Answer:
Desertification?
Explanation:
Desertification is when fertile lands become desert like
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 daysHydrogen gas can be produced in the laboratory by the reaction of magnesium metal with hydrochloric acid, according to the following equation:
Mg(s) + 2HCl(aq) --> MgCl2(aq) + H2(g)
a. How many grams of hydrogen can be produced when 4.00 g of HCl is added to 3.00 g of Mg?
b. Assuming STP, what is the volume of this hydrogen?
Answer: 0.11 g H2
Explanation: just took test and got it right
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
https://brainly.com/question/13458865
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!
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
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.
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
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
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
1. What is the new volume of a sample of neon if 5.23 L of the gas, which was originally at 214 mmHg, is compressed until the pressure increases to 796 mmHg?
2. When a balloon containing 635 mL of air is taken from sea level (at standard pressure) to a higher altitude, the balloon expands to 829 mL. What is the air pressure at this new altitude (in atm)?
3. A 465 mL sample of gas at 55°C is cooled to standard temperature (0°C). What is its new volume?
4. To what Celsius temperature does 750. mL of gas originally at −12°C need to be heated to bring the volume to 2.10 L?
5. The pressure in a car tire is 217 kPa at 24°C. After being driven on a hot summer day, the pressure in the tire increases to 258 kPa. What is the Celsius temperature of the air in the tire?
6. A gas sample originally at −39°C is heated to standard temperature (0°C), at which point its pressure is measured to be 808 mmHg. What was the original pressure of the gas?
7. A 400. mL sample of gas at 15°C and 113 kPa is heated to 227°C while expanding into a 900. mL container. What is the new pressure of the gas in kPa?
8. 2.50 g of CO2 gas is confined in a rigid cylinder at a pressure of 4.65 atm. If 0.42 g of gas is released from the cylinder, what is the new pressure?
Please help I'm so bad at chemistry
Here are attached photos, I don’t think they ar links, lmk if they don’t work
in the answering section it didn’t show me the full question so I only saw a little of question 5. Hopefully you get the idea of how to identify which equations to use tho! Good luck!
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.
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.
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
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.
which process is a chemical change
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!
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
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.
True or False: When it is spring in the Northern Hemisphere, it is autumn in the Southern Hemisphere.
Answer:
That is true
Explanation:
(reporting links) brainly
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 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
Select all of the HOMOGENEOUS mixtures from this list (click all that apply).
A. Paint
B. Chili
C. Blood
D. Soil
E. Salt water
Answer:
E is answer
Explanation:
salt water is the answer
Answer:
E.Salt water
Explanation:
Salt water is a homogeneous because the dissolved salt is evenly distributed throughout the entire salt water sample. The amount of salt in the salt water can vary from one sample to another.
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.
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.
A2 Could you remove the iron from the iron sulfide using
magnet?
Explain your answer.
What product is formed when sodium and chlorine undergo a synthesis reaction? sodium chlorite
sodium chlorate
sodium and chloride
sodium chloride
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.Find the molality of a solution of 58.5 g NaCl dissolved in 0.556 kg of water
Answer:lmk
Explanation:
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. ^^
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.