how many molecules are in 18 grams of water
Answer:
6.023×10^23
Explanation:
Molecular mass= 2 (H)+1 (O) =2*1+1*16=2+16= 18 gm per 1gm molecule of water
napthalene combustion can be used to calibrate the heat capacity of a bomb calorimeter The heat of combustion of naphthalene is -40.1kj/g. When .8210g of naphthalene was burned in a calorimeter containing 1,000g of water, a temperature rise of 4.21C was observed. What is the heat capacity?
A bomb calorimeter with a heat capacity of 3.63 kJ/°C experiences a temperature rise of 4.21 °C when .8210 g of naphthalene is burned.
The combustion of naphthalene is used to calibrate the heat capacity of a bomb calorimeter.
What is a bomb calorimeter?It is a device used to measure the change in the internal energy of a reaction.
To determine the heat capacity of the calorimeter (C), we need to follow a series of steps.
Step 1: Calculate the heat released by the combustion.The heat of combustion of naphthalene is -40.1kJ/g and .8210g were burned.
Qcomb = -40.1kJ/g × .8210g = -32.9 kJ
Step 2: Determine the heat absorbed by the bomb calorimeter.According to the law of conservation of energy, the sum of the heat released by the combustion and the heat absorbed by the bomb calorimeter is zero.
Qcomb + Qbomb = 0
Qbomb = -Qcomb = 32.9 kJ
Step 3: Calculate the heat capacity of the bomb calorimeter.32.9 kJ were absorbed, part by the calorimeter itself and part by the 1,000 g (m) of water, whose specific heat capacity (c) is 4.18 J/g°C.
A temperature rise (ΔT) of 4.21 °C is observed. We can determine the heat capacity of the bomb calorimeter (C) using the following expression.
Qbomb = Qcal + Qwater
32.9 kJ = C × ΔT + c × m × ΔT
32.9 kJ = C × 4.21 °C + (4.18 × 10⁻³ kJ/g.°C) × 1,000 g × 4.21 °C
C = 3.63 kJ/°C
A bomb calorimeter with a heat capacity of 3.63 kJ/°C experiences a temperature rise of 4.21 °C when .8210 g of naphthalene is burned.
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What do the colors red, green, and blue have to do with light?
Answer:
The three specific cone cells in our eyes work together, allowing us to translate these three colors of light into millions of different colors. ... When green and blue light are combined, they make cyan. Red and green light make yellow. And when all three primary colors of light are combined, we see white light.
Explanation:
Heart, 5 stars, Brainiest, and 40 coins if right! Answer needed ASAP
Which statement describes what happens when Bret runs up a flight of stairs?
A. His kinetic energy is destroyed.
B. His potential energy decreases.
C. His kinetic energy is converted into potential energy.
D. His potential energy is converted into kinetic energy.
Answer:
His kinetic energy is converted into potential energy.
Explanation:
Why was the war in Peru difficult?
Answer:
in contrast, peru and Bolivia entered the war hindered by numerous domestic fractures and by an economic and insititutional backwardness that nearly prevented the two countries from fighting the war at all
A block has 73 kg is being pushed and accelerated at rate of 10 m/s. what force is being applied to the block?
730 N
7.3 N
7300 N
730 Kg
Answer:
730 N
Explanation:
force =mass ×acceleration
force= 73kg×10m/s
F=730N
a solid substance a is soluble in water to the extent of 10 mg/ml of water at 25oc and 100 mg/ml of water at 100oc. you have a sample that contains 100 mg of a and 25 mg of an impurity b. a and b have the same solubility behavior. if one 10ml portion of water was used for the recrystallization, what was the % recovery of a
Answer:
join the provisonal IRA and help free and unite ireland
Explanation:
fight aganst the english oppressors and free ireland
erinn go braugh
Please help due tomorrow
Giving Brainlesst
Answer:
Down arrow:
-a car comes to a stop when a traffic light turns red
Up arrow:
-race car accelerates when a race begins
Circle:
-car driving 45 mile per hour down straight road
Explanation:
and i think the car going around a bend would be an up arrow
I don’t wanna fail if you know the answer pls help me :(
Answer:
liquid and gas........................
Which of the following statements is true about CO?
а
The carbon and oxygen share electrons.
b
Carbon is the cation and oxygen is the anion.
с
It is the element cobalt.
d
Its name is monocarbon monoxide.
e
none of these
Answer:
it is the element cobalt with atomic number 27
Why must labs that use mercury thermometers calculate Kelvin ?
Answer:
because those are the only thermometers that are truly accurate for kelvins
Explanation:
The Kelvin temperature in thermometers is used by scientists because it provides a temperature where zero indicates the complete absence of thermal energy.
What is the Kelvin scale?All thermometers have a scale on them that we use to find the temperature, known as a temperature scale. Kelvin proposed that the temperature interval from the ice point to the steam point be defined as 100° containing earlier centigrade scales.
Lord Kelvin had given an absolute temperature scale based on the Carnot cycle. The zero point is 273.15 on Kelvin’s scale below that of the Celsius scale.
On the kelvin scale, Each division is called a Kelvin (K) and is equal to a degree on the Celsius scale. On the Celsius scale, zero degrees is the freezing point of water while on the Kelvin scale the zero point is at absolute zero temperature.
Therefore, 0 K is equal to - 273.15°C, and 0°C is equal to 273.15 kelvins. A mathematical expression that gives the relation between the Celsius and Kelvin scales:
Temperature (K) = Temperature (°C) + 273
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what is the chemical formula of copper (ii) hyddroxide
Answer:
Cu(OH)₂
Explanation:
Hope that helps
Answer: The chemical formula is Cu(OH)₂
What is the required mass to prepare a 0.5M potassium chloride solution using 250mL of water
Make a atomic model of carbon-12 in mine craft
(If it's good I'll give a lot of points)
Here is the atomic model in the picture.
Answer to question in picture
Answer:
methyl 2-methyl-ethane
Explanation:
Which molecule does not obey the Octate rule of valence electrons .
BeCl2
FeCl2
CuCl2
ZnCl2
Explanation:
Which molecule does not obey the Octate rule of valence electrons .
BeCl2
FeCl2
CuCl2
ZnCl2
→BeCl2
Explaination:
BeCl2 violates the octet rule because the boron should be in a suitable valence state such that it binds to 3 chlorines. However, in this molecule boron is associated with six electrons.
Answer:
BeCl2
Explanation:
hope Its useful for you
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A quantity of 1.922 g of methanol (CH3OH) was burned in a constant-volume bomb calorimeter. Consequently, the temperature of the water rose by 4.20 Ce … lsius. If the heat capacity of the bomb plus water was 10.4 kJ/degree Celsius, calculate the molar heat of combustion of methanol
The formula for calculating the amount of energy or heat released is:
ΔH = C ΔT
where ΔH is heat of combustion, C is heat capacity, while ΔT is change in temperature
ΔH = 8.69 kJ / °C * (5.14°C)
ΔH = 44.67 kJ
Then we calculate the moles of CH3OH which has molar mass of 32.04 g/mol:
moles = 1.922 / 32.04 = 0.05999 mol
SO the molar heat of combustion is:
ΔHm = 44.67 kJ / 0.0599875 mol
ΔHm = 744.60 kJ / mol
When vectors are added or subtracted, the net force is called the _____.
will give brainliest to whoever gets it right
Answer:
resultant
Explanation:
Which of the following statements are true about energy and bonds?
Check all that apply.
A. The formation of bonds does not absorb or release energy.
B. When bonds are formed, energy is released.
C. Energy is absorbed to break bonds.
D. Breaking bonds does not absorb or release energy.
Answer:
A. Energy is necessary for bond formation.
C. Breaking bonds takes energy.
D. When bonds are formed, energy is released.
Energy is always required for bond formation because when a chemical reaction occurs, either molecular bonds are broken or other bonds are formed to make different molecules. Energy is released during bond formation and is an exothermic process because bond formation represents a stable configuration and the energy lost is released as heat energy that makes it more stable. Breaking bonds takes energy and is an endothermic reaction because energy is absorbed to break bonds.
Hope that helps. x
Explain what is meant by the term 'conservation of mass'.
Give your answer in terms of the atoms that take part in a chemical reaction
Answer:
Below
Explanation:
In a chemical reaction, per the law of conservation of mass, no atoms or subatomic particles will be created or destroyed; for example, H2O2 will decompose into H2 and O2, meaning no matter was created or destroyed.
what is the element found in all living matter.
Answer:
There are four elements that are found in all living animals, that are:
Oxygen (O)
Carbon (C)
Hydrogen (H)
Nitrogen (N).
No matter what container it is in, a liquid usually:
A.has the same volume
B.has a different volume
C.has the same shape
D.has a different color
Answer:
A
Explanation:
A liquid will will have the same color, it will not have the same shape and its volume will always be constant because you are not creating mass.
Hope this helps!
How are the sensory clues from watching a fire different from the sensory clues from watching a firefly?
Answer:
sensory experience of a chemical reaction called combustion. In a way, fire is like the leaves changing color in fall, the smell of fruit as it ripens, or a firefly's blinking light. All of these are sensory clues that a chemical reaction is taking place
Explanation:
Sensory encounter with the combustion chemical process. Fire can be compared to the fall foliage's shifting hues, the aroma of ripe fruit, or the blinking light of fireflies. These are all sensory indicators that a chemical reaction is occurring.
What is combustion?Combustion is defined as a chemical interaction between different compounds, usually involving oxygen, that produces heat and light in the form of flames. Hydrocarbons and oxygen are the only reactants in a combustion reaction. The fuel is a hydrocarbon, and oxygen is required for burning.
It stimulates several of our senses at once, producing the vivid experience we anticipate from a tangible object. By using fuel, heat, and oxygen during combustion, that sensory experience is produced.
Thus, sensory encounter with the combustion chemical process. Fire can be compared to the fall foliage's shifting hues, the aroma of ripe fruit, or the blinking light of fireflies. These are all sensory indicators that a chemical reaction is occurring.
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a
What did you discuss in your response? Check all that
apply.
Sample Response: Using a historical perspective helps
the reader understand that Nnaemeka's decision to marry
Nene goes against long-standing traditions. He marries
for love instead of taking part in an arranged marriage.
He also marries outside of his tribe. As a result of his
choice, his father shuns him. A feminist perspective
reveals the marriage also goes against patriarchal values
in this society. Women are expected to be homemakers.
However, Nene is a teacher and does not fit the
expectation. Both perspectives help the reader
understand opposition to the marriage. However, one
approach focuses on tradition, while the other focuses on
the treatment of women in their culture.
cultural values
feminist perspective
historical perspective
similarities between the two perspectives
differences between the two perspectives
One approach focuses on tradition, while the other focuses on the treatment of women in their culture the response is cultural value. Hence option A is correct.
What are traditions?Traditions are defined as a notion or practice that has been passed down within a community or society and has unique importance or symbolic value that dates back in time. Traditions are notions and convictions that are passed down from generation to generation.
Cultural value are defined as the fundamental values and concepts that underpin a community's existence and provide a foundation for its protection and reliance on peaceful coexistence. Cultural values are the fundamental notions of right and wrong held by a culture.
Thus, one approach focuses on tradition, while the other focuses on the treatment of women in their culture the response is cultural value. Hence option A is correct.
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Answer: only culture value
Explanation: just answered it
According to Hebrews 11, what did Abraham believe God would do if Isaac was slain as a sacrifice? Please help me I need it for tonight!
Answer:
ABRAHAM DIDN’T THINK ISAAC WOULD DIE!
When they reached the mountain, Abraham told his servant, “Stay here with the donkey; I and the boy will go over there and worship and come again to you” . The text is careful to include both Abraham and Isaac in the return journey.
Or consider Isaac’s question about where the lamb for the sacrifice would come from. Abraham responds, “God himself will provide the lamb”. It seems Abraham prepared himself to do what God asked, but he expected something else to happen.
The author of the book of Hebrews gives us insight to Abraham’s thoughts. It says, “He considered that God was able even to raise [Isaac] from the dead” Instead of a resurrection, Abraham was spared the sacrifice.
pa help thank yoeee <3333
Answer:
1.c
2.c
3.a
4.b
5.a
i think that's the answer
What is the mass of a 2.5 mole sample of MgO2
Heart, 5 stars, and Brainiest if right! Answer needed ASAP PLEASE!What type of forces do not change the motion of an object?
A. Acceleration forces
B. Balanced forces
C. Inertia forces
D. Unbalanced forces
Answer:
unbalanced force
Explanation:
pls mark me brainliest
Answer:
B. balanced forces
Explanation:
the motion of an object will not change if the forces pushing or pulling the object are balanced
The stage in which the hair begins to destroy itself as it disconnects from the
papilla is called?
3. Carbon dioxide gas lowers the amount of oxygen that enters the blood? True or false
Answer:
true
Explanation:
because carbon dioxide is dencer than oxygen therefore it displaces it