A chemical change means that a new substance was formed. Different from what it was before the change took place.
Flammability and decomposition are examples of chemical changes. <<<This is chemical change. An example can be seen in fruit. When a cut apple stays to long in the open it turns brown. This is because it is oxidized. Even if the apple tastes the same on the molecular level it has changed
Chemical changes involve a rearrangement of atoms to form new substances. <<< It states even in the definition of chemical change that a new substance has to be formed
Chemical changes can often be identified by the formation of a gas or a solid or the release of heat. <<< In a chemical change something extra may be created. This is different from an ice cub melting (which would be physical change). Although it goes from solid to liquid it is still water, and there is no extra product
Nothing is altered at the molecular level during a chemical change. <<<This is false
Hope this helped!
Which of the following is true for the equilibrium constant of a reaction?
It is a ratio of coefficients of reactants to products.
It has a different value at different temperatures.
It is represented by the symbol H.
Its value is always less than 1.
Answer:
It has a different value at different temperatures.
Explanation:
For any system in equilibrium, the molar concentration of all the species on the right hand side are related to the molar concentrations of those at the left side by a constant known as the equilibrium constant.
The equilibrium is a constant at a given temperature as it is temperature dependent.
A change in temperature of an equilibrium system shifts the system to a new equilibrium point. A rise in temperature actually shifts equilibrium position to the direction that absorbs heat and vice versa.
The shift in equilibrium as a result of temperature change is actually a change in the value of the equilibrium constant. Equilibrium constant is represented as [tex]K_{eq}[/tex]
The derivation of the equilibrium constant is based on the Law of Mass Action which states: the rate of a chemical reaction is proportional to the product of the concentrations of the reacting substances.
Answer:
It has a different value at different temperatures.
Explanation:
I took the test, and this answer was correct
which of the following natural resources does not contribute to global warming
coal
natural gas
nuclear power
oil
Answer:
The right choice is "nuclear power "
Explanation:
Human activities like burning coal for warming or for using in industries, heat our homes with oil, or switching on our natural gas stoves for cooking produce carbon dioxide gas and other gases (i.e. greenhouse gas) responsible for global warming .
while, nuclear power doesn't contribute to the universe with any of this greenhouse gas
So, the right choice is "nuclear power "
Need help on this ASAP !!!!
Answer:
2.5 moles of O₂
Explanation:
2RbNO₃⇒2RbNO₂+O₂-------------The equation is balanced
Mole ratio for the equation
2RbNO₃⇒2RbNO₂+O₂
2 2 1
RbNO₃:O
2:1---------------------------------------For every mole of oxygen produced ,two moles of RbNO₃ are required
Given
5 moles of RbNO₃ will produce ? moles of oxygen
2 moles of RbNO₃=1 mole of oxygen
5 moles of RbNO₃=?
=(5×1)/2 = 2.5 moles
what is matter and energy
Answer:
Matter is something that is made of atoms like a liquid, solid, or gas and energy is when water becomes a gas and the energy starts to get faster to where there is steam because the gas is being trapped inside the pot or any other object.
Explanation:
Explain how to convert a mass of compound A to a mass of compound D in words with no equations using the following reaction 2A + 4B -> C + 3D
Answer:
Explanation:
The given reaction equation is:
2A + 4B → C + 3D
We know the mass of compound A in the reaction above. We are to find the mass of compound D.
We simply work from the known mass to calculate the mass of the unkown compound D
Using the mole concept, we can find the unknown mass.
Procedures
We first find the molar mass of the compound A from the atomic units of the constituent elements. We then use the molar mass of A to calculate its number of moles using the expression below:Number of moles of A = [tex]\frac{mass of A}{molar mass of A}[/tex]
Using the known number of moles of A, we can work out the number of moles of D.From the balanced equation of the reaction, it is shown that:
2 moles of compound A was used up to produced 3 moles of D
Then [tex]\frac{3}{2}[/tex] x number of moles of A would give the number of moles of D
Now that we know the number of moles of D, we can find its mass using the expression below:Mass of D = number of moles of D x molar mass of D
Engineers increase output in crop production by combining the strengths of
two plants. This can be done by using one plant to pollinate a different plant
so that their strengths are combined into a new plant. What is this technique
called?
Answer:
Cross-pollination
Explanation:
This technique is used to create new varieties, usually with stronger characteristics than the two original varieties. When the pollen of one variety is placed to a different plant's stigma, the resulting seeds create a new variety. This cross-pollination is used in plants of the same species.
Answer:
Crossbreeding
Explanation:
apex
If a reaction has a ΔG of -136kJ at 110 ºC, will it be spontaneous at this temperature (110 ºC)?
Answer:
The reaction will be spontaneous.
Explanation:
The change in free energy (ΔG) is the difference between the heat released during a process and the heat released for the same process occurring in a reversible manner. The sign of ΔG gives an indication for the spontaneity of the reaction:If ΔG is negative, the reaction is spontaneous.
If ΔG = zero, the reaction is at equilibrium.
If ΔG is positive, the reaction is non-spontaneous.
Answer: The Answer is Yes! at least on odyssey ware
Explanation: I Know this is right because I was right and got a solid 100% on it. So there is the answer for yall legends!
Which statement about concentration cells is correct?
A.
The concentrations are the same and the reactions are the same, so the cell potential is 0.00 volts.
B.
The concentrations are the same and the reactions are different, so the cell potential is greater than 0.00 volts.
C.
The concentrations are the same and the reactions are different, so the cell potential is less than 0.00 volts.
D.
The concentrations are different and the reactions are different, so the cell potential is 0.00 volts.
Final answer:
The correct statement is that in a concentration cell, the reactions are the same but the concentrations are different, which results in a cell potential greater than 0.00 volts until equilibration.
Explanation:
The correct statement about concentration cells is: The concentrations are different and the reactions are the same, so the cell potential is not 0.00 volts. Essentially, concentration cells consist of two half-cells with identical electrodes and the same redox active species at different concentrations. The standard electrode potential (E°) in a concentration cell is zero because the electrodes are identical; however, there is a potential difference, calculated with the Nernst Equation, due to varying concentrations. As the reaction in a concentration cell proceeds, the concentrations equilibrate and the cell potential (ΔEcell) decreases until the concentrations become equal and ΔEcell reaches zero.
Which chemical equation is balanced? This is timed, please help!
Answer: It's the first one,
A gas in a rigid container at 25C has a pressure of .96atm. A change in temperature causes the pressure to increase to 1.25 atm. What is the new temperature of the gas
The answer is:
The new temperature of the gas is equal to 388.22 K
Why?Since we have a rigid container, we can safely assume that the volume is kept constant.
To solve the problem, we need to use the Gay Lussac's Law, which states that the pressure and the volume of an ideal gas are proportional when the volume is kept constant.
Also, we need to remember that Gay Lussac's Law works with absolute temperature, so, we need to convert the given temperature (in celsius degrees) to Kelvin.
[tex]T(K)=273.15 + T(\°C)\\\\T(K)=273.15 +25=298.15K[/tex]
So, using the Gay Lussac's equation, we have:
[tex]\frac{P_1}{T_1}=\frac{P_2}{T_2}[/tex]
Where,
[tex]P_1[/tex] is equal to the first pressure.
[tex]T_1[/tex] is equal to the first temperature.
[tex]P_2[/tex] is equal to the new pressure.
[tex]T_2[/tex] is equal to the new temperature.
We are given the following information:
[tex]P_1=0.96atm[/tex]
[tex]T_1=298.15K[/tex]
[tex]P_2=1.25atm[/tex]
Then, substituting and calculating, we have:
[tex]T_2=P_2*\frac{T_1}{P_1}\\\\T_2=1.25atm*\frac{298.15K}{0.96atm}=388.22K[/tex]
Hence, the new temperature of the gas is equal to 388.22 K.
Have a nice day!
Answer: the person up there had the correct answers so far, but didn’t complete it, but after converting it , finish it .
temperature in celcius - 388 K - 273 = 115 °C
answer is C. 115 °C
What’s the charge of cu3PO4
Answer:No charge
Explanation:
Cu3PO4 is an ionic compound which my definition has no charge (or a charge of 0). But if you are referring to the ions themselves that make up the compound, PO4 is a polyatomic ion so you can look up its charge in a polyatomic ion chart (it is 3-). Thus since there are 3 Cu's per PO4^3-, each Cu must have a charge of 1+.
The charge of Cu3PO4 is neutral, and each Cu ion in the molecule carries a +1 charge to balance the -3 charge from the phosphate ion.
Explanation:The compound Cu3PO4 is made up of Cu (Copper) and PO4 (Phosphate) ions. When these ions bind to form an ionic compound such as Cu3PO4, the total charge of the compound should be neutral.
The charge of Cu3(PO4)2 is +2.
In this case, phosphate has a charge of -3, and for the molecule to be neutral, the total charge from the 3 Copper ions must be +3, making the charge of each Cu (Copper) ion as +1.
Learn more about Ionic Compound here:https://brainly.com/question/33500527
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Determine the volume in liters of a 1.00 ounce bottle. (1.06 qt. = 1 L; 32 ounces= 1 qt)
A 1.00-ounce bottle holds approximately 0.0295 liters of liquid, by converting ounces to quarts (1.00 ounce / 32 ounces), and then quarts to liters (the resulting number of quarts / 1.06).
Explanation:Given that there are 32 ounces in 1 quart and 1.06 quarts in 1 liter, we can first convert ounces to quarts, and then quarts to liters. So, if we have 1.00 ounce, we simply divide this number by 32 to get the equivalent in quarts. The answer is about 0.03125 quarts. Then, we convert quarts to liters by dividing the number of quarts obtained by 1.06, yielding approximately 0.0295 liters.
Thus, a 1.00-ounce bottle would hold about 0.0295 liters of liquid.
Learn more about Volume conversion here:https://brainly.com/question/34663568
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Which type of fire should never be put out with water?
paper fire
clothing fire
wood fire
grease fire
Answer:
grease fire. The others are solids that will easily be put out with water.
Answer:
grease fire
Explanation:
DOING THAT WILL JUST MAKE IT WORSE
hope it helps
At 40.0°C, the pressure inside a nitrogen-filled tennis ball with a volume of 148
cm is 235 kPa. How many moles of nitrogen (N2) are in the tennis ball?
A 13.4 mol
B 4.22 * 102 mol
C 1.34 x 10-2 mol
OD 0.105 mol
Answer:
the answer is
n = 0.01336 mol
Explanation:
To determine the number of moles of a gas, we need to have an expression that relates the pressure, temperature and volume of the system. For simplification, we assume that this gas is ideal so we use the equation PV=nRT. We calculate as follows:
PV=nRT
n = PV / RT
n = 235000(1.48x10^-4) / (8.314)(40+273.15)
n = 0.01336 mol
Answer : The correct option is, (B) [tex]1.34\times 10^2mol[/tex]
Explanation :
To calculate the moles of nitrogen gas we are using ideal gas equation:
[tex]PV=nRT[/tex]
where,
P = pressure of nitrogen gas = 235 kPa = 2.319 atm
Conversion used : (1 atm = 101.325 kPa)
V = volume of nitrogen gas = [tex]148cm^3=148mL=0.148L[/tex]
Conversion used : (1 L= 1000 mL)
T = temperature of nitrogen gas = [tex]40.0^oC=273+40.0=313K[/tex]
R = gas constant = 0.0821 L.atm/mole.K
n = moles of nitrogen gas = ?
Now put all the given values in the ideal gas equation, we get:
[tex](2.319atm)\times (0.148L)=n\times (0.0821L.atm/mole.K)\times (313K)[/tex]
[tex]n=0.0134mol=1.34\times 10^2mol[/tex]
Therefore, the number of moles of nitrogen gas are, [tex]1.34\times 10^2mol[/tex]
which of these energy
resource is non rewnable?
Nonrenewable resources are those found inside the earth, and they took millions of years to form. These include the fossil fuels, oil, natural gas, and coal and nuclear energy
_______________ reactions transfer energy to the surroundings, usually as heat. A) Decomposition B) Endothermic C) Exothermic D) Synthesis
Answer: C EXOTHERMIC
Explanation:
Answer: C
Explanation:
if you supply 3600 kJ of heat, how many grams of ice at 0°C can be melted, heated to its boiling point? (Make M your X in equations) (figure out which q you need)
Answer:
=1.36kg
Explanation:
First heat is absorbed to melt the ice- latent heat of fusion of ice then heat is absorbed to raise the temperature to 373K
The specific heat capacity of water is 4.187kJ/kg/K while the latent heat of fusion of ice is 2230kJ/kg/K.
Letting the mass of the ice to be =x
x×2230kJ/kg/K + x×4.187kJ/kg/K×100K= 3600kJ
2230x+418.7x=3600
2647.8x=3600
x=1.36 kg
Under what conditions will a gas be least likely to exhibit the ideal gas properties predicted by the ideal gas law?
A gas deviates most from the ideal gas law at low temperatures and high pressures due to the increased significance of molecule volume and intermolecular attractions.
Explanation:A gas will be least likely to exhibit the ideal gas properties predicted by the ideal gas law under conditions of low temperatures and very high pressures. At high pressures, gas molecules are forced closer together, which means they occupy a more significant volume relative to the space they are in, challenging the assumption that their volume is negligible. At low temperatures, the decreased kinetic energy of the gas particles means that intermolecular attractions become more significant, further deviating from ideal behavior.
In what zone of the ocean are thermal vents found? How are they related to organisms in this zone?
the very bottom of the ocean and they are relevant by most of the animals feed off of the animals that come out of he vents
Neutralization of HCl and NaOH
Answer:
the reaction with the hydrochloric acid and the sodium hydroxide gives you HCl + NaOH which gives you H2O + NaCl.
Explanation:
Balance the chemical equation. Balancing the neutralization reaction involves the process of making sure that there is an equal number of moles of each of the elements on both sides of the equation.
Why resolution power in TEM microscope is higher than SEM microscope
Answer:
Here's what I get.
Explanation:
Two factors:
1. Higher accelerating voltages
Both types use a beam of accelerated electrons as a source of illumination.
Resolution depends on the wavelength of the electron beam. The shorter the wavelength, the smaller the objects you can "see."
SEMs usually use acceleration voltages up to 30 kV, while TEMs can set them as high 300 kV. Thus, the electron wavelengths in TEMs are shorter by a factor of 10.
2. Less spherical aberration
Spherical aberration degrades the quality of the image. It decreases as wavelength decreases, so you can push the magnification higher with a TEM without losing image quality.
Answer:
idfk
Explanation:
A temperature change in a reaction indicates_____.
A temperature change in a reaction indicates a chemical change
A temperature change in a reaction indicates occurrence of chemical change.
Explanation:In chemistry, two types of reaction are always witnessed. One is physical reaction whereas the other is chemical reaction. In a chemical reaction, there is an adjustment in the organization of the substances whereas in a physical change there is a distinction in the appearance, smell, or straightforward showcase of an example of issue without an adjustment in structure.
At the point when bonds are broken and new ones are shaped, a compound change happens. The following happenings indicate the chemical change:
Change in Temperature Change in Color Recognizable Odor Development of a Precipitate or bubblesCan someone plz explain ionic and covalent bonding plzzzz!!!
Answer:
Ionic Bonding: The formation of an Ionic bond is the result of the transfer of one or more electrons from a metal onto a non-metal.
Covalent Bonding: Bonding between non-metals consists of two electrons shared between two atoms.
Explanation:
After a party, a room is known to have high entropy and thus is a good example of which law?
the zeroth law of thermodynamics
the first law of thermodynamics
the law of conservation of energy
the second law of thermodynamics
the second law of thermodynamics
Which is not a strong electrolyte?
Some bases
Water
Some acids
Salts
Answer:
Water
Explanation:
Strong electrolytes will completely ionize in water, and water cannot do that to itself.
which is not a strong electrolyte?
water
(Multiple choice) Which actions are part of the dissolution process of an ionic solute in water?
The ions are pushed together to form molecules.
Each ion is surrounded by water molecules.
The water molecules attract some ions and repel others.
The ions in the solute separate from each other.
The water molecules break apart into ions.
Answer: Each ion is surrounded by water molecules
Explanation: The ions are surround by the water molecules which act as a barrier around the ions and prevent the recombination of ions. The ions are said to be hydrated.
Answer:
Each ion is surrounded by water molecules.
Explanation:
During dissolution of ionic solute in water the following process occur
a) Breaking of molecule into separate ions (need lattice energy)
b) hydration of each ion by water molecules (hydration energy is released)
c) due to hydration the ions of solutes further become far from each other.
There is no breaking of water molecule or the ions do not combine to form molecule.
Chlorine gas react with potassium bromide. Predict the products of this reaction and their states.
Give an explanation for you answer.
can someone please explain how I get to an answer please
Answer:
See below.
Explanation:
Chlorine gas replaces the bromine in potassium bromide to form potassium chloride and bromine liquid is released.
The equation for the reaction is:
Cl2 (g) + 2KBr (s) = KCl (s) + Br2 (l).
This reaction occurs because chlorine is more reactive then bromine.
What volume in mt, of 0.5a M1HCI solution is needed to neutralize 77 ml of 1.54 M NaOH solution?
Answer:
237.2 mL.
Explanation:
We have the rule: at neutralization, the no. of millimoles of acid is equal to the no. of millimoles of the base.(XMV) acid = (XMV) base.
where, X is the no. of (H) or (OH) reproducible in acid or base, respectively.
M is the molarity of the acid or base.
V is the volume of the acid or base.
(XMV) HCl = (XMV) NaOH.
For HCl; X = 1, M = 0.5 M, V = ??? mL.
For NaOH, X = 1, M = 1.54 M, V = 77.0 mL.
∴ V of HCl = (XMV) NaOH / (XV) HCl = (1)(1.54 M)(77.0 mL) / (1)(0.5 M) = 237.2 mL.
A scientist wants to use a model to help present the results of his detailed scientific investigation.
Why would a model be useful?
because the model makes the concepts easier to understand
because the model is easy to put together and to use
because the model prevents other scientists from asking questions
because the model requires the audience to pay full attention to it
Because the model makes the concepts easier to understand.
Answer:
A. because the model makes the concepts easier to understand
Edge.2023
Explanation:
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The inert gas which is substituted for nitrogen in the air used by deep sea divers for breathing, is
A. Argon
B. Xenon
C. Helium
D. Krypton
The gases used in different types of welding would include
A. oxygen and hydrogen
B. oxygen, hydrogen, acetylene and nitrogen
C. oxygen, acetylene and argon
D. oxygen and acetylene
The property of a substance to absorb moisture from the air on exposure is called
A. osmosis
B. deliquescence
C. efflorescence
D. desiccation
In which of the following activities silicon carbide is used?
A. Making cement and glass
B. Disinfecting water of ponds
C. cutting very hard substances
D. Making casts for statues
The average salinity of sea water is
A. 3%
B. 3.5%
C. 2.5%
D. 2%
Answer:
1. C. helium
2. D. oxygen and acetylene
3. B. deliquescence
4. C. cutting very hard surfaces
5. B. 3.5%
Explanation: