Answer: its supposed to be 18.78%.
Explanation:
Amphetamine (C9H13N) is a weak base with a pKb of 4.2.
Calculate the pH of a solution containing an amphetamine concentration of 215 mg/L .
Express your answer to two decimal places.
Weak base: [OH⁻] = √Kb.C
pKb = 4.2
[tex]\tt Kb=10^{-4.2}[/tex]
c = concentration
MM Amphetamine (C9H13N) = 135.21 g/mol
c = 215 mg/L = (0.215 g : 135,21 g/mol) / L = 0.00159 mol/L = 1.59 x 10⁻³ mol/L
[tex]\tt [OH^-]=\sqrt{10^{-4.2}\times 1.59\times 10^{-3}}=3.17\times 10^{-4}[/tex]
pOH = 4 - log 3.17
pH = 14 - (4 - log 3.17)
pH = 10 + log 3.17 = 10.50
Between a water molecule and an anion, like Cl-, a _____A_____ occurs between a _____B_____ of the water molecule and the anion.
Between a water molecule and an anion, like Cl-, a hydrogen bon occurs between hydrogen atom of the water molecule and the anion.
What is hydrogen bond?Hydrogen bond is a weak bond between two molecules resulting from an electrostatic attraction between a proton in one molecule and an electronegative atom in the other. Hydrogen atom in water molecule attract anion due to presence of hydrogen bond.
So we can conclude that hydrogen bond occurs between hydrogen atom of the water molecule and the anion.
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Answer:
Explanation:88766
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How many moles of HCl are in 57 mL of 0.17 M HCl ?
[tex]\text{Given that,}\\ \\\text{Volume,}~V= 57 mL = 0.057 L\\\\\text{Molar concentration,}~ S = 0.17 ~mol/L\\\\\text{Number of moles,} ~ n=?\\\\S = \dfrac{n}{V} \\\\\implies n = SV = 0.17\times 0.057 =0.00969 ~mol ~ HCl[/tex]
Explain how oxygen and carbon dioxide move with breathing.
Answer/Explanation:
With oxygen, it is what you breathe in so obviously, it is going to move around into your body. But with carbon dioxide, it is what you breathe out. When you breathe in, your body takes in the oxygen and the releases the carbon dioxide. Carbon dioxide is what plants actually consume, while they release oxygen.
I hope this helps!
-No one
What is the difference between metallic and non metallic oxides?
Answer:
Metal oxides are compounds composed of metal ions and oxide ions. Nonmetal oxides are compounds composed of nonmetal atoms and oxygen atoms. The main difference between metal oxides and non metal oxides is that metal oxides are basic compounds whereas nonmetal oxides are acidic compounds.
Explanation:
have a great day ahead
tC
Answer:
Metals react with oxygen to form metallic oxide while Nonmetals react with oxygen to form non-metallic oxide. metallic oxides are basic in nature while Nonmetallic oxides are acidic in nature.
Metal oxides are compounds composed of metal ions and oxide ions. Nonmetal oxides are compounds composed of nonmetal atoms and oxygen atoms. The main difference between metal oxides and non-metal oxides is that metal oxides are basic compounds whereas nonmetal oxides are acidic compounds.
METALS:
Metals usually do not combine with hydrogen. Only a few reactive metals combine with hydrogen to form ionic metal hydrides.
--------------------------------------------------------------------
NON-METALS:
Non-metals react with hydrogen to form stable, covalent hydrides.
Explanation:
Have a great rest of your day
#TheWizzer
All of the following are sources of air pollution EXCEPT
-mobile sources
- Factories
-scrubbers
-Landfills
Answer:
Mobile sources
..........................
1) Identify two different mineral nutrients present in the fertilizer
that helped the plant recover. Then, describe how each nutrient
benefits the plant.
The two different mineral elements that a fertilizer can contain are:
Phosphorus - build up of nucleic acid and ATPNitrogen- synthesis of proteinsWhat are fertilizers?Fertilizers are chemical substances added to the soil in order to improve crop growth and development.
Fertilizers are artificially made to contain mineral elements that are needed by the plants. Some of the mineral elements are as follows:
PhosphorusNitrogenPottasiumPhosphorus helps in the build up of nucleic acids and ATP for energy. Nitrogen is useful in the synthesis of proteins.Learn more about minerals at: https://brainly.com/question/18078524
Answer:
is the answer above right? im literally struggling rn
Explanation:
Oxidation Number of Carbon in C6H12O6
Correct option is C)
C
6
H
12
O
6
6x+12−12=0
C has oxidation number = 0
Sorry if my answers wrong.
b. How many grams of H20 is needed to react with 20.0 grams of P4010
P4010 + 6H20 -----> 4H3PO4
20
12 3.2
12bw
7. A certain music box ha the shape of a cube. Ea
cm long. What is the surface area of the box?
8. Find the amount of tin needed to make a milk to
cm and a height of 5cm.
9. Angelo is wrapping a present. The box he is using is
of 10 cm, a width of 7 cm and a height of 5 cm. Find
gift wrapper he needs to wrap the entire box?
10.
The side of the a cube measures 12 cm. Sc
a
Which of the following represents the velocity of a moving object?
Select one:
40 m north.
40.
40 m/s north.
40 m/s.
Answer:
The correct answer would be 40 m/s
Explanation:
The reason 40 m/s is the correct answer is because m/s stands for meters per second.
Hope this helps you with what you're working on! :D
Answer:
40 m/s north
Explanation:
Velocity is a vector quantity, so it have both direction and magnitude.
why is it necessary to standardize a secondary standard before use?
As the name implies, a secondary standard is used by standard laboratories, which include companies involved in the preparation of reagents and kits, as well as laboratories responsible to produce quality control material for use by other laboratories. They use the primary standard as the primary calibrator or primary reference material, and they calibrate their instruments against it. Smaller labs use secondary standards to calibrate control material for analysis of unknown concentrations. For smaller labs, secondary standard serves as an external quality control. As a result, it is essential that the secondary standard be standardized against the primary standard before it can be applied.
I hope this helps you
:)
As a chemical energy is converted into heat energy during a reaction the total energy of the system
When a chemical energy is converted to hear during a chemical reaction, the total energy of the system remain constant.
Law of conservation of Energy?Law of conservation of energy state that the today energy interacting with bodies in a isolated system remain constant
the Law of Conservation state that the total energy in a system remain unchanged, and that oftentimes a chemical reaction will absorb or release energy in the form of heat, light, or both.
Therefore, The total energy of the system remain constant.
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the pH of an acidic solution is 2.47. what is the [H+]
[tex]pH=-\log[H^{+}]\\\\\implies [H^{+}] =10^{-pH}=10^{-2.47}=0.0034~M[/tex]
Calculate the % by mass concentration for each of the following solutions. Match the answers.
1.25g NaCl in 100.0g of solution = [a]%
ce
2.50g K2Cr2O7 in 96.0g of solution = [b]%
nts
10.0g CaCl2 in 250.0g of solution = [c]%
ns
20.0g Kl in 100.Ogof solution = [d]%
The percentage by mass of each of the compounds would be 40%, 2.6%, 4%, and 20% respectively
Percentage by massThe percentage by mass of a substance is given by:
Percent by mass = mass of substance/mass of solution x 100%.
For NaCl: Percent by mass = 25/100 = 40%For K2Cr2O7: Percent by mass = 2.50/96 = 2.6%For CaCl2: Percentage by mass = 10/250 = 4%For KI: Percent by mass = 20/100 = 20%More on percentage by mass can be found here: https://brainly.com/question/27108588
Procedure for Lab: Enthalpy ?
I have a lab on Edge that's about Enthalpy. The assignment is called " Lab: Enthalpy". If someone could help me with the procedure of the lab, that would be nice. (I don't need the data table, just the procedure.)
The enthalpy refers to the thermodynamic characteristics that have chemical systems associated with their internal energy.
What is enthalpy?The enthalpy refers to the thermodynamic features of the chemical systems associated with the energy of such systems.
Enthalpy is used to estimate the ability of the system to perform work and release energy in the form of heat.
It is well known that different types of chemical reactions may exhibit different enthalpies, which can be estimated by the internal energy, pressure of the system and volume.
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Answer:
Here you are <3
Explanation:
I attached the one I just submitted
Which is most reactive out of calcium, potassium, and magnesium?
Answer:
As we have already discussed, reactivity of alkali metals tends to increase as you go down the group. Therefore, sodium is less reactive with water than is potassium, likewise with the alkaline metals; calcium is more reactive than magnesium
help me this is due soon
Answer:
Hot magma change climate continents drift block sunlight folded mountains form rock deposits
Explanation:
brainliest now
what is the volume of
NH4 NO3(s) — N2O(g) + 2H2O(g)
Answer:
Explanation:
NH4NO3(s) N2O(g) + 2H2O(g) What is the total volume of gases produced at 546 K and 1.00 atm pressure when 240 g of ammonium nitrate undergoes the above decomposition reaction? A) 9 × 22.4 L B) 3 × 22.4 L C) 12 × 22.4 L D) 18 × 22.4 L E) 6 × 22.4 L
What are valence electrons?
A electrons in the outermost level of each atom
B electrons found in the s or p orbitals of atoms
C electrons in the innermost level of each atom
D electrons produced by the radioactive decay of the nucleus of an atom
A electrons in the outermost level of each atom
1) A solution is prepared with 0.55 M HNO2 and 0.75 M KNO2. Fill in the ICE Table with the appropriate values
2) The Ka for this solution of HNO2 is 6.8x10^-4. Based on the ICE table, set up the expression for Ka.
3) Based on your ICE table, determine the pH of the buffer solution
Based on the calculations through the ICE table, the pH of the buffer solution is equal to 3.30.
Given the following data:
Concentration of [tex]HNO_2[/tex] = 0.55 M.Concentration of [tex]KNO_2[/tex] = 0.75 M.Rate constant = [tex]6.8 \times 10^{-4}[/tex]How to determine the pH of the buffer solution.First of all, we would write the properly balanced chemical equation for this chemical reaction:
[tex]HNO_2(aq)\rightleftharpoons H^{2+} (aq)+ KNO_2^{-}(aq)[/tex]
Initial cond. 0.55M 0 0.75M
[tex]\Delta C[/tex] -x x x
At equib. 0.55M - x 0 + x 0.75M + x
From the ICE table, the Ka for this chemical reaction is given by:
[tex]K_{a}=\frac{[H^+][NO_2^+]}{HNO_2} \\\\H^+ = K_{a}\frac{[HNO_2]}{[NO_2^+]} \\\\H^+ = 6.8 \times 10^{-4} \times \frac{0.55}{0.75} \\\\H^+ = 6.8 \times 10^{-4} \times 0.733\\\\H^+ = 4.98 \times 10^{-4} \;M[/tex]
Now, we can calculate the pH of the buffer solution:
[tex]pH=-log[H^+]\\\\pH=-log[4.98 \times 10^{-4}]\\\\pH=-(-3.30)[/tex]
pH = 3.30.
Alternatively, you can calculate the pH of this buffer solution by applying Henderson-Hasselbalch equation:
[tex]pH =pka+ log_{10} \frac{A^-}{HA}[/tex]
Where:
HA is acetic acid.[tex]A^-[/tex] is acetate ion.Read more on concentration here: https://brainly.com/question/3006391
In cells, __________ are proteins that are needed to lower the amount of energy required to start chemical reactions
Answer: I think it’s enzymes
Explanation:
1. Can you please put the following chromatography solvents in order of polarity as a chromatography solvent: acetone, n-propanol,
water, hexane, diethyl ether, methanol and explain
2. chromatography with a mixture of n-propanol and water. Would it make sense to add hexane to this mixture to try and make it work better? why?
3. The basic food colors you can buy are red, blue, green, and yellow. Think about what you know about colors
and predict which of these might be a single colored compound and which ones might contain more than one.
Write down your prediction. If you have the colors listed and want a purple color, what would you do?
The order of increasing polarity of the solvents is; hexane< diethyl ether < acetone < n-propanol < methanol < water
What is chromatography?Chromatography literarily means "color writing". It provides a means of separating the components of a mixture based on its components.
The solvent in chromatography is the mobile phase while the adsorbent is the stationary phase. The order of increasing polarity of the solvents is; hexane< diethyl ether < acetone < n-propanol < methanol < water
If we have a mixture of n-propanol and water, it would be good to add hexane to the mixture for the sake of the elution of non-polar solutes.
The secondary color green may be composed of more than one color while red, blue and yellow are single colors.
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How many kJ of heat do you need to raise the temperature of 200 g of Aluminum from 80 °C to 100 °C?
Remember to convert your answer to kJ. Round your answer to two decimal places.
Answer:
0.01
Explanation:
100 -80=20
200/20=10/1000=0.01kj
A 30.4ml sample of 2.38 M solution of KCI (molar mass = 74.55 g/mol) is prepared. How many grams of KCI are in the solution?
Do not report units in your answer. Report your answer with two places past the decimal point.
ignore this, it wont let me exit this screen/ tab for some reason..
At 4.5 atm of pressure, the solubility of a gas is 9.5 g/L.
How much gas, in grams, will dissolve in 1 L if the pres.
sure is reduced by 3.5 atm?
For a gas at 4.5 atm of pressure, the solubility of a gas is 9.5 g/L.
How much gas, in grams, is mathematically given as
s2=8.3782grams
What is the amount of gas in grams?Generally, the equation for the is mathematically given as
Si /S2 √P1/√P2
Therefore
[tex]s2=9.5*\sqrt{3.5}/\sqrt{4.5}[/tex]
s2=8.3782g
In conclusion. The solubility is
s2=8.3782g
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According to the given equation, how many moles of O, are required to react with 4.71 moles of C4H10?
2C4H10 + 1302 —8CO2 + 10 H
According to the given equation, 2C4H10 + 1302 — 8CO2 + 10H, 2 moles of O are required to react with 4.71 moles of C4H10.
How to calculate number of moles?The number of moles of a compound can be calculated stoichiometrically as follows:
The balanced chemical equation is given as follows:
2C4H10 + 1302 — 8CO2 + 10H
Based on the above equation, 2 moles of C4H10 reacts with 13 moles of O
Therefore; 4.71 moles of C4H10 will react with 4.71 × 6.5 = 30.62 moles of O
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Answer: 30.6
Explanation:
What type of molecule is cis-2-pentene?
O A. Alkane
B. Alkyne
C. Branched alkane
D. Alkene
The given molecule, cis-2-pentene, is an Alkene. The correct option is D. Alkene
Saturated & Unsaturated HydrocarbonsAlkanes, Alkenes, and Alkynes are examples of simple hydrocarbons.
Alkanes are the simplest organic compounds. They have only single bonds between carbon atoms and are called saturated hydrocarbons. Their nomenclature usually ends in -ane.Alkenes on the other hand have at least one carbon-carbon double bond. Their nomenclature usually ends in -ene. Alkynes have one or more carbon-carbon triple bonds.Their nomenclature usually ends in -yne. Alkenes and alkynes are called as unsaturated hydrocarbons.The given molecule is cis-2-pentene
Since the name of the molecule ends in "ene", the molecule is an Alkene.
Hence, the given molecule, cis-2-pentene, is an Alkene. The correct option is D. Alkene
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Answer: Alkene
Explanation: just took tha test
What is The fmu (grams/mole) for disulfur hexachloride *the formula for it is S2Cl6*
Hexasulfur Dichloride
Name: Hexasulfur Dichloride
Formula: S2Cl6
Molar Mass:276.848
Example Reactions:
• S2Cl6 + 4H2O = 2SO2 + 6HCl + H2
Find the acceleration of the 2 kg block in the following diagram. ( Hint find the net force!)
The acceleration of the block will be -2 m/s² in the backward direction.
What is force?
Force is defined as the product of mass of the body and the acceleration with which it is moving. Mathematically -
F = ma
It is a vector quantity. In the three dimensional coordinate system, the force vector can be resolved as -
[F] = F[x] a[x] + F[y] a[y] + F[z] a[z]
Given is a diagram in which two forces are acting on a block.
We can write -
Force 1 on block [F1] = 4 a[x]
Force 2 on block [F2] = 8 (- a[x]) = - 8 a[x]
Resultant of forces [F] = [F1] + [F2] = 4 a[x] + ( - 8 a[x]) = - 4 a[x]
Now, we know that -
F = MA
A = F/M
In vector form, acceleration will be -
[A] = - 1/m × (4 a[x])
[A] = -1/2 × (4 a[x])
[A] = - 2 a[x]
Therefore, the acceleration of the block will be -2 m/s² in the backward direction.
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23.4 grams of Al2(SO3)3 is yielded through a chemical reaction. How many moles is this?
Answer:
.0796 mole
Explanation:
Al2 (SO3)3 add the molecular weights
2 * Al = 2 * 26.982 +
3 * S = 3 * 32.06 +
9 * O = 6 * 15.999 = 294.135 gm per mole
Now... you have 23.4 grams of this substance
23.4/294.135 = .0796 mole
EDITED !