A radioactive isotope has a half life of 25 minutes. How many half lives have occurred after 175 minutes?
5
6
7
8
Will give Brainliest

Answers

Answer 1

Answer:

7

Explanation:


Related Questions

When humans plant more trees, carbon can begin entering the ____
a- hydrosphere
b- geosphere
c- biosphere

Answers

Answer:

biosphere

Explanation:

The carbon cycle is the biogeochemical cycle by which carbon is exchanged between the biosphere, geosphere, hydrosphere and atmosphere of the Earth.

The biosphere refers to the regions of the surface and atmosphere of the earth or another planet occupied by living organisms.

Plants are responsible for taking in carbon in nature. When more trees are planted, carbon is absorbed by plants which is a component of the biosphere. Hence planting more trees means increasing the intake of carbon into the biosphere.

Given:
CH4 + 2O2 → CO2 + 2H2O, ΔH = -890 kJ/mol

How much energy is released when 59.7 grams of methane (CH4) reacts with oxygen?

The combustion of 59.7 grams of methane releases ____ kilojoules of energy

Answers

Answer:

The combustion of 59.7 grams of methane releases 3320.81 kilojoules of energy

Explanation:

Given;

CH₄ + 2O₂ → CO₂ + 2H₂O, ΔH = -890 kJ/mol

From the combustion reaction above, it can be observed that;

1 mole of methane (CH₄) released 890 kilojoules of energy.

Now, we convert 59.7 grams of methane to moles

CH₄ = 12 + (1x4) = 16 g/mol

59.7 g of CH₄ [tex]= \frac{59.7}{16} = 3.73125 \ moles[/tex]

1 mole of methane (CH₄) released 890 kilojoules of energy

3.73125 moles of methane (CH₄) will release ?

= 3.73125 moles x  -890 kJ/mol

= -3320.81 kJ

Therefore, the combustion of 59.7 grams of methane releases 3320.81 kilojoules of energy

Answer:

The combustion will release -3,321 KJ/mol of energy

Explanation:

How many grams of CO2 are produced from the burning of 1.0 mol of amyl alcohol, C5H11OH?

Answers

Answer:

220g of CO2

Explanation:

Step 1:

The balanced equation for the reaction.

2C5H11OH + 15O2 —> 10CO2 + 12H2O

Step 2:

Determination of the number of mole of CO2 produced by burning 1 mole of C5H11OH.

From the balanced equation above,

2 moles of C5H11OH produced 10 moles CO2.

Therefore, 1 mole of C5H11OH will produce = (1 x 10)/2 = 5 moles of CO2.

Therefore, 5 moles of CO2 is produced from the reaction.

Step 3:

Conversion of 5 moles of CO2 to grams.

Molar mass of CO2 = 12 + (2x16) = 44g/mol

Number of mole of CO2 = 5 moles

Mass of CO2 =...?

Mass = mole x molar mass

Mass of CO2 = 5 x 44

Mass of CO2 = 220g.

Therefore, 220g of CO2 were obtained from the reaction.

What are the four main parts of the Sun? *

Answers

Answer: The inner layers are core, radiative zone, and convective zone. The putter layers a photosphere, the chromosphere, the transition region and the corona

How might an antioxidant prevent another element from gaining or losing an electron?

Answers

Answer:

An antioxidant helps in the mopping up and elimination of free radicals and a common example is Glutathione. Oxidation reactions Involves the transfer of electrons or addition of oxygen to a substance.

Antioxidants help in decreasing or prevention of the oxidation of the molecules due to free radicals being formed which causes damage in the cells of animals.

A sample of diborane gas has a pressure of 345 torr at a temperature of -15c and volume of 3.48L if conditions are changed so that the temperature is 36c and the pressure is 468 torr what will be the volume of the sample

Answers

Answer: 3.05L= V2

Explanation:

using

P1V1/T1=P2V2/T2

where p1= 345torr

T1, tempertaure= -15c+ 273=258K

T2, temperature= 36+ 273=309K

p2, Pressure= 468 torr

V2=???

P1V1/T1=P2V2/T2

v2=P1V1T2/T1P2= 345X3.46L X 309/ 258X 468=

V2=  3.05L

what is the molarity of 2.3 mol of Kl dissolved in 0.5 L of water

Answers

Answer:

[tex]4.6\,\,moL\,\,L^{-1}[/tex]

Explanation:

Molarity refers to a measure of concentration.

Molarity = moles of solute/Litres of solution

Molarity refers to number of moles of solute present in this solution.

In order to find a solution's molarity, use value for the number of moles of solute  and the total volume of the solution expressed in liters

As molarity of 2.3 mol of Kl is dissolved in 0.5 L of water,

Molarity = [tex]\frac{2.3}{0.5} =4.6\,\,moL\,\,L^{-1}[/tex]

Na2O+H2O= 2NaOH how many grams of Na2O are required to produce 1.06*10^2 grams of NaOH

Answers

Answer:

77.5 grams of Na2O

Explanation:

Convert grams to mols.

1.06 x 10^2 grams x 1 mol NaOH/39.99

= 2.50 mols NaOH

Find the mole ratio of NaOH and Na2O

1:2

Convert mols NaOH to Na2O mols

2.50 mols NaOH x 1 mol Na2O/2 mols NaOH

= 1.25 mols Na2O

Convert to grams

1.25 mols Na2O x 61.98 grams Na2O/1 mol

= 77.5 grams Na2O required to produce 1.06 x 10^2 grams of NaOH

How do astronomers know about the future collision of Andromeda and the Milky Way?
A) All galaxies will collide at some point
B) The two galaxies have collided previously
C) Astronomers have observed their movements over time
D) The Milky Way has changed course to head toward Andromeda

Answers

Answer:

Astronomers have observed their movements over time

Explanation:

Just took the test!!!

The future collision of Andromeda and milky way are known by astronomers because ; ( C ) Astronomers have observed their movements over time

Andromeda also known as messier 31 is a spiral galaxy that appears as a  milky blur when viewed from the earth and it is believed to be slightly over 2.5 million years old.

Astronomers predict that based on its movement and the movement of the Milky way there is most likely going to be a collision in future between the Andromeda and milky way.

Hence we can conclude that The future collision of Andromeda and milky way are known by astronomers because Astronomers have observed their movements over time

Learn more : https://brainly.com/question/2849133

What is the percentage composition of cobalt in cobalt(II) fluoride, CoF2?

Answers

Answer:

60.8%

Explanation:

We'll begin obtaining the molar mass of cobalt(II) fluoride, CoF2. This can be done as shown below:

Molar mass of CoF2 = 59 + (19x2) = 97g/mol.

The percentage composition of cobalt in cobalt(II) fluoride, CoF2 is given by:

Mass of Co/Molar Mass of CoF2 x 100

=> 59/97 x 100 = 60.8%

Therefore, the percentage composition of cobalt in cobalt(II) fluoride, CoF2 is 60.8%

Wax is a nonpolar substance . In which type of substance is it the most soluble ?

Answers

Answer:

nonpolar

Explanation:

Use the phrase "like dissolves like"

- Hope that helps! Please let me know if you need further explanation.

What conclusion can you draw from the heating curve?

Answers

Answer:A heating curve graphically represents the phase transitions that a substance undergoes as heat is added to it. The plateaus on the curve mark the phase changes. The temperature remains constant during these phase transitions.

Why might you have difficulty determining the pH of bleach using ph strips?

Answers

Answer:

pH test strips will lose colour and their pH sensitivity as strips are made from universal indicator. Universal indicator is composed of phenolphthalein, methyl red, methyl orange and thymol blue.

Explanation:

pH test strips are made from the universal indicator. The universal indicator is composed of phenolphthalein, methyl red, methyl orange, and thymol blue. All of these will react with chlorine in bleach. As a result, they will lose color and pH sensitivity. Due to this, it is difficult to determine the pH of bleach using ph strips.

According to one acid-base theory a molecule acts as an acid when the molecule

Answers

Donates an H+ ion {Arrhenius theory}

(Multiple Choice, 30 pts)

A student thinks that halogens are highly reactive because their electrons are weakly attracted to their nuclei. Which is evidence that disputes this student's idea?

A. Halogens react with alkali metals.
B. Halogens cannot react with noble gases.
C. Halogens tend to attract electrons when bonding.
D. Halogens have a full octet of electrons.

Answers

Answer:

c

Explanation:

¨Halogens being non metals have greater electronegativities hence, attract electrons and making the statement disputed. Nobel gases are highly stable; this explains why they are nonreactive. They do not form chemical bonds because they only have a little tendency to either gain or lose an electron; on the other hand, halogens are reactive because they only need one additional electron to complete their octet. ¨

i found that from another users answer for the same question

Answer:

answer c

Explanation:

A reaction starts with 20.0 grams of lithium hydroxide (LiOH) and produces 31.0 grams of lithium chloride (LiCl), what is the percent yield of lithium chloride (LiCl)? *
LiOH + KCl - LiCl + KOH

A) 64.5%
B) 88.6%
C) 81.5%
D) 92.8%

Answers

Answer:

B) 88.6%

Explanation:

Percent yield equals actual yield divided by theoretical yield

actual yield is 31.0g

theoretical yield is 35g

percent yield was 88.57 which rounds up to 88.6%

Which of the following Noble Gases has a mass of 10.0 g?

Answers

Answer:

Option B is correct.

0.119 mole of Kr has a mass of 10.0 g

Explanation:

The complete Question was ontained online, albeit, it was incomplete, even from the online source. But the solution is possible based on the part of the question obtained.

Complete Question

Which of the following Noble Gases has a mass of 10.0 g?

A. 2.02 mol Ne B. 0.119 mol Kr C.

Solution

Number of moles = (Mass)/(Molar Mass)

Mass = (Number of moles) × (Molar mass)

Checking the options, one at a time,

A. 2.02 moles of Neon

Number of moles = 2.02 moles

Molar Mass of Neon = 20.1797 g/mol

Mass = 2.02 × 20.1797 = 40.762994 g ≠ 10.0 g

Not the answer.

B. 0.119 moles of Krypton

Number of moles = 0.119 moles

Molar Mass of Krypton = 83.798 g/mol

Mass = 0.119 × 83.798 = 9.971962 g ≈ 10.0 g

This is definitely the answer.

Hope this Helps!!!

Answer: 0.119 mol Kr

Explanation:

A group of tissues working together is?

Answers

Answer:

An organ

Explanation:

An organ is one or more tissues that work together to form a specific function.

- Hope that helps! Please let me know if you need further explanation.

What mass of sulfuric acid (H2SO4) is contained in 50.00 mL of a 5.85 M solution? grams

Answers

Answer:

28.69 grams

Explanation:

To find the mass, we first need to find the moles. Once we have the moles, it is easy to use the molar mass of H2SO4 to find its mass.

To find the moles, remember that molarity (M) is equal to the moles divided by the volume (L). The volume HAS TO be converted to liters!

M = moles / V

5.85 M = moles / 0.05 L

moles = 0.2925

Now we know that we have 0.2925 moles of sulfuric acid. The molar mass of sulfuric acid is 98.08 g/mol.

0.2925 moles * (98.08 g / mol) = 28.69 grams

Make sense? If you have any questions, don't hesitate to ask!

How many copper atoms are in a 70g copper

Answers

Answer:

[tex]x = 6.634\times 10^{23}\,atoms[/tex]

Explanation:

The quantity of atoms within the mass of copper is determined by multiplying the quantity of moles by the Avogadro's Number:

[tex]x = \left(\frac{70\,g}{63.546\,\frac{g}{mol}} \right)\cdot \left(6.022\times 10^{23}\,\frac{atoms}{mol} \right)[/tex]

[tex]x = 6.634\times 10^{23}\,atoms[/tex]

Answer:

6.64x10^23 atoms.

Explanation:

From Avogadro's hypothesis, 1 mole of any substance contains 6.02x10^23 atoms. This implies that 1 mole of Cu also contains 6.02x10^23 atoms.

1 mole of Cu = 63.5g

If 63.5g of Cu contains 6.02x10^23 atoms,

Then 70g of Cu will contain = (70x6.02x10^23) /63.5 = 6.64x10^23 atoms.

Therefore, there are 6.64x10^23 atoms in 70g oh Cu

Calculate the hyrdrogen ion concentration [h+] for the aquesous solution in which [oh-] is 1 x 10-2 mol/l.Is the solution acidic,basic,or neutral? Show your work

Answers

Answer:

- [tex][H^+]=1x10^{-12}[/tex]

- Basic.

Explanation:

Hello,

In this case, given the concentration of hydroxyl ions, one could compute the pOH as shown below:

[tex]pOH=-log([OH^-])=pOH=-log(1x10^{-2})=2[/tex]

Then, since the pOH and the pH are related by:

[tex]pH+pOH=14[/tex]

One computes the pH:

[tex]pH=14-pOH=14-2=12[/tex]

Now, we compute the concentration of hydronium by:

[tex][H^+]=10^{-pH}=10^{-12}[/tex]

[tex][H^+]=1x10^{-12}[/tex]

Finally, since the pH is greater than 7 (neutral point) we conclude that the solution is basic.

Best regards.

Answer:

A. Hydrogen ion concentration, [H+] is 1x10^–12 mol/L

B. Since the pH is 12, the solution is basic.

Explanation:

Data obtained from the question. This includes the following:

Concentration of Hydroxide ion, [OH-] = 1x10^–2 mol/L

Concentration of Hydrogen ion, [H+] =.?

pH =..?

A. Determination of the hydrogen ion concentration, [H+] .

The hydrogen ion concentration, [H+] can be obtained as follow:

[H+] x [OH-] = 1x10^–14

[OH-] = 1x10^–2

[H+] x 1x10^–2 = 1x10^–14

Divide both side by 1x10^–2

[H+] = 1x10^–14 / 1x10^–2

[H+] = 1x10^–12 mol/L

B. Determination of the pH of the solution.

The pH of the solution can be obtained as follow:

pH = –Log [H+]

[H+] = 1x10^–12 mol/L

pH = –Log 1x10^–12

pH = 12.

Then pH of a solution ranges between 0 and 14.

A pH reading between 0 and 6 is termed an acidic solution, a pH reading of 7 is termed a neutral solution and a pH reading between 8 and 14 indicates an alkaline or a basic solution.

The higher the pH value, the more alkaline or basic the solution becomes.

Since the pH is 12, the solution is basic.

Gas Laws
Assignment Active
Applying Gas Laws to Aerosol Can D
(国座
Explain why it is not a good idea to throw an
aerosol can into a fire. Which gas law applies?
DONE​

Answers

Answer:

Ideal Gas Law

PV = nRT

Explanation:

Pressure is proportional to temperature;

The heat of the fire would cause increased pressure inside the closed aerosol vessel, eventually resulting in explosion of the vessel, once the temperature rises enough.

On May 3, Zirbal Corporation purchased 4,500 shares of its own stock for $36,000 cash. On November 4, Zirbal reissued 800 shares of this treasury stock for $7,200. Prepare the May 3 and November 4 journal entries to record Zirbal's purchase and reissuance of treasury stock.

Answers

Answer:

Explanation:

Each share costs $36000/4500

= $8

800 shares will cost 800*8

= $6400

Find attached the journal

What is the mass of 3.00 moles of carbon

Answers

Answer:

36 grams as 1 mole is 12 grams

Answer:

tbh idk cause I will love to answer your question but ehh

Balance equation: _NO + _H2O = _NH3 + _O2

Answers

Answer:

4NO + 6H2O = 4NH3 + 5O2

Explanation:

Think about it this way: there are 4N's 4O's and 12H's and 10O's on both sides that's what makes it balanced

Hope this helps :)

Which statement describes a gas condensing into a liquid?
A.
The atoms in the molecules get heavier so they move less.
B.
The molecules break into smaller pieces that take up less space.
C.
The molecules stick together to make bigger molecules.
D.
The molecules get closer together and move more slowly.

Answers

Answer: molecules get closer

Explanation:

Condensation is the process in which molecules of a gas slow down, come together, and form a liquid. When gas molecules transfer their energy to something cooler, they slow down and their attractions cause them to bond to become a liquid

hope this helps

pls mark me brainliest

Answer:

D. The molecules get closer together and move more slowly.

The Ka of acetic acid (CH3COOH) is 1.8 x10-5.
Calculate the pH of a 3.0 M solution of acetic acid.

Answers

Answer: 2.13

Explanation: i crawled so you could run :)

5. On what organ does alcohol have the most noticeable effect?

Answers

Answer:

the liver

Explanation:

it processes alcohol, work very hard

Which phrase describes a volcano that is not expected to erupt again?
quiet volcano
extinct volcano
dormant volcano
explosive volcano

Answers

Volcanoes which are not expected to erupt again is known as Extinct Volcanoes.
Extinct because they aren’t expected to erupt again

En la reacción I2(g) + Br2(g) « 2 IBr(g), Keq = 280 a 150°C. Suponga que se permite que 0.500 mol de IBr en un matraz de 1.00 L alcancen el equilibrio a 150°C. ¿Cuáles son las presiones parciales de equilibrio de IBr, I2 y Br2?

Answers

Answer:

P IBr: 15.454atm

I₂: 0.923 atm

P Br₂: 0.923atm

Explanation:

Basados en la reacción:

I₂(g) + Br₂(g) ⇄ 2 IBr(g)

La constante de equilibrio, Keq, es definida como:

[tex]Keq = \frac{P_{IBr}^2}{P_{I_2}P_{Br_2}}[/tex]

Se cumple la relación de Keq = 280 cuando las presiones están en equilibrio

Usando PV = nRT, la presión inicial de IBr es:

P = nRT / V; 0.500mol*0.082atmL/molK*423.15K / 1.00L = 17.3 atm

Siendo las presiones en equilibrio:

P IBr: 17.3 - 2X

P I₂: X

P Br₂: X

Donde X representa el avance de reacción.

Remplazando en Keq:

280 = (17.3 - 2X)² / X²

280X² = 4X² - 69.2X + 299.29

0 = -276X² - 69.2X + 299.29

Resolviendo para X:

X = -1.174 → Solución falsa. No existen presiones negativas

X = 0.923 → Solución real

Así, las presiones parciales en equilibrio de cada compuesto son:

P IBr: 17.3 - 2X = 15.454atm

P I₂: X = 0.923atm

P Br₂: X = 0.923atm

Answer:

[tex]p_{I_2}=0.926atm\\p_{Br_2}=0.926atm\\p_{IBr}=15.5atm[/tex]

Explanation:

Hello,

In this case, given the initial load of 0.500 mol of IBr in the 1.00-L, we compute its initial concentration:

[tex][IBr]_0=\frac{0.500mol}{1.00L}=0.500M[/tex]

Hence, by knowing the original reaction, we should invert it as IBr will produce iodine and bromine considering the initial load:

[tex]2IBr(g)\rightleftharpoons I_2(g) + Br_2(g)[/tex]

Therefore, the equilibrium constant should be inverted:

[tex]K'=\frac{1}{Keq}=\frac{1}{280}=3.57x10^{-3}[/tex]

So we write the law of mass action:

[tex]K'=\frac{[I_2][Br_2]}{[IBr]^2}[/tex]

That in terms of the change [tex]x[/tex] due to the reaction extent turns out:[tex]3.57x10^{-3}=\frac{(x)(x)}{(0.500-2x)^2}[/tex]

In such a way, solving by using solver or quadratic equation we obtain:

[tex]x_1=-0.0339M\\x_2=0.0267M[/tex]

Clearly, the solution is 0.0267M, thus, the equilibrium concentrations are:

[tex][I_2]=x=0.0267M[/tex]

[tex][Br_2]=x=0.0267M[/tex]

[tex][IBr]=0.5M-2x=0.5M-2*0.0267M=0.447M[/tex]

Thus, with the given temperature (150+273.15=423.15K), we compute the partial pressures by using the ideal gas equation:

[tex]p_{I_2}=[I_2]RT=0.0267\frac{mol}{L} *0.082\frac{atm*L}{mol*K}*423.15K\\\\p_{I_2}=0.926atm\\\\p_{Br_2}=[Br_2]RT=0.0267\frac{mol}{L} *0.082\frac{atm*L}{mol*K}*423.15K\\\\p_{Br_2}=0.926atm\\\\p_{IBr}=[IBr]RT=0.447\frac{mol}{L} *0.082\frac{atm*L}{mol*K}*423.15K\\\\p_{IBr}=15.5atm[/tex]

Best regards.

Other Questions
What made the televised operations of Desert Storm distinct from the war footage that had emerged from Vietnam?Choose 1 answer:Choose 1 answer:(Choice A)ADesert Storm was the first American conflict to be broadcast on live television.(Choice B)BThere was no difference in the amount or quality of the footage, but Americans paid much more attention to the Vietnam War than they did to Desert Storm.(Choice C)CThere was considerably more public protest for Desert Storm thanks to its broad media coverage. Which of the following presents a safety hazard while working in the science laboratory?A knowing how to use equipmentB wearing safety gogglesC following directionsD working alone 2x - x-6=0 resuelve Michael Jordan lleva una talla _________. pequea mediana vieja grande The political power of the wealthy, elite Proprietors was decreased. Backcountry settlements were opened and many Scotch-Irish and German settlers caused the population to grow on thefrontier The English government began to import naval stores from South Carolina and allowed merchants to sell rice directly toother countries. Tensions between the Lowcountry and Backcountry increased over the issue of representationThis list of notes would be MOST useful to a student writing a research paper titledA)"South Carolina's Transition from Proprietary Rule to a Royal Colony."B)"South Carolina's Transition from a Royal Colony to Proprietary Rule."C)"Reasons for the Division of the Colony into North and South Carolina."D)"Factors Leading to the Rise of the Regulator Movement in South Carolina." The altitude of an airplane is decreasing at a rate of 44 feet per second. What is the change in altitude of the airplane over a period of 34 seconds? A light beam approaches a plain mirror at an incident angle of 39degrees. What is the angle of reflection? what is the y-intercept of the graph of the equation y=4x(3x) A; (0,4) B: (0,3) C;(0,12) D:(0,8) two integers that multiply to 18 and add to -11 A sample space consists of 80 separate events that are equally likely. What is the probability of each? A sample space consists of 80 separate events that are equally likely. What is the probability of each? In general, when a substance changes from a solid to a liquid, A. the density of the substance increases. B. the substance no longer has density since density is a property only solids have. C. the density of the substance decreases. D. the density of the substance remains the same. Tom and Sam can finish a plowing job in two hours. Tom working alone can do the job in 7 hours. How long would it take Sam to finish the same job alone? Suppose that the standard deviation of monthly changes in the price of commodity A is $2. The standard deviation of monthly changes in a futures price for a contract on commodity B (which is similar to commodity A) is $3. The correlation between the futures price and the commodity price is 0.9. What hedge ratio should be used when hedging a one month exposure to the price of commodity A what is the purpose of the explanation of Benefits? If the sum of 4040 consecutive integer numbers is 2020, find out the absolute difference between the first number and the last number. Construct one circle with center A passing through point B and another circle with center A passing through C. Circles with common centers are called concentric circles. Well refer to the circle that passes through B as AB and the one that passes through C as AC. Besides being concentric, what is the relationship between circles AB and AC? someone please help me Which of the following BEST describes the main difference between scarcity and a shortage? 20 POINTS!! FASTEST ANSWER GET BRAINLY!!!A.While a shortage is a temporary market condition, scarcity is an ongoing condition in the world.B.While scarcity is a temporary market condition, a shortage is an ongoing condition in the world.C.Scarcity is found throughout the world, but shortages only occur in wealthy countries.D.Shortages occur everywhere, but scarcity happens only in countries with very high poverty levels. Which sentence BEST states the main idea of paragraph 4 in Weather Out of This World? Why was Okinawa so important to the US and Japan? The probability that Shruti succeeds at any given free-throw is 80%, percent. She was curious how many free-throws she can expect to succeed in a sample of 12 free-throws.She simulated 25 samples of 12 free-throws where each free-throw had a 0.8, point, 8 probability of being a success.Shruti counted how many free-throws were successes in each simulated sample. Here are her results:Use her results to estimate the probability that she succeeds at 10 or more free-throws in a sample of 12 free-throws.Give your answer as either a fraction or a decimal.