The evidence of chemical changes with an example of each (include all 5)
Answer:
??????????
Explanation:
What is to dissolve?
Answer:
(with reference to a solid) become or cause to become incorporated into a liquid so as to form a solution.
What effect does the addition of a catalyst have on a chemical reaction at equilibrium?
A.
It increases the rate of the forward reaction, only.
B.
It increases the rate of the reverse reaction, only.
C.
It increases the rate of both the forward and reverse reactions.
D.
It decreases the rate of both the forward and reverse reactions.
Answer:
C
Explanation:
In the presence of a catalyst, both the forward and reverse reaction rates will speed up equally. :)
How do stars, like the sun, produce energy?
• Answers MUST include:
○ how the energy is produced AND the kinds of energy produced.
Answer:
The sun, like all stars, is able to create energy because it is essentially a massive fusion reaction. Technically known as nuclear fusion, this process releases an incredible amount of energy in the form of light and heat.
Types of energy produced: Stars produce energy from nuclear reactions, primarily the fusion of hydrogen to form helium.
Explanation:
hope this helped :D
7. A certain hydrocarbon, CxHy, is burned (reacts with O2 gas) and produces 1.955 g of CO2 for every
1.000 g of H20. What is the empirical formula of this hydrocarbon?
CxHy + (X + y/4) O2 -> xCO2 + y/2 H2O
Answer:
The empirical formula of the hydrocarbon is C₂H₅
Explanation:
The formula for the hydrocarbon is [tex]C_xH_y[/tex]
The mass of CO₂ produced per 1,000 g of H₂O = 1,955 g
The equation for the chemical reaction is given as follows;
[tex]C_xH_y[/tex] + (x + y/4) O₂ → XCO₂ + y/2H₂O
From the given chemical equation, counting the number of atoms on both sides of the equation, we have;
The molar mass of CO₂ = 44.01 g/mol
The molar mass of H₂O = 18.01528 g/mol
The number of moles of H₂O in 1,000 g of H₂O = 1,000 g/(18.01528 g/mol) = 55.5084351 moles
The number of moles of CO₂ in 1,955 g of H₂O = 1,955 g/(44.01 g/mol) = 44.4217223 moles
Therefore, given that X moles of CO₂ is produced alongside Y/2 moles of H₂O. we have;
X = 44.4217223, Y/2 = 55.5084351
∴ Y = 2 × 55.5084351 = 111.0168702
The ratio of X to Y = X/Y = 44.4217223/111.0168702 = 0.40013488238
∴ The ratio of X to Y = X/Y ≈ 0.4 = 4/10
X/Y ≈ 4/10
The empirical formula is the representation of molecular formula in the smallest whole number ratio of the elements of the molecules
Therefore, when X = 4, Y = 10, from which we have the smallest ratio as;
When X = 2, Y = 5
The empirical formula of the hydrocarbon is therefore, [tex]C_xH_y[/tex] = C₂H₅
The given chemical equation becomes;
C₂H₅ + (2 + 5/4) O₂ → 2CO₂ + 5/2H₂O
C₂H₅ + 3.25 O₂ → 2CO₂ + 2.5 H₂O
We then have;
4C₂H₅ + 13 O₂ → 8CO₂ + 10 H₂O
The empirical formula of the hydrocarbon, [tex]C_xH_y[/tex] = C₂H₅.
Determine the oxidation number of the element "X" in H2XO4.
How many grams of Ca metal are produced by the electrolysis of molten CaBr2 using a current of 30.0 amp for
5.50 hours?
Answer: 123 g
Explanation: Q =It = nzF. For Ca^2+ z= 2, t = 5.5 x 3600 s and I = 30.0
And F= 96485 As/mol
Amount of moles is n = It /zF = 3.078 mol , multiply with atomic mass 40.08 g/mol
Which substances are compounds? Please help
Answer:
1 and 3
Explanation:
oh this one lol,, hope it helps
Answer:
1 and 3
Explanation:
hope this helps :)
2-ciclopropilpropano
Answer:
cool
Explanation:
What is the process of old crust sinking back into the mantle? *
a. earthquake
b. transform boundary
c. seafloor spreading
d. subduction
Answer:
dddddddddddddd
ddddddddddddddddd
Food chains always begin with what type of organism? Why?
Does somebody know the answer ?
If a 28.0 L balloon with a temperature of
25 °C is cooled in a refrigerator, what will
be the volume of the balloon be when it
reaches 5 °C?
Answer:
5.6 L
Explanation:
We can apply Charles' Law here since our pressure is constant (will not change inside the refrigerator) and we are relating change in volume with change in temperature:
V₁ / T₁ = V₂ / T₂ where V₁ and T₁ are initial volume and temperature, and V₂ and T₂ are final volume and temperature. Let's plug in what we know and solve for the unknown:
28.0 L / 25 °C = V₂ / 5 °C => V₂ = 5.6 L
5.6 L is our new volume (at 5 °C).
dlaczego emaliowane garnki rdzewieją w miejscach uszkodzenia emalii
Answer:
Explanation: I don’t even know what you said
Answer:
so basically
Explanation:
bsuxnssu hhusnn ji
37.2 moles of hydrogen gas would have what mass?
Your answer
Answer:
74.99g
Explanation:
Mass of a substance can be calculated by using the formula;
mole = mass ÷ molar mass
mass = molar mass × mole
According to this question, 37.2 moles of hydrogen gas is given.
Molar mass of hydrogen gas (H2) = 1.008(2) = 2.016g/mol
mass = 2.016 × 37.2
Mass of H2 = 74.995
Mass = 74.99g
What is the molarity of 42.1 g of AgNO3 dissolved in 1.75 L of solution?
2.31 M
B 0.248 M
C 0.142 M
D 24.1 M
Is a animal searching for water a stimulus or response
Answer:
response I believe
Explanation:
i'm pretty sure it's a response cause it's the animal responding to needing water and being thirsty
hope this helps! :)
Slow cooling of magma leads to the formation of large crystals, such as halite and calcite.
Select the correct response:
True
False
Xavier was conducting a long term study of two populations of butterflies. Both populations had the same number of individuals. Both populations lived in forests that were the same size. Population A lived in a forest that was full of milkweed, the favorite food of this butterfly species. Population B lived in a forest that had limited amounts of milkweed and other foods. Over many years, Xavier found that one of the populations was showing signs of evolutionary change. Their mouth parts were changing and they could get food from new kinds of plants. Which statement explains why one population would be more likely to evolve in response to natural selection? *
a. Population B would be more likely to change because it has a ready supply of food, and only certain butterflies would be able to survive
b. Population A would be more likely to change because it has a ready supply of food and only certain butterflies would be able to survive
c. Population A would be more likely to change because it has a limited amount of food and some butterflies might be better able to get enough food, survive, and reproduce
d. Population B would be more likely to change because those butterflies have a limited supply of food, and butterflies with certain traits might be better able to get enough food, survive, and reproduce.
Define what coal is, explain how it forms, and what it is
used for today
Answer:
the main use of coal in the United States is to generate electricity.
Coal is a combustible black or brownish-black sedimentary rock with a high amount of carbon and hydrocarbons
Coal is formed when dead plant matter decays into peat and is converted into coal by the heat and pressure of deep burial over millions of years.
__M+__Q2----->___MQ3
Answer: 2M + 3Q2 -----> 2MQ3
Explanation:
2 Ms either side, and 6 Qs either side
You need 267 mL of .25M NaCl,
but the only supply of NaCl you
have
is 1.75M NaCl. How do you prepare
the required solution?
To prepare 267 mL of 0.25M NaCl, we need to take 38.29 mL of 1.75M NaCl solution and add water to it until it makes the final volume up to 267 mL.
We need to prepare the solution of 0.25 M NaCl using 1.75 M NaCl solution, we can use the dilution formula:
[tex]C_1V_1 = C_2V_2[/tex]
where [tex]C_1[/tex], [tex]V_1[/tex] is the concentration and the volume of the initial solution, [tex]C_2[/tex], [tex]V_2[/tex] is the concentration and the volume of the final solution.
We know the final concentration and the final volume that we are required to make. So we can use the above relation to find [tex]V_1[/tex] of the solution:
[tex]V_1 = (C_2 * V_2) / C_1[/tex]
Now after substituting the values in the relation, we get:
[tex]V_1 = (0.25 M x 267 mL) / 1.75 M\\V_1 = 0.03829 L or 38.29 mL[/tex]
So to prepare 267 mL of 0.25M NaCl, we need to take 38.29 mL of 1.75M NaCl solution and add water to it until it makes the final volume up to 267 mL.
Learn more about the Dilution formula at:
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If the speed of a wave is 150 m/s and its frequency is 2 Hz, what is its wavelength?
A. 300m
B. 75m
C. 152m
D. 148m
Answer:
75m
Explanation:
Calculate the equilibrium constant of the reaction below if the pressures are 1.0atm, 2.0 atm, and 1.0 atm respectively. PCl3 + Cl2 <--> PCl5
Answer:
K = 0.5
Explanation:
Based on the reaction:
PCl₃ + Cl₂ ⇄ PCl₅
The equilibrium constant, K, is defined as:
K = P PCl₅ / P PCl₃ * P Cl₂
Where P represent the pressure at the equilibrium for each one of the gases involved in the equilibrium.
As:
P PCl₅ = 1.0atm
P PCl₃ = 1.0atm
P Cl₂ = 2.0atm
K = 1.0atm / 1.0atm * 2.0atm
K = 0.5Why might an organism have more than one arrow coming from them in the food web
PLEASE HELP
Find the kinetic energy of the horse using KE=1/2mv^2.
Answer:
78878
Explanation:
Acid rain due to air pollution when water reacts with sulfur dioxide, nitric oxide, and carbon dioxide, causes
Answer:
Acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. These substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain.
Explanation:
A gas system has an initial number of moles of 0.693 moles with the volume unknown. When the number of moles changes to 0.928 moles volume is found to be 7.98 L. What was the initial volume in mL?
Answer:
The initial volume in mL is 5959.2 mL
Explanation:
As the number of moles of a gas increases, the volume also increases. Hence, number of moles and volumes are directly proportional i.e
n ∝ V
Where n is the number of moles and V is the volume
Then, n = cV
c is the proportionality constant
∴n/V = c
Hence n₁/V₁ = n₂/V₂
Where n₁ is the initial number of moles
V₁ is the initial volume
n₂ is the final number of moles
and V₂ is the final volume.
From the question,
n₁ = 0.693 moles
V₁ = ?
n₂ = 0.928 moles
V₂ = 7.98 L
Putting the values into the equation
n₁/V₁ = n₂/V₂
0.693 / V₁ = 0.928 / 7.98
Cross multiply
∴ 0.928V₁ = 0.693 × 7.98
0.928V₁ = 5.53014
V₁ = 5.53014/0.928
V₁ = 5.9592 L
To convert to mL, multiply by 1000
∴ V₁ = 5.9592 × 1000 mL
V₁ = 5959.2 mL
Hence, the initial volume in mL is 5959.2 mL
Which reaction type is really part of another type of reaction but treated separately? Explain
Answer:
Oxidation - reduction reaction which is called redox reaction.
Explanation:
The type of reaction that is a part of another type but treated separately is called Oxidation - reduction reaction.
Thus is because they usually involve 2 separate half reactions which are oxidation reactions that involve loss of electrons and then reduction equations which involve gain of electrons.
They are treated separately for example when sodium reacts with chlorine to form sodium chloride.
2Na + Cl2 = 2NaCl
Now, sodium undergoes oxidation by loosing elctrons and it's half reaction is;
2Na → 2Na^(+) + 2e^(-)
Meanwhile chlorine undergoes reduction by gaining electrons and its half reaction is;
Cl2 + 2e^(-) → 2Cl^(-)
Which solute, an electrolyte or a nonelectrolyte, has the greater effect on the boiling point when a given amount of each
solute is dissolved in the same mass of water?
O The nonelectrolyte does because it disperses into molecules.
O The electrolyte does because it disperses into molecules.
O The nonelectrolyte does because it dissociates into ions.
O The electrolyte does because it dissociates into ions.
The solute wether electrolyte or a nonelectrolyte, has the greater effect on the boiling point when a given amount of each solute is dissolved in the same mass of water The nonelectrolyte does because it dissociates into ions.
What is a solute?Solute refers to substances or liquid which can readily dissolve in a solvent. It's concentration is lower to that of solvent.
Therefore, The solute wether electrolyte or a nonelectrolyte, has the greater effect on the boiling point when a given amount of each solute is dissolved in the same mass of water The nonelectrolyte does because it dissociates into ions
Learn more about solute below.
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Answer:
D: The electrolyte does because it dissociates into ions.
Explanation: