What mass of 2-naphthol would have to be ingested by each rat in a sample set of rats in order to kill half the population of rats? Assume each rat weighs 230 g. Show your calculations for full credit.
Answer:
303.6 mg
Explanation:
Given that:
The lethal dose [tex]LD_{50}[/tex] = 1320 mg/kg
The weight of the rat = 230 g
The lethal dose is the dose of a substance likely to cause death. SO a lethal dose of 50 will cause the death of 50% of the sample of test animals.
Therefore;
The mass of 2-naphthol that would have been ingested by each rat in a sample set of rats in order to kill half the population of rats will be equal to:
[tex]=\dfrac{LD_{50}}{1000} \times wt \ of \ rat[/tex]
[tex]=\dfrac{1320}{1000}\times 230[/tex]
= 303.6 mg
The boiling point of propanoic acid is higher than that of 1-butanol because:
Explanation:
The boiling point of propanoic acid is higher than that of 1-butanol due to the prevalence of hydrogen bonding in propanoic acid.
Hydrogen bond forms as a result of the electrostatic attraction between the hydrogen of one molecule and a more electronegative specie on another molecule(N or O or F). In propanoic acid, the hydrogen bonding is more pronounced and strong. For 1-butanol, the bonding is weak and not strong.An organic chemist is planning to extract 1.00 g of an organic compound dissolved in 200.0 mL of water into a diethyl ether solvent. The partition coefficient for this system is 9.5, favoring the diethyl ether solvent. What percentage of the organic compound remains in the aqueous solvent if you perform three successive extractions with 50.0 mL of diethyl ether for each extraction?(a) 29.63% (b) 2.60% (c) 0.00169%
Answer:
(b) 2.60%
Explanation:
Partition coefficient of the organic compound in ether is:
9.5 = Concentration in ether / Concentration in water
In the first extraction, X is the amount of organic compound extracted:
9.5 = X/50mL / (1-X)/200mL
9.5 = 200X / (50-50X)
475 - 475X = 200X
475 = 675X
X = 0.7037g are extracted.
Remains = 1g - 0.7037g = 0.2963g
Second extraction:
9.5 = X/50mL / (0.2963-X)/200mL
9.5 = 200X / (14.815-50X)
140.74 - 475X = 200X
140.74 = 675X
X = 0.2085g are extracted.
Remains = 0.2963g - 0.2085g = 0.0878g
Third extraction:
9.5 = X/50mL / (0.0878g-X)/200mL
9.5 = 200X / (4.3899-50X)
41.70 - 475X = 200X
41.70 = 675X
X = 0.2085g are extracted.
Remains = 0.0878g - 0.0618g = 0.026g remains
Percentage: 0.026g / 1g * 100 =
(b) 2.60%I AM GIVING A LOT OF POINTS SO PLEASE HELP ME!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Can someone please help me with this?
Rules:
Label the section of the roller coaster where the kinetic or potential energy is.
Answer:c
Explanation:
it’s gained kinetic from the gravitational potential energy at the top
SEP Develop Models Each helium atom has two protons. Sketch models
of helium-3 and helium-4, which have approximate masses of 3 amu
and 4 amu, respectively. Label and differentiate protons, neutrons, and
electrons in your models?
Protons and neutrons are located in the nucleus of the atom while the electrons move in the trajectory of the shell
Further explanationIsotopes are atoms whose no-atom has the same number of protons while still having a different number of neutrons.
So Isotopes are elements that have the same Atomic Number (Proton)
Isotopes of Helium : helium-3 and helium-4
₂³He :protons = 2
electrons=protons=2
neutron=mass number-atomic number=3-2=1
₂³He :protons = 2
electrons=protons=2
neutron=mass number-atomic number=3-2=1
₂⁴Heprotons = 2
electrons=protons=2
neutron=mass number-atomic number=4-2=2
Protons and neutron in the nucleus, electrons in the shell
Which statement best describes evidence that a chemical reaction occurs as a cake bakes
Answer: the cake rises as gas bubbles form in the cake
Explanation: Had a quizziz quiz on this
Answer: The cake rises as gas bubbles form in the baking cake.
Explanation: had a test, got it right.
Boron has an average atomic mass of 10.81. One isotope of boron has a mass of 10.012938 and a relative abundance of 19.80%. The other isotope has a relative abundance of 80.20%. What is the mass of that isotope? Report to two decimal places. amu
Answer:
11.01 amu
Explanation:
19.8% • 10.012938 = 1.982561724
10.81 - 1.982561724 = 8.827438276
8.827438276/80.2% = 11.0067808928
Answer: 11.01 amu
Explanation:
Arrange the following compounds in order of increasing acidity, and explain the reasons for your choice of order. Enter your answer in the answer box below. a. 4-nitrophenol b. cyclohexanol c. 2,6-difluorocyclohexanol d. 4-bromophenol
Answer:
(a) > (d) > (c) > (b)
Explanation:
Acidic character is based upon inductive effect of the functional group that are attached to parent chain.
1. Nitro is a -I group which makes phenol acidic due to increased resonance, 2. bromine is a -I group but it is weaker than nitro group
3. phenol is more acidic than cyclohexanol due to resonance stabilization of resonance and among halogen F>Cl>Br>I is the order of acidity
4. cyclohexanol will be weakest as it is not associated with any -I groups here.
so the order of acidity will be
(a). 4-nitropheno > (d). 4-bromophenol > (c). 2,6-difluorocyclohexanol > (b). cyclohexanol
According to the following reaction, how many grams of sulfur are formed when 37.4 g of water are formed?
2H₂S(g) + SO₂(g) → 3S(s) + 2H₂O(l)
Answer:
Mass = 100.8 g
Explanation:
Given data:
Mass of sulfur formed = ?
Mass of water formed = 37.4 g
Solution:
Chemical equation:
2H₂S + SO₂ → 3S + 2H₂O
Number of moles of water:
Number of moles = mass/molar mass
Number of moles = 37.4 g/ 18 g/mol
Number of moles = 2.1 mol
Now we will compare the moles of water and sulfur.
H₂O : S
2 : 3
2.1 : 3/2×2.1 = 3.15
Mass of sulfur:
Mass = number of moles × molar mass
Mass = 3.15 mol × 32 g/mol
Mass = 100.8 g
what are the three states of energy
An energy bill indicates that the customer used 1024 kWh in July. How many joules did the customer use?
Answer:
3,686,400,000 Joules
Explanation:
Energy = 1024 kWh
To be converted to Joules.
The relationship between kwh and joules is;
1 kilowatt-hour = 3600000 J
So we have;
1 = 3600000
1024 = x
x = 1024 * 3600000
x = 3,686,400,000 Joules
can someone put this in other words Conduct an investigation to explore the use of Punnett squares to predict genotypes and phenotypes of offspring.
find examples for each polysaccharides type.
Answer:
Glycogen: It is made up of a large chain of molecules. ...
Cellulose: The cell wall of the plants is made up of cellulose. ...
Starch: It is formed by the condensation of amylose and amylopectin. ...
Insulin: It is made up of a number of fructofuranose molecules linked together in chains.
Explanation:
Explain why a buffer can be prepared from a mixture of NH4CL and NaOH but not from NH3 and NaOH .
A buffer solution is often referred to as a mixture of an aqueous solution of a weak acid and its conjugate base or weak base and its conjugate acid.
NH4CL is a weak base and NaOH is a strong base and when both it gives you a basic buffer and the result will give you an acid/base needed for the buffer.NH 3 is a weak base, but NaOH is a strong base and therefore the combination of these solutes would not make a buffer solution because both will give you a base and no acid.Conclusively we can say that an acid or base needed for making buffer solutions and not base alone
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Nitrogen dioxide (NO2) gas and liquid water (H2O) react to form aqueous nitric acid(HNO3) and nitrogen monoxide gas. Suppose you have 2.0 mol of NO2 and 7.0 mol of H20 in a reactor. Calculate the largest amount of NHO3 that could be produced. Round your answer to the nearest 0.1 mol.
Answer:
1.3 moles of HNO₃ will be produced
Explanation:
Equation for the reaction:
3NO₂ + H₂O ----> 2HNO₃ + NO
From the equation of the reaction, 3 moles of NO₂ reacts with 1 mole of H₂O to produce 2 moles of HNO₃
Suppose there are 2 moles of NO₂ and 7.0 moles of H₂O in a reactor, the limiting reactant will be NO₂ and H₂O will be in excess since 3 moles of NO₂ reacts with every 1 mole of H₂O.
Since 3 moles of NO₂ reacts to produce 2 moles of HNO₃;
2 moles of NO₂ will react to produce 2/3 * 2 moles HNO₃ = 1.3 moles of HNO₃
Therefore, 1.3 moles of HNO₃ will be produced
The largest amount of HNO₃ produced from the reaction between 2 mole of NO₂ and 7.0 mole of H₂O in a reactor is 1.3 mole
We'll begin by determining the limiting reactant. This can be obtained as follow:
3NO₂ + H₂O —> 2HNO₃ + NO
From the balanced equation above,
3 moles of NO₂ reacted with 1 mole of H₂O.
Therefore,
2 moles of NO₂ will react with = [tex]\frac{2}{3}\\\\[/tex] = 0.67 mole of H₂O.
From the calculation made above, we can see that only 0.67 mole of H₂O out of 7 moles given, reacted completely with 2 moles of NO₂. Thus, NO₂ is the limiting reactant and H₂O is the excess reactant. Finally, we shall determine the largest amount of HNO₃ produced from the reaction. This can be obtained by using the limiting reactant as illustrated below:From the balanced equation above,
3 moles of NO₂ reacted to produce 2 moles of HNO₃.
Therefore,
2 moles of NO₂ will react to produce = [tex]\frac{2 *2 }{3} \\\\[/tex] = 1.3 mole of HNO₃.
Thus, the largest amount of HNO₃ produced from the reaction is 1.3 mole
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Calculate the Molarity when a 6.11 mL solution of 0.1 H2SO4 is diluted with 105.12 mL of water
Molarity after dilution : 0.0058 M
Further explanationThe number of moles before and after dilution is the same
The dilution formula
M₁V₁=M₂V₂
M₁ = Molarity of the solution before dilution
V₁ = volume of the solution before dilution
M₂ = Molarity of the solution after dilution
V₂ = Molarity volume of the solution after dilution
M₁=0.1 M
V₁=6.11
V₂=105.12
[tex]\tt M_2=\dfrac{M_1.V_1}{V_2}=\dfrac{0.1\times 6.11}{105.12}=0.0058~M[/tex]
On a statistical basis,smoking a single cigarrette lowers your life expectancy by 642,000--------------------------.Pls answer this question
Thank you, also what are the options then I can help!
Please it's due today
Answer:
The answer is the second one
The molarity (M) of an aqueous solution containing 22.5 g of sucrose (C12H22O11) in 35.5 mL of solution is ________.
Answer:
1.86 M
Explanation:
From the question given above, the following data were obtained:
Mass of sucrose (C12H22O11) = 22.5 g
Volume of solution = 35.5 mL
Molarity of solution =?
Next, we shall determine the number of mole in 22.5 g of sucrose (C12H22O11). This can be obtained as follow:
Mass of sucrose (C12H22O11) = 22.5 g
Molar mass of C12H22O11 = (12×12) + (22×1) + (16×11)
= 144 + 22 + 176
= 342 g/mol
Mole of C12H22O11 =?
Mole = mass /Molar mass
Mole of C12H22O11 = 22.5 /342
Mole of sucrose (C12H22O11) = 0.066 mole
Next, we shall convert 35.5 mL to litres (L). This can be obtained as follow:
1000 mL = 1 L
Therefore,
35.5 mL = 35.5 mL × 1 L / 1000 mL
35.5 mL = 0.0355 L
Thus, 35.5 mL is equivalent to 0.0355 L.
Finally, we shall determine the molarity of the solution as follow:
Mole of sucrose (C12H22O11) = 0.066 mole
Volume of solution = 0.0355 L.
Molarity of solution =?
Molarity = mole /Volume
Molarity of solution = 0.066/0.0355
Molarity of solution = 1.86 M
Therefore, the molarity of the solution is 1.86 M.
An atom of beryllium has 4 protons, 4 electrons, and 5 neutrons. What is its mass number?
Answer:
40 is correct
Explanation:
Your answer should be 4.
Hope this helped!
-candycchandler
1. How isotopes of copper are Cu-63 and Cu-65. How are these two isotopes the same? How are they different?
2. What is an isotope?
3. Why do elements in the same group have similar chemical properties?
4.What are valence electrons?
5.Write the symbol for each of the following elements:
The halogen in period three
The alkali metal in period two
The noble gas in period one
The alkaline earth element in period six
Any transition metal in the 5th period
A metaloid in group 14
A nonmetal in group 16
6. What are two differences between a metal and a nonmeta
PLEASE ASAP!!!!!!!!!!!!!!
Answer:
question 6. answer is Metals are considered to be electropositive in nature due to their ability to donate electrons. Whereas non-metals are electronegative as they generally accept electrons
no question................................
Answer:
ok
Explanation:
Which classes of isomers are easier to separate from each other in the laboratory: enantiomers or diastereomers?
Answer:
diastereomers
Explanation:
Enantiomers are optical isomers that are mirror images of each other. Enantiomers can not be separated by physical methods because the both compounds have almost the same physical properties such as melting points, boiling points, etc. This makes it difficult to separate enanatiomers by conventional methods.
A common method of separating enantiomers is by converting them into diasteromers which are easily separated since diasteromers often have different chemical and physical properties.
1Water molecules can be ligands especially when they are bonded to
..........
A. alkaline earth metals
B. alkali metals
C. transition metals
D. group VII elements
Answer:c
Explanation:
If the mass of a sample of Mg is 0.500 g and is placed in 100.0 g of HCl, the heat gained is 546.5 J. What is the change in temperature assuming the specific heat of HCl is 4.017 J/K*g?
Answer:
1.36 K
Explanation:
We have the following data:
The heat gained by HCl is calculated as:
heat = m x Sh x ΔT
where m is the mass of HCl (100.0 g), Sh is the specific heat of HCl (4.017 J/K.g) and ΔT is the change in temperature. We introduce the data in the mathematical expression to calculate ΔT as follows:
ΔT = heat/(m x Sh) = 546.5 J/(100.0 g x 4.017 J/K.g) = 1.36 K
Therefore, the change in temperature is 1.36 K.
How many moles of hydrogen are present in 5.30 moles of C5H10O2, propyl acetate, the compound that provides the odor and taste of pears.
Note the type of problem this is - you are being asked to relate moles of an element to 1 mole of a compound (subscripts and moles).
a. 10.6
b. 5.30
c. 6.02 x 1023
d. 53.0
Answer:
Option D. 53 moles.
Explanation:
The following data were obtained from the question:
Number of mole of C5H10O2 = 5.3 moles
Number of mole of Hydrogen in 5.3 moles of C5H10O2 =?
From the chemical formula of propyl acetate, C5H10O2,
1 mole of C5H10O2 contains 10 moles of H.
Therefore, 5.3 moles of C5H10O2 will contain = 5.3 × 10 = 53 moles of H.
Thus, 5.3 moles of C5H10O2 contains 53 moles of H.
5.75 x 1021 molecules of oxygen is the equivalent of how many
moles?
765.75
................................
why did Aristotle disagree with Democritus
Answer: He theorized that all material bodies are made up of indivisibly small “atoms.” Aristotle famously rejected atomism in On Generation and Corruption. Aristotle refused to believe that the whole of reality is reducible to a system of atoms.
Explanation:
Aristotle disagreed with Democritus primarily on the nature of matter and the concept of atomism.
Democritus proposed the theory of atomism, suggesting that all matter is composed of indivisible and indestructible particles called atoms. He believed that atoms combine and interact to form different substances.
On the other hand, Aristotle rejected the notion of atomism and instead proposed a different theory of matter. According to Aristotle, matter is continuous and infinitely divisible. He believed that substances are composed of four primary elements - earth, air, fire, and water - which have different inherent properties and undergo transformations through the combination and separation of these elements.
Aristotle's disagreement with Democritus stemmed from their differing views on the fundamental nature of matter. While Democritus emphasized the discrete and fundamental nature of atoms, Aristotle emphasized the continuous and composite nature of matter. Their contrasting viewpoints reflected a broader philosophical divide between atomism and holism in ancient Greek philosophy.
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What does Hess's law state can be done in order to be able to react solid magnesium with oxygen gas safely (that is, without exposing the magnesium to flames)?A. More moles of solid magnesium can be added until the reaction is safe.B. More moles of oxygen gas can be added until the reaction is safe.C. The reaction can be broken down and performed in steps. D. The phase state of the reactants can be changed to match each other.E. The phase state of the products can be changed to match each other.
Answer:
C. The reaction can be broken down and performed in steps
Explanation:
Hess's Law of Constant Heat Summation states that irrespective of the number of steps followed in a reaction, the total enthalpy change for the reaction is the sum of all enthalpy changes corresponding to all the steps in the overall reaction. The implication of this law is that the change of enthalpy in a chemical reaction is independent of the pathway between the initial and final states of the system.
To obtain MgO safely without exposing magnesium to flame, the reaction sequence shown in the image attached may be carried out. Since the enthalpy of the overall reaction is independent of the pathway between the initial and final states of the system, the sum of the enthalpy of each step yields the enthalpy of formation of MgO.
Calculate the heat change in kilocalories for condensation of 6.5 kg of steam at 100 ° C
Answer:
6,500 gm of steam require= 3,510 kilo calories (approx)
Explanation:
Every 1 gram of water at 100° C absorb 540 calories
So,
Total water = 6.5 kg = 6,500 gram
So,
6,500 gm of steam require = 6,500 x 540
6,500 gm of steam require= 3,510 kilo calories (approx)
According to the question,
Total water,
6.5 kg or 6,500 gTemperature,
100°CNow,
Required steam will be:
= [tex]6500\times 540[/tex]
= [tex]3510 \ kilo \ calories[/tex]
Thus the above answer is right.
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