Answer:
In a physical change the appearance or form of the matter changes but the kind of matter in the substance does not. However in a chemical change, the kind of matter changes and at least one new substance with new properties is formed.
Bears stop coming to a river ecosystem where they have been eating many fish each day. The fish the bears eat normally eat smaller fish, which eat plants along the river bottom.
What happens to the ecosystem?
Both the larger and the smaller fish populations grow quickly but then die out because the plant life is insufficient for them all to eat.
The larger fish population will drop first, and the smaller fish population will grow quickly. The plants will die off because too many of the smaller fish are eating them.
The larger fish population explodes at first, and the smaller fish population begins to drop. Eventually, the river runs out of smaller fish so larger fish die out, and the plant population grows.
The smaller fish population begins to eat more plants and to grow. The larger fish have more food to eat so their population is able to grow, too.
Answer:
The larger fish population explodes at first, and the smaller fish population begins to drop. Eventually, the river runs out of smaller fish so larger fish die out, and the plant population grows.
Explanation:
Determine the number of electrons in an Cl ion with a charge of -3
Answer:
There are 20 electrons.
Explanation:
Chlorine has 17 electrons in its atom to begin with (you can tell from the proton number in the periodic table).
A charge of -3 means that the chlorine atom gained 3 electrons, and now needs to lose 3 electrons to return to its atom configuration.
Potassium nitrate, KNO3 , has a molar mass of 101.1 g/mol. In a constant-pressure calorimeter, 13.3 g of KNO3 is dissolved in 213 g of water at 23.00 °C . KNO3(s)−→−−H2OK+(aq)+NO−3(aq) The temperature of the resulting solution decreases to 19.60 °X . Assume that the resulting solution has the same specific heat as water, 4.184 J/(g·°C) , and that there is negligible heat loss to the surroundings. How much heat was released by the solution
Answer:
[tex]Q_{sln}=-3219.25 J[/tex]
Explanation:
Hello there!
In this case, for this calorimetry problem, it is possible for us to infer that the heat of the reaction of dissolution of KNO3 is absorbed by the solution composed by the former and water so that we can write:
[tex]Q_{rxn}=-Q_{sln}[/tex]
Thus, given the mass, specific heat and temperature of the solution, we plug in the data to obtain the heat absorbed, by the reaction:
[tex]Q_{rxn}=-m_{sln}C_{sln}\Delta T _{sln}\\\\Q_{rxn}=-(13.3+213)g(4.184\frac{J}{yg\°C} )(19.60-23.00)\°C\\\\Q_{rxn}=3219.25J[/tex]
Also, we can say the the heat released by the solution was -3219.25 J.
Best regards!
Consider the following data on some weak acids and weak bases
acid
Ka
name formula
acetic acid
HCH3CO2
1.8 x10−5
hydrocyanic acid
HCN
4.9 x 10−10
base
Kb
name formula
pyridine
C5H5N
1.7 x 10−9
ammonia
NH3
1.8 x 10−5
Use this data to rank the following solutions in order of increasing pH. In other words, select a '1' next to the solution that will have the lowest pH, a '2' next to the solution that will have the next lowest pH, and so on.
a. 0.1M NaCH3CO2
b. 0.1M NH4Br
c. 0.1M NaBr
d. 0.1M KCN
Answer:
b < c < a < d
Explanation:
The weak acid with the lowest pKa will be the most acidic. In the other way, the conjugate base which the acid is weak will be strong.
The weak base with the lowest pKb will be the most basic. And the conjugate base of the weak base will be a strong acid.
Ka Acetic acid = 1.8x10-5
Ka HCN = 1.9x10-10
Kb pyridine = 1.7x10-9
Kb NH3 = 1.8x10-5
NH4Br is the conjugate base of a weak base. That means is a strong acid.
NH4Br has the lowest pH
NaBr is the conjugate base of a strong acid, HBr. That means NaBr is neutral
The most basic between the conjugate base of the acetic acid, NaCH3CO2 and KCN is KCN because the acetic acid is the stronger acid regard to HCN.
The rank is:
NH4Br < NaBr < NaCH3CO2 < KCN
b < c < a < dThe Swedish chemist Karl Wilhellm was the first to produce chlorine in the lab
2NaCl + 2H2SO4 + MnO2 -----> Na2SO4 + MnSO4 + H2O + Cl2
If Dr. Wilhellm started with 50.0 g of each reactant, which reactant is the limiting reactant?
Answer:
Explanation:
Remark
Interesting que8stion. You have to figure out how many mols are present in each reactant. Since all periodic tables are different, I'm going to use rounded numbers. If it is too close, I will go further.
NaCl
Na = 23
Cl = 35.5
1 mol = 58.5 grams
given = 50.0 grams
Mols for the reaction = 50/58.5 = 0.855
H2SO4
H2 = 2*1 2
S = 1 * 32 32
O4 = 4*16 64
1 mol = 98 grams
mols present = 50/98 = 0.510
MnO2
Mn = 1 * 55 = 55
O2 = 2*16 = 32
1 mol = 87 grams
mols available = 50/87 = 0.5747
Discussion
Na Cl and H2SO4 both require 2 moles for every mol of Cl2 produces.
H2SO4 has 0.51 mols available for a reaction
NaCl has 0.855 moles available for a reaction
MnO2 has 0.575 moles available for a reaction.
Given those numbers 0.510 mols of H2SO4 will only produce 0.255 mols of chlorine and the rest will be reduced in a similar manner. H2SO4 is the limiting reagent (reactant).
In other words only 0.510 moles of NaCl will be used and 0.855 - 0.510 moles will be left over on the reactants side.
only 0.575 moles of MnO2 will be used and 0.065 moles will be left over.
The oddity in the result shows up because the balance numbers in the equation give a ratio of 2 to 1 for H2SO4 and NaCl The 2 belongs to the reactants and the 1 for the chlorine.
HELPP ASAP I WILL MARK BRAINIST
Answer:
I'm thinking ethier D or A
Explanation:
What is true of an earthquake that causes major damage to buildings in an area?
It has a high magnitude.
It has a high frequency.
It has a low frequency.
It has a low magnitude.
The correct option is :
=》It has a high magnitude.
the damage caused by an earthquake is proportional to its magnitude, as much the magnitude is, that much damage will be caused by it.
The term used to indicate and earthquake that causes major damage to buildings in an area is called a high magnitude earthquake. Hence, option a is correct.
What is high magnitude earthquake?The most typical way to gauge an earthquake's size is by its magnitude. No matter where you are or how violent the shaking is, it is the same number since it represents the size of the earthquake's source.
The USGS no longer uses the outmoded Richter scale to determine the magnitude of major, teleseismic earthquakes. Several magnitude scales measure various aspects of the earthquake, but the Richter scale measures the biggest wobble (amplitude) on the recording.
Currently, the USGS uses the Moment Magnitude scale to report earthquake magnitudes, however many different magnitudes can be calculated for comparison and research. Therefore, option a is correct.
Find more on earthquakes:
https://brainly.com/question/29500066
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To achieve the highest return during recrystallization of a given solid, one must: Group of answer choices Add the minimum amount of boiling solvent necessary to dissolve the solid to be crystallized. Add an excess amount of cold solvent necessary to dissolve the solid to be crystallized. Add the minimum amount of cold solvent necessary to dissolve the solid to be crystallized. Add an excess amount of boiling solvent necessary to dissolve the solid to be crystallized.
Answer:
Option A
Explanation:
Addition of too much of solvent will make the solution dilute due to which the crystals will not form. Hence option D is incorrect
On the other hand adding a minimum amount of boiling solvent will give a saturated solution for recrystallization. Hence, option A is incorrect
Addition of cold solvent will lower the rate of formation of crystals. Hence, both option B and C are incorrect
un MODELO ATÓMICO es:
a. Una esfera con partículas positivas y negativas
b. La estructura mínima de la materia.
c. Una serie de descubrimientos.
d. La representación de un átomo donde se explica su comportamiento y características.
Answer:
Creo que es D pero no tan segura
Explanation:
Are sperm and egg cells exact copies of the plant cell
Answer:
No
Explanation:
thats scientifically impossible
A reaction occurs in which carbon combines with sulfur to form carbon
disulfide. Is this a chemical reaction or a nuclear reaction, and how do you
know?
A. This is a nuclear reaction, because mass was conserved.
B. This is a chemical reaction, because only the electrons were
rearranged.
C. This is a nuclear reaction, because there was a change in the
atoms' nuclei.
D. This is a chemical reaction, because mass was not conserved.
The reaction in which carbon combines with sulfur to form carbon
disulfide. Is
B. This is a chemical reaction, because only the electrons were rearranged.What is a chemical reaction?In a chemical reaction, bonds between molecules of the reactant are broken and new bonds between molecules of the product are established to create a new substance.
Chemical reactions occur all around us, including in our body's digestion of food and the creation of the sunlight's light. Understanding physical and chemical changes is crucial before starting any chemical reactions.
Sulfur and carbon combine to form carbon disulfide in an endothermic reaction that absorbs 92 kJ/mol of heat.
Learn more about carbon disulphide at:
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What's you're favorite year?
Answer:
2020 cause of the lockdown
Explanation:
WILL GIVE BRAINLIEST!!!
Answer:
The answer is B
Explanation:
The answer is B because representative particles can only be atoms.
how a scientist might use a graph of the
relationship between population growth and time to identify
a trend
Which of the following is an advantage of asexual reproduction compared to sexual reproduction?
Both will produce genetically identical offspring from the parent.
Sexual reproduction will increase genetic variability within a species.
Asexual reproduction requires less energy and will produce more offspring over time.
Sexual reproduction has minimal changes of mutations compared to asexual reproduction.
Explanation:
sexual reproduction has minimal changes of mutations compared to asexual reproduction
Answer:
sexual reproduction has minimal changes of mutations compared to asexual reproduction
I hope this helps
PLEASE HURRY!!!
It took Mrs. Murphy 5.5 hours traveling at a rate of 113 km/hr to finally reach her parents house.
How far did she travel?
How many grams of N2 is needed to produce 2000 grams NH3?
Answer:
1644 g
Explanation:
Step 1: Write the balanced equation
N₂ + 3 H₂ ⇒ 2 NH₃
Step 2: Calculate the moles corresponding to 2000 g of NH₃
The molar mass of NH₃ is 17.03 g/mol.
2000 g × 1 mol/17.03 g = 117.4 mol
Step 3: Calculate the moles of N₂ needed to produce 117.4 moles of NH₃
The molar ratio of N₂ to NH₃ is 1:2. The moles of N₂ needed are 1/2 × 117.4 mol = 58.70 mol
Step 4: Calculate the mass corresponding to 58.70 moles of N₂
The molar mass of N₂ is 28.01 g/mol.
58.70 mol × 28.01 g/mol = 1644 g
You are performing an acid-base neutralization reaction in the laboratory to determine the concentration of an unknown base. You are supposed to titrate it with a monoprotic acid, but your lab partner accidentally fills your buret with sulfuric acid, a diprotic acid, with the same concentration as the acid called for in the experiment. How will the volume of diprotic acid compare to the volume of monoprotic acid you would have used
Answer:
Volume is reduced to half
Explanation:
Acid base titration are commonly used reactions in a lab, and are ofter used to get pH or different kind of solutions.
The neutralization of an acid base reaction is reached, when the solution (having added an indicator previously) changes its original color. chemically speaking, this occurs when the number of moles of the acid and the base are balanced and equal. In other words the following:
n₁ = n₂ (1)
This expression can also be expressed in function of concentration and volume:
M₁V₁ = M₂V₂ (2)
From here, solving for V₁:
V₁ = M₂V₂ / M₁
Now, this expression is true only when we have the same kind of substance that can lose or gain the same number of hydrogens.
Lets suppose that we have as base NaOH (Monoprotic base) and HCl (monoprotic acid), the titration reaction would be:
NaOH + HCl --------> NaCl + H₂O
As both of the species are monoprotic, the number of moles are the same when they reach the equilibrium, so, expression (2) can be used, and calculate volume or concentrations.
However, in this case, a partner made a mistake and use a diprotic acid, in this case, H₂SO₄, In this case, things chance because H₂SO₄ is diprotic, meaning that we need to dissociate two hydrogens in equilibrium, therefore, expression (2) would be something like this.
Acid: 1; Base: 2
H₂SO₄ + 2NaOH ------> Na₂SO₄ + H₂O
nH₂SO₄ = n₁ = 1
nNaOH = n₂ = 2
n₁/n₂ = 1/2
2n₁ = n₂ (3)
Writting this, in function of concentration and volume, it would be:
2M₁V₁ = M₂V₂ (4)
From here, if we solve for the volume of the acid (V₁):
V₁ = M₂V₂ / 2M₁
Therefore, according to this expression, we can see that the volume required of the acid would be half the volume required of the monoprotic acid. For example, if we need 50 mL of Chloridic acid to reach the equivalence point with NaOH, then, with H₂SO₄ it will only need 25 mL. This, of course, assuming that concentrations are the same, and volume of the base used, the same.
Hope this helps
If a substance has a density of 0.123 g/mL, 10.0 dL would weigh in g?
Answer:
123 g
Explanation:
First, we convert 10.0 dL into mL, keeping in mind that:
1 dL = 100 mL; then10.0 dL * 100 = 1000 mLNow we can multiply the density by the volume in order to calculate the mass:
Density = mass / volumeDensity * volume = mass0.123 g/mL * 1000 mL = 123 g10.0 dL of a substance with a density of 0.123 g/mL would weigh 123 grams.
Write a balanced equation for the double-replacement precipitation reaction described, using the smallest possible integer coefficients. A precipitate forms when aqueous solutions of nickel(II) nitrate and sodium carbonate are combined. Do not include states such as (s) or (aq). It is not necessary for you to indicate which of the products is the precipitate.
Answer:
Ni(NO₃)₂ + Na₂CO₃ ⇒ NiCO₃ + 2 NaNO₃
Explanation:
Let's consider the unbalanced equation for the reaction that occurs when aqueous solutions of nickel(II) nitrate and sodium carbonate are combined. This is a double-replacement precipitation reaction.
Ni(NO₃)₂ + Na₂CO₃ ⇒ NiCO₃ + NaNO₃
We will balance the equation using the trial and error method.
First, we will balance Na atoms by multiplying NaNO₃ by 2.
Ni(NO₃)₂ + Na₂CO₃ ⇒ NiCO₃ + 2 NaNO₃
As we can see, the equation is balanced.
Please help me on 6 and 8 thanks
Answer:
6.) 3, 12, 1, and 4 8.) 4, 1, and 3
Explanation:
By multiplying subscripts inside and outside of the parentheses you can count the number of atoms that are present. I recently answered a question for you and I did the math wrong I am going to go back and comment so you know which one and I will correct my errors. Sorry for the inconvenience!
the number of atoms in number 6:
N: 3
H: 12
P: 1
O: 4
the number of atoms for number 8:
Ca: 4
C: 1
O: 3
hope I clarified my mistake and helped you! :)
Here are the atomic masses of hypothetical elements:
X = 13.25 amu
Y = 69.23 amu
Z = 109.34 amu
3.8 moles of X2Y5Z3 is equivalent to how many grams?
Enter your answer to zero decimal places (round to the ones place). Do
not include the units of "g", just the numerical answer.
Answer:
2663 g
Explanation:
We'll begin by calculating the molar mass Of X₂Y₅Z₃. This can be obtained as follow:
Molar mass of X₂Y₅Z₃ = (13.25×2) + (69.23×5) + (109.34×3)
= 26.5 + 346.15 + 328.02
= 700.67 g/mol
Finally, we shall determine the mass of 3.8 moles of X₂Y₅Z₃. This can be obtained as follow:
Molar mass of X₂Y₅Z₃ = 700.67 g/mol
Mole of X₂Y₅Z₃ = 3.8 moles
Mass of X₂Y₅Z₃ =?
Mass = mole × molar mass
Mass of X₂Y₅Z₃ = 3.8 × 700.67
Mass of X₂Y₅Z₃ = 2663 g
Therefore, the of 3.8 moles of X₂Y₅Z₃ is
2663 g
Which of the following is a characteristic shared by all living things?
A. They have tissues and organs,
B. They take in oxygen.
C. They make more individuals of the same kind.
D. They move.
How many grams are there in 1.8055 x 10^25 molecules of sodium sulfate? Hint: Convert to moles first
Answer:
4258.82 g of Na₂SO₄
Explanation:
From the question given above, the following data were obtained;
Number of molecules of Na₂SO₄ = 1.8055x10²⁵ molecules.
Number of mole of Na₂SO₄ =?
From Avogadro's hypothesis,
6.02×10²³ molecules = 1 mole
Therefore,
6.02×10²³ molecules = 1 mole of Na₂SO₄
Next, we shall determine the mass of 1 mole of Na₂SO₄. This can be obtained as follow:
1 mole of Na₂SO₄ = (23×2) + 32 + (16×4)
= 46 + 32 + 64
= 142 g
Thus,
6.02×10²³ molecules = 142 g of Na₂SO₄
Finally, we shall determine the mass of Na₂SO₄ that contains 1.8055x10²⁵ molecules. This can be obtained as follow:
6.02×10²³ molecules = 142 g of Na₂SO₄
Therefore,
1.8055x10²⁵ molecules
= (1.8055x10²⁵ × 142) / 6.02×10²³
= 4258.82 g of Na₂SO₄
Thus, 4258.82 g of Na₂SO₄ contains 1.8055x10²⁵ molecules
What happens to the entropy when a solution is made?
A. The entropy increases.
B. The entropy decreases.
C. The entropy goes to zero.
D. The entropy is unaffected.
Answer:
The entropy increases
Explanation:
Just took the quiz
give same examples of ways that people destroy the plant animals relationship?
During energy conversions, some energy is always lost as _____.
heat
electricity
chemical energy
light
Answer:
electricity
Explanation:
I know this because I am currently learning about this and remember doing it
2 Which of the gases in air are elements? Explain how you can tell.
Answer:
I'll explain.
Explanation:
The molecules of two different elements, nitrogen and oxygen, make up about 99 percent of the air. The rest includes small amounts of argon and carbon dioxide. Oxygen is the life-giving element in the air. You can tell because they're on the periodic table which is a table for elements.
Explanation:
nitrogen and oxygen are the gases in the air which are elements you can simply say it by looking the periodic table
Which of the following regions has an economy based on processing food and consumer goods?
A. Western Europe
B. Eastern Europe
C. northern Europe
D. southern Europe
No links plz
Answer:
B. Eastern Europe
Explanation:
The economy of Eastern Europe depends on producing foods. For example, Poland and Belarus are two countries in Eastern Europe, and they both produce chocolates. Producing foods isn't the only detrimental part of the region's economic data. The other half depends on consumer goods. For example, Estonia and Latvia are good countries in packaging food. The answer to the question is B.
Write the balanced equation for the equilibrium reaction for the dissociation ofsilver chloride in water, and write the K expression for this reaction. Then create an ICE chart. Since we know the equilibrium concentration of the silver ion, we can solve for Ksp.Does it agree with the literature value
Answer:
See explanation
Explanation:
Hello there!
In this case, since the the concentrations are not given, and not even the Ksp, we can solve this problem by setting up the chemical equation, the equilibrium constant expression and the ICE table only:
[tex]AgCl(s)\rightleftharpoons Ag^+(aq)+Cl^-(aq)[/tex]
Next, the equilibrium expression according to the produced aqueous species as the solid silver chloride is not involved in there:
[tex]Ksp=[Ag^+][Cl^-][/tex]
And therefore, the ICE table, in which x stands for the molar solubility of the silver chloride:
[tex]\ \ \ \ \ \ \ \ \ \ \ \ \ \ AgCl(s)\rightleftharpoons Ag^+(aq)+Cl^-(aq)[/tex]
I - 0 0
C - +x +x
E - x x
Which leads to the following modified equilibrium expression:
[tex]Ksp=x^2[/tex]
Unfortunately, values were not given, and they cannot be arbitrarily assigned or assumed.
Regards!
