Answer:
Density is mainly responsible for the difference in melting rate between salt water and fresh water.
Explanation:
Hoped this helped.
Methane (CH4) is used in laboratory burner. When 1 mole of methane burns at constant pressure, it produces 804 kJ of heat and does 3 kJ of work.Methane (CH4) is used in laboratory burner. When 1 mole of methane burns at constant pressure, it produces 804 kJ of heat and does 3 kJ of work.
The enthalpy ΔH of combustion is - 804 kJ. The change in internal energy ΔE of the reaction process is -801 kJ
The objective of this question is to determine the value of ΔH and ΔE of combustion is for 1 mole of methane.
If we look closely at the question, we will realize that at constant pressure, methane burns and produces heat of 804 kJ into the surroundings.
Since heat is released;
ΔH = -804 kJ
It also does a work of 3kJ, since work is done on the system
W = - 3kJ
According to the first law of thermodynamics;
ΔE = ΔH - W
ΔE = (-804 - (-3 )) kJ
ΔE = -801 kJ
Therefore, we can conclude that the in 1 mole of methane, the enthalpy ΔH of combustion is - 804 kJ. The change in internal energy ΔE of the reaction process is -801 kJ
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Explain why Florida does not have long winters?
agine that you are just outside the International Space Station (ISS) orbiting Earth, working in space. You brought your speaker with you so you could listen to some music while you work. You find the right song, and you hit play. What do you hear? Write your response below in complete sentences. 3) Include the answers to these questions in your response: • Would you hear your music? • Why or why not?
Answer:
There is no atmosphere outside the space station, so there is nothing to vibrate, therefor there is no sound.you better install your earphones in your space suit.
Explanation:
Imagine that you are just outside the International Space Station (ISS) orbiting Earth, working in space. You brought your speaker with you so you could listen to some music while you work. You find the right song, and you hit play. What do you hear? Write your response below in complete sentences.
Include the answers to these questions in your response: •
Would you hear your music? •
Why or why not?
You need matter that can vibrate and finally vibrate your ear drum in order to transmit sound waves. that you hear
There is no atmosphere outside the space station, so there is nothing to vibrate, therefor there is no sound.you better install your earphones in your space suit.
You will hear no music as there is no sound in the space because there are no molecules to vibrate.
Why no sound in the space?Sound is generally considered a form of energy that consists of mechanical waves which travel in a medium. Sound is produced by a vibrating body which generates a disturbance in the medium and the medium helps to propagate the sound.
The medium of sound transmission is air where the molecules in the air are in the form of longitudinal waves. The vibrating body generates a disturbance in the rarefaction and compression of waves. The disturbance of the particles of the surrounding medium produces sound.
Sound always requires a medium to be traveled and reach its destination. As space does not have any medium for sound to generate disturbance. Space has a vacuum due to which sound cannot be heard in space.
Therefore, you will hear no music when you play a song in the space.
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Place the events of a fight or flight situation in the correct order.
Question 3 options:
You spring into action
Your heart and lungs prepare to fight or run
You see the bear
Your brain sends signals to you adrenal and pituitary glands
Answer:
you see le bear
you brain sends signals
your heart and lungs receive said signals
spring to action
Consider the following chemical equation:
C2H8 + O2 --> CO2 + H2O
Which of the following would be the best practice(s) for balancing the equation? There may or may not be more than one correct answer.
A.Reduce the coefficients if possible.
B.Put a 2 in front of the hydrocarbon.
C.Split the hydrocarbon into individual elements.
D.Split the water into HOH.
E.Keep the hydrocarbon together.
The best way to balancing a combustion equation of an organic compound, like the one in the question, is to start balancing the carbon, then the hydrogen and finish with the oxygen. For that you have to split the hydrocarbon into individual elements. And once you have finished you shall always try to reduce the coefficient if possible. Therefore, the answers are A. and C.
what are the strongest acids and bases in chemstry
Potassium metal reacts with water according to the following balanced equation.
2 K(s) + 2 H2O(l) — 2 KOH(aq) + H, (8)
If one mole of potassium reacts in this manner, how many moles of water are consumed?
Answer: 1 mole
Explanation:
One mole reacts because there is a 1:1 ratio between the potassium and water at the beginning of the equation. 2K+2H2O has a 1 to 1 ratio. If one potassium reacts there is one h2o that also reacts.
Taking into account the reaction stoichiometry, if one mole of potassium reacts, 1 mole of water are consumed.
Reaction stoichiometryIn first place, the balanced reaction is:
2 K + 2 H₂O → 2 KOH + H₂
By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:
K: 2 moles H₂O: 2 moles KOH: 2 moles H₂: 1 moleMoles of water consumedThe amount of water consumed is calculated from the following rule of three: if by stoichiometry 2 moles of K react with 2 moles of H₂O, 1 mole of K react with how many moles of H₂O?
[tex]amount of moles of H_{2} O=\frac{1 mole of Kx2 moles ofH_{2} O }{2 moles of K}[/tex]
amount of moles of H₂O= 1 mole
In summary, if one mole of potassium reacts, 1 mole of water are consumed.
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PLEASE HELP
1. A closed bottle contains a mixture of Ar and O2 at 25.3°C. If the partial pressure of Ar in
the bottle is 0.447 atm and the total pressure of the bottle is 1.024 atm, what is the partial
pressure of O2 in the bottle?
Answer: 0.79 atm
Explanation:
The Ideal Gas Law is PV=nRT.
since both Ar and O2 have the same volume and temperature, the only variable causing the differnce in pressure betwwen the 2 gases is the number of moles
the total pressure = the partial pressure of Ar + the partial pressure of O2
1.024 atm = 0.447 amt + ?
so
? = 1.24 -0,447 = 1.24 - 0.45= 0.79 atmthe total pressure of the bottle is 1.024 atm, what is the partial
pressure of O2 in the bottle? is PV
Question 3 of 10
Which event indicates an endothermic chemical reaction?
A. Decrease in temperature
B. Release of heat
C. Increase in thermal energy
D. Production of light
Plz help
Answer:
A. Decrease in temperature
Explanation:
The statement indicates an endothermic chemical reaction is "Decrease in temperature".
What is endothermic reaction?Endothermic reactions generate products by absorbing heat energy from the environment.
The temperature of the reaction mixture rises as energy is released in an exothermic process. The temperature drops when energy is absorbed in an endothermic reaction. A thermometer can be used to monitor temperature changes in the reaction mixture.
An endothermic reaction happens when the temperature of an isolated system drops while the temperature of its surroundings rises. The overall heat of reaction in endothermic reactions is positive (q > 0).
Hence the correct option is A.
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What is the expression for the equilibrium constant for the
reaction N2+ 3H2 = 2NH3?
Answer:
For the reaction N2 + 3H2 2NH3 , the equilibrium expression may be written as K [ NH3 ]^2/ [ N2 ] [ H2 ]^3 .
Explanation:
Answer:
s K [ NH3 ]^2/ [ N2 ] [ H2 ]^3 .
Explanation:
because I know -_-
What is a solution?
A. A mixture of two solids blended together
B. A compound that is in liquid and gas states
C. A liquid with something dissolved in it
OD. A clear liquid with nothing dissolved in it
8) What mass of chlorine reacts with 20.0 g of iron to form iron(III) chloride?
Answer:
38.3 g
Explanation:
8) What mass of chlorine reacts with 20.0 g of iron to form iron(III) chloride?
first write, then balance the equation
Fe + Cl2-------------> FeCl3
2Fe + 3Cl2----------> 2FeCl3
2 moles of Fe require 3 moles of Cl2
the atomic mass of Fe is 56
20/56= 0.36 moles of Fe
this requires o.36 X 3/2 = 0.54 moles of Cl2
Cl2 has a molar mass of 35.5 X 2=71
1 mole of Cl2 is 71g
0.54 moles is 0.54 X 71 g= 38.3 g
The mass of chlorine reacts with 20.0 g of iron to form iron(III) chloride is 38.3 g.
What is mass?Mass is defined as a numerical representation of the fundamental characteristic of all matter, inertia.
It can also be defined as a dimensionless number used to describe the mass of a particle or item.
[tex]\rm 2Fe + 3Cl_2\rightarrow2FeCl_3[/tex]
As per the reaction 3 mole of chlorine is required for 2 mole of fluorine.
Atomic mass of fluorine = 56
Moles of Fe = 20 / 56
= 0.36 moles
This require 0.36 x 3/2 = 0.54 moles of Cl₂
Molar mass of Cl = 35.5
So for Cl₂ = 2 x 35.5 = 71 moles
For 1 mole of Cl₂ = 71 moles is needed
So, for 0.54 moles = 71 x 0.54
= 38.3 g
Thus, the mass of chlorine reacts with 20.0 g of iron to form iron(III) chloride is 38.3 g.
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A sample of carbon dioxide gas has a pressure of 8.33 bar and a volume of 10.3 mL at a temperature of 29.1 °C. How many
molecules of carbon dioxide gas are in the sample?
molecules:
Recreational drug users often obtain the drug as a white powder with unknown purity. Some users snort the power, whereas others make a solution and take it orally or inject it. To achieve a ketamine high, users usually need to take between 0.1 mg/kg and 1 mg/kg of ketamine. However, taking 2 mg/kg can lead the user to experience a K-hole or to enter an unconscious state.
If the user dissolves exactly 1 g of ketamine in 1/4 cup of water, what is the concentration of ketamine in milligrams per milliliter (mg/mL)? 1 cup=236.5 mL
What volume, in milliliters, of the recreational ketamine in the previous question would a 59.0 kg user need to take to experience a high at 0.600 mg/kg?
How many milliliters would that same user need to take to become unconscious at 2.00 mg/kg?
A user dissolves exactly 1 g of ketamine in 1/4 cup of water.
Given 1 cup = 236.5 mL, the volume of 1/4 cup of water is:
1/4 cup × (236.5 mL/1 cup) = 59.13 mL
1 g of ketamine is dissolved in 59.13 mL of water. The concentration of ketamine, in mg/mL, is:
C = 1000 mg / 59.13 mL = 16.91 mg/mL
Part 2The volume of this solution that a 59.0 kg user (body mass) would have to consume to experience a high at 0.600 mg/Kg is:
[tex]59.0 kgBM \times \frac{0.600mgKetamine}{1kgBM} \times \frac{1mL Soluiton}{16.91mgKetamine} = 2.09 mL[/tex]
Part 3The volume of this solution that a 59.0 kg user (body mass) would have to consume to become unconscious at 2.00 mg/kg is:
[tex]59.0 kgBM \times \frac{2.00mgKetamine}{1kgBM} \times \frac{1mL Soluiton}{16.91mgKetamine} = 6.98 mL[/tex]
If a user dissolves exactly 1 g of ketamine in 1/4 cup of water, the resulting concentration is 16.91 mg/mL. A 59.0 kg user would have to consume 2.09 mL of this solution to experience a high of 0.600 mg/kg. The same user would have to consume 6.98 mL of this solution to become unconscious at 2.00 mg/kg.Learn more about concentration units here: https://brainly.com/question/14594475
Most chloride salts are soluble. Which of the following is an exception to this generalization?
A. NH4Cl
B. AlCl3
C. ZnCl2
D. CuCl2
E. PbCl2
The exception to the rule concerning the solubility of chlorides in water is PbCl2.
The solubility rules give us an idea of which substances are soluble in water and what substances are not soluble in water. According to the solubility rules, chlorides are soluble in water.
However, chlorides of lead are not soluble in water hence, the exception to the rule is PbCl2.
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From the options given, the chloride salt that is not soluble is PbCl₂.
Solubility simply means the ability of liquid, solid, or gaseous chemical substance to be bake to dissolve in solvent and then form a solution.
It should be noted that most chloride salts are soluble. Examples include NH₄Cl, AlCl₃, ZnCl₂, CuCl₂, etc. However, the chloride of lead aren't soluble in water. Therefore, PbCl₂ isn't soluble in water.
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What is a reaction that alkanes undergo ?
A. precipitation reactions
B. combustion reaction
C. acid base reactions
D. all of the above
Calculate energy output (ATP production) of full oxidation of saturated fatty acid with 24 carbons in the chain?
..
Explain
give some practical examples where prefixes are used
Why do we need to build models of molecules to study atomic composition?
Answer:
for better understanding and visual understanding
please help me! giving brainliest!!
Answer:
It is a covalent bond because both carbon and oxygen are nonmetals. The formula will be CO² because the electrons between the atoms are being shared equally.
Answer:
Option C
Explanation:
CO₂ is a covalent bond because we know that both elements are nonmetals. The carbon atoms shares 2 electrons with each oxygen atom and each oxygen atom shares two electrons with the carbon atom. CO₂ forms a nonpolar covalent bond, meaning that the electrons are shared equally.
(100 POINTS!!!!) In one to two sentences, describe the process by which the ionic compound, LiCl, would dissolve in the polar solvent, CH3COCH3
Answer:
LICL as an Ionic compounds has covalent ability and they are soluble in polar solvent such as CH3COCH3 but they are insoluble in non-polar solvents. Due to their polarity, CH3COCH3 will decreases the electrostatic forces of attraction thereby resulting in free ions in aqueous solution.
Water is the known as a polar solvent that can dissolve an ionic compounds very easy and as a polar solvent, the arrangement of oxygen and hydrogen atoms in water is in bent shape.
Ionic compounds like LICL that is very polar is soluble in the polar solvent water.
Polar solvents like CH3COCH3 will dissolve polar and ionic solutes because of the attraction of the opposite charges on the solvent and solute particles.
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Explanation:
I will give brainlist
How much Ba(OH)2, in grams, is needed to make a 1.00m aqueous solution?
Answer:
We can say that we need 171 g barium hydroxide needed to make one model equals solution.
Explanation:
I hope this answered your question.
171 gram of Ba(OH)2, in grams, is needed to make a 1.00 m aqueous solution.
What is mass?Mass is the quantity of matter. The mass is calculated by the density divide by the volume.
In 1.00 solution, the mass of Ba(OH)2 is 171 gram.
Thus, the mass of Ba(OH)2 is 171 gram.
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1) Which example shows a change in a state
of matter?
A. Liquid pouring
2
B. Wood Burning
1
C. Ice Melting
Answer:
C
Explanation:
because an ice is a solid and when it melts it becomes a liquid
Answer:
C
Explanation:
1) Which example shows a change in a state
of matter?
A. Liquid pouring
2
B. Wood Burning
1
C. Ice Melting
C when ice melts it goes from a solid to a liquid state
What equipment is generally used to make lyophilized medications suitable for administering to the patient? a) Test tubes or sterile ampules b) Petri dishes and sterile droppers c) Sterile syringes or graduated cylinders d) Measuring cups and clean, warm water
Answer:
B) Sterile droppers and petri dishes
How do models help scientists study atomic composition?
Models can be used to represent a process or show the composition of a material. For example, a model of an atom shows what matter is made out of and how it is composed. Scientists have been using models since ancient times to help explain the world around us. Models help you understand something that you cannot see or touch by making it visible or giving it a form that you can physically explore. In this case, the model lets scientists explore atoms without having to use an electron microscope. This method provides them with up-close images from different angles so they can learn about their properties in detail.
help me. correct answer will be marked as brnlst
Answer:
PCI3
Explanation:
It does not obey the octet rule on the nitrogen atom.
Using the metric "stairs" convert the following:
Calculate the freezing point of a solution of 3.46 g of a compound, X, in 160 g of benzene. When a separate sample of X was vaporised, its density was found to be 3.27 g/Lat 116°C and 773 torr. The freezing point of pure benzene is 5.45°C, and Kis 5.12°C kg/mol.
Answer:
Calculate the freezing point of a solution of 3.46 g of a compound,X,in 160 g of benzene. When separate sample of X was vaporised, its density was found 3.27 g/L at 116 c and 773 torr. The freezing point of pure benzen is 5.45 c, and kf is 5 .12 c/m.
Explanation:
First determine molar mass from
P*molar mass = density*R*T
Solve for molar mass. Then
moles = grams/molar mass
Solve for moles
molality = moles/kg solvent
Solve for molality
delta T = Kf*m
Solve for delta T, then convert to freezing point
4. The half-life of C-14 is 30 years. If a scientist had 100.0 g at the beginning, how
many grams would be left after 120 years has elapsed?
Half Lives
0
1
2
Time (years)
Amount (grams)
Show table
Answer:
6,25 gm
Explanation:
4. The half-life of C-14 is 30 years. If a scientist had 100.0 g at the beginning, how
many grams would be left after 120 years has elapsed?
10 years would be 120/30 = 4 half lives0
s0 the fraction of c-14 left would be four (1/2) multiplied together
1/2 X 1/2 X 1/2 X 1/2 = 1/16
SO 1/16 OF THE 100.0 gm would be left
100.0/16 = 6,25 gm
HELPP PLEASE
this is a weird place to ask but does anyone know a good physical science experimental project that the scientific method can be used on? with homemade materials that doesn’t take more than 2 days to do?
Experiment: Does it Dissolve?
Materials Needed:
4 clear, glass jars filled with plain tap waterFlourSalt Talcum or baby powderGranulated sugarStirrerStep 1: Form a question before starting the experiment.
Step 2: Make a hypothesis for each substance.
Step 3: Scoop a teaspoon of each substance in the jars, only adding one substance per jar. Stir it up!
Step 4: Observe whether or not each substance dissolves and record the findings.