False100% sure of it
The following question appears on a quiz: "You fill a tank with gas at 60°C to 100 kPa and seal it. You decrease the temperature to 10°C but keep the volume constant. What happens to the pressure?" A student answers that the new pressure will be 17 kPa. Which of the following explanations is true?
The student did not solve for the correct parameter, and the answer should be 50 kPa.
The student did not solve for the correct parameter, and the answer should be 600 kPa.
The student did not work with absolute temperatures, and the answer should be 85 kPa.
The student did not work with absolute temperatures, and the answer should be 888 kPa.
Answer:
The student did not work with absolute temperatures, and the answer should be 85 kPa.
Explanation:
We can use the general law of ideal gas: PV = nRT.where, P is the pressure of the gas in atm.
V is the volume of the gas in L.
n is the no. of moles of the gas in mol.
R is the general gas constant,
T is the temperature of the gas in K.
If n and V are constant, and have two different values of P and T:P₁T₂ = P₂T₁
P₁ = 100.0 kPa, T₁ = 60.0°C + 273 = 333.0 K.
P₂ = ??? kPa, T₂ = 10.0°C + 273 = 283.0 K.
∴ P₂ = P₁T₂/T₁ = (100.0 kPa)(283.0 K)/(333.0 K) = 84.98 kPa ≅ 85.0 kPa.
So, the right choice is:
The student did not work with absolute temperatures, and the answer should be 85 kPa.
The student did not work with absolute temperatures, and the answer should be 85 kPa.
Explanation:
We can use the general law of ideal gas: PV = nRT.
where, P is the pressure of the gas in atm.
V is the volume of the gas in L.
n is the no. of moles of the gas in mol.
R is the general gas constant,
T is the temperature of the gas in K.
If n and V are constant, and have two different values of P and T:
P₁T₂ = P₂T₁
P₁ = 100.0 kPa, T₁ = 60.0°C + 273 = 333.0 K.
P₂ = ??? kPa, T₂ = 10.0°C + 273 = 283.0 K.
∴ P₂ = P₁T₂/T₁ = (100.0 kPa)(283.0 K)/(333.0 K) = 84.98 kPa ≅ 85.0 kPa.
So, the right choice is:
The student did not work with absolute temperatures, and the answer should be 85 kPa.
calculate the empirical formula 9.1 g of lithium and 10.4 g of oxygen
To find the empirical formula of a compound with 9.1 g of lithium and 10.4 g of oxygen, we calculate the moles of each element and express their ratio in the simplest whole numbers. The empirical formula is determined to be Li₂O.
Explanation:To calculate the empirical formula of a compound formed from lithium and oxygen, we need to determine the moles of each element present in the 9.1 grams of lithium and 10.4 grams of oxygen. The molar mass of lithium (Li) is approximately 6.94 g/mol, and the molar mass of oxygen (O) is about 16.00 g/mol.
First, we calculate the moles of lithium:
Moles of Li = mass (g) ÷ molar mass (g/mol) = 9.1 g ÷ 6.94 g/mol = 1.31 moles of Li
Next, we calculate the moles of oxygen:
Moles of O = mass (g) ÷ molar mass (g/mol) = 10.4 g ÷ 16.00 g/mol = 0.65 moles of O
Now we determine the simplest whole number ratio of the elements in the compound:
Li to O ratio = 1.31 moles of Li ÷ 0.65 moles of O = 2:1
Therefore, the empirical formula is Li₂O
-Material A has a melting point of 34°C whereas Material B has a melting point of 56°C. Both materials have been placed in an oven at 50°C Describe the state of each material after being being in the oven for a period of time.
I'm confused, if material B is on for the same amount of time does that mean that it has liquified and material A has melted slightly?
Answer:
Explanation:
Material A has a melting point of 34°C
Material B has a melting point of 56°C
Both materials, lets say a metal have been subjected to a temperature of 50°C
After a period of time, both of them would have melted to their liquid state.
The atoms of the solids would vibrates and the bonds would begin to break to form melt.
Material A would be the first to melt as it has a lower melting point. The lower the melting point, the faster and quicker it would reach its melting temperature.
Material B would need to accumulate more heat and its temperature would continue to rise for the phase change to occur. As it reaches the 50°C mark, the bonds are set free and a melt forms.
When 2 grams of powdered lead (IV) oxide was added to 100 cm3 of hydrogen peroxide, water and oxygen were produced. Lead (IV) oxide was not used up in the reaction. Based on the information, which of the following is likely to decrease the rate of formation of the products?
Replacing the powdered lead oxide with its large crystals
Removing lead (IV) oxide from the reaction mixture
Using 50 cm3 of hydrogen peroxide
Using 1.0 gram of lead (IV) oxide
Answer:
The right answer is:
Replacing the powdered lead oxide with its large crystals
Removing lead (IV) oxide from the reaction mixture
Using 1.0 gram of lead (IV) oxide
Explanation:
Based on the given information this reaction is the catalytic decomposition of H₂O₂ into water and oxygen using Lead (IV) oxide as a catalyst.
The catalyst surface area is directly proportional to the reaction rate So, Replacing the powdered lead oxide with its large crystals would decrease the reaction rate due to the has larger surface area than its large crystals.2. Also, Removing lead (IV) oxide from the reaction mixture the reaction rate decreased because as the catalyst is removed.
3. Using 50 cm³ of hydrogen peroxide doesn't affect the rate because the concentration of the reactant doesn't change.
4. Using 1.0 gram of lead (IV) oxide would decrease the reaction rate because the amount of catalyst decreased
So, The right answer is:
Replacing the powdered lead oxide with its large crystals
Removing lead (IV) oxide from the reaction mixture
Using 1.0 gram of lead (IV) oxide
Consider the following three-step representation of a reaction mechanism.
Step 1: A + B --> AB (fast) and the rate = k[A][B]
Step 2: AB + B --> AB2 (slow) and the rate = k[AB][B]
Step 3: AB2 + B --> AB3 (fast) and the rate = k[AB2][B]
Overall: A + 3B --> AB3 and the rate = k[A][B]2
Which explains why the rate law for the overall equation is not the same as the rate equation for the rate-determining step?
A; The fastest step determines the overall rate law.
B: The overall rate law is determined from the balanced equation.
C: AB is an intermediate; therefore the rate law is determined from the reactants in the previous step.
D: B is an intermediate; therefore the rate law is determined from the reactants in the previous step.
Answer:
The answer is C. AB is an intermediate; therefore the rate law is determined from the reactants in the previous step.
I just took the test and C. was correct. Please mark me as brainliest!
Answer: C: AB is an intermediate; therefore the rate law is determined from the reactants in the previous step.
Explanation: : Rate law is usually determined from the slowest step of the reaction mechanism.
Thus as we can see that the reaction which is slow has AB as its intermediate, rate law can be determined from the same.
Moreover , we can see that the overall rate law is very different from the rat law determined from the slowest step.
34. Given the fact that the concentrations of reactants and
products are not changing, why is the word dynamic
used to describe chemical equilibrium?
Answer:
The word dynamic is used to describe chemical equilibrium because even though the concentration of reactants and products remains constant, the reaction does not stop, but still continues with the rate of forward reaction equal to the rate of backward reaction. This is opposed to static equilibrium where there is no reaction at all.
Hope this helps you out!
The word dynamic is used to describe chemical equilibrium because, despite concentrations of reactants and products being constant, reactions continue in both directions at the same rate, indicating continuous exchange.
Given the fact that the concentrations of reactants and products are not changing, the word dynamic is used to describe chemical equilibrium because, at this state, the forward and reverse reactions are happening at the same rate. Even though there is no net change in the concentrations of reactants and products, reactions continue to occur in both directions. This means that molecules of reactants are constantly being converted into products at the same rate as products are being converted back into reactants, maintaining a constant concentration of both. Therefore, the equilibrium is dynamic because the reactants and products are in a state of continuous, but balanced, exchange.
which statement defines activation energy?
Answer:
The statement which defines activation energy is that it is the difference between reactant energy and maximum energy.J
Explanation:
A reaction that does not have activation energy will not take place at all.
Answer:
c
Explanation:
What is the mass of 2.30 ×1022 molecules of NaOH (Molar mass = 40.0 g/mol)?
Answer:
1.52 g NaOH
Explanation:
The molar mass M is a physical property defined as the mass of a given substance (chemical element or chemical compound) divided by the amount of substance.
Molar mass of NaOH is 40.0 g/mol
40.0 g/mol contains 6.022 × 10²³ molecules
∴ 2.30 × 10²² molecules will contain (2.30 × 10²²) * (40.0)/6.022× 10²³
= 1.52 g NaOH
What is the rate law for the reaction?
Answer:
The correct answer option A.
Explanation:
The reaction rate is determined experimentally for different concentrations of the reactants. These data indicate that by changing the concentration of Nh4 + or NO2-, the reaction rate changes. If the concentration of Nh4 + is doubled, keeping constant at NO2- the reaction rate is doubled, and if the concentration of that same reactant is changed by a factor of 4, it is quadrupled, and so on. If the concentration of NO2- is now modified in the same way as the previous one, it is observed that it also changes the reaction rate in this way. And he overall dependence of the reaction on the concentration will be the same for both reactants.
Therefore the reaction rate is proportional to the concentration of Nh4 + and NO2-.
Snow forms when clouds cool to the dew point. True False
Answer:
False.
Explanation:
Snow forms when tiny ice crystals in clouds stick together to make snowflakes.
Answer:
what he said lol.
Explanation:
the half reaction occuring at the cathode in the balanced reaction shown below is 3MnO4- (aq) + 24H+ + 5Fe (s) ——-> 3Mn2+ + 5Fe3+ + 12H2O
MnO4- (aq) + 8H+ (aq) + 5e− → Mn2+ (aq) + 4H2O (l)
According to the ionic equation, the half reaction which occurs at cathode is MnO₄[tex]^-[/tex] (aq) + 8H [tex]^+[/tex](aq) + 5e− → Mn²[tex]^+[/tex](aq) + 4 H₂O (l).
What is ionic equation?Ionic equation is defined as a chemical equation which represents electrolytes in aqueous solutions and are expressed as dissociated ions. Ions present in aqueous solutions are stabilized by ion dipole interactions with the water molecules which are present.
An ionic equation can be written for any electrolyte which dissociates and reacts with the polar solvent. In a balanced ionic equation , number and type of atoms on each sides of reaction arrow are same. Even the net charge on both sides of the arrow is same.
Strong acids and bases exist as dissociated ions present in the solution and are written in forms of ions in ionic equation.Weak acids and bases do not dissociate completely and hence are written in the form of molecular formula.
Learn more about ionic equation,here:
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To which mineral group do most of the rocks in Earths crust belong?
Answer: silicate
Explanation:
Answer:
Silicates
Explanation:
About 90 percent of the earth's crust is composed from silicate class of minerals. They are the various compounds of silicon and other chemical elements. Quartz and feldspar are the two most common types of silicate types that are found in Earth’s crust. Mica and olivine, which are the lesser concentrates of silicates are also found abundantly in the earth's crust.
What is the overall order of reaction for this rate law: Rate = k ? A. zero B. first C. second D. third
Answer: hey plato buddie, the answer is A! zero
Explanation:
Answer : The overall order of reaction is, (A) zero order reaction.
Explanation :
Rate of reaction : It is defined as the rate of change in concentration of reactant or product with respect to time.
Order of reaction : It is defined as the sum of the exponents or powers to which the molar concentration in the rate law equation are raised to express the observed rate of reaction. It depends on the power of concentration of reactant.
As per question, the given rate expression is,
[tex]Rate=k[/tex]
From this expression we conclude that there is no power of concentration of reactant. That means, it is a zero order reaction.
Hence, the rate order of reaction is, zero order reaction.
which of the following is not a base?
A. bleach
B.toothpaste
C.shampoo
D.orange
Answer:
c. shampoo
Explanation:
The temperatures of the two glasses of water shown in the photograph above are 30°C and 0°C. Which of the following is a correct statement about two glasses of water?
A. The cold water has a higher average kinetic energy
B. The warmer water has lower thermal energy
C. The molecules of the cold water move faster
D. The molecules of the warm water have more kinetic images
A hydrocarbon with this formula C10H22:
is unstable
is unsaturated
is relatively unreactive except for combustion
shares 3 pairs of electrons in the C-C bond
Answer:
is relatively unreactive except for combustion
Explanation:
Answer:
Option 3
Explanation:
Did the odyssey and it's the right answer
which two traits best help a cactus conserve water in the dry conditions of a west texas desert ecosystem?
The answer is sharp spines and waxy stems. Hope this helped.
What products are formed in the electrolysis of 1.0 M
aqueous HBr?
In the electrolysis of 1.0 M aqueous HBr, hydrogen gas is formed at the cathode, while bromine gas and hydroxide ions are formed at the anode.
Explanation:In the electrolysis of 1.0 M aqueous HBr, the following products are formed: hydrogen gas (H2) at the cathode, and bromine gas (Br2) and hydroxide ions (OH-) at the anode.
At the cathode, reduction occurs where two hydrogen ions (H+) gain electrons to form hydrogen gas:
2H+ + 2e- -> H2
At the anode, oxidation occurs where bromide ions (Br-) lose electrons to form bromine gas and hydroxide ions:
2Br- - 2e- -> Br2
2H2O - 4e- -> 4OH- + O2
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If the amount of CFCs in the atmosphere decreases, then __.
Plato users: ozone holes could begin to shrink in size
Answer:
Ozone holes could begin to shrink in size.
Explanation:
The use of CFCs today is one of the anthropogenic causes of ozone depletion. CFCs are found in Air conditioners, refrigerators and are excellent coolants.
When CFCs are released into the atmosphere, they react spontaneously with ozone.
Ozone is made up of 3 oxygen atoms and it serves as a protective covering for the very harmful ultraviolet rays from reaching the earth. Ozone cuts off these radiation and it reflects them back into space.
Chloroflurocarbons release Chlroine atoms when they get broken down by ultraviolet rays. The Cl released produces a series of reactions in the presence of ozone.
Chlorine is very reactive as it is an halogen. It requires just an electron to complete its octet.
Chlorine freely reacts with the ozone producing a range of compounds. Most of the ozone becomes oxygen molecules.
This would deplete the ozone greatly. The increasing use of CFCs leaves holes in the ozone layer. The holes allow for harmful UV rays to reach the earth surface. This can lead to various harm on human lives on the earth surface.
This is why CFCs are not permitted in appliances again.
Someone help pls.
A s a p
A s a p
A s a p
It’s C. One or more substances with different chemical properties will form.
At 0 degrees Celsius, a gas occupies 22.4L. How hot must the gas be in celcius to reach a volume of 25.0L
Answer:
31.7 °C
Explanation:
Charles law states that for volume of a gas is directly proportional to the absolute temperature for a fixed amount of gas at constant pressure
we can use the following equation
V1/T1 = V2/T2
where V1 is volume and T1 is temperature at first instance
V2 is volume and T2 is temperature at second instance
temperature should be in kelvin scale
T1 - 0 °C + 273 = 273 K
substituting the values in the equation
22.4 L / 273 K = 25.0 L / T2
T2 = 304.7 K
temperature in celcius is - 304.7 K - 273 = 31.7 °C
the gas must be 31.7 °C to reach a volume of 25.0 L
what is the percent by mass of a solution that contains 30 grams of potassium nitrite in 0.5 kilograms of water?
Answer:
5.66 %.
Explanation:
mass percent is the ratio of the mass of the solute to the mass of the solution multiplied by 100.
mass % = (mass of solute/mass of solution) x 100.
mass of potassium nitrite = 30.0 g,
mass of the solution = mass of water + mass of potassium nitrite = 500.0 g + 30.0 g = 530.0 g.
∴ mass % = (mass of solute/mass of solution) x 100 = (30.0 g/530.0 g) x 100 = 5.66 %.
This is the process where wind, water or ice may add a layer of sediment to a landform.
Answer:
Deposition
Explanation:
Answer:
Deposition...
Explanation:
Deposition is a process in which the water, ice and wind for layers of sediments when the fluid flow loses it's kinetic energy. After losing energy, the flow of soil in restricted and a layer over layer of soil is formed by deposition called sediments.
How are acids and bases similar and different
Answer & Explanation:
Similarities:
Both acids and bases are electrolytes which means that they're good conductors of electricity. Acids and bases both produce ions in water solution.Difference:
Acids release hydrogen ions (H⁺) whereas, bases release hydroxide ions (OH⁻).Which property describes how much energy must be added to an atom to remove an outermost election
Answer:
By definition, the first ionization energy of an element is the energy needed to remove the outermost, or highest energy, electron from a neutral atom in the gas phase. The process by which the first ionization energy of hydrogen is measured would be represented by the following equation.
Explanation:
25) If an object’s density is greater than 1.00 g/mL, it will ______________ in water.
A) Sink
B) Float
__________________________________________
If an object’s density is less than 1.00 g/mL, it will ______________ in water.
A) Sink
B) Float
_______________________________________________________
26) What is the density of a rock if it has a mass of 50 g and a volume of 10 mL? (You must show your work!)
Answer:
1- Option A = Sink
2- Option B = Float
Explanation:
1- If an object’s density is greater than 1.00 g/mL, it will sink in water.
For example, the density of aluminum is 2.7g/cm³. That is why it will sink in water.
2- If an object’s density is less than 1.00 g/mL, it will float in water.
For example, the density of oak is 0.7 g/cm³. That is why oak will float in water.
3- Given data:
Mass, m = 50 g
Volume, v = 10 cm3 ( 1ml = 1cm3)
Formula of density :
Density = mass/ volume
d = m/v
d = 50g/10cm3
d = 5 g/cm3
Niagara Falls is a good example of
A.kinetic energy being converted into potential
B.potential energy being converted into kinetic energy
C.energy being lost
D.energy being created
Which one ?^
B. Potential energy being converted into kinetic energy. Hope this helps!
The second answer choice
which technique often results in the greatest habitat loss
a. silverculture
b. clear- cutting
c. thinning
d. shelterwood harvests
Answer: b. Clear cutting
Explanation:
Clear cutting is the correct option. Clear cutting involves the clearing up of entire vegetation cover of the region or cutting up of trees. This will lead to loss of canopy cover from a region. This will cause loss of biodiversity of a region as the animals, birds and insects will loose their habitat. Such faunal species may translocate to new region, decrease in number or may extinct.
Answer:
It is clear cutting
Explanation:
Clearcutting, clearfelling or clearcut logging is a forestry/logging practice in which most or all trees in an area are uniformly cut down.Clearcutting has been a controversial subject because of its environmental impact. While those who favour this method argue that it allows regenerating trees to have more access to sunlight while it reduces the risk of forest fires in some high-risk areas, opponents point out that in many cases, mass tree removal has caused soil erosion and the destruction of natural habitats for some animals.
In sexual reproduction, an offspring is produced with genes from both parents. When the offspring has a new genetic variation that it got from neither of its parents, it is called A. an autosome. B. a recessive gene. C. a mutation. D. a phenotype.
Answer:c a mutation
Explanation:
Final answer:
In sexual reproduction, a new genetic variation in offspring that did not come from either parent is called a mutation. Mutations are a key source of genetic diversity and contribute to the evolution of new characteristics within a population. So the correct option is C.
Explanation:
In sexual reproduction, when an offspring exhibits a new genetic variation not found in either parent, this is known as a mutation. Mutations are changes in DNA that serve as the ultimate source of new alleles or new genetic variation within a population. This genetic diversity is essential for the evolution of species, as it allows for adaptations to changing environments and the development of new traits.
Harmless mutations and sexual recombination play a crucial role in the evolution of new characteristics by contributing to genetic diversity. While sexual reproduction can introduce unique combinations of existing genes, it is through mutations that entirely new genetic variations can arise, potentially influencing an organism's phenotype—the observable characteristics of an individual.
What will the final volume of a gas be if it is heated from 9 K to 117 K, and the initial volume is 85.5 L?
Answer:
1111.5L
Explanation: