Answer: 130 ppm Pb
Explanation:
We use parts per million to express the concentrations of solutions that contain very, very small amounts, often called trace amounts, of a given solute.
More specifically, a solution's concentration in parts per millions tells you the number of parts of solute present for every
10
6
=
1
,
000
,
000
parts of solution. You can thus say that a
1 ppm
solution will contain exactly
1 g
of solute for every
10
6
g
of solution.
In your case, you know that you have
38
mg Pb
⋅
1 g
10
3
mg
=
3.8
⋅
10
−
2
.
g Pb
in exactly
300.0 g
=
3.000
⋅
10
2
.
g solution
This means that you can use this known composition as a conversion factor to scale up the mass of the solution to
10
6
g
10
6
g solution
⋅
3.8
⋅
10
−
2
.
g Pb
3.000
⋅
10
2
g solution
=
130 g Pb
Since this represents the mass of lead present in exactly
10
6
g
of solution, you can say that the solution has a concentration of
concentration
ppm
=
130 ppm Pb
−−−−−−−−−−−−−−−−−−−−−−−−−−−−
The answer is rounded to two sig figs, the number of sig figs you have for the mass of lead present in the sample.
Se midió el pH de una muestra del agua de lluvia en la ciudad de México, y se obtuvo un valor de 3.5 Calcula la [H+] en dicha muestra.
Answer:
[tex][H^+]=3.16x10^{-4}M[/tex]
Explanation:
¡Hola!
En este caso, dado que el pH de una solución se entiende como el potencial de los iones hidrógeno en la misma, es posible recordar la ecuación que se usa para calcularlo:
[tex]pH=-log([H^+])[/tex]
De este modo, al conocer el pH, se resuelve para la concentración de iones hidrógeno como se muestra a continuación:
[tex][H^+]=10^{-pH}[/tex]
Así, reemplazamos el pH para obtener:
[tex][H^+]=10^{-3.5}=3.16x10^{-4}M[/tex]
¡Saludos!
For the following equation insert the correct coefficients that would balance the equation. If no coefficient is need please insert the NUMBER 1.
1. CH4 + O2 --> CO2 + H2O
Answer:
1CH₄ + 2O₂ -> 1CO₂ + 2H₂O
Explanation:
Reactants:
1 C
4 H
4 O
Products:
1 C
4 H
4 O
The equation is balanced.
These diagrams show two atoms of fluorine and an atom of magnesium.
On the left, a purple circle labeled F is shown twice, both times surrounded by 2 concentric circles. The inner circle has 2 small green spheres. The outer circle has 7 small green spheres. On the right, a purple circle labeled M g surrounded by 3 concentric circles. The inner circle has 2 small green spheres. The middle circle has 8 small green spheres. The outer circle has 1 small green sphere.
Which shows the correct steps in the formation of an ionic bond between these atoms?
A magnesium atom accepts six electrons from the fluorine atoms → Each fluorine atom donates three of the electrons → The magnesium atom becomes a -2 ion → Each fluorine atom becomes a +1 ion
A magnesium atom donates two electrons to the fluorine atoms → Each fluorine atom accepts one of the electrons → The magnesium atom becomes a -2 ion → Each fluorine atom becomes a +1 ion
A magnesium atom accepts two electrons from the fluorine atoms → Each fluorine atom donates one of the electrons → The magnesium atom becomes a -2 ion → Each fluorine atom becomes a +1 ion
A magnesium atom donates two electrons to the fluorine atoms → Each fluorine atom accepts one of the electrons → The magnesium atom becomes a +2 ion → Each fluorine atom becomes a -1 ion
Answer: D
Explanation:
took test
Answer:
D
Explanation:
got it right
is mixing colored light (like using this equipment in this lab) the same as mixing colored paint (as if you were mixing actual paint together)?
The mixing of colored light and colored paint follows different color models and produces different outcomes due to the properties of light and pigments.
Mixing colored light and mixing colored paint are not the same. When mixing colored light, such as using equipment in a lab, the primary colors are red, green, and blue (RGB). By combining different intensities of these colors, you can create various shades and hues. Mixing all three primary colors at full intensity produces white light.
On the other hand, mixing colored paint involves using the subtractive color model. The primary colors are cyan, magenta, and yellow (CMY). When you mix paints, the pigments absorb certain wavelengths of light, and the reflected light determines the perceived color. Mixing all three primary colors in paint results in a dark, muddy color, not white.
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.Consider the phase diagram below. If the dashed line at 1 atm of pressure is followed from 100 to 500 °C, what phase changes will occur (in order of increasing temperature)?
sublimation, followed by vaporization
sublimation, followed by deposition
melting, followed by vaporization
vaporization, followed by deposition
No phase change will occur under the conditions specified.
2. The phase changes that will occur from 100 to 500 °C at 1 atm of pressure are sublimation followed by deposition.
Based on the information provided, the correct answer is:
2. sublimation, followed by deposition
Following the dashed line at 1 atm of pressure on the phase diagram from 100 to 500 °C, the phase changes that will occur are sublimation, followed by deposition.
At lower temperatures, the substance will undergo sublimation, transitioning directly from the solid phase to the gas phase. As the temperature increases, the substance will exist as a gas.
However, at higher temperatures, as the temperature decreases again, the gas will undergo deposition, transitioning directly from the gas phase back to the solid phase.
Therefore, the substance will experience sublimation and deposition as the temperature changes within the specified range, without undergoing melting or vaporization.
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1+1
[tex]1 + 1[/tex]
11
A canister of neon contains 4.8x1024 atoms of the gas. How many moles of neon are present in the canister?
Answer:
7.97 moles of neon are present in the canister.
Explanation:
Avogadro's constant or "Avogadro's number" is the number of constituent particles found in the amount of substance in one mole.
In other words, Avogadro's number is the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023*10²³ particles per mole. Avogadro's number applies to any substance.
So, you can apply the following rule of three: if 6.023*10²³ atoms are present in 1 mole, 4.8*10²⁴ atoms are present in how many moles?
[tex]amount of moles=\frac{4.8*10^{24}atoms*1 mole }{6.023*10^{23}atoms}[/tex]
amount of moles= 7.97 moles
7.97 moles of neon are present in the canister.
is it unsaturated, saturated, or super saturated
Answer:
saturated
Explanation:
It is not dense enough to be supersaturated.
Answer:
unsaturated
Explanation:
salts arent fatty
place the following in order of increasing standard molar entropy. n2o4 (g) no (g) no2 (g)
The standard molar entropy of no₂ is 240.0 J/(mol.K).Therefore, the order of increasing standard molar entropy of the given gases is n₂o₄ (g) < no (g) < no₂ (g).
Entropy is the measure of disorder in a system. It is a thermodynamic property that depends on the degree of randomness in the molecules of a substance. The unit of entropy is Joules per Kelvin. In general, the entropy of a substance increases with an increase in temperature.
This is because at higher temperatures, the molecules of a substance have more kinetic energy and can move more freely, leading to an increase in the number of possible arrangements of molecules, which increases entropy.
Increasing Standard Molar Entropy Order n₂o₄ (g) < no (g) < no₂ (g)The standard molar entropy (S°) is the entropy of one mole of a substance at standard temperature and pressure (STP). In the order of increasing standard molar entropy, the gases listed are as follows: n₂o₄ (g) has the least entropy because it is a relatively heavy and rigid molecule. It has fewer possible arrangements of molecules, which results in a lower entropy.
The standard molar entropy of n₂o₄ is 304.3 J/(mol.K).no (g) has more entropy than n₂o₄ because it is a lighter molecule that is more mobile. It has more possible arrangements of molecules, leading to higher entropy.
The standard molar entropy of no is 210.6 J/(mol.K).no₂ (g) has the highest entropy because it is the lightest and most mobile molecule of the three gases. It has the most possible arrangements of molecules, leading to the highest entropy. The standard molar entropy of no₂ is 240.0 J/(mol.K).
Therefore, the order of increasing standard molar entropy of the given gases is n₂o₄ (g) < no (g) < no₂ (g).
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please helpp: All things that are acidic will eventually produce ___ in an aqueous solution?
Answer:
Protons / H+ ions
Explanation:
The acids are compounds with a pH range between 1-7, while the base has a pH range of 7-14. Acids produce hydrogen ions or protons in the solution.
What is pH?The pH can be defined as the hydrogen ion concentration in the solution. The higher the proton concentration in the solution, the lower will be the pH.
The pH of 7 has an equal number of hydrogen and hydroxide ions contributing to the neutral pH. The alkaline pH is contributed by the hydroxide ion concentration.
The acids fall at the lower pH range with a high hydrogen ion concentration. Thus, acids produce hydrogen ions or protons in the aqueous solution.
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T/F A reaction which is endothermic and has an overall increase in entropy is spontaneous only at high T
"A reaction which is endothermic and has an overall increase in entropy is spontaneous only at high T" is incorrect.
"A reaction which is endothermic and has an overall increase in entropy is spontaneous only at high T" is false.A spontaneous process occurs naturally and without any assistance. The rate of the process does not affect its spontaneity; instead, spontaneity is determined by the change in free energy that occurs during the reaction.A reaction is spontaneous if the Gibbs free energy of the reaction is negative (∆G < 0). Gibbs free energy is calculated using the equation: ∆G = ∆H - T∆S, where ∆H is the enthalpy change, T is the temperature, and ∆S is the entropy change of the reaction.A reaction that is endothermic (∆H > 0) and has an increase in entropy (∆S > 0) can be spontaneous at any temperature if the free energy change is negative. As a result, the given statement "A reaction which is endothermic and has an overall increase in entropy is spontaneous only at high T" is incorrect.
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Which element is oxidized in the reaction below?
Fe(CO)5 (l) + 2HI (g) →Fe(CO)4I2 (s) + CO (g) + H2(g)
The answer is Fe...but I'm messing up on setting up my oxidationcharges. Can someone clearly explain how to do this?
The element that is oxidized in the reaction Fe(CO)5 (l) + 2HI (g) → Fe(CO)4I2 (s) + CO (g) + H2(g) is iron (Fe). When determining the oxidation state of iron (Fe), we use the rule that the oxidation state of a monatomic ion is equal to its charge.
The oxidation state of Fe in Fe(CO)5 is zero. In Fe(CO)4I2, the oxidation state of Fe is +2. So, Fe is oxidized in the reaction.Balancing the redox reaction:Fe(CO)5 (l) + 2HI (g) → Fe(CO)4I2 (s) + CO (g) + H2(g)The oxidation half-reaction is:Fe(CO)5 (l) → Fe(CO)4I2 (s) + I- (aq)The reduction half-reaction is:2H+ (aq) + 2e- → H2 (g)By adding both half-reactions, the balanced redox reaction is:Fe(CO)5 (l) + 2HI (g) → Fe(CO)4I2 (s) + CO (g) + H2(g)The oxidation half-reaction shows that iron (Fe) has lost electrons, thereby being oxidized.
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A 148.20 sample of an unknown substance was heated from 25°C to 40°C. In the process, the substance absorbed 5683 J of energy. What is the
specific heat of the substance.
Answer: 2556.455 J/(kg.°C)
Explanation:
Im assuming the 148.20 is in grams
The equation is Q=mcΔT
Q= Heat (J)
m= Mass
c= SHC (specific heat capacity)
ΔT= Temp change
What is the Molar Mass of MgO?
Answer:
The answer should be 40.3044 g/mol
0.39 moles of a gas fill a 5.0 l container that connects to a balloon through a closed valve. if the valve is opened an pressure remains the same, what would be the total number of moles of gas needed in order to inflate the balloon by 1.5
Answer: 5.39
Explanation: you are adding the balloon's volume and the container's volume
Name the compound and determine the number of moles present. SHOW YOUR WORK.
60.0g Na2SO4
Answer:
60.0g Na2SO4
Na2SO4 molar mass 142.04g
divide 60.0 by 142.02
And you get the answer .422moles Na2SO4
let me know if you need more explanation
HELP PLEASE!!!!!!!!!!!!
Answer:
it is a practical question..ASAP
If you were traveling from Earth to Neptune in a spaceship, what would
you see between Mars and Jupiter?
Imposters
little green men
Pluto
the asteroid belt
Answer:
I believe it would be Asteroid Belt
Explanation:
little green men and imposters seem very unlikely, and Pluto is definetely not between earth and Jupiter
Answer:
the asteroid belt
Explanation:
it orbits between mars and jupiter
In the following reaction, identify the element getting oxidized and element getting reduced: Ba(s) + 2H+ (aq) → Ba2+ (aq) + H2(g) Ba getting oxidized/H getting reduced Ba2 getting oxidized / Ba2+ getting reduced H getting oxidized/H* getting reduced H getting oxidized / Ba getting reduced NO
The correct answer is:Ba getting oxidized/H getting reduced.
Explanation: In the following reaction, Ba is getting oxidized and H is getting reduced. Given reaction is: Ba(s) + 2H+ (aq) → Ba2+ (aq) + H2(g)In the given redox reaction, the Ba is being oxidized to Ba2+. Its oxidation state is increasing from 0 to +2. This means that Ba is losing electrons and getting oxidized. Hence, Ba is the element that is getting oxidized in the given reaction.The H+ is getting reduced to H2. Its oxidation state is decreasing from +1 to 0. This means that H is gaining electrons and getting reduced. Hence, H is the element that is getting reduced in the given reaction.Therefore, the correct option is:Ba getting oxidized/H getting reduced.
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What problems may global warming cause?
Answer:
Global warming stresses ecosystems through temperature rises, water shortages, increased fire threats, drought, weed and pest invasions, intense storm damage and salt invasion, just to name a few.
Explanation:
Global warming stresses ecosystems through temperature rises, water shortages, increased fire threats, drought, weed and pest invasions, intense storm damage and salt invasion, just to name a few.
calculate the molar solubility of baso4 in a 0.250 m solution of nahso4? ka for hso4- = 1.2 x 10-2.
The required answer for the molar solubility of BaSO4 in a 0.250 M solution of NaHSO4 is 1.05 × 10-5 M.
Explanation: Molar solubility is defined as the number of moles of a solute that can dissolve per liter of solution before the solution becomes saturated. It can be determined by calculating the equilibrium concentration of the solute using the solubility product expression for the given ionic compound, BaSO4. We are given the concentration of NaHSO4 and the acid dissociation constant for HSO4-.
The balanced chemical equation is:BaSO4(s) ↔ Ba2+(aq) + SO42-(aq)We are assuming the solution is dilute and that the ionic strength is low. Therefore, we can simplify the expression for the solubility product to:Ksp = [Ba2+][SO42-]The expression for the acid dissociation constant of HSO4- is:Ka = [H+][SO42-]/[HSO4-]
The first step is to calculate the concentration of HSO4-. We can use the equilibrium expression for the acid dissociation reaction to solve for [HSO4-]:Ka = [H+][SO42-]/[HSO4-]Rearranging the expression and solving for [HSO4-]:[HSO4-] = [H+][SO42-]/Ka[HSO4-] = (0.250 × x)/(1.2 × 10-2)[HSO4-] = 20.8333 × xThe molar solubility of BaSO4 in a 0.250 M solution of NaHSO4 is x. At equilibrium, the concentration of Ba2+ and SO42- are both x. Using the solubility product expression:Ksp = [Ba2+][SO42-]Ksp = x2x = sqrt(Ksp)[BaSO4] = x = sqrt(Ksp) = sqrt(1.1 × 10-10) = 1.05 × 10-5 MTherefore, the molar solubility of BaSO4 in a 0.250 M solution of NaHSO4 is 1.05 × 10-5 M.
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given the following experimental data, find the rate law and the rate constant for the reaction nh4 no2 -> n2 2 h2o rate = k {nh4 ] ^ [no2]
The rate law for the reaction is `rate = k[NH4][NO2]` and the rate constant is `k = 0.004 M^-2 s^-1`.
The rate law for the reaction:
`NH4NO2 -> N2 + 2H2O` is `rate = k[NH4NO2]`.
Given that the reaction is first order with respect to both NH4 and NO2, it can be written as `rate = k[NH4][NO2]`. The rate constant k is calculated by plugging in the rate data from the experiment and solving for k.
Example of how to solve for the rate constant k:
Suppose the following rate data was obtained in an experiment where the concentration of NH4 and NO2 were varied:| Experiment | [NH4] (M) | [NO2] (M) | Rate (M/s) || 1 | 0.1 | 0.2 | 4.0x10^-4 || 2 | 0.2 | 0.2 | 8.0x10^-4 || 3 | 0.2 | 0.1 | 4.0x10^-4 |Substituting the given data into the rate law:
Experiment 1: 4.0x10^-4 = k(0.1 M)(0.2 M) = 0.002 k
Experiment 2: 8.0x10^-4 = k(0.2 M)(0.2 M) = 0.008 k
Experiment 3: 4.0x10^-4 = k(0.2 M)(0.1 M) = 0.002 k
Taking the average of the three k values:
k = (0.002 + 0.008 + 0.002)/3 = 0.004 M^-2 s^-1
Therefore, the rate law for the reaction is `rate = k[NH4][NO2]` and the rate constant is `k = 0.004 M^-2 s^-1`.
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Identify which redox reactions occur spontaneously in the forward direction.
Check all that apply.
2Ag+(aq)+Ni(s)→2Ag(s)+Ni2+(aq)
2Cr(s)+3Pb2+(aq)→2Cr3+(aq)+3Pb(s)
Ca2+(aq)+Zn(s)→Ca(s)+Zn2+(aq)
Sn(s)+Mn2+(aq)→Sn2+(aq)+Mn(s)
The redox reactions that occur spontaneously in the forward direction are:
2Ag+(aq) + Ni(s) → 2Ag(s) + Ni2+(aq)
Ca2+(aq) + Zn(s) → Ca(s) + Zn2+(aq)
Among the given redox reactions, the ones that occur spontaneously in the forward direction are: 2Ag+(aq) + Ni(s) → 2Ag(s) + Ni2+(aq) and Ca2+(aq) + Zn(s) → Ca(s) + Zn2+(aq). These reactions occur because the reduction potentials of Ag+ and Ca2+ are higher than those of Ni2+ and Zn2+, respectively. As a result, Ag+ and Ca2+ are reduced, while Ni and Zn are oxidized. The other two reactions, 2Cr(s) + 3Pb2+(aq) → 2Cr3+(aq) + 3Pb(s) and Sn(s) + Mn2+(aq) → Sn2+(aq) + Mn(s), do not occur spontaneously in the forward direction due to the lower reduction potentials of the species being reduced.
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What is the difference between soil and sand
Explanation:
The terms ‘sand’ and ‘soil’ are often interchanged and used synonymously with one another. Many people consider them the same, but when scrutinized, they are quite different from each other. First and foremost, sand is a type of soil–so is silt, clay, peat, and loam. These types of soils are generated when rocks break up into their constituent parts and are acted upon by outside forces, such as wind, water, and natural salts. The broad definition of soil refers to the loose layer of earth that covers the surface of the planet. Sand, on the other hand, is defined as loose material that consists of rocks or mineral grains.
Answer:
soil is defined as the top layer of the land surface of the earth that is composed of disintegrated rock particles, humus, water, and air.
sand is defined as a loose material that consists of rocks or mineral grains.
Explanation:
choose the substance with the lowest surface tension. a) ch3oh b) ch3ch2ch2ch3 c) c6h14 d) h2o e) (ch3)2co
(CH₃)₂CO, also known as acetone, is a liquid at room temperature and has a surface tension of 23.8 mN/m.
Surface tension is defined as the tendency of the surface of a liquid to behave like an elastic sheet. The substances with the lowest surface tension are those that tend to spread out to a greater extent on the surface rather than to form a droplet.
Out of the given substances, the one with the lowest surface tension is (e) (CH₃)₂CO, which is acetone.
A) CH₃OH, also known as methanol, is a liquid at room temperature and has a surface tension of 22.6 mN/m.
B) CH₃CH₂CH₂CH₃, also known as butane, is a gas at room temperature and therefore does not have a surface tension value.
C) C₆H₁₄, also known as hexane, is a liquid at room temperature and has a surface tension of 18.4 mN/m.
D) H₂O, also known as water, is a liquid at room temperature and has a surface tension of 71.97 mN/m.
E) (CH₃)₂CO, also known as acetone, is a liquid at room temperature and has a surface tension of 23.8 mN/m.
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. I am described as being conductive, malleable, shiny, and reactive with HCl. I am one of the most reactive elements. I turn black within seconds when I am exposed to air. If someone drops water on me, I will explode. When I do explode I send off characteristic purple-red (violet) flame. Who am I?
Answer:
Potassium
Explanation:
Most reactive metal in the reactivity series
The element in the question is referred to the alkali metal which is known as Potassium
Potassium is a highly reactive metal and reacts with Hydrochloric acid to
form a salt known as Potassium chloride and hydrogen gas.
Hcl + K ⇒ Kcl₍s₎ + H₂₍g₎
Potassium has a white color but when it reacts with water it explodes and
gives out a purple-red color as a result of the high excitation of electrons.
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____________ are traits characteristics or features of an organism that are passed from parent to offspring
Answer:
Heredity, also called inheritance or biological inheritance, is the passing on of traits from parents to their offspring; either through asexual reproduction or sexual reproduction, the offspring cells or organisms acquire the genetic information of their parents.
Explanation:
Plss markk mee brainlistt
Fossil Fuels are an ________ resource that people are hoping to replace with ______ resources.
Answer:
fossil fuels are an nonrenewable resource that people are hoping to replace with renewable resources
Explanation:
A system gains 652 kJ of heat, resulting in a change in internal energy of the system equal to +241 kJ. How much work is done?
Answer:
-411 kj
Explanation:
We solve by using this formula
∆U = ∆Q + ∆W
This formula is the first law of thermodynamics
Change in internal energy U = +241
Heat gained by system Q = 652
Putting the value into the equation
+241 = 652 + W
Workdone = 241 - 652
Workdone = -411 kj
Since work done is negative it means that work was done by the system
help please. What type of reaction is this: barium nitrate --> barium oxide + nitrogen dioxide + oxygen
Answer:
Decomposition Reaction
Explanation:
Ba(NO₃)₂(s) ⇒ BaO(s) + N₂(g) + 3 O₂(g)
Barium nitrate decomposes into the chemical species that were used to create it.