Answer:
0.268 L
Explanation:
concentration is the number of moles of solute in 1 L of solution
number of moles of KCl - 5.0 g / 74.5 g/mol = 0.067 mol
the concentration of the solution to be prepared - 0.25 mol/L
concentration = number of moles of KCl / volume of solution
substituting the values in the equation
0.25 mol/L = 0.067 mol / V
V = 0.268 L
solution should be diluted to 268 mL to make a 0.25 M solution
Final answer:
To prepare a 0.25 M KCl solution, 5.0 g of KCl should be diluted to approximately 268 mL.
Explanation:
To find out to what volume we should dilute 5.0 g of KCl to prepare a 0.25 M solution, we first need to calculate the number of moles of KCl. The molar mass of KCl is approximately 74.55 g/mol. Therefore, the moles of KCl in 5.0 g can be calculated by dividing the mass of KCl by its molar mass:
Moles of KCl = mass / molar mass = 5.0 g / 74.55 g/mol ≈ 0.067 moles
Since Molarity (M) is defined as moles of solute per liter of solution, we can rearrange the formula to solve for volume (V).
M = moles of solute / volume of solution in liters
V = moles of solute / M = 0.067 moles / 0.25 M ≈ 0.268 liters or 268 mL
Therefore, to prepare a 0.25 M solution of KCl, we need to dilute 5.0 g of KCl to approximately 268 mL.
Which of these is a chemical property?
boiling point
flammability
density
solubility
Answer:
The second choice, or flammability.
Explanation:
The flammability of something is how easy it is for it to burn or ignite.
Answer:
The Answer in flammability
Explanation:
Both fire and the fire starter are chemicals therefore its B.
1. Which color is absorbed and which is reflected by the leaves of most plants?
A. Green and violet are reflected; red is absorbed.
B. Red and blue are absorbed; green is reflected.
C. Blue and green are absorbed; red is reflected.
D. Red and violet are reflected; green is absorbed.
D. Red and Violet are reflected, Green is absorbed
Leaves of plants are green because chlorophyll pigments absorb red and blue light and reflect green light. The correct answer is B - red and blue are absorbed, and green is reflected.
The color absorbed and reflected by the leaves of most plants can be understood by examining the pigments chlorophyll a and chlorophyll b, which absorb light for photosynthesis. Chlorophyll a absorbs light primarily in the blue-violet and red regions, and chlorophyll b absorbs red-blue light. Both pigments reflect green light, which is why leaves appear green to us. Addition to this, there are carotenoids that absorb light in the blue-green and violet region and reflect longer yellow, red, and orange wavelengths.
The correct answer to the question is B. Red and blue are absorbed; green is reflected. This is because chlorophyll a and b absorb light at blue and red wavelengths, which are essential for photosynthesis, and reflect the green wavelengths that they do not absorb.
Can you accurately determine a person genotype just by observing their phenotype
Answer:
Yes.
Explanation:
All of the heterozygous pairs are either really close or the same as the homozygous.
Radio waves are ____________ waves
I'm not sure if this is the right one because there are 3 choices haha...
So it's either
1. Sound
2. Mechanical
3. Low frequency
Nitrogen has an atomic mass of about 14 amu and an atomic number of 7. How many neutrons does nitrogen have ?
Answer:
The atomic mass is 14, which is the combined mass of protons and neutrons. The atomic number is the number of protons. SO if we have a total mass of 14 and we know 7 of that is protons, 14-7=7
the nitrogen has 7 neutrons
if i add 25 ml of water to 135 ml of a 0.25 M NaOH solution what will the molarity of the diluted solution be
Answer:
0.21 M. (2 sig. fig.)
Explanation:
The molarity of a solution is the number of moles of the solute in each liter of the solution. The unit for molarity is M. One M equals to one mole per liter.
How many moles of NaOH in the original solution?
[tex]n = c \cdot V[/tex],
where
[tex]n[/tex] is the number of moles of the solute in the solution.[tex]c[/tex] is the concentration of the solution. [tex]c = 0.25 \;\text{M} = 0.25\;\text{mol}\cdot\textbf{L}^{-1}[/tex] for the initial solution.[tex]V[/tex] is the volume of the solution. For the initial solution, [tex]V = 135\;\textbf{mL} = 0.135\;\textbf{L}[/tex] for the initial solution.[tex]n = c\cdot V = 0.25\;\text{mol}\cdot\textbf{L}^{-1} \times 0.135\;\textbf{L} = 0.03375\;\text{mol}[/tex].
What's the concentration of the diluted solution?
[tex]\displaystyle c = \frac{n}{V}[/tex].
[tex]n[/tex] is the number of solute in the solution. Diluting the solution does not influence the value of [tex]n[/tex]. [tex]n = 0.03375\;\text{mol}[/tex] for the diluted solution.Volume of the diluted solution: [tex]25\;\text{mL} + 135\;\text{mL} = 160\;\textbf{mL} = 0.160\;\textbf{L}[/tex].Concentration of the diluted solution:
[tex]\displaystyle c = \frac{n}{V} = \frac{0.03375\;\text{mol}}{0.160\;\textbf{L}} = 0.021\;\text{mol}\cdot\textbf{L}^{-1} = 0.021\;\text{M}[/tex].
The least significant number in the question comes with 2 sig. fig. Keep more sig. fig. than that in calculations but round the final result to 2 sig. fig. Hence the result: 0.021 M.
Answeri think 0.21 M
Explanation:
Sally wants to see which fertilizer makes tomato plants grow the tallest. She use 3 types (A, B, C) and leaves one group in soil without any fertilizer. Identify the independent variable, dependent variable, and the control group in this experiment.
Answer:
Independent: The types of fertilizer. (Independent I Change)
Dependent: The plants height. (Dependent is Dependent on the Independent)
Control: The Type of plants (What isn't being changed throughout the experiment.)
Can anyone help me please?
Answer:
question 1:
The right choice is → c. KNO₃
question 2:
The right choice is → c. 784 mm Hg
Explanation:
===============================================================
question 1:
From the figure, the solubility of the different salts at 90 °C is:
NaCl:
It is 40 g per 100 g water.
KBr:
It is 100 g per 100 g water.
KNO₃:
It is about 240 g per 100 g water.
NaClO₃:
It is about 220 g per 100 g water.
∴ The most soluble salt in water at 90°C is KNO₃.
So, the right choice is
→ c. KNO₃
===============================================================
question 2:
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 T are constant, and have two different values of P and V:
P₁ * V₁= P₂ * V₂
from the given data :
P₁ = 3060 mm Hg
V₁ = 0.520 L.
V₂ = 2.03 L.
∴ P₂ = [P₁ * V₁] / V₂ = [3060 mm Hg * 0.520 L] / 2.03 L = 783.84 mm Hg
≅ 784 mm Hg
So, the right choice is
→ c. 784 mm Hg
===============================================================
is Tetracarbon decoxide ionic or covalent?
Answer: covalent bond
Explanation: Tetracarbon Hexahyride is built using covalent bonds
Hope this helps please mark brainlist it would be greatly appreiciated :)
-Please answer if you are sure!-
The question is:
How many seconds does it take light from the sun to reach Earth? How many nimutes is this? Show work.
(don't google it, i must answer based on numbers given to me)
Here's what it gives me to find the answer:
Light travels at a speed of 0.002 AU per second,
Earth is 1.00 AU from the sun (distance)
Earth's diameter is 12,00 (km)
Can you PLEASE tell me what numbers i need to put together to get the answers? i have multiple questions like this and i don't know how to solve.
Answer:8.35
Explanation:first subtract 0.002 by 1.00 witch is 1.002 then divid by 12,00 witch is 8.35
If 6.1 moles of copper react completely with 6.1 moles of oxygen, what is the mole ratio for the compound
Answer:
CuO with (1: 1) mole ratio.
Explanation:
When 6.1 moles of copper react completely with 6.1 moles of oxygen.They are equimole reactants with a (1: 1) mole ratio.Then, the compound has the molecular formula CuO.Which scientist performed the cathode ray experiment leading to the discovery of electrons?
A.
Dalton
B.
Rutherford
C.
Democritus
D.
Bohr
E.
Thomson
The scientist is E. Thomson .
Explanation:In the late nineteenth century, physicist J.J. Thomson started trying different things with cathode beam tubes. Cathode beam cylinders are fixed glass tubes from which the greater part of the air has been emptied. A high voltage is applied crosswise over two terminals toward one side of the cylinder, which makes a light emission stream from the cathode (the contrarily charged anode) to the anode (the emphatically charged cathode).
The cylinders are called cathode beam tubes on the grounds that the molecule bars or “cathode beam” begins at the cathode. The beam can be distinguished by painting a material known as phosphors onto the most distant finish of the cylinder past the anode. The phosphors sparkles, or produces light, when affected by the cathode beam.
PLEASE HELP ASAP ILL GIVE BRAINLIEST ITS PLATO!!!
———————————
An uncovered pot of water lies out in the sun. Which statements correctly describe what happens at the surface of the liquid water? (More than one answer)
——————————
1) The vapor pressure remains constant regardless of the water temperature.
2)The vapor pressure is produced by water molecules that have evaporated.
3) The vapor pressure increases as the Sun heats the water in the pot.
4) Evaporation stops once the vapor pressure reaches a certain point.
5) Evaporation and condensation both occur on the liquid’s surface.
Explanation:
At a given temperature, the pressure exerted by the vapors on its condensed phases in a closed system is known as vapor pressure.
Therefore, when an uncovered pot of water lies out in the sun then heat caused due to radiation of sun will heat the water. As a result, vapors start to form after a certain interval.
So, when heat inside the system increases then there will be increase in vapor pressure of the system.
Thus, we can conclude that the following statements correctly describe what happens at the surface of the liquid water:
The vapor pressure is produced by water molecules that have evaporated.The vapor pressure increases as the Sun heats the water in the pot.H2O2, hydrogen peroxide, naturally breaks down into H2O and O2 over time. MnO2, manganese dioxide, can be used to lower the energy of activation needed for this reaction to take place and, thus, increase the rate of reaction. What type of substance is MnO2 ?
a. a reactant
b. an inhibitor
c. an enhancer
d. a catalyst
Final answer:
MnO2 is a catalyst that increases the decomposition rate of H2O2 into H2O and O2 by lowering the reaction's activation energy and is not consumed in the process.
Explanation:
MnO2, manganese dioxide, serves as a catalyst in the decomposition of H2O2 into H2O and O2. A catalyst is a substance that increases the rate of a chemical reaction by lowering the activation energy needed for the reaction to proceed, without being consumed in the process. After the reaction, the catalyst returns to its initial state and can be used repeatedly. Therefore, the correct answer to the question concerning the role of MnO2 is (d) a catalyst.
How many moles of air molecules are contained in a 2.00 L flask at 98.8 kPa and 25.0 degrees of C show work plz
Answer:
7.97 x 10⁻² mol.
Explanation:
To calculate the no. of moles of a gas, we can use the general law of ideal gas: PV = nRT.where, P is the pressure of the gas in atm (P = 98.8 kPa = 0.975 atm).
V is the volume of the gas in L (V = 2.0 L).
n is the no. of moles of the gas in mol (??? mol).
R is the general gas constant (R = 0.0821 L.atm/mol.K).
T is the temperature of the gas in K (T = 25°C + 273 = 298 K).
∴ n = PV/RT = (0.975 atm)(2.0 L)/(0.0821 L.atm/mol.K)(298 K) = 7.97 x 10⁻² mol.
5 drops of 0.15 M Ki added to
40 drops of Na2S2O3
What is the final concentration of ki?
Final answer:
To find the final concentration of KI after adding 5 drops of 0.15 M KI to 40 drops of Na2S2O3, assuming each drop is equal in volume, the total volume is calculated and used to compute the final concentration, which is approximately 0.0167 M.
Explanation:
The question asks for the final concentration of KI (potassium iodide) after 5 drops of 0.15 M KI solution are added to 40 drops of Na₂S₂O₃ solution. To find the final concentration, we need to consider the total volume and the initial amount of KI. Assuming each drop has the same volume, the initial volume of KI solution is 5 drops and the final volume after mixing is 45 drops.
Initial moles of KI = Concentration × Volume = 0.15 M × 5 drops
Assuming 1 drop = 0.05 mL for calculation purposes, then 5 drops = 0.25 mL (converted to liters = 0.00025 L)
Initial moles of KI = 0.15 M × 0.00025 L = 0.0000375 mol
To find the concentration of KI in the final solution:
Final concentration = initial moles ÷ final volume = 0.0000375 mol ÷ (5 drops + 40 drops)
Assuming the volume per drop is constant, the final volume = 45 × 0.05 mL = 2.25 mL = 0.00225 L
Final concentration = 0.0000375 mol ÷ 0.00225 L = 0.0167 M
Therefore, the final concentration of KI in the mixture is approximately 0.0167 M.
What is the energy content in joules of a 1.28g sample of oatmeal that raises the temperature of 1.50 kg of water in a calorimeter from 25.0 C to 27 C
Answer:
12560 J.
Explanation:
To calculate the energy, we use the relation:The amount of heat absorbed by water = Q = m.c.ΔT.
where, m is the mass of water (m = 1.5 kg = 1500.0 g).
c is the specific heat capacity of water = 4.186 J/g°C.
ΔT is the temperature difference = (final T - initial T = 27°C - 25°C = 2°C).
∴ The amount of heat absorbed by water = Q = m.c.ΔT = (1500.0 g)(4.186 J/g°C)(2°C) = 12560 J.
NEED ANS ASAP PLSSS HELP
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:
17,140 g = 17.14 kg.
Explanation:
To solve this problem, we can use the relation:Q = m.c.ΔT,
where, Q is the amount of heat absorbed by ice (Q = 3600 x 10³ J).
m is the mass of the ice (m = ??? g).
c is the specific heat of the ice (c of ice = 2.1 J/g.°C).
ΔT is the difference between the initial and final temperature (ΔT = final T - initial T = 100.0°C - 0.0°C = 100.0°C).
∵ Q = m.c.ΔT
∴ (3600 x 10³ J) = m.(2.1 J/g.°C).(100.0°C)
∴ m = (3600 x 10³ J)/(2.1 J/g.°C).(100.0°C) = 17,140 g = 17.14 kg.
HEEEEEEEEEEELP MEEE pls.
Answer:
ummmm have no clue
Explanation:
where are the electrons found in Bohrs atomic atom
a. the electrons orbit the protons at the atoms center.
b. the electrons circle the nucleus in specific orbits.
c. the electrons occupy the atoms center, with protons orbiting.
d. the electrons are evenly distributed throughout the atom.
Answer:
The elections circle ITS B TRUST ME I JUST DID IT
Explanation:
Apex
The electrons circle the nucleus in specific orbits in Bohr's atomic atom.
Hence, Option (B) is correct answer.
What is Bohr's Atomic Model ?According to the Bohr's Atomic model the electrons orbit the nucleus at fixed energy levels. This model was proposed by Neil Bohr in 1915.
What is Orbit ?The electrons which move around in predictable path is known as orbit.
Thus from the above conclusion we can say that The electrons circle the nucleus in specific orbits in Bohr's atomic atom.
Hence, Option (B) is correct answer.
Learn more about the Bohr's Atomic Model here: https://brainly.com/question/18002213
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What is bias in an experiment?
a process where the scientists performing the research influence the results, in order to show a certain result
Answer:
Explanation:
An experimental bias can be define as the type of variable which is selectively chosen so as to obtain a desired result. It can also be said that a bias can be any kind of manipulation which is done by the experimenter so as to obtain a desired outcome or findings of the experiment. An experimenter can also take the advantage of choosing the desired samples from the collection of samples.
To avoid bias, a blinded study can be used in which the random variables as well as no bias while collecting the samples for study takes place.
A certain reaction has an equilibrium constant of 3.5 × 108 at 25°C and 6.0 × 10–2 at 500°C. Is the reaction exothermic or endothermic?
Answer:
The reaction is exothermic.
Explanation:
When the temperature changes in a balanced system, it ceases to be in equilibrium because the value of the equilibrium constant is modified. Thus, at a temperature T1 the constant is K1, and at a temperature T2, the constant is K2. The relationship between these magnitudes is given in the so-called Van't Hoff equation.
The Wan't Hoff equation is:
[tex]\frac{lnK1}{lnK2}=-\frac{H}{R} (\frac{1}{T1}-\frac{1}{T2})[/tex]
Where:
ΔH: standard enthalpy of the reaction
R: constant of ideal gases
K1: equilibrium constant at temperature T1
K2: equilibrium constant at temperature T2
The Van't Hoff equation allows us to study how the chemical equilibrium shifts with temperature depending on whether we have an endothermic or exothermic reaction. So if the reaction is exothermic, ΔH <0, increasing the temperature decreases the equilibrium constant and the reaction moves to the left, while if the temperature decreases, the equilibrium constant increases and the equilibrium moves to the right.
Therefore, given the values of the equilibrium constant at different temperatures and observing that it decreases when the temperature rises, the reaction is exothermic.
Which of these definitions could be used to define SO2 as a base? Check all that apply. Arrhenius concept Bronsted-Lowry concept Lewis concept
Answer:
Lewis concept
Explanation:
edg
Lewis concept could be used to define SO[tex]_2[/tex] as a base. Inorganic chemical sulfur dioxide (SO[tex]_2[/tex]) is a heavy, colorless gas.
What is sulfur dioxide?Inorganic chemical sulfur dioxide (SO2) is a heavy, colorless gas that is very toxic. It is created in enormous amounts during the transitional stages of the production of sulfuric acid. The stench of sulfur dioxide is as strong and unpleasant as that of a freshly struck match.
Sulfur dioxide, which naturally occurs as volcanic gases and also in solution inside the waters of certain warm springs, is often made industrially by burning sulfur or other sulfur-containing compounds like iron pyrite and copper pyrite in air or oxygen. Lewis concept could be used to define SO[tex]_2[/tex] as a base.
Therefore, lewis concept could be used to define SO[tex]_2[/tex] as a base.
To learn more about sulfur dioxide, here:
https://brainly.com/question/17021671
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Element Y is composed of three isotopes; Y-20 is 15.00%, Y-22 is 50.00%, and Y-24 is 35.00%. What is the element Y’s relative atomic mass
We take in account the following formula tot determine the relative atomic mass:
Relative atomic mass = atomic mass of isotope (1) × abundance of isotope (1) +
atomic mass of isotope (2) × abundance of isotope (2) + ... and so on
For element Y we have:
Relative atomic mass of Y = 20 × 0.15 + 22 × 0.5 + 24 × 0.35 = 22.4
Based on the image how many protons does carbon have
Carbon has 6 protons.
Hope that helped you!
I think the answers is D.12
protons and neutrons are made from which of the following?
hadrons
down quarks only
up quarks and down quarks
up quarks only
Answer: it would be c. Protons are made of two Up and one Down quark. The neutron is made of two Down and one Up quark
Protons and neutrons are made up from quarks and in protons two up quarks & in neutron two down quarks are present.
What are quarks?Quarks are the fundamental or elementary particle of any matter present in the system, and quarks are combined together for the formation of a hadron.
Protons and neutrons are the examples of hadrons which are also made up of quarks.
Protons are formed by the combination of two ups quarks and one down quark.Neutrons are formed by the combination of two dowm quarks and one up quark.Hence protons and neutrons are formed by the quarks.
To know more about quarks, visit the below link:
https://brainly.com/question/10253303
what type of solar radiation is the most powerful
Answer:
Gamma Rays are the most powerful kind of rays :p
Gamma rays are the most powerful type of solar radiation! If you need to know more on how harmful they are and what they can do let me know!
A disruption to an established ecosystem can lead to:
A.) more resources for all the organisms that make up the community.
B.) new organisms being prevented from moving into the area.
C.) hurricanes or volcanic eruptions.
D.) changes in the populations of the community.
Answer:
D.) changes in the populations of the community
Explanation:
Any disruption of any ecosystem always leads to some changes, some minor ones, some dramatic ones. All of the organisms living in a particular ecosystem are adapted to live in the conditions that it provides, so when a change occurs it causes a big stress on the populations. Depending on the change that has occurred, it can cause changes in the populations, or it can even cause extinction to some populations.
what is the grams of carbon dioxide needed to occupy a container that is 9 liter at 32 degrees Celsius and 35 kpa
Answer:
44.01 g/mol.
Explanation:
We can use the general law of ideal gas: PV = nRT.where, P is the pressure of the gas in atm (P = 35.0 kPa/101.325 = 0.345 atm).
V is the volume of the gas in L (V = 9.0 L).
n is the no. of moles of the gas in mol (n = ??? mol).
R is the general gas constant (R = 0.0821 L.atm/mol.K),
T is the temperature of the gas in K (T = 32.0°C + 273 = 305.0 K).
∴ n = PV/RT = (0.345 atm)(9.0 L)/(0.0821 L.atm/mol.K)(305.0 K) = 0.124 mol.
∴ n = mass/molar mass
∴ mass = (n)(molar mass) = (0.124 mol)(44.01 g/mol) = 5.457 g.
Which energy source contributes to the greatest emissions of gases in the environment during the energy production process
Answer:
Natural gas, emitting fewer harmful chemicals into the atmosphere than other fossil fuels, can help to mitigate some of these environmental issues. These issues include: Greenhouse Gas Emissions. Smog, Air Quality and Acid Rain
Explanation:
Final answer:
Coal combustion, part of the fossil fuels category, contributes the most to greenhouse gas emissions during energy production, particularly carbon dioxide (CO2). However, renewable energy alternatives like solar and wind power present viable solutions to reduce these emissions.
Explanation:
The energy source that contributes to the greatest emissions of gases in the environment during the energy production process is the burning of fossil fuels, notably coal, oil, and natural gas. This is primarily due to their capacity to release significant amounts of carbon dioxide (CO2) when combusted. Coal is the most carbon-intensive of these fuels, especially when used for electricity generation, leading to the highest CO2 emissions per unit of energy produced.
Coal combustion not only releases more greenhouse gas carbon dioxide per unit of energy output than any other energy-yielding process but also produces pollutants like fly ash and sulfur dioxide. However, innovations in renewable energy sources such as solar and wind power are emerging as viable alternatives to reduce reliance on fossil fuels and mitigate greenhouse gas emissions.
Given the significant environmental impact of burning fossil fuels, transitioning to renewable energy sources, enhancing energy efficiency, and investing in green technology research and development are critical steps toward combating climate change and reducing global greenhouse gas emissions.