ppm is used to describe very small amounts of substance?

Answers

Answer 1

parts per million (ppm), parts per billion (ppb) and parts per trillion (ppt) are the most commonly used terms to describe very small amounts of substances. a ppm of a chemical in water means that, in a million units of water, there would only be one unit of the chemical.


Related Questions

calculate the mass of N2 gas which has a volume 0.227 at STP​

Answers

Hi I just wanted you know I have to work at the gym I will call when you I have a good night love I will

what does celery, a wooden spoon, and oil/gasoline have in common?

Answers

Answer:

All of them are organic compounds which have carbon as their main atom in the structure.

Explanation:

Hello.

In this case, since organic chemistry is the study of all the compounds having the carbon atom as their main atom, all the vegetables, animals, an in general, living things are composed by lipids, proteins, and other organic substances with this feature. Moreover, wood-based materials are mainly composed by lignin which is an organic polymer also having carbon as the main atom. In addition, oil and gasoline are organic chemical compounds with a lot of applications in daily life which also contain carbon atoms in their structure.

In such a way, a celery, a wooden spoon, and oil/gasoline have the carbon atom in common as their main atom in their chemical structures.

Best regards.

the half life of I -137 is 8.07 days. if 24 grams are left after 40.35 days, how many grams were in the original sample?

Answers

Answer:

768g

Explanation:

We can use to formula [tex]N(A) = N_0(\frac{1}{2})^\frac{t}{t_{1/2}}[/tex] . Here, N(A) is the final amount. N0 is the initial amount. t is the time elapsed, and [tex]t_{1/2}[/tex] is the half life. Plugging in, we get the answer above.

The half life of I -137 is 8.07 days. if 24 grams are left after 40.35 days, 800 gram  were in the original sample.

What is half life?

The half-life (symbol t12) is the amount of time it takes for a volume (of material) to be reduced to half of its original value. In nuclear physics, the phrase is typically used to indicate how rapidly unstable atoms experience radioactive decay or even how long stable nuclei survive.

The phrase is sometimes used more broadly to describe any form of exponential (or, in rare cases, non-exponential) decay. The biological ½ of medications and other compounds in the human body, for example, is referred to in the medical sciences. In exponential growth, the inverse of half-life is doubling time.

ln P = kt + C

P = amount of I-137 at time t

C = constant

k = 1/time

t = time

1st condition:

P = Po, t = 0 days

2nd condition: (half-life)

P = 0.5Po, t = 8.07 days

3rd condition:

P = 25 grams, t = 40.35 days

Po = 800 grams

mass of I-137 = 800 gram

Therefore, 800 gram were in the original sample.

To learn more about  half life, here:

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When 28.0 g of acetylene reacts with hydrogen, 24.5 g of ethane is produced. What is the percent yield of C2H6 for the reaction?
C2H2(g) + 2H2(g) → C2H6(g)

Answers

Answer:

[tex]Y=75.6\%[/tex]

Explanation:

Hello.

In this case, since no information about the reacting hydrogen is given, we can assume that it completely react with the 28.0 g of acetylene to yield ethane. In such a way, via the 1:1 mole ratio between acetylene (molar mass = 26 g/mol) and ethane (molar mass = 30 g/mol), we compute the yielded grams, or the theoretical yield of ethane as shown below:

[tex]m_{C_2H_6}^{theoretical}=28.0gC_2H_2*\frac{1molC_2H_2}{26gC_2H_2}*\frac{1molC_2H_6}{1molC_2H_2} *\frac{30gC_2H_6}{1molC_2H_6}\\ \\m_{C_2H_6}^{theoretical}=32.3gC_2H_6[/tex]

Hence, by knowing that the percent yield is computed via the actual yield (24.5 g) over the theoretical yield, we obtain:

[tex]Y=\frac{24.5g}{32.3g}*100\%\\ \\Y=75.6\%[/tex]

Best regards.

The empirical formula of CBr2 has a molar mass of 515.46 g/mol. What is the molecular formula of this
compound

Answers

Answer:

C3Br6

Explanation:

C= (1 X 12.011) = 12.011

Br= (2 X 79.904)= 159.808

159.808+12.011 = 171.819

515.46 divided by 171.819 = 3.00

so you mulitpy CBr2 by 3 which gives you C3Br6

2.
(3x – 4y = -10
(6x + 3y = –42
SOLUTION:

Answers

Answer:

Is like for solving for the solution for both equations??

Determine the number of moles of oxygen atoms in each of the following.
1) 4.93 mol H2O2
2) 2.01 mol N2O

Answers

Answer :

Part 1: 4.93 moles of [tex]H_2O_2[/tex] contains 9.86 moles of oxygen atoms.

Part 2: 2.01 moles of [tex]N_2O[/tex] contains 2.01 moles of oxygen atoms.

Explanation :

Part 1: 4.93 mol [tex]H_2O_2[/tex]

In 1 mole of [tex]H_2O_2[/tex], there are 2 atoms of hydrogen and 2 atoms of oxygen.

As, 1 mole of [tex]H_2O_2[/tex] contains 2 moles of oxygen atoms.

So, 4.93 moles of [tex]H_2O_2[/tex] contains [tex]4.93\times 2=9.86[/tex] moles of oxygen atoms.

Thus, 4.93 moles of [tex]H_2O_2[/tex] contains 9.86 moles of oxygen atoms.

Part 2: 2.01 mol [tex]N_2O[/tex]

In 1 mole of [tex]N_2O[/tex], there are 2 atoms of nitrogen and 1 atom of oxygen.

As, 1 mole of [tex]N_2O[/tex] contains 1 mole of oxygen atoms.

So, 2.01 moles of [tex]N_2O[/tex] contains [tex]2.01\times 1=2.01[/tex] moles of oxygen atoms.

Thus, 2.01 moles of [tex]N_2O[/tex] contains 2.01 moles of oxygen atoms.

Y-Chart
Explain how an invasive species can influence each aspect of an ecosystem.

Answers

Answer:

Invasive species are an organism that causes ecological or economic harm in a new environment where it's not native.

Explanation:

An invasive species can harm both the natural resources in the ecosystem as well it threaten the human use of these resources and invasive species can be introduced to a new area via the ballast water of oceangoing ships, intentional and accidental releases of aquaculture species, aquarium specimens or bait, and etc.

Invasive species is capable of causing extinctions to native plants and animals, reducing biodiversity, competing with native organisms for limited resources, and altering habitats. This can also result a huge economic impacts and fundamental disruptions of coastal and the great lakes of the ecosystems.

I hope it helps you.

What is the density of a block of gold that occupies 1000 ml and has a mass of 3.5 kg? Show your work

Answers

Answer:

We are given:

mass of the block = 3500 grams

volume of the block = 1000 mL

Finding the density:

Density = mass of the object (in grams) / volume of the object (in mL)

Density = 3500 / 1000

Density = 3.5 g / mL

These are two metamorphic rocks.

Left: red and white rock with rounded grains and coarse texture. Right: flat, gray rock composed of thin layers.

Which statement about the rocks is accurate?

The rock on the right is foliated.
The rock on the left formed from granite.
The rock on the left is formed from cooled magma.
The rock on the right has randomly arranged grains.

Answers

It is either the 3rd choice or the first

Answer:

A. the rock on the right is foliated

Explanation:

because if you look at the image then you see that the rock is arranged in layers so you can see that it is a foliated rock and also I got it right on my quiz

HOPE IT HELPS!!!

PLEASE PLEAS HELP Which of the following compounds is insoluble in water?
a) ZnSO4
b) K2SO4
c) Na2CO3
d) Ag2CO3

Answers

Answer:

Your answer is d

Explanation: silver carbonate Ag2CO3 is insoluble in water

Give Me An Atom With The Following Characteristics Lanthanide series

Answers

Atoms in the Lanthanide series are Lanthanum, Cerium, Neodymium, Europium, terbium, to name a few.

Select the term that matches each definition:
a) A decrease in the solubility of an ionic compound as a result of the addition of a common ion.
b) The mass of a salt in grams that will dissolve in 100 mL of water.
c) A solution that has dissolved the maximum amount of a compound at a given temperature. Any further addition of salt will remain undissolved.
d) The product of the molarities of the dissolved ions, raised to a power equal to the ion's coefficient in the balanced chemical equation.
e) The maximum number of moles of a salt that will dissolve in 1 L of solution.
*** Answer options for all questions: ***
- Solubility
- Molar Solubility
- Solubility product constant
- Common ion effect
- Saturated Solution

Answers

Answer:

a) common ion effect

b) solubility

c) saturated solution

d) solubility product constant

e) molar solubility

Explanation:

When a substance, say BA2 is dissolved in a solution and another substance CA2 is dissolved in the same solution. The solubility of BA2 is decreased due to the addition of CA2. This is known as common ion effect.

The mass of a substance that will dissolve in a given Volume of solvent is known as it's solubility.

The molar solubility is the amount of moles of solvent that dissolves in 1 dm^3 of solvent.

A solution that contains just as much solute as it can normally hold at a given temperature is known as a saturated solution.

Lastly, the product of molar solubilites raised to the power of the molar coefficient is know as the solubility product constant.

The correct matches and their explanation are:

a) A decrease in the solubility of an ionic compound as a result of the addition of a common ion: Option 4. common ion effect

It relates to the equilibrium effect that occurs due to the addition of common ions.

b) The mass of salt in grams that will dissolve in 100 mL of water: Option 1. solubility

Solubility is the property of solute to form a solution with the solvent of another substance.

c) A solution that has dissolved the maximum amount of a compound at a given temperature. Any further addition of salt will remain undissolved: Option 5. saturated solution

When the solution cannot accommodate any more addition of solute of a substance is called a saturated solution.

d)  The product of the molarities of the dissolved ions, raised to a power equal to the ion's coefficient in the balanced chemical equation: Option 3. solubility product constant

It is an equilibrium constant for the solid solute dissolved in the solution.

e) The maximum number of moles of a salt that will dissolve in 1 L of solution: Option 2. molar solubility

Before the saturation of a solution, the amount of solute it can dissolve is called molar solubility.

To learn more about molar solubility and common ion effect follow the link:

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molecular formula of C4H5​

Answers

Answer:

Cyclopropylmethylene

A student asks why the ashes from a fire have a much lower mass than the wood that was burned.

Which is the correct answer to the student’s question?

Gases are released into the air.

Atoms in the wood are destroyed.

Heat causes the molecules to change color.

Water inside the wood solidifies.


(I am not in college)

Answers

Gases are released into the air.

A stream of oxygen enters a compressor at 298 K and 1.00 atm at a rate of 127m3/h and is compressed to 358 K and 1000 atm. Estimate the volumetric flow rate of compressed O2 using the compressibility-factor equation of state.

Answers

Answer:

The value is  [tex]V_2  =   0.246 \  m^3/h[/tex]  

Explanation:

From the question we are told that

  The temperature at which the gas enters the compressor is  

         [tex]T_i = 298 \  K[/tex]

  The pressure  at which the gas enters the compressor is  

       [tex]P_I =  1.0 \ atm[/tex]

  The volumetric rate at which the gas enters the compressor is

      [tex]V  =  127 m^3/h[/tex]

   The temperature to which the gas is compressed to is  

      [tex]T_f  =  358 \ K[/tex]

  The pressure  to which the gas is compressed to is  

     [tex]P_f=  1000 \  atm[/tex]

Generally the volumetric flow rate of compressed oxygen is evaluated from the compressibility-factor equation of state as

    [tex]V_2  =  V_1 *\frac{z_2}{z_1} * \frac{T_2}{T_1} * \frac{P_1}{P_2}[/tex]

Here [tex]z_1[/tex] is the inflow compressibility factor with value [tex]z_1 = 1[/tex]

Here [tex]z_1[/tex] is the outflow compressibility factor with value [tex]z_2 = 1.61[/tex]

So

    [tex]V_2  =  127*\frac{1.61}{1} * \frac{358}{298} * \frac{1}{1000}[/tex]  

    [tex]V_2  =   0.246 \  m^3/h[/tex]  

   

calculate the equilibrium concentration for the nonionized bases and all ions in a solution that is 0.25M

Answers

Answer:

The equilibrium concentration of [CH₃NH₂] = 0.23965 M.

The equilibrium concentration of CH₃NH₃⁺ and  OH⁻ =  0.01035 M respectively.

Explanation:

The first step is to write out the dissociation reaction. Therefore, the equation showing the dissociation is given as below;

CH₃NH₂ + H₂0   <--------------------------------------------------------> CH₃NH₃⁺ + OH⁻.

Kindly note that ''<----------->'' arrow shows that the reaction is an equilibrium reaction.

Therefore, at the start of the reaction [that is time, t =0], we have that the concentration of CH₃NH₂ = 0.25M, thus, the concentration of CH₃NH₃⁺  and  OH⁻ is zero respectively at this time, t =0.

At equilibrium, the concentration of CH₃NH₂ = 0.25M - x, thus, the concentration of CH₃NH₃⁺  and  OH⁻ is x respectively.

Therefore, kb =  4.47 × 10-4 = [CH₃NH₃⁺ ][OH⁻]/[CH₃NH₂].  Hence, slotting in the values into this equilibrium equation showing the relationship between kb and concentration of the species involved, we have that;

kb = 4.47 × 10⁻⁴ = x² /0.25 - x.

x² +  4.47 × 10⁻⁴x - 1.1175  × 10⁻⁴ = 0.

Solving this quadratic equation gives us the value of x as 0.01035 M.

Thus, the concentration of [CH₃NH₂] = 0.25 M - 0.01035 M = 0.23965 M

The equilibrium concentration of [CH₃NH₂] = 0.23965 M.

The equilibrium concentration of CH₃NH₃⁺ and  OH⁻ =  0.01035 M respectively.

To what volume would you need to dilute 200 mL of a 5.85M solution of Ca(OH)2 to make it a 1.95M solution?

Answers

Answer: 600 mL

Explanation:

Given that;

M₁ = 5.85 m

M₂ = 1.95 m

V₁ = 200 mL

V₂ = ?

Now from the dilution law;

M₁V₁ = M₂V₂

so we substitute

5.85 × 200 = 1.95 × V₂

1170 = 1.95V₂

V₂ = 1170 / 1.95

V₂ = 600 mL

Therefore final volume is 600 mL

where are electrons found in an atom

Answers

Answer:

The electrons are found on the outer shell of the atom.

Explanation:

Determine the molar mass of CaO

Answers

56.0774 g/mol just took the test

Compute the values of the diffusion coefficients for the interdiffusion of carbon in both α-iron (BCC) and γ-iron (FCC) at 900°C. Which is larger? Explain why this is the case.

Answers

Answer:

α-iron (BCC) has faster diffusion rate because of lower values in activation energy and pre-exponential value.

Explanation:

Taking each parameters or data at a time, we can determine the values/a constant for each parameters in the diffusion coefficient equation.

For α-iron (BCC), the diffusion coefficient = pre-exponential value,Ao × e^( -Activation energy,AE)/gas constant,R × Temperature.

Converting the given Temperature, that is 900°C to Kelvin which is equals to 1173.15K.

For α-iron (BCC), the pre-exponential value, Ao = 1.1 × 10^-6, and the activation energy, AE = 87400.

Thus, we have that the diffusion coefficient = 1.1 × 10^-6 × e(-87400)/1173.15 × 8.31.

Diffusion coefficient for α-iron (BCC) = 1.41 × 10^-10 m^2/s.

Also, For the γ-iron (FCC), the pre-exponential value, Ao = 2.3 × 10^-5 and the activation energy, AE = 148,00.

From these values we can see that both the exponential value, Ao and the activation energy for γ-iron (FCC) are higher than that of α-iron (BCC).

Thus, the diffusion coefficient for the γ-iron (FCC) = 2.3 × 10^-5 × e ^-(14800)/8.31 × 1173.15.

Then, the diffusion coefficient for the γ-iron (FCC) = 5.87 × 10^-12 m2/s.

Therefore, there will be faster diffusion in α-iron (BCC) because of lower activation energy and vice versa.

The natural abundance for boron isotopes is 19.9% 10B and 80.1%
11B Calculate boron's atomic mass.

Answers

Answer:

10.801 amu

Explanation:

From the question given above, the following data were obtained:

Isotope A (¹⁰B):

Mass of A = 10

Abundance (A%) = 19.9%

Isotope B (¹¹B):

Mass of B = 11

Abundance (B%) = 80.1%

Atomic mass of Boron =?

The atomic mass of boron can be obtained as illustrated below:

Atomic mass = [(Mass of A × A%)/100] + [(Mass of B × B%)/100]

= [(10 × 19.9)/100] + [(11 × 80.1)/100]

= 1.99 + 8.811

= 10.801 amu

Thus, the atomic mass of boron is 10.801 amu

The atomic mass of boron with natural abundance of 19.9% of 10 B and 80.1%  of 11 B is 10.801 amu

Boron has 2 isotopes.

First isotopes

mass = 10

% abundance = 19.9%

Second Isotopes

mass = 11

% abundance = 80.1%

Therefore,

Atomic mass = (19.9% of 10) + (80.1% of 11)

Atomic mass = (19.9 / 100 × 10) + (80.1 / 100 × 11)

Atomic mass = 199 / 100 + 881.1 / 100

Atomic mass = 1.99 + 8.811

Atomic mass = 10.801

Atomic mass = 10.801 amu

read more: https://brainly.com/question/14440832?referrer=searchResults

Helpppp!!!!! Please help me

Answers

Answer:

10.)Weight and mass are different because only weight describes the force of gravity on an object.

11.)On a planet with more mass than earth your weight would be higher because greater gravitational pull.

On a planet with less mass than earth your weight would be less because of the lower gravitational pull.

Explanation:

Label each of the following changes as a physical change or chemical change. Give evidence to support your answer.


A catalytic converter changes nitrogen dioxide to nitrogen gas and oxygen gas

Answers

Answer:

A catalytic converter changes nitrogen dioxide to nitrogen gas and oxygen gas is a chemical change.

Explanation:

Hello.

In this case, since physical changes do not modify the molecular composition and structure of the material undergoing it whereas the chemical change does, for catalytic converters we should know they promote chemical reaction in which the composition is changed; for instance, for the given example, the following chemical reaction is the evidence:

[tex]2NO_2\rightarrow N_2+O_2[/tex]

As you can see, nitrogen and oxygen are no longer bonded but separated by themselves, therefore, this is a chemical change.

Best regards.

What do you learned about homogeneous mixture?

Answers

Answer:

homogeneous is consisting a part of or people are similar to each other or are if same type.

If 0.4743 moles of H2O are produced, how many grams of VOCl3 will also be produced?
(V2O5 + 6 HCl → 2 VOCl3 + 3 H2O)

Answers

Answer:

i hope this helps. sorry if it totally doesn't

help me please i’ll give u a good rating

Answers

Answer:

d

Explanation:

I think possibly the answer would be “d”

13. (6C) An unknown chemical has the
following properties: it is a white crystal,
reacts with water, and has a high boiling
point. Which of these properties is
physical?
A White color only
B Reacts with water, high
boiling point
C Reacts with water only
D White color, high boiling
point

Answers

Answer: it is B

Explanation:

To vaporize/condense a substance, does the substance have to absorb or release heat?

Answers

Answer: it would release heat because the thermal energy it absorbed to become a gas. so it would release heat. hope this helps :)

Explanation:

How many grams of H2SO4 are needed to prepare 5.0 L of a 2 M H2SO4 solution? You must show your work in order to receive credit.

Answers

Molar mass H2SO4 = 98g/mol

To prepare 5L of a 2.0M solution you require: 98g/mol * 5mol * 2mol /L = 980g H2SO4
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Which service industry thrives and Belize and Guatemala A. FinanceB. Tourism C. Insurance D. Health care 27. If there is a full moon on Sept. 13, When is the next full moon? Read this excerpt from a play.JUNE and SYLVIO speak to MR. TELLER in the driveway of their farmhouse. It is raining hard, and they all carry umbrellas. A dog sits on the steps of the house.JUNE: We didnt think youd be coming back for the puppy.MR. TELLER: I said I would when I dropped the puppy off.SYLVIO: Yes, but that was months ago. We thought youd be back for the puppy in a couple days. Now shes a full-grown dog. We have raised her ourselves, we buil Find the measure of an angle such that the sum of its supplement and four times itscomplement is 13 less than twice the angle.Show work write an expression for a number that is 5 times greater than 2For pre-algebra classPlease help thanks i need it thanks a lot for helping me thank you alot Compute the values of the diffusion coefficients for the interdiffusion of carbon in both -iron (BCC) and -iron (FCC) at 900C. Which is larger? Explain why this is the case. the half life of I -137 is 8.07 days. if 24 grams are left after 40.35 days, how many grams were in the original sample? Write an equation in slope-intercept form if the y-intercept is (0, -4) and the slope is 6? What is the main function ofthe respiratory system? A push lawnmower is priced at $299.50. There is an 8% sales tax rate. What is the sales tax of the pusher lawnmower in dollars and cents? Sarah is having a party with 30 people. She has 212 large pizzas at the party. She gives equal amounts of pizza to each person. What fraction of pizza does each person get? solve for x: 1/2(x-10)=3/4(x+20) If an object is moving with a constant velocity to the right, what direction is the net force.Group of answer choicesA.To the rightB.To the leftC.Net force is 0D.Not enough information Describe two properties that you could use to distinguish subatomic particles. What equation could be used to represent the verbal representation below?Sanju wants to sell his artwork at a local fair. He has created 10 pieces of artwork and has spent $44 in creating them. He wants to make a profit of $300 at the fair. What is the price he needs to sell each piece to make that profit? If a Ferris wheel takes 45 seconds to make a complete rotation, how many rotations will it complete in 3 hours? How would the particles of a solid, liquid, and gas ALL at room temperature compare? *A.solid particles have lower average kinetic energyB.the gas particles are larger than both solid and liquidC.the pas particles are moving the slowestD.the spacing of the particles is different, but all have the same average kinetic energyPlz help If an organism has a cell wall, it can only be a ______ cell A customer will get gallons for 3.50 2 16/7 then put it in its simplest form (it will be a mixed number)