Answer: Btu, British Thermal Unit is used to express thermal energy when working in pounds and degrees Farenheit.
Calories are used when working in grams and degrees Centigrade or Kelvin (SI units)
A Joule is the British system unit used to measure heat transfer.
Explanation:
Which of the following is a chemical change? A. soil drying as water evaporates B. a rock eroding as the wind removes particles from it C. a solution of salt water being diluted as water is added to it D. silver tarnishing as the silver metal reacts with sulfur
Answer:
Its D
Explanation:
I took the quiz
Answer:
D
Explanation:
IT IS REACTING
Please help on the image below.
Heat capacity of Calorimeter = 10.7 J/°c
Further explanationHeat lost=Heat gained
Q in = Q out
-Q lost(hot water)=Q gained (cold water+calorimeter)
-m.c.Δt=m.c.Δt+C.Δt
[tex]\tt \rightarrow -50\times 4.18\times (32.7-43)=50\times 4.18\times (32.7-22.9)+(32.7-22.9)\times C_{cal}\\\\\rightarrow 2152.7=2048.2+9.8\times C_{cal}\\\\104.5~J=9.8\times C_{cal}\\\\C_{cal}=\dfrac{104.5}{9.8}=10.7~J/^oC[/tex]
Perform the arithmic shown AND round your answers to the correct number of significant digits.
56.5in + 95.3in + 15 in
(Fill in the blank)
Answer:
167in
Explanation:
Given arithmetic;
56.5in + 95.3in + 15in
To determine the correct significant digits, the sum cannot be more precise than the least precise value in the addition;
The least precise is 15in and it is in 2significant places;
56.5in
95.3in
+ 15 in
......................
166.8in
......................
The value is 167in
What is the change in internal energy (ΔΕ) of a system when 5 kJ of work is done on the system while it releases 13 kJ of energy to the surroundings?
The change in internal energy (ΔΕ) of a system : -8 kJ
Further explanationThe laws of thermodynamics 1 state that: energy can be changed but cannot be destroyed or created
The equation is:
[tex]\tt \Delta U=Q+W[/tex]
Energy owned by the system is expressed as internal energy (U)
This internal energy can change if it absorbs heat Q (U> 0), or releases heat (U <0). Or the internal energy can change if the system does work or accepts work (W)
The sign rules for heat and work are set as follows:
• The system receives heat, Q +
• The system releases heat, Q -
• The system does work, W -
• the system accepts work, W +
5 kJ of work is done on the system : W = +5 kJ
releases 13 kJ of energy to the surroundings : Q = -13 kJ
[tex]\tt \Delta E=-13+5=-8~kJ[/tex]
branches of sicence
Answer:
Natural science can be divided into two main branches
Explanation:
life science and physical science. Life science is alternatively known as biology, and physical science is subdivided into branches: physics, chemistry, astronomy and Earth science.
Answer:
Astronomy
Biology
Geology
Chemistry
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Write the thermochemical equation for the combustion of acetylene, C2H2 (g), in oxygen, for which the standard enthalpy of reaction is -1300 kJ per mole of acetylene.
Answer:
C₂H₂(g) + 2.5 O₂(g) ⇒ 2 CO₂(g) + H₂O(l) ΔH° = -1300 kJ/mol
Explanation:
In the combustion of acetylene, it reacts with oxygen to produce carbon dioxide and water. The corresponding chemical equation is:
C₂H₂(g) + 2.5 O₂(g) ⇒ 2 CO₂(g) + H₂O(l)
The thermochemical equation includes the balanced chemical equation, stating the states of aggregation and the enthalpy of the reaction.
C₂H₂(g) + 2.5 O₂(g) ⇒ 2 CO₂(g) + H₂O(l) ΔH° = -1300 kJ/mol
2. Which of the following is NOT a necessary input for the process of photosynthesis?
A. CO2 (carbon dioxide)
B. Sunlight
C. H20 (water)
D. O2 (oxygen)
The answer option which is not a necessary input for the process of photosynthesis is: D. [tex]O_2[/tex] (oxygen)
Photosynthesis can be defined as a biological and chemical process through which living organisms such as green plants, transform light energy (sunlight) into chemical energy.
Basically, both sunlight, carbon dioxide ([tex]C0_2[/tex]) and water ([tex]H_2O[/tex]) contained in the Earth's atmosphere plays a significant role in photosynthesis because they serve as an input.
Hence, the necessary input for the process of photosynthesis to take place include the following:
Water ([tex]H_2O[/tex]) Sunlight (light energy).Carbon dioxide ([tex]C0_2[/tex]).In conclusion, [tex]O_2[/tex] (oxygen) is an end product (output) of photosynthesis rather being an input.
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In which direction will the following equilibrium shift when solid sodium fluoride is added to an aqueous solution of acetic acid? CH3COOH â CH3COOâ + H+ A. The equilibrium shifts to the right, to form more products. B. The equilibrium shifts to the left, to form more reactants. C. There is no change; the system is still at equilibrium.
Answer:
A. The equilibrium shifts to the right, to form more products.
Explanation:
When sodium fluoride, NaF, is added to an aqueous solution, some HF is produced:
NaF + H₂O ⇄ OH⁻ + Na⁺ + HF.
That is, some H⁺ reacts decreasing its concentration.
Now, the equilibrium of the acetic acid is:
CH3COOH ⇄ CH3COO⁻ + H⁺
As the concentration of H⁺ decreases:
A. The equilibrium shifts to the right, to form more products.
In order to restore the initial equilibrium.
Compare and contrast the applications and benefits of circle graphs and bar charts. Explain
Answer:
A circle graph, or a pie chart, is used to visualize information and data. A circle graph is usually used to easily show the results of an investigation in a proportional manner. Bar graphs are used to compare things between different groups or to track changes over time. However, when trying to measure change over time, bar graphs are best when the changes are larger.
Explanation:
In short, bar graphs are better to keep track of data over long periods of time, and circle graphs are better when you are trying to visualize a specific set of data.
Circle graph can be also be called pie chart, which is more widely used. It is usually made up of a circle, divided into parts or pies. In the divided parts, it is used to differentiate between different data.
Bar charts on the other hand are like graphs having both x and y axis. It is used to represent data with respect to the height of the graph. Each data is divided into different smaller parts on the graph.
Example of what they look like is attached below.
First one is bar chart while the second is a circle graph
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X-rays are often used in medical settings to create images of the body's internal structures such as bones. This is made possible by the
fact that X-rays are able to pass through the body's softer tissues without being absorbed.
Radio waves are also able to pass through the body's softer tissues without being absorbed. Why are radio waves not used to generate
medical images?
OA. The electrons in most atoms are not in high enough energy states to absorb the photons of radio waves.
OB. Radio waves tend to bend too much when they encounter solid materials to be used for generating accurate images,
OC
The frequency of most radio waves is too low to allow them to pass through bones or other solid materials.
OD.
Radio waves carry so little energy that they tend to pass through most atoms without an interaction taking place.
Answer:D
Explanation:I did it on study island.
Radio waves are not used to generate medical images because as per the electromagnetic spectrum ,the radio waves carry little energy that they pass through most atoms without interaction.
What is an electromagnetic spectrum?The electromagnetic spectrum consists of radiation which consists of waves made up of electromagnetic field which are capable of propogating through space and carry the radiant electromagnetic energy.
The radiation are composed of electromagnetic waves which are synchronized oscillations of electric and magnetic fields . They are created due to change which is periodic in electric as well as magnetic fields.
In vacuum ,all the electromagnetic waves travel at the same speed that is with the speed of air.The position of an electromagnetic wave in an electromagnetic spectrum is characterized by it's frequency or wavelength.They are emitted by electrically charged particles which undergo acceleration and subsequently interact with other charged particles.
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An organic thiol compound is 38.66% C, 9.73% H, and 51.61% S by mass. What is the empirical formula of this compound?
Answer:
Empirical formula is C₂H₆S
Explanation:
Given data:
Percentage of hydrogen = 9.73%
Percentage of carbon = 38.66%
Percentage of sulfur = 51.61%
Empirical formula = ?
Solution:
Number of gram atoms of H = 9.73 / 1.01 = 9.6
Number of gram atoms of S = 51.61 / 32 = 1.6
Number of gram atoms of C = 38.66 / 12 = 3.2
Atomic ratio:
C : H : S
3.2/1.6 : 9.6/1.6 : 1.6/1.6
2 : 6 : 1
C : H : S = 2 : 6 : 1
Empirical formula is C₂H₆S.
8. What do the results tell you about your hypothesis(es)?
Answer: Results will tell you which hypothesis is true.
Explanation: The hypothesis becomes a theory if the results support it. d.A new experiment is designed to provide additional data about the hypothesis. Imagine that a team of scientists test a certain hypothesis, and the experimental results show that it is false. ... The results will show which other hypotheses must be true.
What does Gravity means
Please it’s due today need help please
unit factor method
convert a)26 cm in to meter
Which of the following has a nonpolar bond? *
02
HCI
NH3
CH4
Answer: CH4
Explanation:
BRAINLESS PLEASE
Answer:
O₂
Explanation:
The example of the compound or the molecule that forms a non-polar bond is oxygen gas.
Oxygen gas has a formula of O₂
Since this is a homonuclear molecule, the two bonding atoms have the same kind of electronegativity. The difference is therefore zero. In such a molecule, there is equal sharing of the electron pair between the atoms and no electrostatic charge on the molecule.A buffer solution of volume 0.500 L contains 1.68 g NH3and 4.05 g (NH4)2SO4.
Required:
a. What is the pH of this solution?
b. If 0.88 g of NaOH is added to the solution, what will be the pH?
Answer:
wait
Explanation:
a. The pH of this solution is 9.45.
b. If 0.88 g of NaOH is added to the solution, the pH will be 9.74.
What is pH means?a way to gauge how basic or acidic a material or solution is. On a scale of 0 to 14, pH is measured. A pH of 7 indicates neutrality on this scale, which implies it is neither acidic nor basic. More basic substances have a pH value more than 7, whereas more acidic substances have a pH value less than 7.
first of all we should calculate the molarity of the compounds
no. of moles of NH₃ = weight / molecular weight = 1.68 / (14+3) = 0.099
no. of moles of (NH₄)2SO4 = 4.05 / {2×(14+4) + 32 + 64} = 0.031
no. of moles of NH4+ = 2×0.031 = 0.062
[NH₃] = no. of moles / volume(L) = 0.099/ 0.5 = 0.198
[(NH₄⁺] = 0.031/0.5 = 0.124
1) now we know that
pH + pOH = pkw
pOH = pkw - pH = 14 - pH ---- -1
also
pOH = pkb + log ( [salt]/[base])
from 1
14 - pH = pkb + log ( [salt]/[base])
putting values
14- pH = -log(1.8e-5) + log(0.124/0.198)
14 - pH = 4.54
pH = 9.45
2) if 0.88g NaOH is added then as we know that NaOH is a base then it will reduce the buffer capacity
as there would be OH- ions initially present
hence the buffer action will move backward
i.e
pOH = pkb + log {(salt-x) / (base+x)}
where x= molarity of NaOH
no of moles of NaOH = 0.88 / (23+16+1) = 0.022
molarity of NaOH = 0.022/0.5 = 0.044
then 14 - pH = -log(1.8e-5) + log{ (0.124-0.044) / (0.198+0.044) }
14 - pH = 4.26
pH = 9.74
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6.0 L of a gas exert a pressure of 2.5 atm. When the pressure is increased 2 points
to 10.0 atm, what is the new volume of the gas?
O 1.0L
O 1.5L
O 1.7L
O 25L
An element has 4 protons, 5 neutrons, and 4 electrons. Choose the correct answer. *
Answer:
4
Explanation:
[tex]\int\limits^a_b {x} \, dwetjernjtnx[/tex]
A strong electrolyte is one that ________ completely in solution. a) reacts.b) decomposes.c) disappears.d) ionizes.
Answer:
A.
Explanation:
elctrolytes decomposes
Answer:
D. ionizes
Explanation:
Describe the bodys first line of defense
Answer:
The main function of the immune system is to provide immunity to the body. Immunity is the body's ability to protect itself from the pathogens it is exposed to. Immunity depends on the body's ability to differentiate between things that belong in the body and those that do not. The immune system's first line of defense includes physical and chemical barriers that are always ready and prepared to defend the body from infection.
The skin acts as a barrier against pathogens. Some structures of the first line of defense include the skin, mouth, eyes, ears, nose, and stomach. The skin produces sweat and oil that work together to keep pathogens from the entering the body. Saliva and tears contain substances the can destroy pathogens. The ears and the stomach help fight pathogens.The ears produce ear wax that prevent pathogens from entering the ears. The stomach produces a liquid the kills pathogens.
Mucus is produce by the nose, lungs, throat, and stomach. Mucus traps pathogens. Mucus also prevent pathogens from getting into deep tissues. Anyway, the very first line of defense against any invasion of the human body is a set of physical barriers between the inside of the body and the outer world.
*my notes from edge2020*
Hope this helps ^-^
Helium is a....
a. metalloid
b. nonmetal
c. metal
Answer:
NonmetalExplanation:
Explain how the immune system responds to pathegons
Answer:
The immune system responds to antigens by producing cells that directly attack the pathogen, or by producing special proteins called antibodies. Antibodies attach to an antigen and attract cells that will engulf and destroy the pathogen. The main cells of the immune system are lymphocytes known as B cells and T cells.
Using the equations
2 Fe (s) + 3 Cl₂ (g) → 2 FeCl₃ (s) ∆H° = -800.0 kJ/mol
Si(s) + 2 Cl₂ (g) → SiCl₄ (s) ∆H° = -640.1 kJ/mol
Determine the enthalpy (in kJ/mol) for the reaction
3 SiCl₄ (s) + 4 Fe (s) → 4 FeCl₃ (s) + 3 Si (s)
The enthalpy : 320.3 kJ/mol
Further explanationThe change in enthalpy in the formation of 1 mole of the elements is called enthalpy of formation
The enthalpy of formation measured in standard conditions (25 ° C, 1 atm) is called the standard enthalpy of formation (ΔHf °)
Based on the principle of Hess's Law,
the change in enthalpy of a reaction will be the same even though it is through several stages or ways
Reaction
2Fe (s) + 3Cl₂ (g) → 2FeCl₃ (s) ∆H° = -800.0 kJ/mol x 2
4Fe (s) + 6Cl₂ (g) → 4FeCl₃ (s) ∆H° = -1600.0 kJ/mol
Si(s) + 2 Cl₂ (g) → SiCl₄ (s) ∆H° = -640.1 kJ/mol
Reverse
SiCl₄ (s) → Si(s) + 2 Cl₂ (g) ∆H° = 640.1 kJ/mol x 3
3SiCl₄ (s) → 3Si(s) + 6Cl₂ (g) ∆H° = 1920.3 kJ/mol
------------------------------------------------------------------------ +
3 SiCl₄ (s) + 4 Fe (s) → 4 FeCl₃ (s) + 3 Si (s) ∆H° = 320.3 kJ/mol
The enthalpy for the formation of 4 moles of [tex]\rm FeCl_3[/tex] has been 320.3 kJ/mol.
The enthalpy of formation of 1 mole at standard temperature and pressure has been termed the standard enthalpy of formation.
The reaction enthalpy to be calculated has reactants of 3 moles of [tex]\rm SiCl_4[/tex], and 4 moles of Fe.
The enthalpy for the formation of [tex]\rm SiCl_4[/tex] has been -640.1 kJ/mol.
The enthalpy for the dissociation of [tex]\rm SiCl_4[/tex] has been the reverse of the formation reaction = +640.1 kJ/mol.
The enthalpy for the dissociation of 3 moles of [tex]\rm SiCl_4[/tex] has been = 3 [tex]\times[/tex] 640.1 kJ/mol.
The enthalpy for the dissociation of 3 moles of [tex]\rm SiCl_4[/tex] has been = 1920.3 kJ/mol.
The enthalpy for the formation of 2 moles of [tex]\rm FeCl_3[/tex] = -800 kJ/mol
The enthalpy for the formation of 4 moles of [tex]\rm FeCl_3[/tex] = -1600 kJ/mol.
The final reaction has 3 moles of [tex]\rm SiCl_4[/tex], and 4 moles of [tex]\rm FeCl_3[/tex].
Thus, the final enthalpy of reaction will be: 1920 kJ/mol + (-1600 kJ/mol)
The final enthalpy of reaction will be = 320.3 kJ/mol.
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Calculate the concentration (M) of arsenic acid (H3AsO4) in a solution if 25.00 mL of that solution required 35.21 mL of 0.1894 M KOH for neutralization.
Answer:
[tex]M_{acid}=0.08892M[/tex]
Explanation:
Hello!
In this case, since the reaction between arsenic acid and potassium hydroxide is:
[tex]H_3AsO_4+3KOH\rightarrow K_3AsO_4+3H_2O[/tex]
Thus, since the mole ratio between the acid and the base is 1:3, at the equivalence point we can write:
[tex]3n_{acid}=n_{base}[/tex]
That in terms of molarities and volumes is:
[tex]3M_{acid}V_{acid}=M_{base}V_{base}[/tex]
Thus, the concentration of the arsenic acid is:
[tex]M_{acid}=\frac{M_{base}V_{base}}{3V_{acid}}=\frac{0.1894M*35.21mL}{3*25.00mL} \\\\M_{acid}=0.08892M[/tex]
Best regards!
The concentration (M) of arsenic acid in a solution of 25.00 mL is 0.088M.
How we calculate the molarity?Molarity of any solution will be calculated as:
M = n/V, where
V = volume
n is the moles and it will be calculated as:
n = W/M, where
W = given mass
M = molar mass
Given chemical reaction is:
H₃AsO₄ + 3KOH → K₃AsO₄ + 3H₂O
Moles of 35.21 mL of 0.1894 M KOH will be calculated as:
n = (0.1894)(0.035) = 0.0066 moles
From the stoichiometry of the reaction it is clear that:
1 mole of H₃AsO₄ = react with 3 moles of KOH
0.0066 moles of KOH = react with 1/3×0.0066= 0.0022 moles of H₃AsO₄
Now we calculate the molarity of H₃AsO₄ in 25mL of solution as:
M = 0.0022/0.025 = 0.088 M
Hence, required molarity is 0.088 M.
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An Sulfur tetrafluoride gas is collected at 23.0 °C in an evacuated flask with a measured volume of 20.0 L. When all the gas has been collected, the pressure in the flask is measured to be 0.230 atm . Calculate the mass and number of moles of sulfur tetrafluoride gas that were collected. Be sure your answer has the correct number of significant digits. mass: 1 g N10 mole: mol X & ? Explanation Check
mass = 20.48 g
moles=0.1895
Further explanationIn general, the gas equation can be written
Pv=nRTwhere
P = pressure, atm
V = volume, liter
n = number of moles
R = gas constant = 0.08205 L.atm / mol K
T = temperature, Kelvin
P=0.23 atm
V=20 L
T=23+273=296 K
[tex]\tt n=\dfrac{PV}{RT}=\dfrac{0.23\times 20}{0.082\times 296}=0.1895[/tex]
mass SF₄ (MW=108,07 g/mol) :
[tex]\tt 0.1895\times 108,07 g/mol=20.48~g[/tex]
What electrically neutral atom has 30 neutrons and 25 electrons?
Answer:
Manganese (Mn)
Explanation:
We know it's manganese because we are told it is an electrically neutral atom. This means it has the same number of protons and electrons. If it has 25 electrons, it has 25 protons. Protons tell us the atomic number of the atom, which also tells us the name of the element. Manganese is element 25 on the periodic table.
How would I find the answer?
Answer:
Kr
Explanation:
The noble gas that is isoelectronic with Br⁻ is krypton.
This is because krypton is the closest noble gas to Br on the periodic table.
Electronic configuration of Bromine is;
2, 8, 18, 7
Br⁻ becomes; 2, 8, 18, 8
Krypton is; 2, 8, 18, 8
i really need help with the rest of this assignment. theres 10 pages of multiple choice questions, i can mark brainliest and pay money if you help me :)
Answer:
Hey! I'll help you.
Explanation:
I got your back.
The temperature at which a particular liquid becomes a gas
5 points
A melting point
B boiling point
C freezing point
D sublimation point
5 points
a substance made of at least two atoms that are chemically combined
Apure substance
B element
C compound
D mixture
Answer:
A: melting point and the other one is i think element
PLZ HELP ME NO WRONG ANSWERS
Answer:
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