The mole fraction of the 2.2 molal solution whose solvent is naphthalene is 0.28.
Using the relation;
molality = mole fraction × 1000/MA
Where MA = molar mass of the solvent
We know from the question that the molaity of the solution is 2.2 molal
Making the mole fraction the subject of the formula;
mole fraction = molality × MA/1000
MA = 128 g/mol
mole fraction = 2.2 × 128/1000
Mole fraction = 0.28
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The number of carbon atoms in 45.21g C
Answer:
2.26 X10^24 carbon atoms
Explanation:
The number of carbon atoms in 45.21g C
carbon has an atomic mas of 12.01 gm
45.21 g has 45.21/12.01 = 3.76 moles of C
a mole contains Avogadros number of particles
6.022 X 10^23
3.76 moles contain 3.76 X6,022 X 10^23 =
2.26 X10^24 carbon atoms
If 20.3 g of NO and 13.8 g of O₂ are used to form NO₂, how many moles of excess reactant will be left over?
2 NO (g) + O₂ (g) → 2 NO₂ (g)
Answer:
0.02 moles of O₂ will be leftover.
Explanation:
When the volume of a closed container containing hydrogen gas is increased by a factor of two, how will this affect the number of hydrogen atoms in the container
We have that for the Question "When the volume of a closed container containing hydrogen gas is increased by a factor of two, how will this affect the number of hydrogen atoms in the container"
Answer:
Number of hydrogen atoms depend only on amount of gas which remains constant. Hence, increasing the volume of container has no affect on number of hydrogen atoms.Explanation:
The number of hydrogen atoms will remain the same in the container. Because the container is closed and amount of hydrogen gas remains constant, which means that no extra amount of hydrogen gas is removed or added from the container when volume increases.
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PLEASE HELP ASAPPPPPP
Answer:
accelerating upward would be your answer
how many chemical bonds are formed in CH4 molecule
Answer:
4 covalent bonds
The specific heat of a certain type of cooking oil is 1.75J(g. °C). How much heat energy is needed to raise the temperature of 2.44 kg of this oil from 23. °C to 191 °C?
Answer:
The amount of heat needed is 593.88 kJ.
THE POINT (-7,4) IS REFLECTED OVER THE LINE X=-3. THEN, THE RESULTING POINT IS REFLECTED OVER THE LINE Y=X. WHERE IS THE POINT LOCATED AFTER BOTH REFLECTIONS?
Answer: 4,2
The graph should show how to do it.
What is the density of an object that has a mass of 1.08 kg and displaces 50.50 cm3 of water? (Please report your answer in g/cm3 ) Please report your answer in decimal notation not scientific notation the computer will mark it incorrect.
Answer:
Explanation:
1.08kg/50.5 cm^3(1000g/kg)=21.386 g/cm^3
Answer:
[tex]\boxed {\boxed {\sf 21.4 \ g/cm^3}}[/tex]
Explanation:
We are asked to find the density of an object.
The density of a substance is its mass per unit volume. It is calculated by dividing the mass by the volume.
[tex]\rho= \frac{m}{v}[/tex]
The mass of the object is 1.08 kilograms. The object displaced 50.50 cubic centimeters of water, so this value is its volume.
We are asked to give the density in grams per cubic centimeter, so we must convert the mass. There are 1000 grams in 1 kilogram. Set up a conversion factor.
[tex]\frac {1000 \ g}{1 \ kg}[/tex]
Multiply by the given mass: 1.08 kg
[tex]1.08\ kg *\frac{1000 \ g }{ 1\ kg}[/tex]
The units of kilograms cancel.
[tex]1.08*\frac{1000 \ g }{1}[/tex]
[tex]1.08*{1000 \ g } = 1080 \ g[/tex]
Now we know the mass in grams and the volume:
m= 1080 g v= 50.50 cm³Substitute the values into the density formula.
[tex]\rho= \frac{1080 \ g }{50.50 \ cm^3}[/tex]
Divide.
[tex]\rho= 21.3861386 \ g/cm^3[/tex]
The original measurements of mass and density have 3 and 4 significant figures. Our answer must have the least number of significant figures, or 3.
For the number we found, that is the tenths place. The 8 in the hundredth place tells us to round the 3 in the tenths place up to a 4.
[tex]\rho \approx 21.4 \ g/cm^3[/tex]
The density of the object is approximately 21.4 grams per cubic centimeter.
FREE BRAINLIEST!!!!!!!!!!!!!!!
Why only ionic compounds would produce fluoride in water? Explain your reasoning.
Answer:
Here is your answer!!
Explanation:
YW! :]
What is an example of microorganisms acting in a harmful way?
Answer:
Mark me as brainlest
Explanation:
Microorganisms present in our body Re viruses, bacteria, fungi, algae, and protozoa among which most of them cause immense benefits to the body. There are some harmful microorganisms too known as pathogens which cause disease and cause a threat to all existing life forms of the earth which can result in death at times.
Answer:
An example of microorganisms acting in a harmful way is a bacteria spoiling food.
The missing box would be the number _________ and this is a form of
____________ decay.
Answer: 86,
α-decay
Explanation:
A student would like to determine how heating a liquid changes its volume. The student hypothesizes that the liquid will increase in volume. The following list shows the steps taken by the student in order to test the hypothesis.
1.Select the liquid to test.
2.Place the liquid in a sealed container.
3.Use a Bunsen burner to heat the liquid by 10°C.
4.Measure the volume of the liquid.
5.Record the results.
What is wrong with how the student conducted the investigation?
A.
The hypothesis was not valid because it is impossible for liquids to change in volume.
B.
The volume of the liquid should be measured before it is heated.
C.
The student should have increased the temperature of the liquid by more than 10ºC.
D.
The length of time it took for the liquid to be heated should be measured.
Answer:
The volume of the liquid should be measured before it is heated.
Explanation:
Because During an experiment to test how a variable changes a substance, it is important to first observe and record the characteristics of the substance before the variable is introduced. In this case, the variable is heat energy.
How is melting simillar evaporation
Answer:
Melting and evaporation both represent changes in matter that involve behavior at the molecular level.
Answer:
well both disappear over time
Explanation:
The forecast predicted the atmospheric pressure to be 1.03
atm today. What is this pressure in mmHg? (Round to the
nearest ones)
mmHg
The pressure in mmHg forecasted today is 783 mmHg
Pressure is the force acting perpendicular to the area of a surface. Pressure is given by:
Pressure = Force/Area
The pressure of a gas is the force exerted on the walls of its container by the gas. Pressure can be measured in atm, mmHg, etc.
1 atm = 760 mmHg
1.03 atm = 760 mmHg per atm * 1.03 atm = 783 mmHg
Therefore the pressure in mmHg forecasted today is 783 mmHg
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Sugar 2C6H1206 total number of atoms *
Answer:
6 carbon atoms, 12 hydrogen atoms and 6 oxygen atoms
Explanation:
are ions always smaller than their neutral atoms
Answer:
The negative ion is larger than the original atom. but the same number of positive protons, the size of the ionic radius will increase. When an atom has its electrons attracted to another atom it becomes a positive ion. The positive ion is smaller than the original atom.
Which correctly describes the lithosphere? *
A.The crust and the upper part of the core
B.The crust and the upper part of the ocean
C.The crust and the upper part of the mantle
D.The core and the upper part of the mantle
Answer:
its for sure not b. its c the crust and upper part of the mantle.
the whole definition:
the rigid outer part of the earth, consisting of the crust and upper mantle.
Which statement correctly explains how matter is conserved in chemical reactions? (1 point)
Answer:
can you include the choices?
Explanation:
Answer:
Answer b: The law of conservation of matter says that in chemical reactions, the total mass of the products must equal the total mass of the reactants.
Explanation:
hope this helps
What mass of LiOH would need to be dissolved in 500.0 mL of water to produce a solution with a pH of 12.40
Taking into account the definition of pH and pOH, the mass of LiOH needed to be dissolved in 500.0 mL of water to produce a solution with a pH of 12.40 is 0.299375 grams.
First of all, pH is a measure of acidity or alkalinity that indicates the amount of hydrogen ions present in a solution or substance.
The pH is defined as the negative base 10 logarithm of the activity of hydrogen ions, that is, the concentration of hydrogen ions or H₃O⁺:
pH= - log [H⁺]= - log [H₃O⁺]
Similarly, pOH is a measure of hydroxyl ions in a solution and is expressed as the logarithm of the concentration of OH⁻ ions, with the sign changed:
pOH= - log [OH⁻]
The following relationship can be established between pH and pOH:
pOH + pH= 14
In this case, being pH= 12.40, pOH is calculated as:
pOH + 12.40= 14
pOH= 14 - 12.40
pOH= 1.60
Replacing in the definition of pOH the concentration of OH⁻ ions is obtained:
- log [OH⁻]= 1.60
Solving:
[OH⁻]= 10⁻¹ ⁶
[OH⁻]= 0.025 M
Then, the [OH⁻] is 0.025 M.
Strong bases are bases that completely dissociate in water into the cation and OH - (hydroxide ion). LiOH is a strong base, so the OH- concentration is equal to the LiOH concentration:
[OH⁻]= [LiOH]= 0.025 M
Finally, Molarity or Molar Concentration is the number of moles of solute that are dissolved in a certain volume:
[tex]Molarity=\frac{number of moles}{volume}[/tex]
In this case, knowing that molarity is 0.025 M and the volume is 500 mL= 0.5 L, you can replace in the expression for molarity:
[tex]0.025 M=\frac{number of moles}{0.5 L}[/tex]
Solving:
number of moles= 0.025 M× 0.5 L
number of moles= 0.0125 moles
Finally, since the molar mass of LiOH is 23.95 [tex]\frac{g}{mol}[/tex], that is, the amount of mass that the substance contains in one mole, the mass of LiOH that 0.0125 mol contains can be calculated as:
0.0125 mol×23.95 [tex]\frac{g}{mol}[/tex]= 0.299375 g
The mass of LiOH needed to be dissolved in 500.0 mL of water to produce a solution with a pH of 12.40 is 0.299375 grams.
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Learning task 1: as you start exploring the subject answer the following question write your answer on your answer sheet
need help pls
In this exercise, it is necessary to know the systems that our bodies have and complete the sheet that will correspond to these answers:
1- Digestive
2- Urinary
3- Respiratory
4- Skeletal
5- Muscular
6- Integumentary
7- Cardiovascular
8- Endocrine
9- Nervous
10- Reproductive
So looking in more detail, the number one corresponds to the digestive system because it is the digestive process that starts in the mouth. The second is related to the urinary system, which is responsible for the filtration and elimination of excess water. The respiratory system corresponds to the third option, which is the gas exchange that occurs in the pulmonary alveoli.
The numbers 4, 5, and 6 are very important systems for the support of the human body, being respectively the skeleton system, the muscular system, and the integumentary system. The first system is responsible for support while the second is better known for locomotion and finally the third is known for covering the human body by the dermis.
The cardiovascular system is responsible for getting the blood transported throughout the body and pumped by the heart, so this system is related to number 7. Then the endocrine system is responsible for the hormones and how these hormones acted in the body and are number 8.
The number 9 corresponds to one of the most complex and principal systems, the nervous system, which has neurons as its cells and transmits the nervous impulse in response.
The last treated system is the reproductive system, known for its reproductive gametes, and its most important role is to maintain the reproduction of the species.
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The organelle is found in plant cells contains a green pigment and is the site of photosynthesis. this organelle is the _______
Answer: Chloroplast
Explanation:
What is the weight of:
i) 1 mole of oxygen atoms?
ii)
i) 3 moles of iron atoms?
3 ?
iii) 20 moles of calcium carbonate?
Answer:
Oxygen = 15.999 g/mol
Iron = 3 × 55.845 = 167.535 g/mol
CaCO3 = 20 × 100.0869 = 2001.738 g/mol
To determine the heat of neutralisation, Chelsea placed 50 cm' of sodium hydroxide
solution of concentration 1.0 mol dm- in a polystyrene cup and recorded its
temperature. She then recorded the temperature of 50 cm of sulfuric acid, added it
to the cup, stirred the solution and recorded its maximum temperature, as follows:
. initial temperature of NaOH(aq) = 29.5 °C
. initial temperature of H.SO, (aq) = 29.9 °C
• maximum temperature of the solution = 35.8 °C
Calculate the increase in temperature
2 solutions of NaOH and H₂SO₄ at 29.5 °C are mixed in a coffee-cup calorimeter and after the reaction is completed the temperature is 35.8 °C. The increase in the temperature is 6.3 °C.
To determine the heat of neutralization, Chelsea used a coffee-cup calorimeter.
Initially, she had 2 solutions, NaOH and H₂SO₄, both at 29.5 °C. Upon mixing, the heat was evolved and the final temperature of the solution was 35.8 °C. The neutralization reaction was:
NaOH + H₂SO₄ ⇒ Na₂SO₄ + H₂O
The increase in temperature (ΔT) is equal to the difference between the final temperature and the initial temperature.
[tex]\Delta T = 35.8 \° C - 29.5 \° C = 6.3 \° C[/tex]
This data can be used to calculate the heat of neutralization (q) using the following expression.
[tex]q = c \times m \times \Delta T[/tex]
where,
c is the specific heat capacity of the solutionm is the mass of the solution2 solutions of NaOH and H₂SO₄ at 29.5 °C are mixed in a coffee-cup calorimeter and after the reaction is completed the temperature is 35.8 °C. The increase in the temperature is 6.3 °C.
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How much is 1 mole of something?
O A. 6.02 x 10
O B. 6.02 x 10-23
O C. 6.02 × 23
O D. 6.02 x 1023
Answer:
see explanation
Explanation:
How much is 1 mole of something?
O A. 6.02 x 10
O B. 6.02 x 10-23
O C. 6.02 × 23
O D. 6.02 x 1023
look carefully at your picture
use a magnifying glass if you need to
I am rewriting the choices the way it appears i your picture
A. 6.02 X 10
B 6.02 X 10^-23
C. 6.02^23
D. 6.02 X 10^23
the answer is D. you left out "to the pow......"
a significant mistake
what is in your picture is 6.02 X 10^23 and means
6.02 X 100,000,000,000,000,000,000,000
what you wrote 6.02 X 1023 means 6158
when we are talking about the number of teensy tiny atoms in a measurable mass we are talking BIGGGGG GIANTTTTT numberswhen written correctly, the answer is D
for an oxygen gas as 3000kelvin, calculate the characteristics vibrational temperature and the vibrational partition function given that the fundamental vibrational frequency of oxygen molecule obtain from Rama spectrum is 4405.3per cm
Refer to the attachment !!!
A fruit-and-oatmeal bar contains 142 nutritional Calories. Convert this energy to calories
Answer:
a fruit and oatmeal bar contains 142000 calories.
A nutritional calorie, or kilocalorie, is equal to 1000 calories.
E = 142 kcal · 1000 cal/kcal.
E = 142 000 cal.
Calorie (cal), or small calorie, is the amount of energy needed to heat one gram of water by one degree Celsius.
One small calorie is approximately 4.2 joules.
A calorie is a unit of energy.
Explanation:
hope it helps :)
calculate the Mass of lead that will be deposited from an aqueous solution of lead(2)salt by the same quantity of electricity that deposit 2.7g of copper from an aqueous solution of copper (2)salt
Answer:
8.82 gm of Pb
Explanation:
Question
calculate the Mass of lead that will be deposited from an aqueous solution of lead(2)salt by the same quantity of electricity that deposit 2.7 g of copper from an aqueous solution of copper (2)saltSince the oxidation# of the Pb and the Cu is the same, we know that the same amount of electricity that will deposit 1 mole of Cu will deposit 1 mole of Pb
2.7 gm of Cu were deposited
the atomic mass of Cu = 63.5
the number of moles of Cu deposited was 2.7/63.5 = 0.0425 moles
so 0.0425 moles of Pb will be deposited.
The atomic mas of Pb is 207.2
0.0425 mole of Pb weigh 0.0425 X 207.2 =
8.82 gm of Pb
The temperature of an object increases by 26.1 °C when it absorbs 3711 J of heat. Calculate the heat capacity of the object.
C = ________________ J/°C
Answer:
[tex]\displaystyle C = 142\text{ } \frac{J}{^\circ C}[/tex]
Explanation:
We can utilize the heat capacity formula:
[tex]\displaystyle q = C\Delta T[/tex]
Where q is the heat energy, C is its heat capacity, and ΔT is the change in temperature.
By substitution, q = 3711 J and ΔT = 26.1 °C. Hence:
[tex]\displaystyle \begin{aligned} (3711 \text{ J}) & = C(26.1\text{ } ^\circ\text{C}) \\ \\ C & = 142\text{ } \frac{J}{^\circ C}\end{aligned}[/tex]
Hence, the heat capacity of the substance is about 142 J per degrees Celsius.
Chemistry help!
How much 1.50 M H3PO4, in mL, would you need to add to 50.00 mL of 3.50 M Ca(OH)2 in order to neutralize the solution?
_____ of mL of H3PO4
Answer:
I think around 77
Explanation:
hold on let me look more into it
Given 0.10M NaOH (0.10mol/lit NaOH)
0.2M H3PO4 ( 0.2 mol/lit H3PO4)
15 ml of H3PO4 or 0.015 lit of H3PO4
Find the volume of NaOH needed to neutralize the solution
Relate moles of H3PO4 with the moles of NaOH with the help of coefficients in front of NaOH and H3PO4 seen in balanced equations.
moles ↔ Litre use the definition of molarity (moles/liters)
Start with what is given for H3PO4
0.015 lit of H3PO4 x 0.2 moles of H3PO4 / lit of H3PO4 x 3 moles of NaOH/1 mole of H3PO4 x lit of NaOH/0.1 mol of NaOH = 0.09 lit or 90 ml.
What does the word neutralize mean?Definition of neutralizing
transitive verb. 1: to make it chemically neutral. 2a: to counteract the activity or effect of making ineffective propaganda that is difficult to neutralize. b: kill, destroy.
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Which is not an example of vaporization?
Answer:
boi i need the choices idiot
Explanation:
Nobody can add an answer without context.
But if this helps,
"Vaporization of an element or compound is a phase transition from the liquid phase to vapour. There are two types of vaporization: evaporation and boiling. Evaporation is a surface phenomenon, whereas boiling is a bulk phenomenon." - Wikipedia
https://en.wikipedia.org/wiki/Vaporization
