element are alike in and size. c) Atoms of different elements have different and sizes. d) Chemical are formed by the union of two or more different atoms of different elements. e) Atoms combine to form compounds in simple numerical , such as one to one, one to two, etc. f) Atoms of two may combine in different ratios to form more than one compound.
Answer:
a. Indivisible.
b. Mass.
c. Masses.
d. Compound.
e. Elements.
Explanation:
An atom can be defined as the smallest unit comprising of matter that forms all chemical elements. Thus, atoms are basically the building blocks of matters and as such defines the structure of a chemical element.
Generally, these atoms are typically made up of three distinct particles and these are protons, neutrons and electrons.
Hence, all the physical properties of a mineral result from the mineral's internal arrangement of atoms.
The following are statements postulated by the Dalton's atomic model;
a) Elements are composed of minute, indivisible particles called atoms.
b) Atoms of the same element are alike in mass and size.
c) Atoms of different elements have different masses and sizes.
d) Chemical compound are formed by the union of two or more different atoms of different elements.
e) Atoms combine to form compounds in simple numerical ratios, such as one to one, one to two, etc.
f) Atoms of two elements may combine in different ratios to form more than one compound.
Did Dalton believe that atoms could be created or destroyed? Explain
☁️ Answer ☁️
Yes.
"In so doing, he became the first scientist to explain the behavior of atoms in terms of the measurement of weight. He also uncovered the fact that atoms couldn't be created or destroyed. Dalton's theory additionally examined the compositions of compounds, explaining that the tiny particles (atoms) in a compound were compound atoms"
Hope it helps.
Have a nice day noona/hyung.
Question 2
1 pts
Which of the following best describes what families/groups of elements have in common?
O Same number of electrons
O Same number of valence electrons
O Same number of electron shells
O Same number of protons
U
Question 3
1 pts
If the number of bacteria in a colony doubles every 18 minutes and there is currently a population of 200,000 bacteria, what will the population be 36 minutes from now?
Answer:
After 36 minutes, there will be a population of 800,000 bacteria.
Explanation:
After the first 18 minutes, it will double to 400,000. Then, at 36 minutes, it will have doubled again, giving you 800,000.
was
4. When a 1.25-gram sample of limestone, that contains CaCO3 (molar mass = 100 g/mol) and inert impurities
dissolved in acid, 0.22 grams of CO2 was generated (molar mass = 44 g/mol). What was the percent of CaCO3 by
mass in the limestone?
CaCO3 + CO2 + CaO
(a) 20%
(6) 40%
(c) 67%
(d) 80%
(e) 100%
if 4.10 grams of chromium is heated with 9.30 grams of chlorine what mass of chromium(III) chloride is produced?
Answer:
4.1g of Cr will make (317/104) x 4.1 = 12.5g of CrCl3
H2SO4 + 2NaOH → Na2SO4 + 2H2O what volume of water vapor will be produced if you start with 71.5 g of sulfuric acid and excess of sodium hydroxide
Answer:
Explanation:
Find the molar mass of H2SO4
2H = 2 * 1 = 2
S = 1 * 32 =32
O4 = 4*16 = 64
total 98
Find the number of mols in 71.5 grams
mols = given mass / molar mass.
given mass = 71.5
molar mass = 98
mols = 71.5/98
mols = 0.7296 mols of H2SO4
Find the moles of H2O
From the Balanced equation, every mol of H2SO4 produces 2 moles of H2O
mols water = 2 * 0.7296
mols water = 1.4592
That's as far as I can take you. I have to know a great deal more to get the volume of H2O
Characteristic orange light produced by sodium in a fl ame is due to an intense emission called the sodium D line, which is actually a doublet, with wavelengths (measured in vacuum) of 589.157 88 and 589.755 37 nm. The index of refraction of air at a wavelength near 589 nm is 1.000 292 6. Calculate the frequency, wavelength, and wavenumber of each component of the D line, measured in air.
Answer:
a. i. 5.092 × 10²⁰ Hz ii. 588.98554 nm ii. 10667809.11 rad/m
b. i. 5.087 × 10²⁰ Hz ii. 589.58286 nm iii. 10657001.3 rad/m
Explanation:
refractive index, n = λ/λ' where λ = wavelength in vacuum = and λ' = wavelength in air
a. For λ = 589.15788 nm,
i. Frequency,
f = c/λ where c = speed of light in vacuum = 3 × 10⁸ m/s and λ = 589.15788 nm = 589.15788 × 10⁻⁹ m
So, f = 3 × 10⁸ m/s ÷ 589.15788 × 10⁻⁹ m
= 0.005092 × 10¹⁷ /s
= 5.092 × 10²⁰ /s
= 5.092 × 10²⁰ Hz
ii. Wavelength,
Since n = λ/λ' where λ = wavelength in vacuum = and λ' = wavelength in air
and n = 1.0002926
λ' = λ/n
= 589.15788 nm/1.0002926
= 588.98554 nm
iii. Wave number, kk = 2π/λ'
= 2π/588.98554 nm
= 0.01066780911 rad/nm
= 0.01066780911 rad/nm × 10⁹ nm/1m
= 10667809.11 rad/m
b. For λ = 589.755 37 nm.,
i. Frequency,
f = c/λ where c = speed of light in vacuum = 3 × 10⁸ m/s and λ = 589.755 37 nm. = 589.755 37 × 10⁻⁹ m
So, f = 3 × 10⁸ m/s ÷ 589.755 37 × 10⁻⁹ m
= 0.005087 × 10¹⁷ /s
= 5.087 × 10²⁰ /s
= 5.087 × 10²⁰ Hz
ii. Wavelength,
Since n = λ/λ' where λ = wavelength in vacuum = and λ' = wavelength in air
and n = 1.0002926
λ' = λ/n
= 589.755 37 nm./1.0002926
= 589.58286 nm
iii. Wave number, kk = 2π/λ'
= 2π/589.58286 nm
= 0.0106570013 rad/nm
= 0.0106570013 rad/nm × 10⁹ nm/1m
= 10657001.3 rad/m
What form of electromagnetic radiation does gamma radiation use?
Answer:
Gamma-rays are a form of electromagnetic radiation, as are radio waves, infrared radiation, ultraviolet radiation, X-rays and microwaves. Gamma-rays can be used to treat cancer, and gamma-ray bursts are studied by astronomers.
Explanation:
Hope this helped Mark BRAINLIEST!!!
Gamma Rays are ionizing Electromagnetic radiation, obtained by the decay of an atomic nucleus. Gamma rays are more penetrating, in matter, and can damage living cells to a great extent. Gamma rays are used in medicine (radiotherapy), industry ( Sterilization and disinfection) and the nuclear industry.
1. A sample of oxygen gas has a volume of 150 ml when its pressure is 440 mmHg. If the pressure is
Increased to standard pressure and the temperature remains constant, what will the new volume be?
Answer:86.84
Explanation: