Answers
Answer:
Q1= 9.42
Q2= 227 KJ
Q3= 31.4 KJ
Qt=269 KJ
Explanation:
First you have to find the heat needed to make ice at a temperature of -45 C to pass to a temperature of 0 C.
You're given the formula so all you have to do is replace by the data you're given (remember to make the Celsius, Kelvin by adding 273.15 to the Celsius since the magnitudes of temperature they're giving you in the constants are the Kelvin)
Q1= (2.093 J/gxK)(100 g)(45 K)
Q1=9418.5 J
Q1=9.4185 KJ≈9.42 Kj(you're asked to give your answer in KJ)
You know have to find the energy needed to liquify the ice, in other words you need to use the enthalpy of fusion to determine the energy that's being used, and since you have 100 grams of water, you only need to find the number of moles present in 100 grams of water by dividing the number of grams by the molar mass of water (18 g/mol) and then replace in the equation.
Q2=(5.56 mol)(40.7 KJ/mol)
Q2=227 KJ
You know have to find the energy needed to raise the temperature of water from 0 C to 75 C. You do the same thing as you did in the first step:
Q3=(4.184 J/gxK)(100 g/)(75K)
Q3=31380 J
Q3=31.38 KJ≈31.4 KJ
For the final step, you only add the Qs of each step:
9.42KJ+227KJ+31.4KJ= 267.82 KJ ≈ 267.8 KJ
Why do you use these procedures?
Well, you could simply have made a unique equation at first sight that involved the changes of temperature from -45 C to 75 C, but you have a phase change in the middle. Phase change keep temperature constant but they require heat from the surroundings in order to, in the case of ice, break the bonds that keep the molecules tight together.
This heat required from the surroundings is the Enthalpy of phase change, in this case enthalpy of fusion.
Related Questions
Ionic salt does not dissolve in mineral oil because Group of answer choicesa, solvent-solvent interactions are much larger than solute-solvent or solute-solute interactions.b, solute-solute interactions are much larger than solvent-solvent or solute-solvent interactions.c, solute-solvent interactions are similar to solvent-solvent and solute-solute interactions.d, solute-solvent interactions are much larger than solvent-solvent or solute-solute interactions.
Answers
Ionic salt does not dissolve in mineral oil because solute-solvent interactions are similar to solvent-solvent and solute-solute interactions.
Ionic salts are unable to dissolve in mineral oil due to the nature of the interactions between solute and solvent. Specifically, solute-solvent interactions are very similar to both solvent-solvent and solute-solute interactions.
Thus, when the ionic salt and mineral oil come in contact, they do not interact strongly enough for the salt to dissolve. Additionally, the solubility of ionic salts in mineral oil is extremely low due to the difference in the polarity of the two components. Therefore, when dealing with ionic salt and mineral oil, the salt does not dissolve in the oil.
Hence, the correct option is "C".
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A theory is accepted by scientists when
A. It becomes a law
B. It can be shown with a model
C. It describes how nature works
D. It is supported by adequate data
Answers
Answer:
D. It is supported by adequate data
Explanation:
A theory is a well-substantiated explanation
Hope this helps!
Have a great day. :)
what is a dehydrate in chemistry?
Answers
Answer:
hydrate agen
Answer:
In chemistry, a dehydration reaction is a conversion that involves the loss of water from the reacting molecule or ion.
Dehydration reactions are common processes, the reverse of a hydration reaction.
Common dehydrating agents used in organic synthesis include sulfuric acid and alumina.
Explanation:
good luck
why is my car smoking under the hood but not overheating
Answers
A certain fluid has poured on the engine, causing the vehicle to smoke under the hood without overheating.
What do you understand by the term 'fluid' ?fluids are any liquids, gases, or basically any materials that, when under stress, exhibit a continual change in shape and are unable to withstand tangential or shearing forces at rest.
What exactly are fluid properties?Thermostat, density, and composition are a few of the most basic ideas in fluid characteristics. Extensive properties, or properties which are dependent on the quantity of material present, include mass and volume.Temperature, pressure, and density are some examples of intense properties.
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a buffer is composed of 0.150 m hc2h3o2 and 0.215 m nac2h3o2. which ion reacts with added h to resist changes to ph?
Answers
NaH can react with any acid that is introduced to this buffer to resist changes to pH.
What is buffer?A buffer is indeed a solution that is resistant to pH fluctuations and contains whether its a weak acid as well as its salt or even a weak base as well as its salt.
A buffer is, in other words, a liquid of a weak acid base or even a weak base as well as its conjugate acid. A buffer is sometimes referred to as a pH buffer, a H+ ions buffer, or perhaps a buffer solution. The equation for given buffer can be given as CH\(_3\)COOH + CH\(_3\)COONa → CH3COO + NaH. NaH can react with any acid that is introduced to this buffer to resist changes to pH.
Therefore, NaH can react with any acid that is introduced to this buffer to resist changes to pH.
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the primary gas in a volocano is?
Answers
Answer:
By far the most abundant volcanic gas is water vapor, which is harmless. However, significant amounts of carbon dioxide, sulfur dioxide, hydrogen sulfide and hydrogen halides can also be emitted from volcanoes
Explanation:
Suppose you have two liquids that are soluble in each other: liquid a, with a density of 1.00 g/ml and liquid b with a density of 1.45 g/ml. you take 15.0 ml of liquid a and 35.0 ml of liquid b. you combine them and stir well so they are thoroughly mixed. calculate the approximate density of the resulting mixture, assuming the final volume is 50.0 ml.
Answers
Answer: 1.88 g/mL
Explanation:
Mass of liquid a: (1.00)(15.0)=15.0 g
Mass of liquid b: (1.45)(35.0)=50.75 g.
So, the density is:
\(\frac{50.75+15.0}{35} =\boxed{1.88 \text{ g/mL}}\)
1.88 g/ml
Mass of liquid a: (1.00)(15.0)=15.0 g
Mass of liquid b: (1.45)(35.0)=50.75 g.
So, the density is:1.88g/ml
How is density measured?Density is the measurement of how tightly a material is packed together. It is defined as the mass per unit volume. Density Symbol: D or ρ Density Formula: ρ = m/V, where ρ is the density, m is the mass of the object and V is the volume of the object.
Density describes how compact or concentrated something is. For example, suppose you have two boxes, one large and one small. However, they both weigh the same. That means the small box has a higher density than the large box. Density also tells how concentrated or crowded something is.
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HELP WILL MARK BRAINLIEST
If an electrically charged plastic bag is placed close to an uncharged cloth, what will happen?
The charge of the bag will change.
The charge of the cloth will change.
The plastic bag will attract the cloth.
The plastic bag will repel the cloth.
Answers
Answer:the plastic bag will attract the cloth
Explanation:
Answer:
c
Explanation:
hope this helps
If you are given a piece of rock sugar about 2.5 cm in diameter, describe three steps you can take to dissolve it in a beaker of water in the shortest time.
Answers
Answer:
1. Crush the sugar into powder.
2. Heat the water.
3. Dissolve it by stirring continuously
Explanation:
1. Crushing the sugar into powder increases surface area. So it increases the changes of dissolving
2. Heating the water increases the capacity of water to dissolve sugar.
3. Stirring continuously increases randomness of particles so eases mixing up thus increasing dissolving tendency.
A solution of potassium hydroxide (KOH) is added to a solution of hydrochloric acid. How many moles of potassium hydroxide would react with 1 mole of hydrochloric acid? (Hint: It may help to write out a balanced symbol equation for the reaction.)
Answers
The number of moles of potassium hydroxide that would react with 1 mole of hydrochloric acid would be 1 mole.
Stoichiometric mole ratio
The stoichiometric moles of species of a reaction are the coefficients of each species in the balanced symbol equation of the reaction.
The balanced equation of the reaction between potassium hydroxide (KOH) and hydrochloric acid (HCl) is expressed as follows:
\(KOH + HCl --- > KCl + H_2O\)
In this case, the stoichiometric mole of KOH is 1, that of HCl is 1, that of KCl is 1, and that of \(H_2O\) is also 1.
In other words, the stoichiometric mole ratio of KOH and HCl is 1:1. For every 1 mole of KOH, 1 mole of HCl is required for a complete reaction.
Now, the question says what mole of potassium hydroxide will be required to react with 1 mole of hydrochloric acid?
Following the mole ratio, 1 mole of KOH will also be required.
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during the workup steps of this reaction, excess oxidizing agent is removed by adding isopropyl alcohol. draw the product of the reaction of the oxidizing agent with isopropyl alcohol.
Answers
The addition of isopropyl alcohol during the workup steps of this reaction helps to remove excess oxidizing agent and ensures the purity and yield of the final product.
During the workup steps of this reaction, excess oxidizing agent is removed by adding isopropyl alcohol. This step is essential to ensure the purity and yield of the final product. Isopropyl alcohol is used as a solvent and also as a reducing agent in this step. When added to the reaction mixture, it reacts with the oxidizing agent to form a new product.
The product of the reaction between the oxidizing agent and isopropyl alcohol is isopropyl acetate. This reaction is an example of a reduction reaction where the oxidizing agent is reduced by gaining electrons from isopropyl alcohol. The oxidizing agent is reduced to a lower oxidation state and is rendered inactive, which allows for easy removal of excess oxidizing agent.
Overall, the addition of isopropyl alcohol during the workup steps of this reaction helps to remove excess oxidizing agent and ensures the purity and yield of the final product. This step is crucial for the success of the reaction and highlights the importance of careful workup procedures in chemical synthesis.
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a sample of ammonia gas occupies 20.0 ml at 585 torr and 20.0 °c. if the volume of the gas is 50.0 ml at 50.0 °c, what is the pressure?
Answers
To determine the pressure of the ammonia gas at a new volume and temperature, we can use the combined gas law, which states that the ratio of the initial pressure, volume, and temperature is equal to the ratio of the final pressure, volume, and temperature.
Using the combined gas law equation: (P1 * V1) / T1 = (P2 * V2) / T2
Given:
P1 = 585 torr (initial pressure)
V1 = 20.0 ml (initial volume)
T1 = 20.0 °C + 273.15 = 293.15 K (initial temperature)
V2 = 50.0 ml (final volume)
T2 = 50.0 °C + 273.15 = 323.15 K (final temperature)
We need to solve for P2 (final pressure).
Rearranging the equation, we have:
P2 = (P1 * V1 * T2) / (V2 * T1)
Substituting the given values into the equation:
P2 = (585 torr * 20.0 ml * 323.15 K) / (50.0 ml * 293.15 K)
Calculating this expression gives us the final pressure (P2) of the ammonia gas at the new volume and temperature.
In summary, using the combined gas law equation, we can determine the pressure of the ammonia gas at a new volume and temperature. By substituting the given values into the equation and performing the calculation, we can find the final pressure of the gas.
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In lab, you calculate the density of an iron rod to be 7.30 g/cm3. The accepted value
for the density of iron is 7.80 g/cm3. What is your percent error?
Answers
Answer:
6.41 %Explanation:
The percentage error of a certain measurement can be found by using the formula
\(P(\%) = \frac{error}{actual \: \: number} \times 100\% \\ \)
From the question
actual density = 7.80 g/cm³
error = 7.30 - 7.80 = 0.5
We have
\(p(\%) = \frac{0.5}{7.8} \times 100 \\ = 6.410256...\)
We have the final answer as
6.41 %Hope this helps you
Positron emission tomography (pet) imaging relies upon the emission of __________ from radioactive isotopes such as carbon-11.
Answers
Answer:
positron
Explanation:
PET scanning works by injecting a radioactive material, called a tracer, into the body. The tracer emits a positron inside the body, and the positron collides with electrons in the body, thereby annihilating and releasing two gamma rays that travel in opposite directions.
How many valence electrons does nitrogen provide to distribute when constructing the lewis structure of nh3?.
Answers
5 valence electrons are provided by nitrogen to make the lewis structure of NH₃
The nitrogen atom provide 5 electrons and each of the three hydrogen atoms has 1 electron. So the total number of electrons for ammonia will therefore be 8.
In the Lewis structure of ammonia, Nitrogen is present in center and the three hydrogen atoms are present and bonded at sides of nitrogen as indicated in image Nitrogen also has a lone pair above it that is the reason why ammonia act as a Lewis base. Ammonia has tetrahedral geometry due to four pairs of electrons .
The lone pair makes space for itself by pushing the three hydrogen atoms together a little and the H-N-H bond angles are slightly less (106.6°) than the ideal tetrahedral angle of 109.5°.
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Convert 380 mmHg to atm.
Answers
Answer:
50662.5
Explanation:
For the chemical reaction, 2Al+3H2SO4⟶3H2+Al2(SO4)3 what mass of sulfuric acid in grams is needed to produce 4.41 mol of aluminum sulfate? Include step process.
Answers
144.13g mass of sulfuric acid are needed to produce 4.41 mol of aluminum sulfate.
To determine the mass of sulfuric acid needed to produce 4.41 mol of aluminum sulfate (Al2(SO4)3), we need to use stoichiometry. Stoichiometry is a calculation method that relates the amounts of substances in a chemical reaction.
The balanced chemical equation is:
2Al + 3H2SO4 ⟶ 3H2 + Al2(SO4)3
From the balanced equation, we can see that the ratio between aluminum sulfate (Al2(SO4)3) and sulfuric acid (H2SO4) is 3:1.
This means that for every 3 mol of aluminum sulfate produced, 1 mol of sulfuric acid is needed.
Given that we want to produce 4.41 mol of aluminum sulfate, we can set up a proportion to find the corresponding amount of sulfuric acid:
3 mol Al2(SO4)3 / 1 mol H2SO4 = 4.41 mol Al2(SO4)3 / x mol H2SO4
Cross-multiplying and solving for x, we have:
x = (1 mol H2SO4 * 4.41 mol Al2(SO4)3) / 3 mol Al2(SO4)3
x = 1.47 mol H2SO4
Now, we need to convert the amount of sulfuric acid from moles to grams using its molar mass.
The molar mass of H2SO4 is calculated as follows:
(2 * atomic mass of H) + atomic mass of S + (4 * atomic mass of O)
(2 * 1.00784 g/mol) + 32.06 g/mol + (4 * 15.999 g/mol) = 98.09 g/mol
Finally, we can calculate the mass of sulfuric acid needed:
Mass = 1.47 mol H2SO4 * 98.09 g/mol = 144.13 g
Therefore, approximately 144.13 grams of sulfuric acid are needed to produce 4.41 mol of aluminum sulfate.
In conclusion, to determine the mass of sulfuric acid required for the given reaction, we used stoichiometry to calculate the amount of sulfuric acid based on the desired quantity of aluminum sulfate.
By converting moles to grams using the molar mass of sulfuric acid, we found that approximately 144.13 grams of sulfuric acid are needed to produce 4.41 mol of aluminum sulfate.
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Which of these statements are true? Select all that apply. The Delta.Hf for Br2(I) is 0 kJ/mol. The Delta.Hf for He(I) is 0 kJ/mol. The Delta.Hf for Hg(I) is 0 kJ/mol. The Delta.Hf for Cl2(g) is 0 kJ/mol. The Delta.Hf for N2(I) is 0 kJ/mol. CORRECT ANSWER IS A, C, AND D.
Answers
Answer: The correct options are A, C and D.
Explanation:
Enthalpy of formation is defined as the change in the enthalpy when 1 mole of a chemical substance is formed from its pure element at standard conditions. It is represented by the symbol \(\Delta H_{f}\)
Enthalpy of formation for elemental atoms is always equal to 0.
We know:
Bromine (Br) exists in a liquid state.
Helium (He) exists in a gaseous state.
Mercury (Hg) exists in a liquid state.
Chlorine (Cl) exists in a gaseous state.
Nitrogen (N) exists in a gaseous state.
For the given options:
The \(\Delta H_{f}\) for \(Br_2(l), Hg(l)\text{ and }Cl_2(g)\) will be equal to 0 because they are formed by the natural states of their elemental atoms.
Hence, the correct options are A, C and D.
A substance in its standard state has an enthalpy of formation of 0 kJ/mol.
The enthalpy of formation of a substance in its standard state is 0 kJ/mol.
The standard state of a substance refers to its state at 1 atm and at a temperature of 298 K. Bearing this in mind, we can now identify the true and false statements.
So,
ΔHf for Br2(I) is 0 kJ/mol - True
ΔHf for He(I) is 0 kJ/mol - False
ΔHf for Hg(I) is 0 kJ/mol - True
ΔHf for Cl2(g) is 0 kJ/mol - True
ΔHf for N2(I) is 0 kJ/mol - False
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In order to determine if 2 atoms are cooper what must be the same for each
Answers
-atom size
-charge of the atom
-number of protons
Ezra's mother told her she was "moving at a snail's pace." How could Ezra determine the average speed of a snail?
Answers
Ezra's mother told her she was "moving at a snail's pace." The average speed of a snail can be determined as she could divide a set distance by the time it takes the snail to move that distance. The correct option is B.
What is speed?Speed is an entity that tells the pace of going of anything. The average speed is the speed of anything that is constant for a long time. The average speed is calculated by dividing the distance by the time taken by the object.
v = Δx / Δt
v = average velocity
Δx = displacement
Δt = change in time
So, Ezra can calculate the average speed of the snail by dividing the average speed of the snail and the average time taken by the snail.
Therefore, the correct option is B. she could divide a set distance by the time it takes the snail to move that distance.
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What makes a question able to be
answered by science?
Answers
Answer:
Testable questions can be answered through investigations that involve experiments, observations, or surveys. Testable questions are answered by collecting and analyzing evidence that is measurable. Testable questions relate to scientific ideas rather than personal preference or moral values.
Explanation:
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Directions: Answer each of the questions below.
1. Explain how andesite forms.
2. Explain the difference between magma and lava and how lava is formed.
3. Identify some special characteristics of pumice.
4. What are cinder cones and how are they formed.
5. Explain how most continental volcanoes are formed.
Answers
Andesite is a fine-grained intermediate igneous rock of volcanic origin that is mostly composed of plagioclase feldspar.
It is fine-grained due to the rapid cooling of magmas when they erupt onto the Earth's surface and form lava flows. Andesite is formed by magma with less quartz (silica) than rhyolite but more than basalt.
Magma is molten matter within the earth that is the source of lava flows, etc., whereas lava is molten rock that a volcano removes from its crater or fissured sides. Magma is formed when mantle rocks partially melt.
Pumice is a light, porous pyroclastic igneous rock formed during explosive volcanic eruptions when liquid lava is ejected as a froth containing masses of gas bubbles into water or air.
As the lava solidifies, the bubbles are frozen into the rock. Some special characteristics of pumice is as follows:
It is very lightIt is grey to medium grey in colourIt contains a lot of empty gas bubbles, so it is very light and looks rather like a spongePumice is so light that it will float on waterAround a volcano, there are deposits of conical rock fragments called cinder cones. They are the kind of volcanoes that are generated by pyroclastic debris, such as volcanic ash, lava clinkers, pumice, and hot gases.
Where oceanic crust subducts beneath continental crust, continental volcanoes or a continental volcanic arc are formed.
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what is the main safety hazard of tmscl in this lab, and what precautions should you take when handling tmscl?
Answers
The main safety hazards of trimethylsilyl chloride (tmscl) in the lab are,
It could cause severe eye burns.
It is harmful if absorbed through the skin. It could cause severe burns.
It may be harmful if swallowed. Causes severe digestive tract burns.
It may be harmful if inhaled. Causes chemical burns to the respiratory tract.
Prolonged or repeated skin contact may cause dermatitis.
Trimethylsilyl chloride, commonly referred to as chlorotrimethylsilane, is a silyl halide (organosilicon chemical) with the formula (CH3)3SiCl. It is also referred to as Me3SiCl or TMSCl. It is a volatile, colorless liquid that is stable when there is no water present. It has many applications in organic chemistry.
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lab report solubility edge
Answers
Answer:
i'm attaching the report i made
Explanation:
(It does include the chart information)
hope this helps! have a wonderful day :)
The solubility of a solid solute increases with temperature.
What is the effect of temperature on the solubility of a solute?The solubility of a solute is the amount of solute that dissolves in a given volume of solvent at a particular temperature.
The solubility of a solute increases with increase in temperature.
Based on the lab results, it was seen that with increase in temperature, the mass of sugar that dissolves in water increases.
50 mL of water at 2 °C dissolved only 80 g of sugar whereas at 102 °C, 250 g of sugar dissolved.
Therefore, it can be concluded that solubility of a solute increases with temperature.
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How many atoms of aluminum (Al) are contained in 3.73 moles of alumni
Answers
Number of atoms : 2.245 x 10²⁴
Further explanationA mole is a number of particles(atoms, molecules, ions) in a substance
This refers to the atomic total of the 12 gr C-12 which is equal to 6.02.10²³, so 1 mole = 6.02.10²³ particles
Can be formulated :
N = n x No
N = number of particles
n = mol
No = 6.02.10²³ = Avogadro's number
n= 3.73 moles
Number of atoms :
\(\tt 3.73\times 6.02\times 10^{23}=\boxed{\bold{2.245\times 10^{24}}}\)
What is igneous rock?
Answers
Answer: A) Rock formed by...magma or lava
Explanation:
As the question says, igneous rocks are formed from the cooling and solidification of magma or lava.
just a bit of visual aid thanks to Thoughtco.
Answer:
It is the first one - Rock formed by the cooling and solidification of hot liquid magma or lava.
Explanation:
Which is an acidic functional group that can dissociate and release h into a solution?
Answers
The acidic functional group that can dissociate and release h into a solution is -COOH.
Characteristics of a carboxyl group -COOHCarbon atom is bonded to a high electronegative oxygen and a hydroxyl group in the Carboxyl groupExample: Acetic acid CH3COOHThe acidic functional group ( -COOH ) dissociate and releases H atom from the hydroxyl group into a solution as a proton or as a H+ ionHence the Oxygen atom gets a negative chargeThis negative charge moves between both the oxygen atom.From the characteristics of -COOH group we can conclude it as the acidic functional group that can dissociate and release H into a solution.
Disclaimer: The question was incomplete
Which is an acidic functional group that can dissociate and release h into a solution?
A. -OH
B. -COOH
C. -NH2
D. -SH
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At a pressure of 710 atm, gas has an unknown volume. When the pressure is decreased
to 0.96 atm, the volume is 3700 mL. What was the original volume of the gas?
Answers
Answer:
5.00 mLExplanation:
The original volume can be found by using the formula for Boyle's law which is
\(P_1V_1 = P_2V_2\)
Since we are finding the original volume
\(V_1 = \frac{P_2V_2}{P_1} \\\)
From the question we have
\(V_1 = \frac{3700 \times 0.96}{710} = \frac{3552}{710} \\ = 5.002816...\)
We have the final answer as
5.00 mLHope this helps you
What is the difference between single-wall carbon and multi-wall carbon?
Answers
Answer:
A single-walled carbon nanotube (SWCNT) is a seamless cylinder which consists of only one layer of graphene.The multi-walled carbon nanotube (MWCNT) is also cylindrical in shape, with multiple concentric layers of graphene composing it.
How many oxygen atoms are in the formula Tetrasulfur pentoxide?
a. 3
b. 4
c. 5
d. 2