Answer:
To calculate the pH of an aqueous solution you need to know the concentration of the hydronium ion in moles per liter (molarity). The pH is then calculated using the expression: pH = - log [H3O+].
Example: Find the pH of a 0.0025 M HCl solution.
A fire that is burning wood will release water vapor and carbon dioxide
true or false?
Answer:
true.
Explanation:
Read the temp what is it?
17.3 or 17.25??
Answer:
I would say 17.25.
Explanation:
PLEASE HELP ME ASAP!!!!!!!!!!!!!
Convert 1.65 moles of nitrogen gas at STP to liters.
What is the coefficient of the scientific notation answer ? What is the exponent of the scientific notation answer ? How many significant figures are there in the answer ? What is the right most significant figure in the answer ?
Answer:
See explanation
Explanation:
We know that 1 mole of a gas occupies 22.4 L
Hence, 1.65 moles of nitrogen gas occupies 1.65 moles * 22.4 L/1 mole = 36.96 L or 3.696 * 10^1 L = 3.70 * 10^1 L
The exponent of the scientific notation answer = 1
The significant figures there are in the answer = 4
The right most significant figure in the answer = 2
Which of the following adaptations found in animals in deciduous forests protects against predators?
a.
fat storage
b.
migration
c.
hibernation
d.
camouflage
Please select the best answer from the choices provided
A
B
C
D
Should be D
Answer:
The answer is D. Camouflage
Answer:
THE ANSWER IS D) CAMOUFLAGE
How many moles of NaCl are found in 5.2L of a 0.75 M solution?
Answer 4.45 moles
Explanation:
If you start with 13 mole H2O and 50 grams of O2 what is the percent yield of H202 if 100 grams of H202 is actually made?
Answer:
94.1 %
Explanation:
We firstly determine the equation:
2H₂O + O₂ → 2H₂O₂
2 moles of water react to 1 mol of oxygen in order to produce 2 moles of oxygen peroxide.
We convert the mass of oxygen to moles:50 g . 1mol /32g = 1.56 mol
Certainly oxygen is the limiting reactant.
2 moles of water react to 1 mol of oxygen.
13 moles of water may react to 13/2 = 6.5 moles. (And we only have 1.56)
As we determine the limiting reactant we continue to the products:
1 mol of O₂ can produce 2 moles of H₂O₂
Then 1.56 moles of O₂ will produce (1.56 . 2) = 3.125 moles
We convert the moles to mass: 3.125 mol . 34 g/mol= 106.25 g
That's the 100% yield or it can be called theoretical yield.
Percent yield = (Yield produced / Theoretical yield) . 100
(100g / 106.25 g) . 100 = 94.1 %
1. Which of the following would not be a good way to describe a body system?
A. Body systems are like computer programs that have to communicate with each
other in order to make the computer work.
B. Body systems are like runners in a marathon who each run alone and don't need the
other runners to finish the race.
C. Body systems are like machines with many different moving parts.
D. Body systems are like individual parts of one big story.
Answer:
the answer would be b
Explanation:
the body sytsem needs to depend on eah other in order to work
Body systems are like runners in a marathon, who each run alone and don't need the other runners to finish the race, is not a good way to describe a body system, hence option B is correct.
How body systems work together?Your digestive tract takes nutrients and water from the food you eat in to your body. The body's cells receive oxygen, water, and nutrients through your circulatory system.
Your skin, excretory system, and respiratory system all function to remove wastes from your cells.
Your body's many systems depend on one another to function properly. While your heart's muscles require oxygen from your lungs to beat, your respiratory system depends on your circulatory system to distribute the oxygen it collects.
Therefore, option B is correct.
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Indicate whether each statement is true or false. Drag the appropriate statements to their respective bins. the octet rule is based on the fact that filling in all s and p valence electrons in a shell gives eight electrons. compounds in which nitrogen is the central atom are frequent exceptions to the octet rule because they have too many electrons surrounding the nitrogen. boron compounds are frequent exceptions to the octet rule because they have too few electrons surrounding the boron. the si in sih4 does not follow the octet rule because hydrogen is in an unusual oxidation state.
Answer:
the octet rule is based on the fact that filling in all s and p valence electrons in a shell gives eight electrons--- True
boron compounds are frequent exceptions to the octet rule because they have too few electrons surrounding the boron......True
compounds in which nitrogen is the central atom are frequent exceptions to the octet rule because they have too many electrons surrounding the nitrogen...... false
the si in sih4 does not follow the octet rule because hydrogen is in an unusual oxidation state......false
Explanation:
The octet rule simply means that atoms tend to be stable when they have eight electrons in their outermost shell. This rule mostly applies to the s and p orbitals and not to the d and f orbitals. The sum of the total electrons in the outermost s and p orbitals is often equal to eight for an atom to be considered stable, for example, the noble gases.
Boron often forms compounds which has less than eight electrons around the boron central atom because the compounds of boron often have a sextet of electrons owing to the fact that boron is trivalent and forms mostly covalent compounds.
Nitrogen compounds mostly obey the octet rule and do not have excess electrons. The oxidation state of hydrogen in SiH4 is not unusual.
HURRY!!!!!! HELP PLEASEEE
To begin the experiment, 1.65g of methane CH4 is burned in a bomb calorimeter containing 1000 grams of water. The initial temperature of water is 18.98oC. The specific heat of water is 4.184 J/g oC. The heat capacity of the calorimeter is 615 J/ oC . After the reaction the final temperature of the water is 36.38oC.
2. Calculate the change in temperature, ΔT. Show your work. (1pt)
3. Calculate the heat absorbed by water. Use the formula qwater = m • C • ΔT
Show your work (2pts)
4.Calculate the heat absorbed by the Calorimeter. Use the formula:
qcal = Ccal • ΔT Show your work. (2pts)
5. The total heat absorbed by the water and the calorimeter can be calculated by adding the heat calculated in steps 3 and 4. The amount of heat released by the reaction is equal to the amount of heat absorbed with the negative sign as this is an exothermic reaction. (2pts)
a.Using the formula ΔH = - (qcal + qwater ) , calculate the total heat of combustion. Show your work.
b. Convert heat of combustion (answer from part a) from joules to kilojoules. Show your work.
6. Evaluate the information contained in this calculation and complete the following sentence: (2pts)
This calculation shows that burning _______ grams of methane [TAKES IN] / [GIVES OFF] energy (Choose one).
7. The molar mass of methane is 16.04 g/mol. Calculate the number of moles of methane burned in the experiment. Show your work. (2pts)
8. What is the experimental molar heat of combustion in KJ/mol? Show your work. (2pts)
9. The accepted value for the heat of combustion of methane is -890 KJ/mol . Explain why the experimental data might differ from the theoretical value in 2-3 complete sentences. (2pts)
10. Given the formula:
% error= |(theoretical value - experimental value)/theoretical value)| x 100
Calculate the percent error. Show your work. (2pts)
The calorimter is equal to the heat released by the reaction. Calculate the heat released by the reaction.
What is the reaction?The reaction to the news can vary depending on who you are speaking to. For some, the news may be welcomed as a sign of progress and a move in the right direction. Others may be apprehensive, uncertain of the potential outcomes or changes that may come as a result. Some may be angry and frustrated, feeling as though the news has been a long time coming and they have not been given a say in the matter.
1. ΔT = 36.38oC - 18.98oC = 17.4oC
2. qwater = m • C • ΔT
qwater = (1000g)(4.184J/g oC)(17.4oC)
qwater = 71376.8 J
3. qcal = Ccal • ΔT
qcal = (615J/ oC)(17.4oC)
qcal = 10666.1 J
4. qreaction = qwater + qcal
qreaction = 71376.8 J + 10666.1 J
qreaction = 82042.9 J
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Complete the following molecular models to represent balanced equations by
drawing additional molecules but not changing the identity of them. When you are
done, the total number of atoms of each element on the reactant side of the equation
must equal the total number of atoms of the same elements on the product side.
a)
Answer:
I do not know the Answer I'm just trying to get my point
Explanation:
Thank you
A bottle contains 2.5 moles of KOH dissolved in water, and the molarity of the solution is 0.16 M.
What volume of solution is in this bottle?
Answer:
V = 15.6 L
Explanation:
Hello there!
In this case, according to the definition of molarity in terms of the moles of solute divided by the volume of the solution, it is possible for us to write:
[tex]M=n/V[/tex]
Thus, given the moles and concentration of the solution, we can find the volume as shown below:
V=n/M
Therefore, we plug in the given data to obtain:
V = 2.5mol /(0.16mol/L)
V = 15.6 L
Best regards!
How does Gibbs free energy predict spontaneity?
O A. If AG > 0, the reactigais spontaneous.
B. If AG = 0, the reaction is spontaneous.
C. If AG < 0, the reaction is spontaneous.
O D. If AG = TAS, the reaction is spontaneous.
Answer:
C
Explanation:
plz mark brainliest
Gibbs free energy predict spontaneity if G < 0, the reaction is spontaneous and the correct statement is option C.
What is Gibbs Free Energy?Gibbs free energy is a quantity that is used to measure the maximum amount of work done in a thermodynamic system when the temperature and pressure are kept constant.
Gibbs free energy is denoted by the symbol ‘G’. Its value is usually expressed in Joules or Kilojoules.
Gibbs free energy can be defined as the maximum amount of work that can be extracted from a closed system.
Gibbs free energy to determine the spontaneity of a process.
Therefore, Gibbs free energy predict spontaneity if G < 0, the reaction is spontaneous and the correct statement is option C.
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How many moles of gas is contained in 2.21 L at STP?
Answer:
its an helium gas are contained in a 4.0L at STP? 0.17
Explanation:
because the elements in column 2.21 is what quantity of gas in holes
Describe how the size of the sun compares to the sizes of the other stars.
Answer:
The sun's circumference is about 2,713,406 miles (4,366,813 km). It may be the biggest thing in this neighborhood, but the sun is just average compared to other stars. Betelgeuse, a red giant, is about 700 times bigger than the sun and about 14,000 times brighter.
Explanation:
looked it up
Explanation:
The sun's circumference is about 2,713,406 miles (4,366,813 km). It may be the biggest thing in this neighborhood, but the sun is just average compared to other stars. Betelgeuse, a red giant, is about 700 times bigger than the sun and about 14,000 times brighter
What happens when you mix calcium chloride and hydrogen peroxide?
Answer:
Explanation: When chlorine reacts with hydrogen peroxide, hydrogen peroxide falls apart into water and oxygen. Chlorine gas hydrolyses into hypochlorous acid (, which subsequently into hypochlorite ions . The reaction between hydrogen peroxide and hypochlorite takes place very quickly.
help i give more point this time
Answer:
It's a type of chemical bond that emerges because of electrostatic force between electrons and positive metal charges.
Explanation:
I don't know if this is what you are looking for but i don't mind if you copy it.
Organisms are more closely related to the species that they share the most DNA with
True or False
Answer:
True
Explanation:
Hello, I need help in this part of chemistry, I need the chemical names of the following four:
1) B and F3
2) Se and I2
3) As2 and Se3
ASAP! Please,,,
I need help with number 17 pls someone pls ???
Answer:
can you pls say what subject it is pls and thank u
Explanation:
Answer:
glass cup as it can trap oxygen from getting in and out meaning that the fire can't grow
Describe how ultrasonic waves help ships navigate and how ultrasonic waves can be used for medical purposes
Describe what happens to the molecules in the ice as temperature of the ice increases
Answer:
When you heat ice, the individual molecules gain kinetic energy, but until the temperature reaches the melting point, they don't have energy to break the bonds that hold them in a crystal structure. They vibrate more quickly within their confines as you add heat, and the temperature of the ice goes up.
Answer:
As energy is transferred to the water molecules in the ice, the motion of the molecules increases. The motion of the molecules increases enough that it overcomes the attractions the water molecules have for each other causing the ice to melt.
What can lead to being curious and also lead to fascinating scientific investigations? a. Questions b. Answers c. Qualitative Measurements d. Quantitative Measurements
Answer:
Questions
Explanation:
The word "science" was obtained from the Latin word "Scire" which means "to know". Hence science is a systematic investigation into the nature of the universe.
Scientific investigations begin with asking questions about the universe. It is this curiosity to know about occurrences in the universe as well as how to solve problems in the universe that leads to fascinating scientific investigations and discoveries.
The temperature of 200 mL of gas originally at STP is changed to –25o C at constant volume. Calculate the final pressure of the gas in mmHg.
Answer:
691.6 mmHg
Explanation:
At standard temperature and pressure, temperature of a system = 273K, and pressure= 1atm
T1= 273.15K
P1= 1atm
T2= (–25°C +273.15 )= 248.15K
From Gay-Lussac's law which expressed that at constant volume, pressure of a particular mass of gas is directly proportional to temperature . It can be expressed as
P1 / T1 = P2 / T2
Where P1= initial pressure
T2= final temperature
T1= initial temperature
P2= final pressure
Making P2 subject of the formula
P2= (P1 × T2)/ P1
Substitute the values we have
P2= (1 atm × 248.15K)/273.15
P2= 0.91 atm
But
1atm= 760 mmHg
0.91 atm= X mmHg
If we cross multiply we have
X mmHg= (760× 0.91)/1
= 691.6 mmHg
Hence, the final pressure of the gas in mmHg is 691.6 mmHg
What is the poh of a solution with a ph of 1.30? PLZZ ANSWER
Answer:
12.70
Explanation:
Regions that receive up to 20 inches of rainfall per year are referred to as __________ because they receive more precipitation than most deserts.
semiarid deserts
polar deserts
coastal deserts
subtropical deserts
Answer:
The answer is in fact semi-arid deserts. This just serves as a confirmation cause sometimes the answers be wrong.
Semiarid deserts is the region that receive up to 20 inches of rainfall per year.
What is Rainfall?
This is defined as the amount of precipitation in the form of water droplets that falls onto the surface of Earth from the clouds due to gravity influence.
Semi-arid desert receive more precipitation which is around 20 inches of rainfall than most deserts.
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plz help i’m gonna cry i’m in class rn
Answer:
if ur gonna cry then just dont cry its simple logic guyss!!!!!!!!!!!!
Explanation:
I NEED HELP PLEASE ASAP THANK YOU!
Answer:
K = °C +273
°C = K - 273
1. 59 °C.
2. 300K.
5. 673K
6. 927 °C
a student needs to use 0.485 moles of sodium chloride in an experiment how many grams should he measure out in grams. (show work)
Answer:
the answer is 28.4 g NaCl
Explanation:
Please answer as many question as possible ty