Is changing the color of the coin from copper to silver a physical or chemical change?
Answer:
physical
Explanation:
The zinc (which was already silver) coated the penny. The NaOH dissolved the zinc. (that was what made the water murky) And small pieces of zinc adhered to the penny (coated) It was a physical change because no NEW color was created.
1) A) Balance the following equation:
2 Fe + 6HCI →
3 H2 +
2 FeCl3
B) How many moles of hydrogen gas would be produced in a reaction that yields 7.5
moles of iron chloride?
Answer:
A) 2Fe+6HCl=3H2+2FeCl
B) 11.25
Explanation:
A)---
B) 2 - 7.5
3 - x ⇒ 2x = 7.5*3 ⇒x = 22.5/2 = 11.25
What is climate and what are the two main factors that affect climate?
Need answers within 5 minutes!
Answer:
climate:the weather conditions prevailing in an area in general or over a long period.
2 main factors: temperature and precipitation
Explanation:
draw a lewis structure for XZ2 (X has 6 valence electrons, F has 7 valence electrons)
Answer:
yhpcfjfkg original ogigoyy chandanPlease help, i will mark brainliest.
Answer:
It’s the second option ; 2,1,3,2
Explanation:
PLEASE HELP!! Answer whatever ones you can please and thank you!!!!
1. A gas with a volume of 4.0 L at a pressure of 2.03 atm is allowed to expand to a volume of 12.0 L. What is the pressure in atm in the container if the temperature remains constant. Please show work (including the equation you used).
2.The volume of a gas is 200 mL at 350.0 kPa pressure. What will the volume be when the pressure is reduced to 120.0 kPa, assuming the temperature remains constant. Please show all work for full credit. Please show work (including the equation you used).
3.What is the original pressure of a bike tire if the current pressure is 150 atm and the volume changed from 1000 mL to 700 mL. Please show work (including the equation you used).
These problems can be solved using the gas laws. The combined gas law states that PV/T = k, where P is the pressure, V is the volume, T is the temperature (in Kelvin), and k is a constant. From this relationship, you can figure out the change in pressure, volume, or temperature of a gas provided that one of those three parameters remains unchanged. This will be shown in the problems given.
1. Here, the pressure and volume of a gas change while the temperature remains constant. Since PV/T = k, if T is also constant, then the relationship becomes PV = k. In other words, the pressure and volume of a gas at a constant temperature are inversely proportional to each other. This can be expressed mathematically as [tex]P_1V_1=P_2V_2[/tex] (also called Boyle's Law), where P₁ and V₁ denote the initial pressure and volume, and P₂ and V₂ denote the final (or changed) pressure and volume, respectively.
We are given a gas with an initial pressure, P₁, of 2.03 atm and an initial volume, V₁, of 4.0 L. We are also told that the gas expands to a final volume, V₂, of 12.0 L. So, we are looking for P₂: The pressure of the gas when the volume has expanded from 4.0 to 12.0 L. From Boyle's Law,
[tex]P_2=\frac{P_1V_1}{V_2}[/tex].
Thus,
[tex]\[P_2=\frac{\left ( 2.03 \text{ atm} \right )\left ( 4.0 \text{ L} \right )}{\left ( 12.0 \text{ L} \right )}\] = 0.67 atm.[/tex]
Since the pressure and volume of a gas are inversely proportional, as one increases, the other decreases, and vice versa.
2. This is another Boyle's Law problem, but this time, we have to figure out what the final volume will be when the pressure of a gas is changed. Since the pressure is reduced, we can deduce that the volume must increase (notice the parallel with the previous question). We again turn to Boyle's Law, and this time we solve for V₂:
[tex]V_2=\frac{P_1V_1}{P_2}[/tex]
from which we obtain
[tex]\[V_2=\frac{\left ( 350.0 \text{ kPa} \right )\left ( 200 \text{ mL} \right )}{\left ( 120.0 \text{ kPa} \right )}\] = 583 mL.[/tex]
It's not clear whether 200 mL (V₁) should be assigned three significant figures or one. I gave the answer to three significant figures; the answer to one significant figure would be 600 mL.
3. We use Boyle's Law once more here, but our word problem has us working backwards (it's also not explicitly mentioned that temperature remains constant, but it should be reasonable to assume so). The current pressure of the gas inside the bike tire is 150 atm at a volume of 700 mL . But we want to know what the initial pressure of the gas was at a volume of 1000 mL. In other words, we want to solve for the P₁ in Boyle's Law:
[tex]P_1=\frac{P_2V_2}{V_1}.[/tex]
Since the volume of the gas had decreased from 1000 mL (V₁) to 700 mL (V₂), and the pressure and volume of a gas at a constant temperature are inversely proportional, we would expect the pressure of the gas to have increased; that is, our P₁ should be less than 150 atm.
[tex]\[P_1=\frac{\left ( 150 \text{ atm} \right )\left ( 700 \text{ mL} \right )}{\left ( 1000 \text{ mL} \right )}\] = 105 atm.[/tex]
Acetic acid (ch3cooh) and trifluoroacetic acid (cf3cooh) are shown by these particulate models. the ka for trifluoroacetic acid is 104 times greater than acetic acid. use the models to account for the differences in magnitude for the ka constant. the green atoms are fluorine, the red atoms are oxygen, the black atoms are carbon, and the white atoms are hydrogen.
Answer:
See explanation
Explanation:
If we look at the models, we will see that the three fluorine atoms in CF3COOH are attached to the carbon that is next to the -COOH group.
As a result of the electron withdrawing effect of the three fluorine atoms, CF3COOH is much more acidic (104 times more acidic) than CH3COOH. This is reflected in the value of the Ka for each acid.
This electron withdrawing effect of the three fluorine atoms also stabilizes CF3COO- much more than CH3COO-.
1. A green rat snake that lives in the grass and a brown rat snake that lives
in the desert is a form of
A. Human genetic modification
B. Selective breeding
C. Natural selection
D. Artificial breeding
Answer:
It is an example of natural selection (option c)
Natural selection is demonstrated by a green rat snake living within that grass as well as a brown rat snake living throughout the desert.
Natural selection:The process throughout which communities of sentient creatures adapt but instead transform is known as natural selection. Persons within a demographic are inherently varied, which means they are all unique under certain manner.
This variance indicates that certain people have qualities that are more adapted to their surroundings over others.
Thus "Option C" is correct.
Find out more information about Natural selection here:
https://brainly.com/question/14485249
Which is the best description of Darwin’s theory of evolution?
A.
It is the same as natural selection.
B.
It is based on the same ideas as Lamarck’s acquired characteristics.
C.
It states that all species evolve over time through natural selection.
D.
It describes DNA passed from parent to offspring as the driving force of evolution.
Answer:
d
Explanation:
stop answering people questions and not actually helping them typing random stuff like i just did here
It describes DNA passed from parent to offspring as the driving force of evolution.
What is evolution?
The basic idea of biological evolution is that populations and species of organisms change over time. Today, when we think of evolution, we are likely to link this idea with one specific person: the British naturalist Charles Darwin.In the 1850s, Darwin wrote an influential and controversial book called On the Origin of Species. In it, he proposed that species evolve (or, as he put it, undergo "descent with modification") and that all living things can trace their descent to a common ancestor.Darwin defined evolution as "descent with modification," the idea that species change over time, give rise to new species and share a common ancestor. The mechanism that Darwin proposed for evolution is natural selection.
therefore option D is the correct answer.
to learn more about Darwin’s theory of evolution: https://brainly.com/question/23131212
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true or false. a short circuit cannot cause a fire
Answer:
false
Explanation:
Answer:
FalseExplanation:
A short circuit can cause a spark or fire.
In an isolated system, mass can neither be
created or destroyed.
ube
FALSE
TRUE
Answer:
True
Explanation:
The law of conservation of mass states that mass in an isolated system is neither created nor destroyed by chemical reactions or physical transformations. According to the law of conservation of mass, the mass of the products in a chemical reaction must equal the mass of the reactants.
Hope it helps
Но Water Lewis steucture
what are asking commet it and I might be able to help
What is the chemical formula for aluminum tartrate?
Answer: C12H12Al2O18
Explanation:
What happens to the average kinetic energy of gas particles as temperature increases?
Answer:
it dies
Explanation:cause its too cold
Sea water contains 2% salt (NaCl) by weight. Given that water has a
density of 1g/mL. Determine the concentration of salt in:
(a) mg/L , (b) ppm.
Answer:
a) Concentration of salt in mg/L = 2g/100mL
b) concentration in ppm = 20000 ppm
Explanation:
Percentage composition of salt by weight in water = 2%
Density of water = 1 g/mL
100 mL of water will has a mass of 100 g
Mass of salt in 100 g of water = 2% ×100 g = 2 g
Therefore, 2 g of salt is dissolved in 100 mL of solution
Concentration of salt in 100 mL of solution = 2g/100mL
a) Concentration in mg/L
Mass of salt = 2 g = 2000 mg
Volume of solution = 100 mL = 0.1 L
Concentration in mg/L = 2000 mg/0.1 L
Concentration in mg/L = 20000 mg/L
b) Concentration in ppm
1 ppm = 1mg/L
Therefore, concentration in ppm = 20000 ppm
I visit the Grand Canyon __________I go to arizona.(once,whenever,wherever)
the answer for your question is whenever
That's the answer. hope you have a great day
Matching
Enter the letter of the box whose contents best match the description.
8
8
8
a
b
с
e
f
v a mixture of molecules
atoms of a pure elementa metal
molecules of an element
va solid compound
a mixture of elements
a. box a
b. box e
c. box b
d. box f
e. box d
f. box c
QUESTION 10
Answer:
a mixture of molecules - Box f
atoms of a pure elementa metal - Box D
a solid compound - Box C
a mixture of elements - Box A
Explanation:
Box a has mixture of elements which forms a solid like shape but there are different elements present in the box. The box f has mixture of molecules in which many atoms are combined together. Box c has solid compound with single element.
Which of the following best defines base isolation?(1 point)
Base isolation is a technique used by engineers to help prevent damage to buildings by volcanoes. The main structure of the building is separate from the base, which allows lava to pass under the building without causing much damage.
Base isolation is a technique used to prevent large-scale damage from volcanoes. New communities being built are set as far back as possible from the base of a volcano.
Base isolation is a technique used to prevent damage to buildings during tsunamis. The main structure of the building is separate from the base, which allows water to pass beneath buildings without causing much damage.
Base isolation is a technique used by engineers to help prevent damage to buildings by earthquakes. The main structure of the building is separate from the base and sits on a bed of springs.
Base isolation is a technique used by engineers to help prevent damage to buildings by earthquakes. The main structure of the building is separate from the base and sits on a bed of springs.
What is base isolation?Base isolation is a technique developed to prevent or minimise damage to buildings during an earthquake.
A base isolation system is a method of seismic protection where the structure (superstructure) is separated from the base (foundation or substructure). By separating the structure from its base the amount of energy that is transferred to the superstructure during an earthquake is reduced significantly.
Hence, option D is correct.
Learn more about base isolation here:
https://brainly.com/question/11337994
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Which best represents a balanced equation?
A. HgO → Hg + O2
B. 2Fe + O2 → Fe2O3
C. 2H2 + 02->2H2O
Explanation:
none of them
mark me as brainlist ok
Answer:
C
Explanation:
4 - H - 4
2 - O - 2
each side of the arrow has an equal amount of elements
Describe the effect of resonance on the amount of rotation that can occur in the main chain of your tripeptide (phenylalanine, alanine, and tyrosine), which affects protein folding.
Answer:
use research.
Explanation:
How many grams of KNO3 will dissolve in 100 g of water at 50° to make a saturated
solution
How many moles are there in 4.7 x 10^24 molecules of water?
Answer:
7.81 moles
Explanation:
(4.7×10^24 )×1 moles divided by 6.02×10^23 molecules
A 334 mL sample of hydrogen was collected over water at 23C on day when the atmospheric pressure was 756 mm Hg.The vapor pressure of water under these conditions is 17.54 mm Hg. What volume, in liters, will the dry hydrogen ( No water vapor) occupy at STP?
Answer:
0.299 L
Explanation:
We'll begin by calculating the pressure of dry gas. This can be obtained as follow:
Measured pressure = 756 mm Hg
Water vapor pressure = 17.54 mm Hg
Pressure of dry gas =?
Pressure of dry gas = (Measured pressure) – (Water vapor pressure)
Pressure of dry gas = 738.46 mmHg
Finally, we shall determine the volume occupied at STP. This can be obtained as follow:
Initial volume (V₁) = 334 mL = 334 / 1000 = 0.334 L
Initial pressure (P₁) = 738.46 mmHg
Initial temperature (T₁) = 23 °C = 23 °C + 273 = 296 K
Final pressure (P₂) = 760 mmHg
Final temperature (T₂) = 273 K
Final volume (V₂)
P₁V₁/T₁ = P₂V₂/T₂
738.46 × 0.334 / 296 = 760 × V₂/273
Cross multiply
296 × 760 × V₂ = 738.46 × 0.334 × 273
224960 × V₂ = 67334.2597
Divide both side by 224960
V₂ = 67334.2597 / 224960
V₂ = 0.299 L
Thus, the volume of the dry gas st STP is 0.299 L.
generators need sources of energy to produce electricity. which form of energy is a noble where source of energy
A. hydro (water) energy
B. geothermal energy
C. fossil fuel
D. wind energy
Answer:
B
Explanation:
3NaHCO, +CHO - CH. Na 0, +300, +3H, 0.
Name one reactant and one product
How many moles in 0.672L of F2?
Answer:
c
Explanation:
i think if not tell me ok
Gases Test
Chemistry
Answer:
6.64 l is the answer.......
How would you prepare a 1 L solution of 3 M MgO?
Answer: 175.35g
Explanation: A 3 M solution has 3 moles of solute per litre.
The mass of one mole of NaCl equals the MW of NaCl MW = 35.45 + 23 =58.45 g/mol
The mass of 3 moles is 58.45 g/mol ×3 mol=175.35 g NaCl or 200 g rounded to one sigfig.
What happens when you try to separate the atoms by pulling on them?
Answer:
They explode!!!
Explanation:
When atoms separate they release all the energy and particles in themselves and cause a chain reaction to all other atoms causing an explosion
Hope this helps, and have a nice day!
Lemon juice is an example of
A. bound water
B. free water
C. hydrates
D. All of the above.
Answer:
B. Free water