Answers
Answer:
Explanation:
elemant
compound
mixture
Related Questions
an ld50 (lethal dose 50%) is a dose of a toxic chemical that _____
Answers
An ld50 (lethal dose 50%) is a dose of a toxic chemical that "is capable of causing death to 50% of the animals exposed to it."
The ld50 is a measure of the toxicity of a chemical, which is the ability of a substance to cause harmful effects on living organisms. It is usually expressed as the amount of a chemical required to produce a specific response in a given population or species of organism. The ld50 is an important measure in toxicology as it provides a standardized method of evaluating the toxicity of different chemicals. It is often used to determine the safety of new drugs, pesticides, and other chemicals. A low ld50 value indicates a highly toxic substance, while a high ld50 value indicates a less toxic substance.
It is important to note that ld50 values are determined using animal studies, usually rodents, and may not be directly applicable to humans. Moreover, it is unethical to conduct ld50 tests on humans. Therefore, the ld50 values are used as a guideline rather than a definitive measure of toxicity.
In summary, an ld50 is a dose of a toxic chemical that is lethal to 50% of animals exposed to it, and it is an important measure of the toxicity of chemicals used in various industries.
For more such questions on lethal dose
https://brainly.com/question/30463329
#SPJ11
What is the difference between pcr and sanger sequencing with regard to the materials needed to perform these reactions?.
Answers
Sanger sequencing requires dideoxynucleotides, although PCR does not.
What is DNA sequencing?
A DNA molecule's exact nucleotide or base sequence can be found using a general laboratory procedure known as DNA sequencing. The bases' order encodes the biological information that cells utilize to grow and function (commonly referred to by the initial letters of their chemical names: A, T, C, and G).
Polymerase chain reaction (abbreviated PCR) is a laboratory technique for rapidly producing (amplifying) millions to billions of copies of a specific segment of DNA, which can then be studied in greater detail. PCR involves using short synthetic DNA fragments called primers to select a segment of the genome to be amplified, and then multiple rounds of DNA synthesis to amplify that segment.Sanger sequencing is a technique for DNA analysis that uses electrophoresis and is based on DNA polymerase's haphazard incorporation of chain-terminating dideoxynucleotides during in vitro DNA replication. It was the most extensively used sequencing technique for over 40 years after Frederick Sanger and colleagues initially developed it in 1977. In 1986, Applied Biosystems launched the first commercialization of it. For large-scale, automated genome analysis, next-generation sequencing techniques have lately displaced greater volume Sanger sequencing. For smaller-scale initiatives and the verification of deep sequencing results, the Sanger method is still widely used.Hence, Sanger sequencing requires dideoxynucleotides, although PCR does not.
To know more about Sanger sequencing from the given link
https://brainly.com/question/26225212
#SPJ4
What is the maximum number of grams of nickel bromide that can be produced from the reaction of 67.8 g of nickel with 37.3 g of bromine? _ Ni + __Br2 —-> NiBr2
Answers
Answer:
The answer to your question is a) 51.07 g of NiBr₂ b) Nickel, 54 g
Explanation:
Data
mass of NiBr₂ = ?
mass if Ni = 67.8 g
mass of Br = 37.3 g
Balanced chemical reaction
Ni + Br₂ ⇒ NiBr₂
Process
1.- Find the atomic mass of the reactants and the molar mass of the product
Ni = 59 g
Br = 79.9 x 2 = 159.8 g
NiBr₂ = 59 + 159.8 = 218.8 g
2.- Find the limiting reactant
theoretical yield Ni/Br₂ = 59/159.8 = 0.369
experimental yield Ni/Br₂ = 67.8/37.3 = 1.81
The limiting reactant is Bromine because the experimental yield was lower than the theoretical yield.
3.- Calculate the mass of NiBr₂
159.8 g of Br₂ --------------- 218.8 g of NiBr₂
37.3 g of Br₂ -------------- x
x = (37.3 x 218.8) / 159.8
x = 8161.24/159.8
x = 51.07 g of NiBr₂
4.- Find the excess reactant
The excess reactant is Nickel
59 g of Ni ---------------- 159.8 g of Br₂
x ---------------- 37.3 g of Br₂
x = (37.3 x 59)/159.8
x = 2200.7/159.8
x = 13.77 g of Ni
Excess Ni = 67.8 - 13.77
= 54 g
Please mark as brainliest
Have a great day, be safe and healthy
Thank u
XD
Which of the following is the correct structure of 2-methyl-3-heptene
a. CH3-CH2-C(CH3)=CH-CH2-CH2-CH3
b. CH3-CH2CH=CH-CH2CH(CH3)-CH3
c. CH3-CH2-CH=CH-CH-(CH3)-CH2-CH3
d. CH3-CCH(CH3)-CH=CH-CH2CH2-CH3
Answers
Answer:
answer d
Explanation:
methy group is in the second position while the double bond is in the third position
What happens when two or more substances are mixed together to form a solution 80 properties of a solution may be different from those of the original substances be the properties of the solution will always have the same properties as the original Simpsons see the solutions will always be the same color as the original substance DD solutions will always be a different state of matter than the original
Answers
A homogeneous mixture, also known as a solution, is created when two or more components are combined to produce a combination. The solute and the solvent are the two substances that are combined.
The material that is being dissolved is known as the solute, whereas the substance that dissolves the solute is known as the solvent.
SolutionThe qualities of a solution may differ from the properties of the original ingredients. The boiling point, freezing point, density, and refractive index of the mixture are some of the most frequent modifications that take place when ingredients are mixed to form a solution.The right answer is: "A solution's properties may differ from those of the original substances." This is so that both the solute's and the solvent's properties, as well as the solute's concentration in the solution, can affect a solution's characteristics.All of the other claims are false. Depending on how some substances interact with one another, a solution's color may or may not match the color of the original ingredient.learn more about solution here
https://brainly.com/question/25326161
#SPJ1
A Carnot cycle operates between the temperatures limits of 400 K and 1600 K, and produces 3600 kW of net power. The rate of entropy change of the working fluid during the heat addition process is
Answers
The rate of entropy change:
The rate of entropy change of the working fluid during the heat addition process is 3 kW/K
What is the Carnot cycle?
The Carnot Cycle is a thermodynamic cycle made up of reversible isothermal expansion, adiabatic expansion, isothermal compression, and adiabatic compression processes in succession. The ratio of the heat absorbed to the temperature at which the heat was absorbed determines the change in entropy.The entropy of a system:
The rate of heat addition is expressed as,
Q = \(\frac{WT_{H}}{T_{H}- T_{L}}\)
The entropy of a system is a measure of how disorderly a system is getting. The rate of entropy generation during heat addition is,
\(S_{gen} = \frac{Q}{T_{H}} = \frac{W}{T_{H} - T_{L}}\)
Calculation:
Given:
\(T_{L}\) = 400K
\(T_{H}\) = 1600K
W = 3600 kW
Put all the values in the above equation, and we get,
\(S_{gen} = \frac{W}{T_{H} - T_{L}}\) = \(\frac{3600}{1600-400}\) = 3 kW/K
The rate of entropy change is 3 kW/K
Learn more about the Carnot cycle here,
https://brainly.com/question/13002075
#SPJ4
How many Protons, Electrons, and Neutrons are there in Oxygen
Answers
Answer:
Name Oxygen
Atomic Mass 15.999 atomic mass units
Number of Protons 8
Number of Neutrons 8
Number of Electrons 8
Explanation:
draw the remaining products of the saponification of the following triacylglycerol (triglyceride):
Answers
The remaining products for the process of the saponification for the following triacylglycerol or the triglyceride : the glycerol and the soap.
The Saponification process is the process of the reacting of the triglyceride with the sodium or the potassium hydroxide that will create the soap. The former use of the hydroxide will be creates the hard soaps.
The water will not be created as the part of the reaction. The three glycerol molecules will be form the glycerol. The three soap molecules will be produced. So, these are the salts of the sodium hydroxide and the monocarboxylic acid that is the soap.
To learn more about saponification here
https://brainly.com/question/2263502
#SPJ4
Calculate the heat evolved kJ for the reaction of
1.00 g of elemental sulfur.
Answers
Answer: Calculate the heat evolved (per mo SO2) for the reaction of sulfur with oxygen to form SO . Calculate the heat evolved from a reaction mixture of 13.4L SO at 1 ATM and 273K ... N-2 (g) + Os (g) → 2 NO (g) H = +180.6 kJ.
Explanation: I hoped that was helpful!
How much energy is required to raise 10.0 grams of water (c=4.18j/gC) by 20*C?
Answers
Answer:
Q = 836 J
Explanation:
Given data:
Mass of water = 10.0 g
Temperature increased =ΔT = 20°C
Specific heat capacity of water = 4.18 J/g.°C
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
Q = 10.0 g × 4.18 J/g.°C × 20°C
Q = 836 J
Which is an organic molecule? c_{3}*h * n * o; ceb * r_{3}; cus * o_{4}; cd * l_{2}
Answers
An organic molecule is a compound that contains carbon atoms bonded to other elements such as hydrogen, oxygen, nitrogen, and other organic elements. Out of the given options, the organic molecule is c_{3}*h * n * o.
This compound contains carbon (C), hydrogen (H), nitrogen (N), and oxygen (O) atoms. The other options (cab * r_{3}, cus * o_{4}, cd * l_{2}) do not contain carbon atoms, so they are not organic molecules.
C_{3}H_{8} is an organic molecule known as propane. It consists of three carbon atoms and eight hydrogen atoms bonded together. Organic molecules contain carbon atoms and are typically associated with living organisms and their compounds.
to know more about moles here:
brainly.com/question/15209553
#SPJ11
Based on what is known about the involvement of calcium ions in exocytosis, what should happen if Ca2+ ions are injected into a cell? Wholesale exocytosis of nuclear contents occurs. O Wholesale exocytosis of secretory product occurs. Wholesale endocytosis of secretory product occurs O Secretion stops. O Endocytosis rates are accelerated.
Answers
If Ca2+ ions are injected into a cell, wholesale exocytosis of secretory product occurs. Exocytosis is the process by which cells release substances to the extracellular space.
Calcium ions play a crucial role in regulating exocytosis. When Ca2+ ions bind to specific proteins called synaptotagmins in the plasma membrane, it triggers the fusion of secretory vesicles with the membrane, leading to the release of their contents. This process is essential for the release of neurotransmitters in neurons and the secretion of various hormones and enzymes in other cell types.
When Ca2+ ions are artificially introduced into a cell by injection, they can bind to synaptotagmins, mimicking the natural signaling process. As a result, there is an uncontrolled and widespread activation of exocytosis, leading to wholesale exocytosis of secretory product. This means that all the secretory vesicles within the cell, containing various substances, will fuse with the plasma membrane and release their contents simultaneously. This can have significant consequences on the cell's function and can result in the rapid and massive release of substances that were originally meant to be released in a regulated manner.
The injection of Ca2+ ions into a cell would trigger wholesale exocytosis of secretory product. The uncontrolled activation of exocytosis caused by the artificially introduced Ca2+ ions would lead to the simultaneous release of the cell's secretory vesicles, resulting in the widespread and unregulated secretion of their contents.
Learn more about Calcium here: brainly.com/question/28206480
#SPJ11
The nucleus of the cell
a
Is found inside the chloroplast
b
Is found inside the membrane of a bacterial cell
c
contains DNA and controls the cell's activities
Answers
Answer:
c
Explanation:
it is c because that is the andwer
2.9g of a gas at 95°C occupied the same volume as 0.184g of dihydrogen at 17°C at the same pressure. What is the molar mass of the gas?
Answers
The molar mass of the gas at the same pressure is M = 40g/mol.
Equation :Let M, be the molar mass of the gas
The number of moles of the gas,
n= 2.9 / M
The volume of the gas,
V= P/nRT
V = 2.9R x 368 / MP
The number of moles of dihydrogen,
n = 0.184 / 2
n =0.092
The volume of dihydrogen gas,
v = 0.092×R×290 / P
At the same pressure P,
The volume of gas = volume of dihydrogen
0.092R×290= 2.9R×368 / M
M= 2.9×368 / 0.092×290
M = 40
Hence, the molar mass of the gas is 40g/mol.
To know more about dihydrogen :
https://brainly.com/question/16934482
#SPJ9
The students are studying the process of how controlled gasoline explosions that take place in a cars engine change the potential chemical energy into the kinetic mechanical energy that moves the car.
which statement is true about this reaction?
A..This is an exothermic reaction because energy is absorbed.
B.this an endothermic reaction because energy is absorbed.
C.this is an exothermic reaction because energy is released
D.this is an endothermic reaction because energy is released
Answers
Answer:
C.this is an exothermic reaction because energy is released
Explanation:
The explosion of gasoline in a car engine is an exothermic reaction.
An exothermic reaction is one in which heat is given out to the environment. That means, heat is released during the reaction.
When gasoline undergoes controlled explosion in car engines, heat is released, hence the answer.
what will be the result of the reaction
(CH3COO)2+redP +Cl2
Answers
Answer:
(CH3COO)2 + redP + Cl2 → ClCH2COOH + HCl
Explanation:
This is an example of halogenation of carboxylic acids at alpha carbon atom. In this reaction, red phosphorus and chlorine are treated with carboxylic acids having alpha hydrogen atom followed by hydrolysis to form alpha chloro carboxylic acid.
Explain on any two materials that you would expect to use for the wheelchair (both back support and
arm support) with less generation of heat during the hot summers.
Answers
Answer:
In the backrest use materials where it is easy to clean and where they do not absorb fluids, in this way it would be cooler, such as an ecological leather simulator.
And in the armrest as well, but in both areas we must not rule out that if or if it should have even a minimum of padded surface so that the patient or the person who spends most of the day in the wheelchair does not suffer from joint pain.
Explanation:
Some wheelchair factories also implement modern chairs where they are made of stainless steel structures lined with padded material with perforated fabrics that allow breathing and aeration of body areas that have contact with the fabric.
If a book has a weight of 23.2 N on Earth, what is its mass?
Answers
Answer: Mass is 2,37 kg
Explanation: Weight G = mg, and g = 9.81 m/s² on Earth.
m = W/g = 23.2 N / 9.81 m/s²
Balance the chemical reaction for the combustion of methanol by adding the correct coefficients below
__CH3OH +__O2(little box)__CO2 +__H2O
Answers
Answer:
\(2~CH_3OH+3~O_2\rightarrow2~CO_2+4~H_2O\\\)
The coefficients would be 2, 3, 2, and 4.
Explanation:
If we want to check this we would multiply the coefficient by each element. What we want is to have the same number of atoms on each side.
Reactant side:
# of carbon atoms: 2# of hydrogen atoms: 8# of oxygen atoms: 8Product side:
# of carbon atoms: 2# of hydrogen atoms: 8# of oxygen atoms: 8And that's it!
What happens to water when it warms above 4 C
Answers
Answer:
it will expand.
Explanation:
The expansion of water when you cool it to lower temperatures is unusual, since most liquids contract when they're cooled.
A titanium block (20°C) is placed in contact with a lead block (30°C), which is already in contact with an iron block (70°C).
What will happen in this situation?
O Heat will flow from the titanium to the lead to the iron until the temperatures are equal.
Heat will flow from the iron to the lead and from the lead to the titanium until the temperatures are equal.
O
Heat will flow from the titanium to the lead and from the iron to the lead until the temperatures are equal.
O Heat will flow from the lead to the titanium to the iron until the temperatures are equal.
Answers
Heat will flow from the titanium to the lead and from the iron to the titanium until the temperatures are equal.
What is the general law for the heat flow, in an ideal situation?Heat always flows from a region of higher temperature to a region of lower temperature until both regions reach thermal equilibrium. In this case, since the lead block is initially warmer than the titanium block and the iron block is initially even warmer than the lead block, heat will flow from the iron block to the lead block and from the lead block to the titanium block until all three blocks reach the same temperature.
However, it's important to note that heat will not flow directly from the iron block to the titanium block, because there is an intermediate block (the lead block) between them. Heat can only flow directly between the adjacent blocks in contact with each other, and the heat transfer process continues until all the blocks reach thermal equilibrium.
To know more about Heat, visit:
https://brainly.com/question/4978085
#SPJ1
a sample of 0.8360 g of an unknown compound containing barium ions (ba2 ) is dissolved in water and treated with an excess of na2so4. if the mass of the baso4 precipitate formed is 0.9712 g, what is the percent by mass of ba in the original unknown compound?
Answers
The percent by mass of barium in the original unknown compound is 68.25%.
When barium ions in a solution are treated with an excess of sodium sulfate, a white precipitate of barium sulfate (BaSO₄) is formed. The balanced chemical equation for the reaction will be:
Ba₂⁺(aq) + SO₄²⁻(aq) → BaSO₄(s)
From the given information, we can calculate the amount of barium present in the unknown compound as follows:
Calculate the moles of BaSO₄ precipitated:
moles of BaSO₄ = mass of BaSO₄ / molar mass of BaSO₄
moles of BaSO₄ = 0.9712 g / 233.38 g/mol
moles of BaSO₄ = 0.004159 mol
Since barium sulfate is formed in a 1:1 stoichiometric ratio with barium ions, the number of moles of barium ions in the original sample is also 0.004159 mol.
Calculate the mass of barium in the sample:
mass of Ba = moles of Ba × molar mass of Ba
mass of Ba = 0.004159 mol × 137.33 g/mol
mass of Ba = 0.5708 g
Calculate the percent by mass of barium in the original unknown compound:
percent by mass of Ba = (mass of Ba / mass of unknown compound) × 100%
percent by mass of Ba = (0.5708 g / 0.8360 g) × 100%
percent by mass of Ba = 68.25%
To know more about percent by mass here
https://brainly.com/question/14990953
#SPJ4
5. What conclusion might scientists draw if they found drastic changes in the types of sediment found in different rock layers?
the area went through major changes in climate over geologic time
the rock layers in that area formed slower than surrounding areas
the rock layers in that area were not exposed to normal weather
the area was likely under water for long periods of time
Answers
Answer:
the area went through major changes in climate over geologic time
Explanation:
Different types of sediment is a good indication of different climates.For example, if an area just experienced the same type of climate, like a desert, we would expect to observe the same types of sediment/rocks in the area
Hope this helps :D
Solve for missing values using the ideal gas law formula:
1. 10°C, 5. 5 L, 2 mol, __ atm. What is the atm?
2. __ °C, 8. 3 L, 5 mol, 1. 8 atm. What is the temperature in celsius?
3. 12°C, 3. 4 L, __ mol, 1. 2 atm. What is the mole?
Answers
The ideal gas law formula is used to determine the missing values in questions. When dealing with problems that require solving for missing values using the ideal gas law formula, always ensure that all values are expressed in the correct units and temperature is converted to kelvin.
The ideal gas law formula is represented as PV = nRT, where P represents pressure, V represents volume, n represents the number of moles of gas, T represents the temperature in kelvin, and R represents the universal gas constant. Solve for missing values using the ideal gas law formula:1. 10°C, 5. 5 L, 2 mol, __ atm.The temperature must be converted to kelvin first: T(K) = T(°C) + 273.15K = 10°C + 273.15 = 283.15KPV = nRT
Rearrange the equation to isolate P: P = nRT / V
Substitute the given values:
P = (2 mol)(0.0821 L•atm/mol•K)(283.15K) / 5.5 L
: P = 8.28 atm
2. __ °C, 8. 3 L, 5 mol, 1. 8 atm.The equation PV = nRT can be rearranged to T = PV / nRThe temperature must be converted to kelvin first: T(K) = T(°C) + 273.15T = PV / nR
Substitute the given values: T = (1.8 atm)(8.3 L) / (5 mol)(0.0821 L•atm/mol•K)T(K) = T +
: T = 332 K or 59°C
The temperature must be converted to kelvin first:
T(K) = T(°C) + 273.15K
= 12°C + 273.15
= 285.15
KPV = nRT
Solve for n by rearranging the equation: n = PV / RT
Substitute the given values: n = (1.2 atm)(3.4 L) / (0.0821 L•atm/mol•K)(285.15K): n = 0.141 mol
The ideal gas law formula is used to determine the missing values in questions. When dealing with problems that require solving for missing values using the ideal gas law formula, always ensure that all values are expressed in the correct units and temperature is converted to kelvin.
To know more about ideal gas law visit:
brainly.com/question/30458409
#SPJ11
What type of chemical reaction is demonstrated by this equation? A+BX-AX+B
Answers
Answer:
d an acid - base reaction.
Explanation:
Answer:
single replacement
Explanation:Look it up and got it from quizlet it should be right.
convert 7.1 grams of potassium to atoms.
Answers
Answer:
In 7.1g of potassium, there are 1.09 * 10^23 atoms
Explanation:
HERE, we want to get the number of atoms on 7.1g of potassium
The first thing we have to do here is to convert the given mass to moles
We can do this by dividing the mass by the atomic mass unit of potassium
The atomic mass unit of potassium is 39.1 amu
We can get the number of moles mathematically as follows:
\(\frac{7.1}{39.1}\text{ = 0.1816 moles}\)Finally,we can get the number of atoms
In 1 mole of a substance, the number of atoms is:
\(6.02\text{ }\times10^{23\text{ }}\text{ atoms}\)To get the number of atoms in 0.1816 mole, we simply multiply the two as follows:
\(0.1816\times\text{ 6.02}\times10^{23}\text{ = 1.09 }\times10^{23}\text{ atoms}\)
In each of the following groups, pick the substance that has the given property. Provide a BRIEF justification your answer.
a. highest boiling point: CCl4 CF4 CBr4
b. lowest freezing point: LiF F2 HCl
c. lowest vapor pressure at 25°C: CH3OCH3 CH3CH2OH CH3CH2CH3
d. greatest viscosity: H2S HF H2O2
e. greatest enthalpy of vaporization: H2CO CH3CH3 CH4 f. smallest enthalpy of fusion: I2 CsBr CaO
Answers
Highest boiling point compound is CBr4. The compound which has lowest freezing point is F2. The compound which has lowest vapor pressure is CH3CH2OH. The compound which has greatest viscosity is H2O2.
What is boiling point?
The boiling point of a substance is directly related to the strength of the intermolecular forces between the particles of the substance. The compound with the highest boiling point in this group is CBr4 because of its stronger London dispersion forces.
The freezing point of a substance is directly related to the strength of the intermolecular forces between the particles of the substance. A covalent compound has weak van der Waal forces between its particles, and the smaller the particle, the weaker the van der Waal force. F2 has the smallest particle size and therefore the lowest freezing point.c. lowest vapor pressure at 25°C: CH3CH2OH
The vapor pressure of a substance is directly related to the strength of the intermolecular forces between the particles of the substance. The compound with the lowest vapor pressure at 25°C. is CH3CH2OH.
The compound with greatest viscosity: H2O2. Viscosity is a measure of a liquid's resistance to flow. The greater the viscosity, the greater the resistance to flow.
Enthalpy of vaporization is the amount of energy required to vaporize a unit quantity of a substance. The enthalpy of vaporization is related to the strength of the intermolecular forces between the particles of the substance. The compound with smallest enthalpy of fusion is I2.
The enthalpy of fusion is the amount of energy required to melt a unit quantity of a substance. I2 has the weakest intermolecular forces and therefore the smallest enthalpy of fusion.
Learn more about Compounds here:
https://brainly.com/question/81085
#SPJ11
What is the frequency of a wave whose wavelength is 5.67 x 10^-7
Answers
Explanation:
substance that cannot be changed into simpler substances by chemical means:
Answers
Answer:
Elements
Explanation:
Elements are pure substances that cannot be broken down into simpler substances by ordinary chemical means.
Putting rock salt on the roads during a snowstorm is an example of: A. Boiling point elevation B. Vapor pressure raising C. Vapor pressure lowering D. Freezing point depression
Answers
Answer:
The correct answer is - D. Freezing point depression.
Explanation:
When rock salt is spread over snow-covered icy roads, it generates a liquid layer over it by melting from the surface thereby lowering or depression in the freezing point below the ice.
Therefore, due to this liquid layer comes into the contact with the ice present on the road and causes other ice to melts. This keeps on decreasing the volume of the ice on the road therefore, rock salts spread on the roads during a snowstorm.