A radioactive isotope has a half life of 25 minutes. How many half lives have occurred after 175 minutes?
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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%

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

Answer:

36 grams as 1 mole is 12 grams

Answer:

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

Answer:

the liver

Explanation:

it processes alcohol, work very hard

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

Answer:

Explanation:

Each share costs $36000/4500

= $8

800 shares will cost 800*8

= $6400

Find attached the journal

Answer: 2.13

Explanation: i crawled so you could run :)

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.

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]

Answer:

nonpolar

Explanation:

Use the phrase "like dissolves like"

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

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:

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.

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

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:

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.

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.

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.

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.

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

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!

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.

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 :)

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

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Answer:

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

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.

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.

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:

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%

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

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