Answer: 8.2
Explanation:
pH of a solution is - Log [ H+].
pH = - Log [ 6.2 x 10-9 M]
= 9 - 0.7924
pH = 8.24 approx 8.2
round 23,455 into 4 significant figures: ______ cm 23.46
23.40
23.45
Answer:
23.46
Explanation:
A 100g sample of Carbon-14 has a half-life of 5 years. How much Carbon-14 is left after 10 years?
Answer: The amount of carbon-14 left after 10 years is 25 g
Explanation:
Formula used :
[tex]a=\frac{a_o}{2^n}[/tex]
where,
a = amount of reactant left after n-half lives = ?
[tex]a_o[/tex] = Initial amount of the reactant = 100 g
n = number of half lives =[tex]\frac{\text {given time}}{\text {half life}}=\frac{10}{5}=2[/tex]
Putting values in above equation, we get:
[tex]a=\frac{100g}{2^2}[/tex]
[tex]a=\frac{100g}{4}=25g[/tex]
Therefore, the amount of carbon-14 left after 10 years is 25 g
what is the total number of moles of solute in 2230 ml of 3.0 M NaOH solution.
The total number of moles of solute in 2230 mL of a 3.0 M NaOH solution is calculated by converting the volume to liters and multiplying by the molarity, resulting in 6.69 moles of NaOH.
The total number of moles of solute in 2230 mL of 3.0 M NaOH solution can be calculated by using the definition of molarity, which is the number of moles of solute per liter of solution. The following steps are used for the calculation:
Convert the volume from milliliters (mL) to liters (L), knowing that 1 L = 1000 mL.Multiply the volume in liters by the molarity (M) to find the total moles of solute.First, convert 2230 mL to liters: 2230 mL
1000 mL/L = 2.23 L.
Next, multiply the volume by the molarity: 2.23 L × 3.0 M = 6.69 moles of NaOH.
Therefore, the correct answer is that there are 6.69 moles of NaOH in 2230 mL of a 3.0 M NaOH solution.
Muscles perform what types of energy transformation?
a.) Kinetic to Potential
b.) Kinetic to Electrical
c.) Thermal to Radiant
d.) Chemical to Kinetic
Answer:
d
Explanation:
Inside of your muscles, there are fibers that are always ready to use your body's energy currency - ATP - and convert that into motion. Since they use ATP, which is a form of chemical energy, and turn it into motion, or kinetic energy, the correct answer is d. Hope this helps!
Final answer:
Option d) Muscles transform chemical energy into kinetic energy during contraction, using oxygen and food molecules to perform work and produce motion.
Explanation:
During muscle contraction, the potential energy stored in the form of chemical bonds in food molecules and oxygen is transformed into the kinetic energy of motion as the muscles do work. This can be observed through the consumption of oxygen and nutrients, the production of waste products like carbon dioxide, and the release of heat.
Moreover, the transformation of energy in muscles also results in an increased blood supply to bring nutrients and oxygen to the muscle cells efficiently and to carry away waste products.
The correct answer to the question 'Muscles perform what types of energy transformation?' is (d) Chemical to Kinetic.
vanuation Question
1. What is the number one killer of teenagers?
O Speeding
Reckless driving
Driving under the influence
O Distracted driving
Choose the correct energy transformation for the burning of a piece of wood. A. heat energy to light energy B. light energy to heat energy C. chemical potential energy to heat energy D. heat energy to chemical potential energy
Answer:
C
Explanation:
In the case of burning wood, stored potential energy in the wood is released due to heating by other excited atoms.
Final answer:
The burning of wood transforms chemical potential energy stored in the wood into heat energy, making option C the correct answer.
Explanation:
The correct energy transformation for the burning of a piece of wood is chemical potential energy to heat energy. This process is an example of a chemical reaction where the chemical energy stored in wood's molecules is released as heat and light energy when the wood combusts.
The chemical potential energy stored in the bonds of the wood is released as heat and light during the combustion process. This chemical potential energy is converted into heat energy, which is evident through the warmth generated by the burning wood. Additionally, some of this energy may also be transformed into light, but the primary conversion is from chemical potential energy to heat.
Which answer choice correctly describes the gas law and physical changes represented by the image?
a. The image shows Boyle’s law because volume increases as pressure increases.
b. The image shows Boyle’s law because volume decreases as pressure increases.
c. The image shows Charle’s law because volume decreases as pressure increases.
d. The image shows Charle’s law because as volume increases as pressure increases.
Answer:
A. The image shows Boyle's Law because volume decreases as pressure increases.Explanation:
According to Boyle's Law, at constant temperature, pressure and volume have inverse relation that is as pressure would increase, volume would decrease.
According to Charles Law, at constant pressure, the volume is directly proportional to temperature.
According to the given graph and diagram, the temperature is constant and volume and pressure have inverse relation.
Thus, option A is correct.
What is the coefficient of MnO2when you balance the equation for this redox reaction? KCN( aq) + KMnO4( aq) + H2O( l) → KCNO( aq) + MnO2( s) + KOH( aq)
Answer:
2MnO2 (s)
Explanation:
3KCN(aq) + 2KMnO4(aq) + 1H2O(l) → 3KCNO(aq) + 2MnO2(s) + 2KOH(aq)
Reactants:
K: 5
C: 3
N: 3
Mn: 2
O: 9
H: 2
Products:
K: 5
C: 3
N: 3
Mn: 2
O: 9
H: 2
How many moles of gas are contained in 890.0 mL at 21.0 °C and 750.0 mm Hg pressure?
Answer:
(0.9868 atm)(0.89 L) = (x)(0.0821 L-atm)(294 K)
0.87825 = (x) 24.1374
x = 0.03638 moles :)
Explanation:
Given the value of the temperature and the pressure, the amount of the ideal gas contained in the given volume is 0.036mol.
Ideal Gas Law
The Ideal gas law or general gas equation emphasizes on the state or behavior of a hypothetical ideal gas. It states that "the pressure multiplied by volume is equal to moles multiply by the universal gas constant multiply by temperature.
It is expressed as;
PV = nRT
Where P is pressure, V is volume, n is the amount of substance, T is temperature and R is the ideal gas constant ( 0.08206 Latm/molK )
Given the data in the question;
Volume of gas V = 890.0 mL = 0.89LTemperature T = 21.0°C = 294.15KPressure P = 750.0mmHg = 0.986842atmAmount of gas n = ?To determine the amount of gas, we substitute our values into the expression above.
PV = nRT
n = PV / RT
n = ( 0.986842atm × 0.89L ) / ( 0.08206 Latm/molK × 294.15K )
n = 0.87828938Latm / 24.137949Latm/mol
n = 0.036mol
Therefore, given the value of the temperature and the pressure, the amount of the ideal gas contained in the given volume is 0.036mol.
Learn more about Ideal Gas Law here: brainly.com/question/4147359
13. What instrument is used routinely to check a person's exposure to radiation?
Geiger counter
scintillation counter
film badge
moderating rod
WILL MARK BRAINLIEST FOR CORRECT ANSWER!!!!!!!!!!
The emission of what type of particle from a nucleus will not cause a transmutation?
A) positron
B) proton
C) neutron
D) alpha particle
Answer:
the answer is c
Explanation:
Jill is studying the temperature output of an ammonium chloride hand warmer. What apparatus will best help her monitor the
temperature change of the reaction?
calorimeter
colorimeter
hydrometer
thermometer
Answer:
Thermometer
Explanation:
Because a thermometer helps to measure temperatures
Answer:
calorimeter
Explanation:
hope this helps :)
Explain what domain would best be represented by the "?" in the diagram.
A) Eukarya because the organisms are all eukaryotic.
B) Eukarya because the organisms are all prokaryotic.
C) Bacteria because some of the organisms are autotrophs.
D) Archaea because the organisms are all diverse bacteria.
The correct answer is 'Eukarya because the organisms are all eukaryotic' since the organisms mentioned have cells with nuclei. Bacteria and Archaea are both prokaryotic and do not contain organisms with eukaryotic cells.
Explanation:The correct answer to the question is A) Eukarya because the organisms mentioned are all eukaryotic. This means that the cells of these organisms contain nuclei. The domain Eukarya includes diverse groups such as animals, plants, fungi, and protists. These kingdoms are distinguished by the presence of eukaryotic cells, which differentiate them from prokaryotic cells found in the other two domains, Bacteria and Archaea, both of which lack a nucleus. Bacteria and Archaea are known as prokaryotes and often consist of single-celled organisms. Eukarya, on the other hand, can consist of both unicellular and multicellular organisms. Therefore, Option B 'Eukarya because the organisms are all prokaryotic' is incorrect as eukaryotes have a nucleus. Option C 'Bacteria because some of the organisms are autotrophs' is not correct either since autotrophy is not exclusive to Bacteria and does not define domain classification on its own. Lastly, Option D 'Archaea because the organisms are all diverse bacteria' is incorrect because Archaea is a separate domain, and it encompasses organisms that are genetically distinct from bacteria and eukaryotes, despite their prokaryotic cell structure.
What advantage does gasoline have over electricity for cars?
Final answer:
Gasoline has a higher energy density than electricity stored in lithium-ion batteries, enabling more energy to be carried per unit of weight. Gasoline vehicles can refuel quickly, offering convenience for long-distance travel, while electric vehicles require longer recharge times. Additionally, gasoline's safety profile is relatively high given its energy content, as it burns rather than explodes.
Explanation:
One of the main advantages that gasoline has over electricity for powering cars is its higher energy density. Gasoline contains approximately 13 kWh/kg, while the energy density of lithium-ion batteries is about 0.2 kWh/kg, which is substantially lower. This means that gasoline can deliver more energy per unit of weight than batteries can, making it a more energy-dense fuel source.
An additional advantage is the rapid refueling capability of gasoline vehicles. A car can fill its tank with gasoline at a rate of 15 MW, allowing it to be ready for further travel in a matter of minutes, whereas electric cars often require hours to fully recharge. This convenience factor is a significant benefit for long-distance travel or in situations where quick refueling is necessary.
Safety is another aspect where gasoline has an advantage. Although gasoline is flammable, it is not as explosive as one might think—the vapor mix with oxygen burns rather than explodes, making it relatively safe for an energy source with such high energy content.
The weight of the atmosphere is called what?
A. Wind
B. Gravity
C. Air pressure
D. Temperature
Answer:
The correct answer is C. Air pressure. :)
Explanation:
Air preasure is the amount of gravitational force acting against an object.
Andrew noticed that the plastic in his chair seat didn't feel as cold as the metal legs. What statement best explains this observation?
A) Plastic is an insulator, so it stores warmth in the room.
B) The metal absorbs cold air in the room at a faster rate than plastic.
C) Metal is a conductor of heat so it transmits warmth away from Andrew's hand at a faster rate than plastic.
D) Metal is a conductor of heat, so it transmits its heat to the plastic until the plastic reaches room temperature.
Answer:
Metal is a conductor of heat so it transmits warmth away from Andrew's hand at a faster rate than plastic.
Explanation:
remember, cold air never existed. only the lack of heat :)
For an Ohmic conductor, tripling the voltage without changing the resistance will cause the current to
A.
increase by a factor of 9.
B.
decrease by a factor of 9.
C.
increase by a factor of 3.
D.
decrease by a factor of 3.
Answer:
a
Explanation:
does anyone know this?
What type of energy does a rock resting on top of the hill have?
A. Electoral energy
B. Kinetic energy
C. Potential energy
D. Radiant energy
disease causing bacteria need oxygen to survive.
true or false
Answer:
true
Explanation:
its a guess
Disease causing bacteria need oxygen to survive is true.
What are diseases?Diseases are defined as a specific aberrant condition that adversely affects an organism's structure or function on the whole or in part but is not immediately caused by an external harm. The onset of chronic diseases may be delayed by eating healthfully, exercising regularly, and abstaining from cigarettes and excessive alcohol use, among other factors.
Bacteria are defined as the creatures without a proper nucleus and only a few organelles that are prokaryotic unicellular organisms. The bacteria in our bodies help our bodies digest food, help us access nutrients, and neutralize poisons. Three distinguishing characteristics of bacteria are: 1) their lack of membrane-bound organelles, 2) their unicellularity, and 3) their small size.
Thus, disease causing bacteria need oxygen to survive is true.
To learn more about disease, refer to the link below:
https://brainly.com/question/8611708
#SPJ2
What mass of H₂O is formed when excess H₂ reacts with 64 g of O₂
2(H2)+(O2)---->2(H2O)
18g
36g
72g
144g
Answer: 72 g of [tex]H_2O[/tex] is formed.
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]
[tex]\text{Moles of} O_2=\frac{64}{32}=2moles[/tex]
[tex]2H_2+O_2(g)\rightarrow 2H_2O[/tex]
As [tex]H_2[/tex] is the excess reagent, [tex]O_2[/tex] is the limiting reagent as it limits the formation of product.
According to stoichiometry :
1 mole of [tex]O_2[/tex] produce= 2 moles of [tex]H_2O[/tex]
Thus 2 moles of [tex]O_2[/tex] will require=[tex]\frac{2}{1}\times 2=4moles[/tex] of [tex]H_2O[/tex]
Mass of [tex]H_2O=moles\times {\text {Molar mass}}=4moles\times 18g/mol=72g[/tex]
Thus 72 g of [tex]H_2O[/tex] is formed.
How many liters of 1.20 M calcium nitrate are required to produce .1 moles of calcium sulfate? Please balance the equation before solving the problem.
Answer:
0.083L
Explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
Ca(NO3)2 + H2SO4 —> CaSO4 + 2HNO3
Next, we shall determine the number of mole of Ca(NO3)2 needed to produce 0.1 mole of CaSO4.
From the balanced equation above,
1 mole of Ca(NO3)2 reacted to produce 1 mole of CaSO4.
Therefore, 0.1 mole of Ca(NO3)2 will also react to produce 0.1 mole of CaSO4.
Finally, we can determine the volume of Ca(NO3)2 needed for the reaction as follow:
Mole of Ca(NO3)2 = 0.1 mole
Molarity of Ca(NO3)2 = 1.20M
Volume =?
Molarity = mole /Volume
Volume = mole /Molarity
Volume = 0.1/1.2
Volume = 0.083L
Therefore, 0.083L of Ca(NO3)2 is needed for the reaction.
Curious Carl and his lab partner added small pieces of various metals to HCl. Magnesium (Mg) and zinc (Zn) reacted vigorously with HCl, releasing hydrogen gas. This equation represents the reaction of zinc in hydrochloric acid.
Zn + 2HCl → ZnCl2 + H2
What is the half reaction for the reduction of hydrogen in the reaction?
A) 2HCl → + 2e- + H2(g)
B) H + Cl → + 2e- + H2(g)
C) 2H+ + 2e- → H2(g)
D) 2H+ - 2e- → H2(g)
Answer:
I just took it on use test prep. the answer is C. 2H + 2e → H2(g)
Answer:B
Explanation:USA test prep
Please need asap. 50 points
Answer:
just do the lab or what ever
Explanation:
because your just taking notes and taking data
How does litmus paper identify a base
A base turns red litmus blue. Litmus paper is paper that has been treated with a specific indicator, a mixture of 10 to 15 natural dyes that turns red in response when the pH is acidic, and blue when it is basic.
Why is water from an aquifer more likely to be cleaner than water from other sources?
Select one:
because it rises to the surface near the ocean
because pollutants are filtered by rock and soil deep within Earth
because it receives water directly from precipitation
because it forms where fresh and salt water meet
Answer:
last one
Explanation:
Answer:
2nd one
Explanation:
Is the following equation balanced? SO3 + 2H2O H2SO4 no yes
Answer: No
Explanation: It's not balanced because four oxygen atoms in H2SO4, whereas there are 5 oxygen atoms in the reactants side. Also, there's more hydrogen atoms on the reactants side.
I hope this helps!
Answer:no
Explanation:
It's not balanced because four oxygen atoms in H2SO4
Science Question:
Why does the same side of the moon always face Earth?
The rotational period of the moon is different than one revolution around Earth.
The rotational period of the moon is equal to one revolution around Earth.
The rotational period of Earth is the same as that of the moon.
The rotational period of Earth is equal to one revolution around Earth.
Answer:
The rotational period of the moon is equal to one revolution around Earth.
I think this is the answer am not that positive.
Explanation
Only one side of the Moon is visible from Earth because the Moon rotates on its axis at the same rate that the Moon orbits the Earth – a situation known as synchronous rotation, or tidal locking. The Moon is directly illuminated by the Sun, and the cyclically varying viewing conditions cause the lunar phases.
Answer:
The rotational period of the moon is equal to one revolution around the earth
Explanation:
I took the test. Hopes this helps :)
PLEASE HELP!!!!!!!!!
The pressure in an automobile tire is 1.88 atm at 25.0 degrees Celsius. What
will be the pressure if the temperature warms up to 37.0 degrees Celsius?
Assume the volume and the amount of the gas are constant. *
a. 1.81 atm
b. 2.78 atm
c. 1.96 atm
d. 1.27 atm
Answer:
Option "C" is the correct answer to the following question.
Explanation:
Given:
Pressure in an automobile tire (P) = 1.88 atm
Temperature (K) = 25°C = 273 + 25 = 298 Kelvin
New temperature (K1) = 37°C = 273 + 37 = 310 Kelvin
Find:
New pressure in an automobile tire (P1) = ?
Computation:
[tex]\frac{P}{K}= \frac{P1}{K1} \\\\\frac{1.88}{298}= \frac{P1}{310}\\\\1.9557[/tex]
New pressure in an automobile tire (P1) = 1.9557
New pressure in an automobile tire (P1) = 1.96 (Approx)
Carlos stomps a soda con flat and throw it away. Which of the following statements BEST describes the change made in the soda can?
The soda can kept the same mass as it changed in shape only
The soda can lost mass as it was changed into a smaller size
The soda con gained more moss because its shape changed
The soda can lost mass as it was crumpled and changed form
Answer:
The soda can kept the same mass as it changed in shape only
Explanation:
Law of Conservation states "mass cannot be created or destroyed" therefore this is why the mass hasn't changed, but when it was smashed the shape changed.
Final answer:
The soda can's mass remains the same after being stomped and flattened, as no matter is added or removed during this physical change, which is explained by the Law of Conservation of Mass.
Explanation:
The statement that best describes the change made in the soda can after Carlos stomps on it is that the soda can kept the same mass as it changed in shape only. This is explained by the Law of Conservation of Mass, which states that the mass of a closed system of substances will remain constant, regardless of the processes acting inside the system. Therefore, even though Carlos changed the can's shape by stomping on it, he did not add or remove matter from the can, so its mass remained unchanged. This principle is crucial in chemistry and holds true for both physical changes, like changing the shape of a can, and chemical changes, where substances may change form but the total mass remains constant.