Answer:
–23000 Calories.
NOTE : The negative sign indicates that heat has been loss to the student back.
Explanation:
The following data were obtained from the question:
Mass (M) of water = 575 g
Initial temperature (T1) = 80 °C
Final temperature (T2) = 40 °C
Heat (Q) transferred =.?
Next, we shall determine the change in temperature (ΔT).
This is illustrated below:
Initial temperature (T1) = 80 °C
Final temperature (T2) = 40 °C
Change in temperature (ΔT) =?
Change in temperature (ΔT) = T2 – T1
Change in temperature (ΔT) = 40 – 80
Change in temperature (ΔT) = –40°C
Finally, we shall determine the heat transferred. This can be obtained as follow:
Mass (M) of water = 575 g
Change in temperature (ΔT) = –40°C
Specific heat capacity (C) of water = 1 Cal/g°C
Heat (Q) transferred =.?
Q = MCΔT
Q = 575 × 1 × –40
Q = –23000 Calories
NOTE : The negative sign indicates that heat has been loss to the student back.
Some Magnesium compounds undergo thermal decomposition.
What are the products of thermal decomposition of Magnesium nitrate Mg(NO3)2 and magnesium hydroxide Mg(OH)2?
Answer:
2 Mg(NO3)2 → 2 MgO + 4 NO2 + O2.
Mg(OH)2=MgO + H2O.
hope. it helps
cloruro de litio mas sodio
Answer:
El cloruro de litio se utiliza para fabricar litio metálico. El cloruro de litio se funde y electroliza. Esto produce litio metálico líquido.
Explanation:
sowwy si mi español es malo
Answer:
give him brainliest
Explanation:
Which of the following sets of descriptors matches the molecule below?
Image of two hydrogen atoms bonded to one oxygen atom to form H2O, or water.
A. Simple structure, molecule, single bonds, two elements
B. One element, triple bond, molecule, diatomic
C. Giant structure, single bond, compound, one element
D. Compound, allotrope, double bond, giant structure
Answer: A. Simple structure, molecule, single bonds, two elements
How much did asbestos exposure decrease during the year 1982 and 1983
The asbestos exposure during the years 1982 and 1983 was 2.5 fibers per cubic centimeter and 0.8 fibers per cubic centimeter respectively. So asbestos exposure decreased by 1.7 fibers per cubic centimeter during the year 1983.
Breathlessness Persistent, dry cough Chest pain or tightness Lack of a dry, crackling sound in the lungs when you breathe in Wider and rounder fingers and toes are some of the symptoms of asbestos exposure.
The largest group of people exposed to asbestos is those working in the construction industry. Historically, asbestos was also used by pipe fitters and shipyard workers. In addition, asbestos was used by military personnel, auto mechanics, and many other occupations.
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in what condition does the electron pair arrangment and geometry of molecules become identical?
A, when the number of bonding electrons is equal to the number of non bonding electrons
B, when the number of of bonding electrons became even
C, when there are no non-bonding electrons
D, when the sum of non-bonding electrons become odd
A. When the number of bonding is equal to the number of non bonging electrons.
What is electron arrangement and geometry of molecules?Geometry of molecules: The geometry of a molecule determines the reactivity, polarity and biological activity of that molecule. Electron arrangement: electron geometry is found by taking both lone electron pairs and bonds in a molecule.
In atomic physics and quantum chemistry, the electron configuration exists as the distribution of electrons of an atom or molecule in atomic or molecular orbitals.
Molecular geometry, also understood as the molecular structure exists as the three-dimensional structure or arrangement of atoms in a molecule. Understanding the molecular structure of a compound can assist specify the polarity, reactivity, phase of matter, color, magnetism, as well as biological activity.
An electron arrangement exists as a path in which electrons are placed in an atom.
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rubidium has two isotope. 85 rb has mass of 84.9117 and 87 rb has a mass of 86.9085 amu. if the average atomic mass of rb is 85.4678 amu. what is the atomic abundance of each isotope?
Answer:
85Rb: 72.15%
87Rb: 27.85%
Explanation:
The average atomic mass of an atom is the sum of all [atomic abundance of isotope]*[mass of isotope].
Rubidium has only two isotopes, so let the atomic abundance of 85Rb be x, thus making the atomic abundance of 87Rb equal to 1-x.
[Average atomic mass of Rb] = [Mass of 85Rb]*[atomic abundance of 85Rb] + [Mass of 87Rb]*[atomic abundance of 87Rb]
85.4678 = 84.9117x + 86.9085*(1-x)
85.4678 = 84.9117x + 86.9085 - 86.9085x
85.4678 = 84.9117x + 86.9085 - 86.9085x
-1.4407 = -1.9968x
Atomic abundance of 85Rb = x = 0.7215 = 72.15%
Atomic Abundance of 87Rb = 1 - x = 1 - 0.7215 = 0.2785 = 27.85%
If 1.60 g of steam at 100.0 ∘C condenses into 40.5 g of water, initially at 28.0 ∘C, in an insulated container, what is the final temperature of the entire water sample? Assume no loss of heat into the surroundings.
when a liquid is cooled the kinetic energy of the particles a)decrease b) increase c) stay the same
Answer:
a) decrease
Explanation:
Hope this will help
c) Discuss precision and Accuracy as they relate to types of errors.
what is the answer
Precision relates to the consistency and reproducibility of measurements, while accuracy reflects how close measurements are to the true value.
Precision and accuracy are two important concepts in the context of errors in measurements. While they both pertain to the quality of data, they refer to different aspects.
Precision refers to the degree of consistency or reproducibility in a series of measurements. It reflects the scatter or spread of data points around the average value. If the measurements have low scatter and are tightly clustered, they are considered precise. On the other hand, if the measurements have a high scatter and are widely dispersed, they are considered imprecise.
Accuracy, on the other hand, refers to the closeness of measurements to the true or target value. It represents how well the measured values align with the actual value. Accuracy is achieved when measurements have a small systematic or constant error, which is the difference between the average measured value and the true value.
Errors in measurements can be classified into two types: random errors and systematic errors.
Random errors are associated with the inherent limitations of measurement instruments or fluctuations in the measurement process. They lead to imprecise data and affect the precision of measurements. Random errors can be reduced by repeating measurements and calculating the average to minimize the effect of individual errors.
Systematic errors, on the other hand, are caused by consistent biases or inaccuracies in the measurement process. They affect the accuracy of measurements and lead to a deviation from the true value. Systematic errors can arise from factors such as instrumental calibration issues, environmental conditions, or experimental techniques. These errors need to be identified and minimized to improve the accuracy of measurements.
In summary, precision refers to the degree of consistency or reproducibility of measurements, while accuracy refers to the closeness of measurements to the true value. Random errors affect precision, while systematic errors affect accuracy. To ensure high-quality measurements, both precision and accuracy need to be considered and appropriate techniques should be employed to minimize errors.
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What do the sections between the lines on a phase diagram represent? A. The areas in which the kinetic energy of a substance is constant B. The regions in which temperature and pressure change a substance's phase C. The conditions in which a substance exists in a certain phase D. The ranges where temperature and pressure are constant in a substance SUBMIT
The sections between the lines on a phase diagram represent Option B. The regions in which temperature and pressure change a substance's phase .
A phase diagram is a graphical representation that shows the conditions at which a substance exists as a solid, liquid, or gas.
It is a graph that represents the relationship between pressure and temperature under which a substance exists as a solid, liquid, or gas.
The sections between the lines on a phase diagram represent the regions in which temperature and pressure change a substance's phase.
Answer: B. The regions in which temperature and pressure change a substance's phase.
Explanation:A phase diagram is a graphical representation of the state of matter that exists under certain conditions of pressure and temperature.
A phase diagram is also known as a phase equilibrium diagram, a phase transition diagram, or a P-T diagram (pressure-temperature).
A phase diagram has three regions, solid, liquid, and gas, which are separated by phase boundaries.
Each boundary represents the conditions of temperature and pressure under which a phase change occurs.
The triple point is the point where all three phases coexist.
The critical point is the point at which the gas and liquid phases become indistinguishable.
The sections between the lines on a phase diagram represent the regions in which temperature and pressure change a substance's phase.
These sections are also called phase boundaries or phase transitions.
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calculate the amount of heat energy required to heat up 23.2 grams of ice from -21° C to 56° C ** please show your work**
The second option 1,870.4 Joules
What are the advantages and disadvantages of using renewable and nonrenewable energy resources?
Answer:an advantage for using a renewable resources is the it really dont take up oil a it could be renewed one disadvantage is that it cost alot
on advantage for a non renewable is that it doesnt cost alot and one disadvantage is that it can't be renewed
Explanation:
Answer:
Renewable energy has several advantages and disadvantages. The advantages of renewable energy include unlimited supply, low environmental impact, and increased opportunities for employment. While these advantages are nice, there are some disadvantages. These include less reliability than nonrenewable energy, difficulty storing and transporting the energy, and higher costs.
Explanation:
Did it on edge
Venus's atmosphere, while primarily CO2, is also 3.5% nitrogen gas (i.e. mole fraction of 0.035). What is the partial pressure of nitrogen on Venus in kPa given that the total atmospheric pressure is 1334 psi?
The partial pressure of nitrogen on Venus is approximately 321.914 kPa.
To find the partial pressure of nitrogen on Venus, we need to calculate the partial pressure using the mole fraction of nitrogen and the total atmospheric pressure. First, we convert the total atmospheric pressure from psi to kilopascals (kPa) since the mole fraction is given in terms of kPa.
1 psi = 6.89476 kPa
Therefore, the total atmospheric pressure on Venus is:
1334 psi × 6.89476 kPa/psi = 9197.53 kPa
Next, we can calculate the partial pressure of nitrogen using the mole fraction. The mole fraction of nitrogen is given as 0.035, which means that nitrogen makes up 3.5% of the total moles of gas in the atmosphere.
The partial pressure of nitrogen is given by:
Partial pressure of nitrogen = Mole fraction of nitrogen × Total atmospheric pressure
Partial pressure of nitrogen = 0.035 × 9197.53 kPa
Partial pressure of nitrogen = 321.914 kPa
Therefore, the partial pressure of nitrogen on Venus is approximately 321.914 kPa.
It's important to note that the given atmospheric composition of Venus's atmosphere and the total atmospheric pressure are approximate values and can vary depending on specific conditions and measurements.
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which element has the electrons configuration 1s22s22p63s23p64s23d104p2
how does a buffer work?
A. it prevents added acids or bases from dissociating
B. it neutralizes acids or bases by precipitating a salt
C. it forms new conjugate pairs with the added ions
D. it bonds with the added H+ or OH- in solution
Answer:
It bonds with the added H+ or OH in solution.
Explanation:
What would happen in the future if global warming is not addressed properly?
Answer and Explanation:
If the future did not address global warming properly, then the world will become too hot faster than it should, and the days will get extremely hot, and in the distant future, lead to our extinction.
To address this problem, we can spread the awareness about it, get people to think open minded and not think that global warming is a joke, and plant trees, which takes in the carbon dioxide we exhale.
#teamtrees #PAW (Plant And Water)
A sample of PCl5 weighting 2.69 gram was placed in 1.00 Litter container and completely vaporized at 250C. The pressure observed at that temperature was 1.00 atm. The possibility exists that some of the PCl5 dissociated according to PCl5 (g) ! PCl3 (g) Cl2 (g) . What must be the partial pressures of PCl5 PCl3 and Cl2 under these experimental conditions
Answer:
Partial pressures:
PCl₅ = 0.558 atm
PCl₃ = 0.22 atm
Cl₂ = 0.22 atm
Explanation:
From the given information:
The number of moles of PCl₅ associated with the evaporation is:
\(n_{PCl_5}= \dfrac {weight \ of \ PCl_5} {M.Wt. \ of \ PCl_5}\)
\(n_{PCl_5}= \dfrac {2.69 \ g} {208.5 \ g/mol}\)
\(n_{PCl_5}= 0.013 \ mol\)
Temperature of the gas = 250° C = (250 + 273.15) K
= 523.15 K
Using the Ideal gas equation to determine the pressure exerted by the completely vaporized PCl₅
PV = nRT
\(P = \dfrac{nRT}{V}\)
\(P = \dfrac{0.0013 \ mol \times 0.082 \ Latm^0 K^{-1} . mol ^{-1} \times 523.15 \ K}{1.0 \ L}\)
P = 0.558 atm
Thus, at 250° C, decomposition of PCl₅ occurs.
In the container, PCl₅ decomposes to PCl₃ and Cl₂.
i.e.
\(PCl_{5(g)} \to PCl_{3(g)}+ Cl_{2(g)}\)
Using Dalton's Law:
\(P_{total } =P_1 + P_2+P_3 +...\)
\(P_1 = P_{Total} \times X_1\)
where;
X = mole fraction
Then, the total no. of moles in the container is:
\(n = \dfrac{PV} {RT}\)
\(n = \dfrac{1\ atm \times 1.0\ L}{0.0821 \ L \ atm \ K^{-1}.mol \times 523.15\ K}\)
n = 0.023 mol
Now, the container contains a total amount of 0.023 mol where initially 0.013 mol are that of PCl₅ and remaining 0.005 mol of PCl₃ and 0.005 mol of Cl₂.
Thus, the partial pressure of PCl₃ is:
\(P__{PCL_3} }= P_{total} \times \dfrac{no. \ of \ moles \ of PCl_5}{total \ no. \ of \ moles}\)
\(P__{PCL_3}} = 1 \ atm \times \dfrac{0.005}{0.023}\)
\(P__{PCL_3}} = 0.22 \ atm\)
Thus, since the no of moles of PCl₃ and Cl₂ are the same, then the partial pressure for Cl₂ is = 0.22 atm
1. As elements go across from left to right in a period,
they hold their electrons more tightly, because they
have more protons in the nucleus attracting the
orbitting electrons in the electron cloud. So across a
period, does atomic radius increase or decrease?
Answer:
decrease.
Explanation:
WHY? - As you go across a period, electrons are added to the same energy level. ... The concentration of more protons in the nucleus creates a "higher effective nuclear charge." In other words, there is a stronger force of attraction pulling the electrons closer to the nucleus resulting in a smaller atomic radius.
If gold is selling presently for $1000.00/oz how much would 1 cubic inch of gold be worth?
Note: 1 inch= 2.54 cm; 1 oz. =28.3 g Density of gold: 19.3 g/cm^3
Answer:
$89.69
Explanation:
$1000 = 1 oz = 28.3g
volume = mass/density
volume = 28.3/19.3 = 1.47cm³
1 inch= 2.54 cm
1 cubic inch = (2.54)³ = 16.39 cm³
16.39/1.47 = 11.15 cubic inch
11.15 cubic inch = $1000
1 cubic inch = 1000/11.15 = $89.69
Which portion of a molecule of F2O has partial positive charge?
Question 3 options:
A)
The F atoms
B)
The central O atom
C)
The partial charge on each atom is zero
D)
The partial charge on each atom is negative
The partial charges on each fluorine atom are negative. Option B) The central O atom is the correct answer. Option B
The partial charges in a molecule are determined by the electronegativity values of the atoms involved. Electronegativity is the ability of an atom to attract electrons towards itself in a chemical bond. In the case of \(F_2O\), fluorine (F) is more electronegative than oxygen.
Fluorine is the most electronegative element on the periodic table, meaning it has a high ability to attract electrons. Oxygen is also relatively electronegative but less so than fluorine. When fluorine atoms bond with oxygen, the shared electrons will be pulled more towards the fluorine atoms, creating a polar covalent bond.
In \(F_2O\), each fluorine atom will pull the shared electrons towards itself, resulting in a higher electron density around the fluorine atoms. This creates a region of partial negative charge around the fluorine atoms.
Conversely, the oxygen atom will have a region of lower electron density and, therefore, a partial positive charge. This is because the shared electrons spend more time around the fluorine atoms due to their higher electronegativity.
Option B
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Which of these is NOT evidence that a chemical change has taken place?
temperature rising when 2 substances are mixed
gas production
color change
melting
write the structural formula for 2-bromo-3-chloro-4,4-dimethylpentanal
Answer:
Br-CH2-CH(CH3)2-C(Cl)H-CH(CH3)2-CHO
Explanation:
The molecule has a total of 14 carbon atoms, 13 hydrogen atoms, and 1 bromine atom. The carbon atoms are arranged in a chain with a methyl group attached to the second carbon atom, a chlorine atom attached to the third carbon atom, and two methyl groups attached to the fourth carbon atom. The fifth carbon atom has a carbonyl group attached to it.
The molecule is an aldehyde, which means that it has a carbonyl group (C=O) at the end of the chain. The carbonyl group is polar, and the oxygen atom has a partial negative charge. The hydrogen atom has a partial positive charge. This polarity makes the aldehyde group susceptible to nucleophilic attack.
The bromine and chlorine atoms are both electrophilic, which means that they have a partial positive charge. This makes them susceptible to nucleophilic attack.
The methyl groups are non-polar and do not have any significant reactivity.
The molecule is a chiral molecule, which means that it has a mirror image that is not superimposable on itself. This is because the carbon atom with the carbonyl group is attached to four different groups.
The molecule is a liquid at room temperature and has a strong odor. It is used in a variety of products, including perfumes, flavorings, and plastics.
actetic acid only partially ionizes in water
Acetic acid only partially ionizes in water as it is a weak acid.
Weak Acids are the acids that do not completely dissociate into their constituent ions when dissolved in solutions.
When dissolved in water, an equilibrium is established between the concentration of the weak acid and its constituent ions.
Acetic acid, also known as ethanoic acid, is a weak acid with the chemical formula CH₃COOH. It is known to be the active component of vinegar.
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The degree of contrast between two opposing forces is called______?
Answer:
polarity
Explanation:
On a mission to a newly discovered planet, an astronaut finds copper abundances of 69.15% for "Cu and 30.85 % for Cu. What is the atomic mass of copper for this location? What are the units
The units for atomic mass are atomic mass units (amu). the atomic mass of copper for this location is 63.55 amu.
The chemical symbol Cu stands for copper. Copper is a soft, malleable, ductile metal that is a good conductor of heat and electricity. Copper is one of the most widely used metals in electrical and electronic equipment due to its superior conductivity and non-corrosive properties. This metal is widely used in wiring, roofing, plumbing, and electronic applications. Its atomic mass is 63.55 amu.The atomic mass of copper for this location can be determined using the following formula:
Atomic mass = (mass of isotope 1 x relative abundance of isotope 1) + (mass of isotope 2 x relative abundance of isotope 2)The atomic mass of copper for this location
= (62.93 x 0.6915) + (64.93 x 0.3085) = 63.55 amu
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a) At 40 °C, what the saturated solubility level of KCl (aq)? (1 mark)
b) If 40 g of KCl is added to 100 g of water at 90 °C, would the solution be saturated? Explain. (2 marks)
c) Describe two ways in which saturation can be achieved if only 40 g of KCl is added to 100 g of water at 90 ° (3 marks)
a) The saturated solubility level of KCl (aq) at 40°C is 35.7 g/100 mL of water.
b) No, the solution would not be saturated at 90°C. At this temperature, the solubility of KCl in water is higher than at 40°C. Therefore, more KCl can dissolve in 100 g of water at 90°C than at 40°C. To determine if the solution is saturated, we need to compare the amount of KCl that actually dissolved in the water to the maximum amount of KCl that can dissolve in the water at that temperature. If the amount of KCl that dissolved is less than the maximum amount, then the solution is unsaturated. If the amount of KCl that dissolved is equal to the maximum amount, then the solution is saturated. If the amount of KCl that dissolved is greater than the maximum amount, then the solution is supersaturated.
c) Two ways in which saturation can be achieved if only 40 g of KCl is added to 100 g of water at 90°C are:
i) Heating the solution to a higher temperature: As the temperature of the solution is increased, the solubility of KCl in water also increases. Therefore, by heating the solution to a higher temperature than 90°C, more KCl can be dissolved in the water until the solution becomes saturated.
ii) Allowing the solution to cool slowly: If the solutionis heated to a temperature higher than 90°C and then allowed to cool slowly, the solubility of KCl in water decreases as the temperature decreases. This means that as the solution cools, KCl will begin to precipitate out of the solution until the solution becomes saturated. Alternatively, if the solution is left undisturbed at 90°C and allowed to cool slowly, KCl will begin to precipitate out of the solution as it reaches its saturation point.
The owner of Grizzly Tea Shack is thinking about adding iced tea to the menu. He
thinks he can do this with minimal effort by adding ice cubes to cups of hot tea.
He decides to measure how changing the number of ice cubes in a glass of
freshly brewed tea affects its cooling rate.
To begin, the owner varies the number of ice cubes, x, he puts in glasses of
freshly brewed tea. He then checks the temperature (in Celsius), y, of each glass
after 10 minutes.
Ice cubes Temperature after 10 minutes (in degrees Celsius)
2
17
3
5
6
6
20
10
11
15
Round your answers to the nearest thousandth.
Answer: 5,266
Explanation:
5,266
Where Did the Water
in the Puddle Go
Six friends were walking to the park on a sunny day. They noticed a big puddle
on their way to the park. When they came back two hours later, the puddle was
gone. They each had different ideas about where the water in the puddle went.
This is what they said:
Bandari: The water went right up to the clouds.
Regina: The sun dried the water up and it no longer exists.
Dylan: All of the water soaked into the ground.
Axel: Much of the water is in the air around us.
The water went into a stream, river, pond, lake, or ocean.
Clinti: The water changed into fog.
Explain your
Which friend do you think has the best idea?
thinking
Answer:
Axel: Much of the water is in the air around us.
Explanation:
When a puddle of water forms on the ground, it indicates that much of the ground around it is saturated with water and as such, the water would not readily soak into the ground. Also, since the puddle was found in a park, it is not likely that the water has gone into a stream, river, pond, lake, or ocean.
Since, the day was a sunny, it means that the heat from the sun has caused the evaporation of the water molecules. However, the water vapor molecules do not just immediately rise up to the atmosphere to form clouds nor do they cease to exist, rather it is dispersed in the air around the surroundings and beyond. Formation of clouds by water vapor takes days to happen.
Also, the water has not changed to fog either as they form usually at cooler temperatures.
Calculate the number of moles of gas produced from the reaction of 2.00g of potassium with an excess amount of water.
The number of moles of gas produced from the reaction of 2.00g of potassium with an excess amount of water is 0.025 moles.
The reaction of potassium with an excess amount of water is:
2K + 2H\(_2\)O \(\rightarrow\) 2KOH + H\(_2\)
To calculate the moles of hydrogen gas first we need to calculate moles of potassium in 2.00g
No. of moles = (mass) / (molecular mass)
The mass given is 2.00 g and the Molecular mass is 39.09 units
∴ No. of moles = (2) / (39.09) = 0.05
From the above reaction, we get that 2 moles of potassium give 1 mole of hydrogen gas. Thus, 0.05 moles of potassium gives 0.025 moles of hydrogen gas.
Therefore, the no. of moles of hydrogen gas produced is 0.025 moles.
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when ammonium nitrate is found at a fire scene, it may undergo thermal decomposition producing which materials?
Answer:
nitrous oxide
Explanation: