Answer:
east
Explanation:
The number 5726.302 written to two significant digits is:
Answer:
2 is the answer your welcom
Water boils at 100°C at sea level. If the water in this experiment did not boil at 100°C, what could be the reason?
Answer:
You are not at sea level.
Explanation:
Assuming empirical observation shows boiling point 'below' 100°C then one concludes boiling experiment is being conducted above sea level where air pressure is lower than sea level air pressure. Generally, it is accepted in most literature publications that atmospheric pressure decreases ~1-inch per 1000-ft increase in elevation.
By definition, the boiling point of a liquid occurs when the atmospheric pressure equals fluid vapor pressure. Thus, if experimentally a water sample boils less than 100°C then one can only conclude the atmospheric pressure is lower than that needed to boil water at sea level atmospheric pressure; i.e., observed boiling point is at elevation greater than sea level.
One can calculate the boiling point of a liquid relative to sea level boiling point by using the Clausis-Clapeyron Equation.
ln(VP₂/VP₁) = ΔH(vap)/R(T₁ - T₂/T₁·T₂) solve for T₂ given Heat of Vaporization of water (ΔH(vap) = 28.2 Kj/mol) at specified temperature (T₁ at sea level = 273 Kelvin - standard) and R = 0.008314 Kj/mol-K).
What is Density in chemistry
Answer:
The density of something is the connection between the mass of the substance and how much space it takes up
A single bond contains ____ shared electrons.
A single bond contains two shared electrons.
Suppose a highly positive ion was attracted to a membrane. At what location would that most likely occur? a) the head of a lipid b) the tail of a lipid c) the nonpolar portion of a protein d) the double bond located within a lipid
Answer:
A highly positive ion was attracted to a membrane and their locations is explained in details.
Explanation:
1.
The Head of a lipid is hydrophilic (polar). This cover can be bearing negative or positive charges. This is that charge that creates the head hydrophilic(communicate with water(a polar molecule, including negative and positive unfair charges).
The tail is hydrophobic (non-polar). This part doesn't include any charge that enhances hydrophobic. (Does not combine with water.
Now a positive ion can be brought only to electron-rich stations. We cannot say that this situation is forever the hydrophilic part.
A dual bond is an electron-rich situation. So the ion will be drawn to the dual bond place of a lipid.
2.
A conveyor that needs energy is active transport.
3.
The use of a membrane is to stop the particles and ions from passing crosswise it openly. So through the membrane, in an active carrier, we require input energy to transfer molecules beyond it.
PLEASE HELP I WILL GIVE YOU BRAINLIEST PLEASE
Answer:
the answer is the second choice actual force
how many molecules are contained in 7.85 moles of oxygen molecules?
Answer:
125.59528999999982
Explanation:
when do you say that a quanitity needs directions to complete its de
scription??
Answer:
This question appear incomplete
Explanation:
This question appear incomplete because of the absence of options. However, it seeks to differentiate between a scalar and a vector quantity. A scalar quantity is a quantity with just magnitude but no direction (example is mass) while a vector quantity is a quantity with both magnitude and direction. Thus, a quantity needs direction to complete it's description when such quantities is a vector quantity such as weight (which is the downward force/gravity acting on an object with relative mass). The mass is the magnitude while the gravity/downward force is the direction. It would just be a scalar quantity if it had just mass and no downward force (as in direction) acting on it.
What else is produced during the combustion of propane, C3H8?
H2O ,
C3H8,
O2,
or
C3H8O2?
Answer:
H20
Explanation:
Answer:
The answer is H20
Explanation:
if 20.2g of NO and 13.8g of O2 are used to form NO2, how many moles of excess reactant will be left over
Answer:
0.095 moles of O₂ are left over.
Explanation:
First of all, state the balanced reaction:
2NO + O₂ → 2NO₂
We determine moles of each reactant:
20.2 g . 1mol / 30g = 0.673 moles of NO
13.8g . 1mol / 32g = 0.431 moles of oxygen
Oxygen is the excess reactant. Let's see.
For 2 moles of NO I need 1 mol of O₂
Then, for 0.673 moles of NO I may use (0.673 .1) /2 = 0.336 moles
I have 0.431 moles of O₂ and I only need 0.336 mol. According to reaction, stoichiometry is 2:1.
In conclussion, the moles of excess reactant that will be left over:
0.431 - 0.336 = 0.095 moles
A solution is made by dissolving
14.57 g of sodium bromide (NaBr) in
415 g of water.
What is the molality of the solution?
[?] m NaBr
Molar mass of NaBr: 102.89 g/mol
Answer:
0.342 m
Explanation:
From the question given above, the following data were obtained:
Mass of NaBr = 14.57 g
Mass of water = 415 g
Molar mass of NaBr = 102.89 g/mol
Molality of NaBr =?
Next, we shall determine the number of mole in 14.57 g of NaBr. This can be obtained as follow:
Mass of NaBr = 14.57 g
Molar mass of NaBr = 102.89 g/mol
Mole of NaBr =?
Mole = mass / molar mass
Mole of NaBr = 14.57 / 102.89
Mole of NaBr = 0.142 mole
Next, we shall convert 415 g of water to kg. This can be obtained as follow:
1000 g = 1 Kg
Therefore,
415 g = 415 g × 1 Kg / 1000 g
415 g = 0.415 Kg
Thus, 415 g is equivalent to 0.415 Kg.
Finally, we shall determine Molality of the solution as follow:
Mole of NaBr = 0.142 mole
Mass of water = 0.415 Kg
Molality of NaBr =?
Molality = mole / mass of water in Kg
Molality of NaBr = 0.142 / 0.415
Molality of NaBr = 0.342 m
Therefore, the molality of NaBr solution is 0.342 m.
Answer:
0.341
Explanation:
as stated underneathe the 'tutor verified' answer. lol
Identify the formula for an alkene.
A. CnH2n
B. CnH2n 2
C. CnH2n 4
C. CnH2n-2
D. CnH2n-4
Answer:
CnH2n-2
im pretty sure thats the answer
number of electrons in 21Sc with L=1
Answer:
There are [tex]12[/tex] electrons with [tex]l = 1[/tex] in each [tex]\rm _{21}Sc[/tex] atom in its ground state.
Explanation:
The azimuthal quantum number (with symbol [tex]l[/tex]) of an electron in an atom specifies the type of the orbital that contains this electron.
For example:
[tex]l = 0[/tex] corresponds to an [tex]s[/tex] orbital.[tex]l = 1[/tex] corresponds to a [tex]p[/tex] orbital.[tex]l = 2[/tex] corresponds to a [tex]d[/tex] orbital.The question is asking for the number of electrons with [tex]l = 1[/tex] in each [tex]\rm _{21}Sc[/tex] atom. Because [tex]l = 1\![/tex] corresponds to [tex]p[/tex] orbitals, this question is equivalently asking for the number of electrons in [tex]p\![/tex] orbitals in one such atom.
Find the electron configuration of a ground-state [tex]\rm _{21}Sc[/tex] atom:
[tex]1s^{2}\; 2s^{2}\; 2p^{6}\; 3\, s^{2}\; 3\, p^{6}\; 3d^{1}\; 4s^{2}[/tex].
In other words, there are [tex]12[/tex] electrons in [tex]p[/tex] orbitals in total in a ground-state [tex]\rm _{21}Sc[/tex] atom in total; [tex]l = 1[/tex] for each of these electrons because of the
Therefore, a ground-state [tex]\rm _{21}Sc[/tex] atom would include [tex]12[/tex] electrons with [tex]l = 1[/tex].
how it is this???????
Answer:
1) Helium (2 electrons)
2) Neon (10 electrons)
3) Argon (18 electrons)
4) Krypton (36 electrons)
Is reacting sodium metal with water a physical or chemical change
[tex]\boxed{\boxed{\pink{\bf \leadsto This \ is \ an \ example \ of \ Chemical \ change .}}}[/tex]
Explanation:Reaction of sodium metal with water is a chemical change . Sodium reacts with water to form sodium hydroxide. This is also an example of exothermic reaction as heat is released in this process. Sodium reacts vigoursly with water , it even reacts with the moisture present in the air . So it is stored in kerosene oil .
The reaction of sodium with water is :-
[tex]\boxed{\red{ \bf \underset{\blue{Sodium}}{2Na} + \underset{\blue{Water}}{2H_2O} \longrightarrow \underset{\blue{Sodium\: Hydroxide}}{2Na(OH)}+ \underset{\blue{Hydrogen}}{H_2}}}[/tex].
The reaction of sodium metal with water is a chemical change, as a result formation of sodium hydroxide occurs.
A Chemical change is any change that occurs to substances which when combine to form a new substance or decompose to form new substances. Here there occurs an internal consistency of the matter involved in that particular change.A physical change is a change with involves the changes in the size, shape, texture, etc. of any substance.The following points to be noted for the reaction of sodium with water:
The sodium reacts with water to give sodium hydroxide.The presence of the single outermost electron (3s1) in sodium makes the metal highly reactive.This is a chemical change which is an exothermic reaction, which means the reaction results in the liberation of heat during the process.Sodium is a very highly reactive metal, which can even react with moisture present in the air.To avoid any unnecessary reactions, sodium is stored in kerosene, where it seems to be inert.Therefore, the reaction of sodium with water is a chemical change.
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A Child with severe poison ivy weighs 25kg. The medicine needed is Benadryl po and for treatment 5mg of Benadryl is required for every 1 kg of the child. The Benadryl is available as a 12.5mg/5mL solution. If one dose of this medicine is equal to 12.5 mL ( 1dose = 12.5mL) how many doses are needed?
Number of doses needed : 4 doses
Further explanationGiven
weight of the child : 25 kg
Treatment of Benadryl : 5 mg/kg weight
The concentration of Benadryl : 12.5 mg/5 ml
1 dose = 12.5 ml
Required
Number of doses needed
Solution
Amount of Benadryl for 25 kg weight :
[tex]\tt 25~kg\times 5~\dfrac{mg}{kg}=125~mg[/tex]
Amount of Benadryl solution :
[tex]\tt \dfrac{125~mg}{12.5~mg/5~ml}=125~mg\times \dfrac{5~ml}{12.5~mg}=50~ml[/tex]
Amount of doses :
[tex]\tt \dfrac{50~ml}{12.5~ml}=4~doses[/tex]
Question 19 of 25 The atomic number of the element radium is 88. How many neutrons does radium-226 have?
A. 98
B. 138
C. 88
D. 116
E. 226
please i need this
Answer:
B. 138
Explanation:
Based on isotope notation:
[tex]^X_nA[/tex]
For the atom A, the mass number, X, is the sum of neutrons and protons and
n is the number of protons = Atomic number.
The number of protons depends of the nature of the atom. For example, Carbon has 12 protons, hydrogen 1 and Radium has 88 protons.
The radium-226 means the mass number is 226. Thus, number of neutrons are:
Mass number - Atomic number
226 - 88 = 138
Right answer is:
B. 138Answer:
Unit 4 Lesson 2:
Energy Release Quick Check
1. 138 neutrons
2. The conversion of an atom of one element into a different element through nuclear changes.
3. A nuclear equation is balanced according to mass number. A chemical equation is balanced according to the total mass before and after the change.
4. 82
5. Some of the matter is converted to energy.
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The formula of a salt is XCl2. The X ion in this salt has 20 electrons. The metal X is ________.
Answer:
titanium
Explanation:
The ion has a charge of +2 since each of the chrlorine atoms have a charge of -1. if x has 20 electrons, the it must have 22 protons to get a charge of +2. The proton number defines the element, so the element with 22 protons is titanium.
10.
What type of pest control uses pesticides, insecticides, and herbicides?
Cultural
Mechanical
Chemical
Biological
A
D
Answer:
C.
Explanation:
Thiols, sulfides and disulfides have high solubility in water. a. True b. False
Answer:
the answer is a true
Explanation:
Thiols, sulfides and disulfides have high solubility in water. This statement is true. Therefore, option A is correct.
What is solubility ?Solubility refers to a substance's ability to form a solution with another substance, the solvent. The inability of the solute to form such a solution is referred to as insolubility.
Temperature, pressure, polarity, and molecular size are all factors that influence solubility. For most solids dissolved in liquid water, solubility increases with temperature. This is due to increased vibration or kinetic energy of the solute molecules at higher temperatures.
A rise in temperature stresses the equilibrium condition, causing it to shift to the right. Because the dissolving process consumes some of the heat, the stress is reduced. As a result, as the temperature rises, so does the solubility.
Thus, option A is correct.
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Kohlberg believed people shift back and forth between the six schemas in his three levels of moral reasoning, depending on the circumstance and the person's current level of cognitive development.
Please select the best answer from the choices provided
T
F
Answer:
False
Explanation:
I got 100 on the test on edge
HELP PLEASE HERE IS THE QUESTION The shape of an apple is a CHEMICAL OR A PHYSICAL CHANGE OR CHEMICAL OR A PHYSICAL PROPITRY.
Answer:
Physical Property
Explanation:
As there is no chemical change or chemical related stuff in it!
Answer:
physical
Explanation:
A rigid 7.80 L sealed vessel containing 2.700 mol of O2(g), 0.600 mol of C2H4(g), and 2.400 mol of Ne(g) has an internal temperature of 85.0∘C
a. Calculate the total pressure in the cylinder.
b. Find the mole fraction of O2 in the vessel.
c. A lab technician ignites the mixture in the vessel and the following reaction occurs:
C2H4(g)+3O2(g)→2CO2(g)+2H2O(g)
Find the mole fraction of each gas in the vessel after the reaction.
A. 21.47 atm
B. 0.4737 mol
C. 0.900moles of O2
1.200 moles of CO2
1.200 moles of H2O
2.400 mol of Ne that doesn't react.
Ideal gas law is valid only for ideal gas not for vanderwaal gas. Therefore, the total pressure in the cylinder is 21.4atm. Ideal gas is a hypothetical gas.
What is ideal gas equation?Ideal gas equation is the mathematical expression that relates pressure volume and temperature. Vanderwaal gas behave as ideal gas at low pressure and high temperature.
Mathematically,
PV=nRT
where,
P = pressure=?
V= volume=7.80 L
n =number of moles=2.700 mol +0.600 mol +2.400 mol
=5.7moles
T =temperature = 358 K
R = Gas constant = 0.0821 L.atm/K.mol
substituting all the given values in the above equation, we get
P × 7.80 L =5.7moles× 0.0821 L.atm/K.mol × 358 K
On calculations, we get
P =21.4atm
Therefore, the total pressure in the cylinder is 21.4atm.
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what is the molar mass of the chemical CH3COOH?
Answer:
60 g/ mol
Explanation:
Carbon, C 12
Hydrogen, H 1
Oxygen, O 16
Molar mass = 12+3+12+16+16+1 = 60 g/ mol
Calculate the molality of a 5.73 M ethanol (C2H5OH) solution whose density is 0.9327 g/mL.
Answer:
Molality = 8.57 m
Explanation:
Given data:
Molarity of solution = 5.73 M
density = 0.9327 g/mL
Molality of solution = ?
Solution:
Molality = moles of solute / kg of solvent.
Kg of solvent:
Mass of 1 L solution = density× volume
Mass of 1 L solution = 0.9327 g/mL × 1000 mL
Mass of 1 L solution = 932.7 g
Mass of solute:
Mass of 1 L = number of moles × molar mass
Mass = 5.73 mol × 46.068 g/mol
Mass = 263.97 g
Mass of solvent:
Mass of solvent = mass of solution - mass of solute
Mass of solvent = 932.7 g - 263.97 g
Mass of solvent = 668.73 g
In Kg = 668.73 /1000 = 0.6687 Kg
Molality:
Molality = number of moles of solute / mass of solvent in Kg
Molality = 5.73 mol / 0.6687 Kg
Molality = 8.57 m
Considering the definition of molality , you obtain that the molality of a 5.73 M ethanol (C₂H₅OH) solution whose density is 0.9327 g/mL is 8.57 [tex]\frac{moles}{kg}[/tex].
Molality is the ratio of the number of moles of any dissolved solute to kilograms of solvent.
The Molality of a solution is determined by the expression:
[tex]Molality=\frac{number of moles of solute}{kilogramof solvent}[/tex]
You have a 5.73 M ethanol (C₂H₅OH) solution whose density is 0.9327 g/mL.
Molarity is the number of moles of solute that are dissolved in a certain volume.
In this case, taking into account that the volume considered is 1 L, the number of moles of solute is 5.73 moles.
On the other side, density is the ratio of the weight (mass) of a substance to the volume it occupies. So, being 1 mL= 0.001 L, 0.9327 g/mL means that you have 0.9327 grams per 1 mL or 932.7 g per 1 L.
So, being the mass of solution calculated as number of moles multiplied by the molar mass, and being the mass of the solution 932.7 grams in 1 L, the mass of water is:
Mass of solvent = mass of solution - mass of solute
Mass of solvent = mass of solution - number of moles× molar mass
Mass of solvent = 932.7 g - 5.73 mol× 46.068 g/mol
Mass of solvent = 932.7 g - 263.97 g
Mass of solvent = 668.73 g= 0.66873 kg
Then, the molality can be calculated as:
[tex]Molality=\frac{5.73 moles}{0.66873 kg}[/tex]
Solving:
molality= 8.57 [tex]\frac{moles}{kg}[/tex]
Finally, the molality of a 5.73 M ethanol (C₂H₅OH) solution whose density is 0.9327 g/mL is 8.57 [tex]\frac{moles}{kg}[/tex].
Learn more about:
density: brainly.com/question/952755?referrer=searchResults brainly.com/question/1462554?referrer=searchResults molalitybrainly.com/question/20366625?referrer=searchResults brainly.com/question/4580605?referrer=searchResults molarity with this example: brainly.com/question/15406534?referrer=searchResults_______ are white blood cells that recognize specific antigens, and ultimately destroy them.
O lymphocytes
O pathogens
O water
Answer:
Lymphocytes
Explanation:
Pathogens are particles that make you sick like bacteria, viruses, amoebas. Water is essential for life but that's for metabolism, not fighting off against infection or viruses.
Answer:
Lymphocytes
Explanation:
lymphocytes are a kind of white blood cell (WBC). Lymphocytes are cells of the immune system and help fight infection. Lymphocytes live in lymph nodes, but also in the bloodstream and all over the body. Lymphocytes come in two main types: B-cells and T-cells
Where as water is totally not white blood cells and pathogens are viruses and bacterium
Which of the following is a characteristic of all chemical changes?A. A different state of matter is produced. B. Some mass is converted to energy. C.Some form of light is given off. D. A new material is formed
Read the excerpt from Kennedy’s inaugural address. To those people in the huts and villages of half the globe struggling to break the bonds of mass misery, we pledge our best efforts to help them help themselves, for whatever period is required—not because the communists may be doing it, not because we seek their votes, but because it is right. If a free society cannot help the many who are poor, it cannot save the few who are rich. What is the main type of appeal that Kennedy uses in this excerpt? an ethical appeal to demand that the communists help around the globe an emotional appeal to emphasize the United States' commitment to justice a logical appeal to help people in poverty since there is no need to help the rich a logical appeal to explain why people around the globe cannot vote for a better life
Answer:
an emotional appeal to emphasize the United States' commitment to justice
Explanation:
The main type of appeal that Kennedy uses in this excerpt is an emotional appeal to emphasize the United States' commitment to justice. Therefore, option B is correct.
What is an appeal?In rhetoric, an appeal is a persuasive approach used to persuade an audience to believe or do something. Appeals can take many forms, but they generally fall into three categories: pathos, ethos, and logos.
Pathos appeals to the audience's emotions, ethos appeals to the credibility of the speaker or source, and logos appeals to the audience's sense of logic and reason.
Effective communication usually involves the use of multiple appeals to convince the audience to accept a particular perspective or take a particular action. Therefore, option B is correct.
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Determine how many moles of Ca (OH) 2 are required to completely neutralize 3.26 mol of HC2H3O2.
Moles of Ca (OH)₂ required to completely neutralize 3.26 mol of HC₂H₃O₂ : 1.63
Further explanationA reaction coefficient is a number in the chemical formula of a substance involved in the reaction equation. The reaction coefficient is useful for equalizing reagents and products.
Reaction
2HC₂H₃O₂ + Ca(OH)₂ → Ca(C₂H₃O₂)₂ + 2H₂O
mol of HC₂H₃O₂ = 3.6
From equation above, mol ratio of HC₂H₃O₂ : Ca(OH)₂ = 2 : 1, so mol Ca(OH)₂ :
[tex]\tt mol~Ca(OH)_2=\dfrac{1}{2}\times 3.26=1.63[/tex]
All of the following are examples of matter EXCEPT
A. Bugs
B. Electricity
C. Soda
D. Air
Answer: Electricity
Explanation: Electricity is the movement of matter. not matter itself