Answer:
neck
Explanation:
through the neck and opening of the thermos, where there is no vacuum.. hence heat is easily transmitted resulting into heat loss
Predict the final temperature of 3.50 kg of water in a calorimeter if the water is at 27.5°C before 0.77 oz of noodles containing 81.0 kcal are burned
The final temperature of the water is determined as 50.55 ⁰C.
Final temperature of the waterThe final temperature of the water is determined from the following calculations;
Q = mcΔθ
Δθ = Q/mc
where;
Q is the amount of energy = 81 kcal = 338904 Jc is specific heat capacity of water = 4,200 J/kgCΔθ = 338904 /(3.5 x 4200)
Δθ = 23.05 °C
Final temperature = T₁ + Δθ
Final temperature = 27.5°C + 23.05 °C = 50.55 ⁰C.
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Caco3(s) ----> cao(s) + co2 (g)
this reaction is not spontaneous at room temperature. what is the sign of ah for this reaction? explain how you arrived at your answer
Since the reaction is not spontaneous at room temperature, the ΔH will be positive.
What are spontaneous reactions?They are reactions that require no additional effort in order for them to take place under certain conditions.
For spontaneous reactions, the change in the energy of the system, otherwise known as ΔH, is always negative. On the other hand, reactions with positive ΔH are non-spontaneous.
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Write BE if the statement is Beneficial Effect to the sun’s heat and light, HE if it is Harmful Effect of the sun’s heat and light and SP to avoid the negative effects of too much exposure to sunlight.
___1. UV rays can help treat some health conditions. It creates Vitamin D.
___2. Use sunblock lotion with SPF 15 during hot days.
___3. With the presence of sunlight, farmers can dry their crops.
___4. UV rays can damage the tissue in your eyes.
___5. Research says that sunlight helps moods.
___6. Too much exposure from the sun can cause skin cancer.
___7. Use sunglasses when you stay under the sun.
___8. Wear a wide- brimmed hat on sunny days.
___9. Humans can do recreational activities on a sunny day.
___10. Wear sunglasses that filter UV light.
___11. Prolonged exposure to the sun’s heat makes your skin age faster than normal.
___12. Too much heat from the sun can cause heat stroke and loss of water.
___13. Sunlight helps strengthen your immune system.
___14. The vitamin D made thanks to the sun plays a big role in bone health.
___15. Avoid sun in the middle of the day, from about 10 a.m. to 3 p.m.
Based on exposure time and place, the Sun's radiation may have harmful or beneficial effects.
What is solar radiation?Solar radiation refers to the radiation from the Sun in the form heat, light and other forms of radiation.
The radiation from the Sun may have harmful or beneficial effects.
The effects of the Sun's radiation can be classified as BE, HE or SP as follows:
BE- UV rays can help treat some health conditions. It creates Vitamin DSP- Use sunblock lotion with SPF 15 during hot days.BE- With the presence of sunlight, farmers can dry their crops.HE- UV rays can damage the tissue in your eyes.BE- Research says that sunlight helps moods.HE- Too much exposure from the sun can cause skin cancer.SP- Use sunglasses when you stay under the sun.SP- Wear a wide- brimmed hat on sunny days.BE- Humans can do recreational activities on a sunny day.SP- Wear sunglasses that filter UV light.HE- Prolonged exposure to the sun’s heat makes your skin age faster than normal.HE- Too much heat from the sun can cause heat stroke and loss of water.BE- Sunlight helps strengthen your immune system.BE- The vitamin D made thanks to the sun plays a big role in bone health.SP- Avoid sun in the middle of the day, from about 10 a.m. to 3 p.m.Learn more about Sun's radiation at: https://brainly.com/question/921530
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It was experimentally determined from three trials that an object had a density of 0.96, 0.99, and 0.95 g/mL. What is the average density and standard deviation of this object
The mean of the sample is 0.97 while the standard deviation of the sample is 0.015.
What is the average density?The average density is the sum of the density values divided by the total number of measurements.
In this case, we have three trials, the mean of the samples is [tex]0.96 + 0.99 +0.95/3 = 0.97[/tex]
The standard deviation is obtained from;
s= [tex]\sqrt{(0.96 - 0.97)^2 + (0.99 - 0.97)^2 + (0.95 - 0.97)^2/(3 - 1)}[/tex]
s = [tex]\sqrt{(0.0001) + (0.0004) + (0.0004)/2}[/tex]
s = 0.015
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Use the drop-down menus to identify each organic reaction as an addition, substitution, elimination, or condensation reaction. (C H 3) subscript 3 C O H plus C H 3 O H right arrow (C H 3) subscript 3 C O C H 3 plus H 2 O. H 3 C H C double bond C H C H 3 plus H upper B r right arrow C H 3 C H 2 C H (upper B r) C H 3. (C H 3) subscript 3 C O H right arrow C H 3 C H 3 C H 2 plus H 2 O. A benzene ring plus upper B r subscript 2 right arrow benzene ring with upper B r bonded to the top, plus upper H upper B r.
A chemical reaction involves an interaction between two or more species to yield a product.
What is a chemical reaction?A chemical reaction involves an interaction between two or more species to yield a product.
The following is the classification of the reactions based on type;
The first reaction shown in the attachment is a condensation reactionThe second reaction is an addition reactionThe third reaction is an elimination reactionThe fourth reaction is a substitution reactionLearn more about reaction:https://brainly.com/question/9524025
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Balance the following chemical reaction :p(s) + cl2(g) = pcl5(s)
Answer:
[tex]2\text{P}+ 5\text{Cl}_2 \rightarrow 2\text{PCl}_5[/tex]
Explanation:
Answer:
2P (s) + 5PCl₂ (g) → 2PCl₅ (s)
Explanation:
There are 2 chlorine atoms on the reactant side and 5 chlorine atoms on the product side.
Hence, multiply the left chlorine molecule by 5 and right compound by 2.
⇒ P (s) + 5 × Cl₂ (g) → 2 × PCl₅
⇒ P (s) + 5Cl₂ (g) → 2PCl₅ (s)
But, now we see that there is 1 phosphorus atom on the reactant side and 2 phosphorus atoms on the right.
So, multiply the left phosphorus atom by 2 to balance.
⇒ 2 × P (s) + 5PCl₂ (g) → 2PCl₅ (s)
⇒ 2P (s) + 5PCl₂ (g) → 2PCl₅ (s)
Calculation: If a compound is 14.40% hydrogen by mass and 85.60% carbon by mass, what is the empirical formula?
Group of answer choices
Answer:
CH2
Explanation:
We are given that a compound is 14.40% hydrogen and 85.60% carbon.
Let the mass of the substance be 100g.
Mass of the hydrogen: 14.40% of 100 = 14.40 g
Mass of the carbon: 85.60% of 100 = 85.60 g
Now, let's find the moles of hydrogen:
[tex]14.40 g*\frac{1 mole}{1gH} = 14.40 mole[/tex]
Moles of carbon:
[tex]85.60g*\frac{1 mol}{12gC} = 7.13mol[/tex]
Let's put these in a ratio and simplify:
7.13 mole C: 14.40 mole H
1 mole C: 2 mole H
Therefore, the empirical formula of this compound is CH2.
Hope this helps!! If you have any questions about my work, please let me know in the comments!
1
select the correct answer from each drop-down menu.
of the wave. this value increases when the
the number of waves that pass through a fixed point per second is the
of the wave decreases.
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The frequency of a wave is the number of waves that pass through a fixed point per second. When the wavelength of the wave decreases, this value increases.
What are waves?A wave is actually a disturbance that travels or promulgates from its point of origin.
Waves transfer energy from one part to another, but not necessarily mass. Light, sound, and ocean waves are all examples of waves.
The frequency of a wave is the number of waves that pass through a fixed point per second. When the wavelength of the wave decreases, this value increases.
Thus, the answers are frequency and wavelength respectively.
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The reaction of an acid and a base will always produce what kind of salt?
A.
a combination of the cation from the acid and the anion from the base
B.
a combination of the cation from a strong base and the anion from a weak acid
C.
neutral salts from the cation of a strong base and the anion from a weak acid
D.
basic salts from the cation of a strong base and a strong acid
E.
depends on the strength of the acid and the base
Answer:
the answer of the question is c
A chemical reaction can be reversed if?
Question 18 options:
The energy of the products exceeds the activation energy threshold.
The energy of the reactants exceeds the activation energy threshold.
The energy of the products is less than the activation energy threshold.
The energy of the reactants is less than the activation energy threshold.
Explanation:
To a reaction to be occured
The formula is
TE=IE+AEIE<TE+AEIE is internal energy of reactant and AE is activation energy and TE is threshold energy .
So option D is correct
Which type of energy resource does not use a turbine to generate electricity?
A. Petroleum
B. Sunlight
C. Biomass
D. Coal
Answer:
B
Explanation:
The answer is sunlight solar cells directly convert the sunlight into electricity
Answer:
B
Explanation:
Sunlight, or solar energy is the type of energy which is not used by a turbine to generate electricity.
A client who weighs 70 kg is receiving a solution of 0.9% sodium chloride (normal saline) 500 ml with dopamine 800 mg at 5 ml/hour. how many mcg/kg/minute is the client receiving
The mcg/kg/minute the client is receiving is 1.904 mcg/kg/min whose weight is 70 kg.
What does mcg kg mean?1 milligram (mg) = 1000 micrograms (mcg) or 0.001 grams (g) 1 g = 1000 mg 1 kilogram (kg) = 1000 g 1 kg = 2.2 pound (lb) 1 liter (L) = 1000 milliliters (mL)
The number of mcg/kg/minute = flow rate × concentration ÷ mass of client
Flow rate = 12 ml/hour = 12 ml/hour × 1 hr/60 min = 0.2 ml/min
Concentration = mass of dopamine/volume
where
mass of dopamine = 800 mg and
volume = 500 ml
Concentration =800 mg/500 ml
= 1.6 mg/ml
= 1.6 mg/ml × 1000 mcg/mg
= 1600 mcg/ml
mass of client = 70 kg
Calculating mcg/kg/minute
So, substituting the variables into the equation, we have
mcg/kg/minute = flow rate × concentration ÷ mass of client
mcg/kg/minute = 0.08 ml/min × 1600 mcg/ml ÷ 70 kg
mcg/kg/minute = 320 mcg/min ÷ 70 kg
mcg/kg/minute = 1.904 mcg/kg/min
Thus, the mcg/kg/minute the client is receiving is 1.904 mcg/kg/min
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20 ml of a mixture of C2H6 and C3H8 gases in X : Y mole ratio, is burnt completely by which 52 ml CO2 gas is evolved. If 20 ml of a mixture of CH4 and C4H10 gases in Y : X mole ratio is burnt completely then what is the volume (in ml) of CO2 gas evolved?
A) 40 B) 44 C) 50 D) 55
The volume of CO2 prodiced when 12 mL of CH4 and 8 mL of C4H10 is burnt is 56 mL.
What is the equation of the reaction?The equation of the combustion of C2H6, CH4, C4H10, and C3H8 gases are given below:
2 C2H6 + 7 O2 ---> 4 CO2 + 6 H20
C3H8 + 5 O2 ---> 3 CO2 + 4 H20
CH4 + 2 O2 ----> CO2 + 2 H2O
2 C4H10 + 13 O2 ---> 8 CO2 + 10 H2O
X moles of C2H6 will produce 2X moles of CO2
Y moles of C3H8 will produce 3Y moles of CO2
Thus;
X + Y = 20 mL
X =20 - Y ---(1)
2X + 3Y = 52 mL ---(2)
Solving for X by substituting in (2)
2 (20 - Y) + 3Y = 52
40 - 2Y + 3Y = 52
Y = 12 mL
Then X = 8 mL
Volume of CO2 produced when 12 mL of CH4 and 8 mL of C4H10 is burnt = (12 × 2 + 8 × 4) = 56 mL
Therefore, the volume of CO2 produced is 56 mL.
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Identify the polarity of an H-I bond and the polarity of an S-S bond?
Answer:
5095 JULLITET LI\
Explanation:
How can you determine whether a solution is acidic or basic?
Answer:
Look at the pH level.
Explanation:
The best way to determine whether a solution is acidic or basic is to look at its pH level. The pH of a solution is a number between 0 and 14.
If a solution has a pH of less than 7, then it is acidic.
If a solution has a pH of 7, then it is neutral.
If a solution has a pH of greater than 7, then it is basic.
hope this helps!! p.s. i really need brainliest :)
In one to two sentences, describe an experiment that would show that intramolecular forces (attractions between atoms within molecules) are stronger than intermolecular forces (attractions between molecules).
thank you !!
short story about The Blind Date by Jeffrey Archer
Which causes winds to blow over the surface of earth
Answer:
the uneven heating of the Earth by the sun and the Earth's own rotation. Winds range from light breezes to natural hazards such as hurricanes and tornadoes.
How many moles of CO2 can be formed from 10 g of CH4?
Answer:
0.625 moles of CO2
Explanation:
Remark
The equation used (I take it) is a hydrocarbon burning. If it is not, leave a note on the question. The method I will use is
Find the moles CH4Use the equation to adjust the number of moles of the product. It the balance numbers are the same, move on.Equation
CH4 + 2O2 ====> CO2 + 2H2O
Givens
10 grams CH4
Solution
Number of moles of CH4
mol CH4 = given mass / molar mass.
given mass = 10 grams
molar mass CH4
C = 12H = 4 * 1 4molar mass 16Moles of CH4
mol = given mass / molar mass
mol = 10 grams / 16 grams
mol = 0.625
Answer
Since the number of moles of CO2 and CH4 are the same in the balanced equation. the answer is 0.625 mols of both.
Which formula represents a hydrocarbon?
A. CaO2
B.C5H12
C.CH2O
D.H2SO4
Answer:
B.C5H12 that is pentane
Explanation:
hydrocarbon has only hydrogen and carbon atoms
2. calcium reacts with oxygen to produce calcium oxide what is the :reactant' :products' and chemical equation" of this problem
Answer:
Calcium reacts with Oxygen to form Calcium Oxide
Explanation:
Reactant: Calcium reacts with Oxygen to form Calcium Oxide
Products: Calcium + Oxygen
Chemical equation: Ca + 02> CaO
Compare how entropy changes for the following two systems:
System A: Two gases mix when the valve separating two containers is opened.
System B: A solid powder decomposes to form a solid product and a gas product.
The measure of the randomness of the system is the change in the entropy. The mixing of two gases and decomposition of the solid will increase the entropy.
What is entropy?Entropy is the disorderliness and the randomness of the system when the thermal energy is not present in a sufficient amount to initiate the reaction. In system A, when two gases are mixed then the entropy increases as the number of gaseous molecules increases.
In system B, when a solid powder gets decomposed to form a solid product and a gaseous product the entropy increases as along the solid particles the gas is also produced.
Therefore, in both the systems the entropy increases.
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What errors did the chemistry teacher make in planning to this demonstration and how could checking her work have made a difference?
*THERE ARE A TOTAL OF 4 ERRORS* NEED HELP ASAP BEFORE 11:59 PM
With the hope of sharing an explosive combustion reaction demonstration in class
for her students, a chemistry teacher decides to synthesize water. This process
occurs when oxygen gas (O₂) in the air is combined with hydrogen gas, H₂, in the
presence of a spark or small flame. Like the reactants, the water (H₂O) product is
also a gas.
She knew she didn't want the demonstration to create too much water product,
only 180.0 grams.
Since the oxygen reactant is abundantly present in the air, she needed only to
determine how much hydrogen gas to prepare before class.
She used the following chemical equation to make her predictions:
O2(g) + H2(g) → H₂O(g)
The teacher used have used standard temperature and pressure values in her calculations of volume of hydrogen gas required.
What is the equation for the synthesis of water?The equation for the synthesis of water is given below as follows:
[tex]2 H_2 + O_2 \rightarrow 2H_2O[/tex]
Based on the planned steps of the synthesis of hydrogen gas by the teacher, the following errors were committed by the teacher:
She used temperature in degrees Celsius for her calculations She used the mass of water required instead of moles of water in her calculation using the ideal gas equation She did not use standard temperature and pressure measurement in her calculations She used an unbalanced chemical equation for her calculationTherefore, in calculation molar volume of gases, the measurements should be taken at standard temperature and pressure values.
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How many moles are 3.20 x102 formula units of calcium iodide?
The number of moles in 3.20 x 10² formula units of calcium iodide is 0.053 moles.
How to calculate number of moles?The number of moles in the formula units of a substance is calculated by dividing the formula unit by Avogadro's number.
According to this question, 3.20 x 10² formula units are in calcium iodide. The number of moles is as follows:
no of moles = 3.20 x 10²² ÷ 6.02 × 10²³
no of moles = 0.53 × 10-¹
no of moles = 0.053 moles
Therefore, the number of moles in 3.20 x 10² formula units of calcium iodide is 0.053 moles.
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What is the volume of a sample of mercury, a liquid metal, if it has a density of 14 g/ml and a mass of 28 g?
Indicate how the gas molecules move between the system and the surroundings based on changes in pressure, temperature, and volume and the number of moles.
The gas molecules move between the system and the surroundings follow PV=nRT.
What are molecules?The smallest particle of a substance has all of the physical and chemical properties of that substance.
An increase in pressure pushes the molecules closer together, reducing the volume. If the pressure is decreased, the gases are free to move about in a larger volume.
In the kinetic theory of gasses, increasing the temperature of a gas increases in average kinetic energy of the molecules, causing increased motion.
The reduction in the volume of the gas means that the molecules are striking the walls more often increasing the pressure, and conversely if the volume increases the distance the molecules must travel to strike the walls increases and they hit the walls less often thus decreasing the pressure.
At constant temperature and pressure the volume of a gas is directly proportional to the number of moles of gas. At constant temperature and volume the pressure of a gas is directly proportional to the number of moles of gas.
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Can someone please help? THIS IS SUPER HARD!!!!!!!
Organic compounds including carboxylic acids are named uisng IUPAC nomenclature technique.
What are Carboxylic acids ?
A carboxylic acid is an organic acid that contains a carboxyl group (C(=O)OH) attached to an R-group.
The general formula of a carboxylic acid is R−COOH or [tex]RCO_2H[/tex], with R referring to the alkyl, alkenyl, aryl, or other group.
Following are the names of given struture ;
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Part A: Dalton’s Atomic Model
Question 1
Using what you can recall from this unit, write one or two short paragraphs describing John Dalton’s atomic model. If needed, search the Internet for descriptions of the model.
John Dalton’s atomic model described atoms as the smallest indivisible part of an element.
What are atomic models?Atomic models are models which are used to represent the structure of the atom.
Different scientists put forward different models to represent the atom.
One of the scientists was John Dalton.
The features of Dalton's atomic model includes:
atoms are the smallest particle of elements atoms are indivisible atoms of the same element were the same and atoms if different elements differed in all aspectsTherefore, John Dalton’s atomic model described atoms as the smallest indivisible part of an element.
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Determine the unknown mineral using the information given below. Be sure to use significant figure rules when doing calculations. Mass is shown on the triple beam. Scale Test Mineral Mineral H. Density, g/cc 10 diamond tellurium 2 2.07 9 corundum galena 2.5 7.58 8 topaz anglesite 2.5 - 3 6.4 7 quartz chalcocite 2.5 - 3 5.6 6 feldspar copper 2.5 - 3 9.0 5 apatite gold 2.5 - 3 19.3 4 fluorite silver 2.5 - 3 10.5 3 calcite arsenic 3.5 5.7 2 gypsum barite 3 - 3.5 4.4 1 talc dolomite 3.5 - 4 2.9 platinum 4.5 21.5 willemite 5.5 4.0 magnetite 6 5.18 pyrite 6 - 6.5 5.02 pyrolusite 6 - 6.5 5.0 cassiterite 6.5 6.9 diamond 10 3.52 Volume of water displaced = 0.051 L
Mass: 981.0, 908, 908.1, 981 g
Density: 192.35, 19,235, 19, 19.2 g/cc
Hardness 4, 2.5, 1, 3, 5.5 - 5, 3, 2, 4.5, 1.5
Determine the unknown mineral.
Platinum, Gold
The unknown mineral is gold because of the similar properties of gold to that unknown mineral.
What is unknown mineral?The unknown mineral is Gold because it has similar properties to the gold. Gold has density of 19.3 grams per cubic centimeter which is same to this unknown mineral. The hardness and mass of the mineral are also similar to the Gold.
So we can conclude that the unknown mineral is gold because of the similar properties of gold to that unknown mineral.
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Which statement
about
gravitational force is most
accurate?
Gravitational force is the force of attraction. This kind of force forms an action-reaction in a situation.
What is gravitational force?Gravitational force is the force present that is directly proportional to the masses and inversely to the square of the distance present from the center of the masses.
It is independent of the medium and remains constant in any matter whether it is water, air, or soil. It is conservative and is a central force that obeys Newton's law of motions.
Therefore, the gravitational force follows the action and reaction.
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Select the correct answer from each drop-down menu. a reaction proceeds with 2.72 moles of magnesium chlorate and 3.14 moles of sodium hydroxide. this is the equation of the reaction: mg(clo3)2 2naoh → mg(oh)2 2naclo3. determine the theoretical amount of each product that the reaction will produce. the reaction will produce of magnesium hydroxide and of sodium chlorate.
334.22 grams of sodium chlorate and 91.56 grams of magnesium hydroxide would be produced respectively.
Stoichiometric calculationFrom the equation of the reaction:
[tex]Mg(ClO_3)_2 + 2NaOH --- > 2NaClO_3 + Mg(OH)_2[/tex]
The mole ratio of magnesium chlorate to sodium hydroxide is 1:2.
With 2.72 moles of magnesium chlorate and 3.14 moles of sodium hydroxide provided respectively, the sodium hydroxide is limiting in availability.
Mole ratio of NaOH and [tex]NaClO_3[/tex] = 1:1
equivalent mole of [tex]NaClO_3[/tex] = 3.14 moles
Mass of 3.14 moles [tex]NaClO_3[/tex] = 3.14 x 106.44 = 334.22 grams
Mole ratio of NaOH and [tex]Mg(OH)_2[/tex] = 2:1
Equivalent mole of [tex]Mg(OH)_2[/tex] = 3.14/2 = 1.57 moles
Mass of 1.57 moles [tex]Mg(OH)_2[/tex] = 1.57 x 58.32 = 91.56 grams
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