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
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
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.
help please please please!
Answer:
I say the second one, im not rlly sure tho
Explanation:
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
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!
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:
The ingredients of a soup include
1,500 grams of water, 350 grams of vegetables, and 210 grams of meat. What is the total mass of the soup?
Answer:
sopas
Explanation:
lagyan mo ng condense
There is a golden role of solubility, polar solute dissolve in polar solvent and non polar solute dissolve in non polar solvent. Therefore, the total mass of the soup is 2,060gram.
What is solution?Solutions are a homogeneous mixture of two or more substances. A solution is a homogeneous mixture of solvent and solute molecules. Solvent is a substance that is in large amount in solution. solute is the substance which is in small amount in a solution. There are two types of mixture that is homogeneous and heterogeneous. Solution is a homogeneous solution.
mass of soup= mass of water+ mass of vegetables + mass of meat
mass of water=1,500 grams
mass of vegetables= 350 grams
mass of meat=210 grams
substituting all the values in the above equation, we get
mass of soup= 1,500 grams+ 350 grams + 210 grams
= 2,060gram
Therefore, the total mass of the soup is 2,060gram.
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In which orbitals would the valence electrons for selenium (Se) be placed?
Answer:
Valence electrons of selenium will be placed in s and p-orbitals.
Explanation:
Hope this helps.
Caffeine, a stimulant found in coffee and soda, has the following elemental composition: 49.48% carbon, 5.19% hydrogen, 16.48% oxygen and 28.85% nitrogen. The molar mass of caffeine is 119.19 g/mol. Determine the molecular formula of caffeine.
Answer:
Explanation:
C = 49.48
H = 5.19
O = 16.48
N = 28.85
ratio of moles
= 49.48 / 12 : 5.19 / 1 : 16.48 / 16 : 28.85 / 14
= 4.123 : 5.19 : 1.03 : 2.06
= 4 : 5 : 1 : 2
so the empirical formula = C₄ H₅O N₂
Let molecular formula = ( C₄ H₅ON₂ )ₙ ,
n ( 48 + 5 + 16 + 28 ) = 119.19
97 n = 194.19
n = 2 ( approx )
molecular formula = C₈ H₁₀O₂ N₄
no question................................
Answer:
ok
Explanation:
what are the three states of energy
can someone put this in other words Conduct an investigation to explore the use of Punnett squares to predict genotypes and phenotypes of offspring.
Which of the two forces is greater the force on the firefly or the force on the bus explain your answer please I really need help please
It’s due today please
Answer: The force on the firefly
The unfortunate firefly hitting the bus does not change the velocity of the bus very much. Technically there is a change, but it's so very small and miniscule that it barely registers. To any casual observer not paying very close attention, they don't notice anything at all. So effectively the force on the firefly is a lot greater since the firefly got the worst end of the deal.
So in short, we look at the velocity of each object and see which velocity changed the most. In this case, the firefly's velocity changed from whatever speed it was flying to 0 when it stops flying all together. That's why the force is greater on the bug.
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.5.75 x 1021 molecules of oxygen is the equivalent of how many
moles?
765.75
................................
how to covert ethanol into 2-butanol.(show reaction)
Explanation:
Conversion -
Ethanol to 2-butanolCH₃–CH₂–OH → CH₃–CH₂– CH(OH)–CH₃
Explaination -
CH₃–CH₂–OH + HCl → CH₃–CH₂– Cl + H₂O
Now,
CH₃–CH₂– Cl + 2Na + Cl–CH₂–CH₃ → CH₃–CH₂–CH₂–CH₃ + 2NaCl (wurtz reaction)
Now,
CH₃–CH₂–CH₂–CH₃ + Cl₂ → CH₃–CH₂–CH₂–CH₂–Cl + HCl (Halogenation)
Now,
CH₃–CH₂–CH₂–CH₂–Cl + KOH (alc.) → CH₃–CH₂–CH=CH₂ + KCl + H₂O
Now,
CH₃–CH₂–CH=CH₂ + H₂O → CH₃–CH₂–CH(OH)–CH₃ (Hydration of alkene by MR addition rule)
What is the definition of an Isomer?
Answer:
Each of two or more compounds with the same formula but a different arrangement of atoms in the molecule and different properties.
Explanation:
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:
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.
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
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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How many liters of CH3OH gas are formed when 3.20 L of H2 gas are completely reacted at STP according to the following chemical reaction?
Remember 1 mol of an ideal gas has a volume of 22.4 L at STP
CO(g) + 2 H₂(g) → CH₃OH(g)
Answer:
1.6 L CH3OH
Explanation:
3.20 L H2 x (1 mol H2/22.4 L H2) x (1 mol CH3OH/2 mol H2) x (22.4 L CH3OH/1 mol CH3OH) = 1.60 LCH3OH
1.602 liters of CH₃OH gas are formed when 3.20 L of H₂ gas are completely reacted at STP according to the following chemical reaction:
CO(g) + 2 H₂(g) → CH₃OH(g)
Remember 1 mol of an ideal gas has a volume of 22.4 L at STP
To find the volume of CH₃OH gas formed when 3.20 L of H₂ gas is completely reacted, we need to use stoichiometry and the given balanced chemical equation.
The balanced equation is:
CO(g) + 2 H₂(g) → CH₃OH(g)
From the balanced equation, we can see that 1 mol of CO reacts with 2 moles of H₂ to produce 1 mole of CH₃OH.
Step 1: Convert the given volume of H₂ gas to moles at STP.
Using the information provided, 1 mol of any ideal gas at STP (Standard Temperature and Pressure) occupies 22.4 L.
Number of moles of H₂ gas = Volume of H2 gas at STP / Volume of 1 mol of H₂ gas at STP
Number of moles of H₂ gas = 3.20 L / 22.4 L/mol
Number of moles of H₂ gas = 0.14286 moles (rounded to 5 decimal places)
Step 2: Use stoichiometry to find the moles of CH₃OH formed.
From the balanced equation, we know that 1 mol of CO reacts with 2 moles of H₂ to produce 1 mole of CH₃OH.
Since the ratio of H₂ to CH₃OH is 2:1, the number of moles of CH₃OH formed will be half of the moles of H₂ used in the reaction.
Number of moles of CH₃OH = (1/2) * Number of moles of H₂
Number of moles of CH₃OH = (1/2) * 0.14286
Number of moles of CH₃OH = 0.07143 moles (rounded to 5 decimal places)
Step 3: Convert the moles of CH₃OH to volume at STP.
Using the information provided, 1 mol of any ideal gas at STP (Standard Temperature and Pressure) occupies 22.4 L.
Volume of CH₃OH gas at STP = Number of moles of CH₃OH * Volume of 1 mol of CH₃OH gas at STP
Volume of CH₃OH gas at STP = 0.07143 moles * 22.4 L/mol
Volume of CH₃OH gas at STP = 1.602 L (rounded to 3 decimal places)
Therefore, approximately 1.602 liters of CH₃OH gas are formed when 3.20 liters of H₂ gas are completely reacted at STP.
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Please it's due today
Answer:
The answer is the second one
What type of change is sugar dissolving in water physical or chemical
Answer:
Physical
Explanation:
No new substance is formed.
The process can be reversed using evaporation to separate the sugar from the water
So the change is physical
Hope this helps :)
in the reaction of magnesium metal with hydrochloric acid, how do you determine when the magnesium metal has reacted completely
Answer:
When there is no spark from the reaction
Explanation:
The reaction between the acid and the magnesium metal goes into completion when there is no more spark from the magnesium. Also, the magnesium would have totally disappeared into solution.
These physical observation marks the end of the reaction.
When Mg reacts with HCl hydrogen bubbles are released. The completion of the given reaction can be determined by the presence of bubbles above the HCl.
The reaction between HCl and Mg:[tex]\bold {Mg+ 2HCl\rightarrow MgCl_2 + H_2}[/tex]
In this reaction, Mg reacts with 2 moles of HCl to form 1 mole of Magnesium chloride and release hydrogen gas.
During reaction,
Magnesium slowly disappears as it reacts with HCl.The hydrogen gas is released during the reaction, bubbles can be observed.Therefore, the completion of the given reaction can be determined by the presence of bubbles above the HCl.
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2)
The amount of energy required to remove all the valence electrons from a cesium atom is
A)
944 kJ/mol
B)
376 kJ/mol
C)
520 kJ/mol
D)
238 kJ/mol
Answer:
c 520kj mol
Explanation:
times all the electrons
What is chemical weathering
Explanation:
Chemical weathering is caused by rain water reacting with the mineral grains in rocks to form new minerals (clays) and soluble salts. These reactions occur particularly when the water is slightly acidic.
Write the balanced chemical equation for the following reaction. Phases are optional. Solid iron(I) oxide reacts with hydrogen gas to form solid iron and liquid water. 2Fe+3H,Ol Fe,O,+ 3H2 â 2Fe+ 3H2O(I)
Answer:
[tex]Fe_2O_3(s)+3H_2(g)\rightarrow 2Fe(s)+3H_2O(l)[/tex]
Explanation:
Hello!
In this case, when writing chemical reactions from the given names we must make sure we know the proper formula for each reacted and produced species; thus, since solid iron (III) oxide is [tex]Fe_2O_3[/tex], hydrogen gas is [tex]H_2[/tex], solid iron is Fe and liquid water is just [tex]H_2O[/tex], we can write:
[tex]Fe_2O_3(s)+H_2(g)\rightarrow Fe(s)+H_2O(l)[/tex]
However, since different amount of atoms of iron, hydrogen and oxygen are present at each side of the equation, we balance it by adding the following coefficients to each molecule:
[tex]Fe_2O_3(s)+3H_2(g)\rightarrow 2Fe(s)+3H_2O(l)[/tex]
And now it is balanced with two iron atoms, three oxygen atoms and six hydrogen atoms at both reactants and products.
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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.