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Amebic dysentery is a disease caused by organisms that live in dirty water. Which is most likely to prevent an epidemic of amebic dysentery?
A. vaccination of the population
B. purification of drinking water
C.public education on the importance of washing hands
D.restriction on travel to places with amebic dysentery
Answer:
The answer would have to be public education on the importance of washing hands.
Explanation: Washing hands is always one of the best ways to prevent a contagious disease.
Which of the gases in air are compounds? Explain how you can tell.
Answer:
[tex]\huge \underline\bold\red{Answer}[/tex]
The air in the atmosphere consists of nitrogen, oxygen, which is the life-sustaining substance for animals and humans, carbon dioxide, water vapour and small amounts of other elements (argon, neon, etc.). Higher in the atmosphere air also contains ozone, helium and hydrogen.
Answer:
The air in the atmosphere consists of nitrogen, oxygen, which is the life-sustaining substance for animals and humans, carbon dioxide, water vapour and small amounts of other elements (argon, neon, etc.). Higher in the atmosphere air also contains ozone, helium and hydrogen.
Balloon has a volume of 600-ml at temperature of 360 K. If the temperature of
the balloon drops to 250 K, find the volume
Answer:
V₂ ≈416.7 mL
Explanation:
This question asks us to find the volume, given another volume and 2 temperatures in Kelvin. Based on this information, we must be using Charles's Law and the formula. Remember, his law states the volume of a gas is proportional to the temperature.
V₁ / T₁ = V₂ / T₂where V₁ and V₂ are the first and second volumes, and T₁ and T₂ are the first and second temperature.
The balloon has a volume of 600 milliliters and a temperature of 360 K, but the temperature then drops to 250 K. So,
V₁= 600 mL T₁= 360 K T₂= 250 KSubstitute the values into the formula.
600 mL /360 K = V₂ / 250 KSince we are solving for the second volume when the temperature is 250 K, we have to isolate the variable V₂. It is being divided by 250 K. The inverse o division is multiplication, so we multiply both sides by 250 K.
250 K * 600 mL /360 K = V₂ / 250 K * 250 K 250 K * 600 mL/360 K = V₂The units of Kelvin cancel, so we are left with the units of mL.
250 * 600 mL/360=V₂416.666666667 mL= V₂Let's round to the nearest tenth. The 6 in the hundredth place tells us to round to 6 to a 7.
416.7 mL ≈V₂The volume of the balloon at 250 K is approximately 416.7 milliliters.
what is electromagnetic?
Answer:
relating to the interrelation of electric currents or fields and magnetic fields.
Which of the following is an example of a molecular element?
a.NaCl b. CO2 c. Na d. O2
Answer:
oxygen (O2) is a molecular element
Explanation:
Molecular compound are chemical compounds that take the form of discrete molecules.
atomic element is an element which occurs independently as atoms and can react with other elements to form a compound
Ionic compounds are the compound which on dissolution form ions in solution
Mixture is the composition of different compounds
On the bottom beam of the triple beam balance, each small division stands for
A.) one centimeter
B.) one milliliter
C.) one gram
D.) one-tenth of a gram
Answer:
Hello There!!
Explanation:
I believe the answer is D.) one-tenth of a gram.
hope this helps,have a great day!!
~Pinky~
[tex]\huge{\textbf{\textsf{{\color{navy}{An}}{\purple{sw}}{\pink{er}} {\color{pink}{:}}}}}[/tex]
D.) one-tenth of a gram
Thanks.Hope it helps.How many moles of O₂ are needed to react completely with 35.0 mol of FeCl₃?
4FeCl3+3O2->2Fe2O3+3Cl2
The 2 for the second half of the equation is not a coefficient it’s supposed to be for 2Fe2 Not 2O3.
26.3 mol
46.7 mol
23.3 mol
10.0 mol
Answer:
26.3 mol O₂
Explanation:
Step 1: Write the balanced equation
4 FeCl₃ + 3 O₂ ⇒ 2 Fe₂O₃ + 6 Cl₂
Step 2: Establish the appropriate molar ratio
According to the balanced equation, the molar ratio of FeCl₃ to O₂ is 4:3.
Step 3: Calculate how many moles of O₂ are needed to react completely with 35.0 mol of FeCl₃
We will use the previously established molar ratio.
35.0 mol FeCl₃ × 3 mol O₂/4 mol FeCl₃ = 26.3 mol O₂
A balloon contains 25.0 L of helium gas at 177 kPa. What is the volume when the balloon rises to an altitude where the pressure is only 43.0 kPa ? Assume the temperature remains constant.
A.34.2 L
B.68.8 L
C.46.5 L
D.103 L
What change would shift the equilibrium system to the left?
A(g) + B(s) + Energy = 309) (3 points)
Adding more of gas C to the system
Heating the system
Increasing the volume
Removing some of gas C from the system
Answer:
C
Explanation:
sorry if its wrong but i think its right
Heating the system will shift the equilibrium system to the left.
The correct option is B.
What is equilibrium?
Chemical equilibrium is a state where no net change in the amounts of reactants and the products occurs during a reversible chemical reaction.
A reversible chemical reaction happens when the products react with the original reactants as soon as they are generated.
On a treadmill, you are walking continuously but not going anywhere, which can be said as equilibrium.
Thus, the correct option is B.
Learn more about equilibrium
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5. How would you calculate the pH (NOT POH) of a base when given
the concentration of [OHJ?
Answer:
pOH = -log₁₀ [OH-]
pH = 14 - pOH
Explanation:
First of all, calculate the value of pOH from the hydroxide concentration do this using the equation below;
pOH = -log₁₀ [OH-]
After obtaining the pOH, calculate pH using the equation below:
pH + pOH = 14
pH = 14 - pOH
1) Escribe oraciones coherentes que incluyan los siguientes términos con los conceptos correspondientes:
CARBÓN-PETRÓLEO-GAS NATURAL-RECURSO NO RENOVABLE-
COMBUSTIBLES FÓSILES-HIDROCARBUROS-RESERVAS-CONTAMINACIÓN-
MAREAS NEGRAS
La respuesta correcta para esta pregunta abierta es la siguiente.
Estas son las oraciones apropiadas.
El carbón, el petróleo, y el gas natural son recursos naturales no renovables.
Estos generadores naturales de energía son considerados combustibles fósiles que produce la mayor parte de hidrocarburos que se usan en el mundo. Sin embargo, estas reservas energéticas se están agotando porque son recursos naturales no renovables. Además, estos combustibles son altos generadores de contaminación como es el caso de las mareas negras.
Independientemente de estas ideas, es apropiado decir que los combustibles fósiles han sido fuertemente cuestionados por los ambientalistas y los científicos porque son causantes del llamado calentamiento global y del cambio climático.
Por esa razón, la sociedad y los expertos ambientalistas están pidiendo que los gobiernos comiencen a utilizar más energías alternativas y renovables como la energía solar y las turbinas de viento o energía eólica.
Hot water is poured into four cups made of different materials (foam, glass, metal, plastic).After one minute, which will feel the warmest when you touch the OUTSIDE of the cup?
Answer:
Metal
Explanation:
Foam, glass, and plastic don't absorb as much heat as metal does.
which process is a chemical change
Given a solution with a hydrogen ion concentration of 9.9 x10-13 M, calculate the
pОН. .
Answer: The pOH value is 2.
Explanation:
Given: [tex][H^{+}] = 9.9 \times 10^{-13} M[/tex]
pH is defined as the negative logarithm of hydrogen ion concentration.
Hence, pH of the given solution is calculated as follows.
[tex]pH = -log [H^{+}]\\= - log (9.9 \times 10^{-13})\\= 12[/tex]
The relation between pH and pOH is as follows.
pH + pOH = 14
Therefore, pOH is calculated as follows.
pH + pOH = 14
12 + pOH = 14
pOH = 14 - 12
= 2
Thus, we can conclude that the pOH value is 2.
What is a jet stream. in your own words but be more detailed about what you say.
(don't send a link)
How many joules of heat are needed to raise the temperature of 62.0 g of ethylene glycol from 13.1 C to 40.5C?
Answer:
Q = 4133.2 J
Explanation:
Hello there!
In this case, since these calorimetry problems are based off the following heat equation involving heat (Q), mass (m), specific heat (C) and temperatures (T):
[tex]Q=mC(T_2-T_1)[/tex]
Thus, we plug in the given variables to obtain:
[tex]Q=62.0 g*2.433 \frac{J}{g\°C}* (40.5\°C-13.1\°C)\\\\Q=4133.2J[/tex]
Regards!
Please help this is due today! 5-11-2021
Observe the chemical reaction below, and identify if the equation is balanced or not. If it is not balanced, then what coefficient should you place for the reactants and products? Justify with scientific reasoning.
Mg + O2---------> MgO
Make sure to include the following details in your answer in complete sentences:
- Is the chemical reaction balanced?
- Is it following the law of conservation of mass, why is not following?
- What can you do to make sure that the equation becomes balanced and follow the law?
Answer:
- The chemical reaction is not balanced. There is two oxygens on the reactant's side while there's only one oxygen on the products side.
- I would not say it's following the law of conservation of mass as it's not a balanced equation.
- To balance this equation, you would need to add the coefficient of '2' to Magnesium (Mg) on the reactants side, and add the coefficient of '2' to the products side. This would make it so that there's 2 Mg's and 2 O's on both the reactant's side and products side.
edit: I hope this helped you in some way. ^^
Name the process by which oxygen moves from alveoli to blood
diffusion...........the blood through the capillaries lining the alveolar walls. Once in the bloodstream, oxygen gets picked up by the hemoglobin in red blood cells.
Concerning the disposal of materials at the end of the experiment, which methods are safe? Check all that apply.
[ANSWERS]
B. Dispose of pH paper in the trash.
C. Dump the cabbage indicator solution down the drain.
D. Ask your teacher to neutralize the acids and bases before disposal.
Answer:
B. Dispose of pH paper in the trash.
C. Dump the cabbage indicator solution down the drain.
D. Ask your teacher to neutralize the acids and bases before disposal.
Explanation:
Safe disposal of waste means disposal of waste in such a way that it does not pose a threat to the environment.
When pH paper is properly disposed in the trash, it does not constitute any risk to the environment.
When a cabbage indicator solution is disposed down the drain it does not contaminate the environment. It moves directly into the sewers and is properly disposed.
When acids and bases are properly neutralized before disposal, they don't lead to acid or base contamination of the environment.
Give examples of how land resources are used in a city setting
Answer:
Land resources such as gravel and bedrock are used to construct buildings, roads, and sidewalks. Land is also where city structures—such as buildings, roads, and sidewalks—are constructed. People use land resources such as bedrock and aggregate to construct buildings, roads, and sidewalks.
I hope this answer helps
How many protons, neutrons, and electrons are found in a neutral atom of hydrogen-333?
Answer:
Explanation:
A hydrogen atom has an atomic number of 1.
So it's proton number will always be 1.
A neutral hydrogen atom does not have any charge.
So it has the same amount of electrons as protons, which turns out to be also 1.
A neutral hydrogen atom has an atomic mass of ≈
1.00794 amu ≈ 1 amu.
To find the amount of neutrons, we take the proton number and subtract it from the mass number.
1 − 1 = 0
So a neutral hydrogen atom has no neutrons.
In summary,
A hydrogen atom has
1 proton
1 electron
0 neutrons
I hope that helps!
What mass of potassium would need 2350 J of energy in order to raise its temperature from 44.3°C to 57.8°C? (cpotassium = 0.753 J/g°C)
Answer:
Explanation:
q = mCΔT
m =CΔT/q
ΔT = 57.8°C - 44.3°C = 13.5°C
m = (0.753*13.5)/2350
m = 0.00433 g
The mass of potassium that will need 2350 J of energy in order to raise its temperature from 44.3°C to 57.8°C is 231.17 g
Data obtained from the question Heat (Q) = 2350 JInitial temperature (T₁) = 44.3 °CFinal temperature of water (T₂) = 57.8 °CChange in temperature (ΔT) = 57.8 – 44.3 = 13.5 °C Specific heat capacity (C) = 0.753 J/gºC Mass (M) =?Q = MCΔT
2350 = M × 0.753 × 13.5
2350 = M × 10.1655
Divide both side by 10.1655
M = 2350 / 10.1655
M = 231.17 g
Learn more about heat transfer:
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Iodine-131 half life 8.040 how long will it take for a 40 gram sample of iodine-131 to decay to 0.75 grams
Answer:
See explanation below
Explanation:
To get this, we need to apply the general expression for half life decay:
N = N₀e(-λt) (1)
Where:
N and N₀ would be the final and innitial quantities, in this case, masses.
t: time required to decay
λ: factor related to half life
From the above expression we need λ and t. To get λ we use the following expression:
λ = t₁₂/ln2 (2)
And we have the value of half life, so, replacing we have:
λ = 8.04 / ln2 = 11.6
Now, we can replace in (1) and then, solve for t:
0.75 = 40 exp(-11.6t)
0.75 / 40 = exp(-11.6t)
ln(0.01875) = -11.6t
-3.9766 = -11.6t
t = -3.9766 / -11.6
t = 0.34 daysDescribe the three-dimensional property of an electromagnetic wave. Use the diagram below
Answer: The are waves that consist of vibrating electric and magnetic fields. They transmit energy through matter or across space. Some electromagnetic waves are generally harmless. Like other waves, electromagnetic waves have properties of speed, wavelength, and frequency.
Explanation:
Consider the reaction.
2HF(g) +
H2(g) + F2(g)
At equilibrium at 600 K, the concentrations are as follows.
[HF] = 5.82 x 10-2 M
[H2] = 8.4 x 10-3M
[F2] = 8.4 x 10-3M
What is the value of Kea for the reaction expressed in scientific notation?
O 2.1 x 10-2
102.1 x 102
1.2 x 103
0 1.2 x 10-3
Answer:
0.021
Explanation:
Step 1: Write the balanced equation
2 HF(g) ⇄ H₂(g) + F₂(g)
Step 2: Calculate the value of the concentration equilibrium constant
The concentration equilibrium constant (K) is equal to the product of the concentrations of the products raised to their stoichiometric coefficients divided by the product of the concentrations of the reactants raised to their stoichiometric coefficients.
K for this reaction is:
K = [H₂] × [F₂] / [HF]²
K = (8.4 × 10⁻³) × (8.4 × 10⁻³) / (5.82 × 10⁻²)² = 0.021
At STP, which of the following would have the same number of molecules at 1 L of C2H4 gas? Assume that each behaves as an ideal gas.
A. 0.5 L of H2 gas
B. 2 L of H2O gas
C. 1 L of Ne gas
D. 3 L of Cl2 gas
Answer: 1L of Ne gas
The answer is Option C , 1L of Ne gas will have the same number of molecules at 1 L of C₂H₄ gas
What is STP ?At standard temperature and pressure, a system is said to have a temperature of zero degrees centigrade (273 Kelvins) and the pressure equal to the atmosphere is always 1 atm.
Additionally, one mole of any gas at STP occupies a volume of 22.414 L.
This concept only holds true for gases.
So for a gas having same pressure , temperature and moles according to the Ideal Gas Law , volume also needs to be same
pV=nRT
and in the given option ,Option C has the same volume as that of 1 L of C₂H₄ gas .
To know more about STP
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How many moles is 8.3 x 10^12 atoms or particles of Br2
urgent
Explanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\[/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
We have
[tex]n = \frac{8.3 \times {10}^{12} }{6.02 \times {10}^{23} } \\ \\ \\ \\ \: \: \: \: \: \: \: = 1.379 \times {10}^{ - 11} \: \: \: \: moles[/tex]
Hope this helps you
1. If you have 8.1 g CO₂ and 2.3 g H₂, which one is the limiting reactant. Show your work. 2. Calculate the theoretical yield of CH₄.
Answer:
2.95 g of CH₄
Explanation:
To start this, we determine the equation:
4H₂ + CO₂ → CH₄ + 2H₂O
4 moles of hydrogen react to 1 mol of carbon dioxide in order to produce 1 mol of methane and 2 moles of water.
To determine the limiting reactant, we need to know the moles of each reactant.
8.1 g . 1 mol/ 44g = 0.184 moles of carbon dioxide
2.3 g . 1mol / 2g = 1.15 moles of hydrogen
4 moles of hydrogen react to 1 mol of CO₂
Then, 1.15 moles may react to (1.15 . 1) /4 = 0.2875 moles
We only have 0.184 moles of CO₂, so this is the limiting reactant. Not enough CO₂ to complete the 0.2875 moles that are needed.
Ratio is 1:1. 1 mol of CO₂ produces 1 mol of methane
Then, 0.184 moles of CO₂ will produce 0.184 moles of CH₄
We convert moles to mass: 0.184 mol . 16 g /mol = 2.95 g
Help meeeeee
A 280.0 sample of neon gas exerts a pressure of 660.0 mm Hg at 26.0°C. Assuming that the pressure remains constant, at what temperature in would the volume change to 440.0 ml?
Answer:
469.9K
Explanation:
Using Charles's law equation:
V1/T1 = V2/T2
Where;
V1 = initial volume (ml)
V2 = final volume (ml)
T1 = initial temperature (K)
T2 = final temperature (K)
Based on the information provided:
V1 = 280.0ml
V2 = 440.0 ml
T1 = 26.0°C = 26 + 273 = 299K
T2 = ?
Using V1/T1 = V2/T2
280/299 = 440/T2
0.936 = 440/T2
T2 = 440 ÷ 0.936
T2 = 469.9K
4. At what temperature will 5.00 g of Cl, exert a pressure of 900. torr at a volume of 750 ml?
Answer:
p=27.8atm
Explanation:
P = 27.8atm
At what temperature will 5.00 g of Cl2 exert a pressure of 900. mmHg at a volume of 750.