Answer:
The reaction in the cold pack is an endothermic reaction
Explanation:
An endothermic reaction is a reaction that absorbs energy (heat) from the surrounding to supply the required energy of activation that allows the occurrence of the reaction
Therefore, when a reaction is endothermic, it boundary or the system where the reaction is occurring feels cold to touch
Hence, the reaction in the cold pack is an endothermic reaction.
The reaction in a cold pack is exothermic, as it releases heat energy to create the cooling effect.
Explanation:Cold packs are designed to treat injuries by providing a cooling effect. When the pack is snapped, a chemical reaction occurs inside the pack, resulting in the release of cold temperatures. This reaction is exothermic because it releases heat energy to the surroundings.
Inside the cold pack, there are reactants separated by a barrier. When the pack is snapped, the barrier breaks, allowing the reactants to mix. One common reactant in cold packs is ammonium nitrate, and when it is mixed with water, it undergoes an exothermic reaction. This reaction releases energy in the form of heat, making the pack feel cold.
In conclusion, the reaction in a cold pack is exothermic because it releases heat energy, resulting in the pack feeling cold when activated.
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What is the medium of sound?
water
solids
Ogases
air, liquids, or solids
Answer:
Air, liquids or solids.
Explanation:
Sound is a form of mechanical waves, which needs a material medium to propagate. There is no sound in the void. Sound can be propagated in gases, liquids and solids. The best choice is "Air, liquids or solids".
Which of the following statements about a base are TRUE?
1. Bases are used in the manufacturing of soap.
2. Bases have a sour taste.
3. Fertilizer manufacture and cotton processing use bases.
1 and 3 only
2and 3 only
All of 1, 2, and 3
1 and 2 only
Answer:
explanation:
1
In which form is energy stored at the end of photosynthesis?
A. Proton energy
B. Electron energy
Oo oo
c. Solar energy
D. Chemical energy
Answer:Chemical energy
Explanation:
Why does a pan of warm water eventually become the same temperature as the room it is in
Final answer:
A pan of warm water will become the same temperature as the room because of heat transfer due to non-equilibrium. Heat will move from the warm pan to the cooler room air until they reach thermal equilibrium. This process is guided by the second law of thermodynamics and the principle of calorimetry.
Explanation:
A pan of warm water will eventually become the same temperature as the room it is in because the water and the pan will exchange heat with the room's air until thermal equilibrium is reached. Initially, the pan is at a higher temperature than the surrounding air. Over time, heat is transferred from the warmer object (the pan with water) to the cooler one (the surrounding air) until both reach the same temperature. This principle is based on the second law of thermodynamics, stating that the heat will always flow from a hotter object to a cooler one until the system reaches equilibrium.
When you pour 0.250 kg of 20.0°C water into a 0.500-kg aluminum pan with a temperature of 150°C and place it on an insulated pad, the pan and the water are initially not in thermal equilibrium. However, due to the rapid heat transfer, they will quickly exchange heat. The heat lost by the pan equals the heat gained by the water. The process continues until they are both at the same temperature, known as the thermal equilibrium.
What would happen to density if the amount of the sample was increased? What is a compound?
Answer:
Density directly proportional to mass and inversely proportional to volume, if you increase the density of the mass increases and vice versa, if you increase the volume density decreases and vice versa.
A compound is something that is composed of two or more separate elements; a mixture.
Explanation:
The Ka of carbonic acid is 4.3 x 10-7.
H2CO3 = H+ + HCO3
This means that H2co3 is a____.
A.good hydrogen-ion donor
B. poor hydrogen-ion donor
C. good hydrogen-ion acceptor
Answer:
poor hydrogen-ion donor
Explanation:
Acid dissociation constant constant chemistry is the equilibrium constant of the dissociation reaction of an acid, it is denoted by Ka. This equilibrium constant is a measure of the strength of an acid in a solution.
Note these as a rule of thumb:
When Ka is large, the dissociation of the acid is favored.
When Ka is small, the acid does not dissociate to a large extent.
Hence, a Ka of 4.3 x 10-7 shows a weak acid. A weak acid is a poor hydrogen ion donor because it does not dissociate to a large extent in solution.
According to its chemical reaction where it donates a hydrogen ion, and despite having a small Ka value, H2CO3 (carbonic acid) can be classified as a relatively good hydrogen-ion donor.
Explanation:Given that the equation H2CO3 = H+ + HCO3- represents the dissociation of carbonic acid into a hydrogen ion (H+) and a bicarbonate ion (HCO3-), H2CO3 can be identified as a good hydrogen-ion donor. This is because in this reaction, it readily gives up a hydrogen ion, which is characteristic of acid behavior. An acid's strength is determined by its ability to donate hydrogen ions, and the bigger the constant Ka value, the stronger the acid. However, a Ka of 4.3 x 10-7 is quite small, indicating that carbonic acid does not completely ionize in solution but it's relatively better at donating hydrogen ions than accepting them.
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Why might a scientist repeat an experiment if he/she did not make a mistake in the first one? An experiment should be
repeated to
A)
increase income for increased work.
B)
prove how interesting the study was.
C)ensure the results are accurate,
D)
eliminate steps and save time.
Answer:
c) ensure the results are accurate
Explanation:
you don't really know they're accurate unless you get them 2+ times
What is the hydrogen ion concentration of a substance with a pH of 4.5?
Answer:
The hydrogen ion concentration of the substance is 3.16*10⁻⁵ M
Explanation:
pH is a parameter used to measure the degree of acidity or alkalinity of a substance. The pH is calculated as the negative logarithm (base 10) of the concentration of hydronium ions [H₃O⁺] or hydrogen ions [H⁺].
pH= - log [H₃O⁺]= - log [H⁺]
Values on the pH scale range from 0 to 14, where pH equal to 7 is neutral, below 7 is acidic and above 7 is basic.
In this case, pH= 4.5
So:
4.5= - log [H⁺]
Solving:
[ H⁺]= 10⁻⁴ ⁵
[H⁺]= 3.16*10⁻⁵ M
The hydrogen ion concentration of the substance is 3.16*10⁻⁵ M
What is the substance called that is being dissolved in a solution?
concentrator
solute
mixture
solvent
What is the substance called that dissolves the other substance in a solution?
mixture
solvent
solute
concentrator
Answer:
Solute, solvent
Explanation:
In a solution, the substance that is dissolved is called the solute, and the substance that does the dissolving is called the solvent. Together, they form a solution, which is a homogeneous mixture where the solute is evenly distributed in the solvent.
Explanation:In a solution, the substance that gets dissolved is called the solute. For instance, when you make a cup of tea, the tea leaves (or tea bag) represent the solute, as they get dissolved in the water. Meanwhile, the substance that does the dissolving is referred to as the solvent. In the tea example, the water would be the solvent because it is the substance that dissolves the tea leaves or tea bag.
The process of a solvent dissolving a solute results in a solution, a homogeneous mixture where the solute is uniformly distributed within the solvent.
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Write the steps that describe the process of water changing from a solid to a liquid, and from a liquid to a gas. Ice, Liquid water, Steam
The steps which we taken into consideration during the changing of state of water from ice to steam are by increasing the temperature or by providing heat.
What is change of state of matter?When any amount of energy is released or absorbed by any matter as a result of which changes in state of matter of substance takes place.
Solid state of water is ice and this form will change into liquid form means into liquid by the absorption of energy.Liquid water will change into steam when we provide heat by increasing the temperature to 100 degree celsius.Hence, the steps that required to change ice to steam is by increasing temperature.
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Based on the kinetic molecular theory, which of the following statements is correct about a sample of gas at a constant temperature and volume?
The net kinetic energy of its particles decreases due to collisions.
The net kinetic energy of its particles increases due to collisions.
It has a constant average kinetic energy.
Its average kinetic energy is always zero.
Answer:
C) It has a constant average kinetic energy
Explanation:
The average kinetic energy of the particles in a gas is directly proportional to the temperature of the gas, according to the equation.
k is the Boltzmann's constant
T is the absolute temperature of the gas
Therefore, temperature of a gas is a measure of the average kinetic energy of the particles.
In this problem, we are told that the gas is at constant temperature (and volume): therefore, according to the previous equation, this means that the average kinetic energy is also constant.
Answer:
C - It has a constant average kinetic energy
Explanation:
Got it right on the test
Which method is most likely used to identify what happened before the start of the paleozoic era?
Answer:C
Explanation:
on edge
Please help! I really don’t understand it
Answer:
C. It makes sure there is a balance inside the body
Explanation:
Hope this helps
Answer:
C. It make sure there is a balance inside the body.
Explanation:
Homeostasis in the body tries to maintain the norm for the survival of the body. This includes temperature & amount of fluids inside the body. If they are too out in the end of the spectrum, your brain will tell you that you need to obtain it, such as drinking more water, going to a cool place if you are in the heat, or to obtain warmth if you are in the cold.
Using your knowledge of the difference
between the three different temperature scales,
what do you think would happen if a human's
body temperature were 98.6 °C? Why do
doctors worry more about a fever of a couple
of degrees Celsius than a fever of a couple of
degrees Fahrenheit?
Besides genetics, what other factors are responsible for
how you will grow and develop?
Answer:
D
Explanation:
It depend on your parents genes. What they have, is what you'll have.
~Jack Pullman
p.s. Mark for brainiest!
Answer:
C. Nutrition and Enviroment
Explanation:
An individual growing up in poverty will not get as the good nutrition as an individual from a rich household. Nutrition affects growth, so malnutrition can make a person shorter and ruining their potentially taller height.
which of the following colors has the highest energy?
a. red
b. green
c. yellow
d. blue
Answer:
Blue
Explanation:
It is the closest color to violet.
The color which has the highest energy is the blue color because it have low wavelength value.
How do we calculate energy of wave?Energy of any waves of color will be calculated by using the below equation as:
E = hυ, where ............... (i)
h = plank's constant
υ = frequency of wave
Frequency is inversely proportional to wavelength (λ) as:
υ = c/λ, where ................. (ii)
c = speed of light
From (i) & (ii)
E = hc/λ
From this we conclude that wavelength is inversely proportional to energy and wavelength of blue color is smaller than other so that it will have higher energy.
Hence blue color has the highest energy.
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Some plant seeds are adapted to sprout with a limited amount of water. For what environmental change are these seeds most likely adapted? earthquake tsunami drought global warming
Answer:
c
Explanation:
edge 2023
Calculate the volume of a 0.323-mol sample of a gas at 265 K and
0.900 atm.
Answer:
V = 7.8 L
Explanation:
Message
The volume of gas of 0.323 mole sample of a gas at 265 K and 0.900 atm is 7.798L.
What is ideal gas equation?Ideal gas equation gives idea about the behavior of gas at different condition & represented as:
PV = nRT, where
P = pressure = 0.9 atmV = volume = ?n = moles = 0.323 molR = universal gas constant = 0.082 L.atm / K.molT = temperature = 265KOn putting all these values on the above equation, we get
V = (0.323)(0.082)(265) / (0.9) = 7.798 L
Hence required volume of gas is 7.79L.
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With the upcoming presidential election, Ira decided to create a survey to find out who might win. He carefully created a vali
survey and gave it to five of his closest friends. He then tallied the results from the surveys and published his data in the sche
newspaper. Which of these would be a reason why Ira's results are not valid?
A)
The survey was not good enough
B)
The sample size of five was too small.
C)
There is not problem; the results are valid
D)
He only published his data in a school newspaper.
Answer:B)
The sample size of five was too small.
Explanation:
Anthony's homework assignment is to demonstrate that an orange has already undergone a chemical change. Which of the following
should he bring to class to best demonstrate a chemical change?
A. Diced orange
B. Rotten orange
C. Peeled orange
D. Mashed orange
All of the following are true about science except (2 points)
it is a body of knowledge.
it can be disproven by philosophy or religion.
it is tested by many scientists over time.
it uses the scientific method.
Any one help me on this one
Answer:
0.0679
Explanation:
A car has initial velocity of 50 m/s and a constant acceleration of 50 m/s2, whats the car velocity after 3 seconds?
Answer:
200 m/s.
Explanation:
The car's velocity after 3 seconds can be calculated using the kinematic equation:
v= u+ at
Given:
- Initial velocity, u = 50m/s
- Acceleration, a = 50m/s2
- Time, t = 3 s
Plugging the values into the equation:
v = 50 + 50 * 3
v = 50 + 150
v = 200 m/s
Therefore, the car's velocity after 3 seconds will be 200 m/s. Hope this helps!!
The car's velocity after 3 seconds is 200 m/s, calculated using the formula for final velocity with an initial velocity of 50 m/s and an acceleration of 50 m/s².
To find the final velocity of a car with an initial velocity and constant acceleration, you can use the formula v = u + at, where v is final velocity, u is initial velocity, a is acceleration, and t is time.
In this case, the car has an initial velocity (u) of 50 m/s and a constant acceleration (a) of 50 m/s². After 3 seconds (t), we can calculate the final velocity using the formula:
v = u + at
v = 50 m/s + (50 m/s² × 3 s)
v = 50 m/s + 150 m/s
v = 200 m/s
Therefore, the car's velocity after 3 seconds is 200 m/s.
- 2 Points
An object is located 75.0 cm from a concave mirror. The magnitude of the
mirror focal length is 15.0 cm. What is the image distance? Use the equation
d = auf
O A. 12.5 cm
O B. -18.8 cm
O C. -12.5 cm
O D. 18.8 cm
SUBMIT
Answer:
18.8
Explanation:
Just trust me it’s Ap3x Things
Answer:
18.8
Explanation:
*wink wink*
How many joules of energy would it take to raise the temperature of 2.5 grams of magnesium metal from
25°C to 50°C
Report your answer with two significant digits, leave a space, and add the unit.
Answer:
Q = 63.75J
Explanation:
Mass = 2.5g
Initial temperature (T1) = 25°C
Final temperature (T2) = 50°C
Specific heat capacity of Mg = 1.020J/g°C
Heat energy = ?
Heat Energy (Q) = mc∇T
Q = heat energy
M = mass of substance
C = specific heat capacity of substance
∇T = change in temperature = T2 - T1
Q = mc∇T
Q = mc(T2 - T1)
Q = 2.5 × 1.020 × (50 - 25)
Q = 2.55 × 25
Q = 63.75J
The heat energy required to raise magnesium metal from 25°C to 50°C is 63.75J
A substance is made up of slow-moving particles that have very little space between them. Based on this information, what
can most likely be concluded about this substance?
It is not a gas because its particles do not move continuously.
It is a gas because its particles move continuously in a straight line,
O It is not a gas because its particles do not have large spaces between them.
O It is a gas because its particles move in many different directions.
Mark this and return
Save and Exit
Next
Submit
Answer:
It is not a gas because its particles do not have large spaces between them.
Explanation:
[BWS.05H] The diagram below shows an incorrect model of an atom.
What best describes a flaw in the model of the atom?
Common errors in atomic models can include incorrect placement of subatomic particles, improper scale, misunderstanding of atomic space, or misrepresentation of electron paths as demonstrated in the Bohr model.
Explanation:Without seeing the specific diagram referenced in the question, it's hard to identify the exact flaw in the model of the atom. However, common mistakes in atomic models often include misplacing the subatomic particles (protons, neutrons, and electrons), misunderstanding the scale of the atom, or ignoring the fact that atoms are mostly empty space. For example, in the Bohr model of the atom, electrons orbit the nucleus in definite paths, which is an inaccurate depiction according to quantum mechanics.
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help need due tonight!!!
Which equation is used to describe reaction rates?
S products−S reactants
∆H−T∆S
pV=nRT
∆(reactant or product)/∆time
Answer: [tex]Rate=\frac{\Delta_{\text {reactants or products}}}{\Delta_{time}}[/tex]
Explanation:
Rate law says that rate of a reaction is directly proportional to the concentration of the reactants each raised to a stoichiometric coefficient determined experimentally called as order.
Rate of reaction can be defined in terms of reactants or products. It is the ratio of disappearance of reactants per unit time or ratio of appearance of products per unit time.
[tex]Rate=\frac{\Delta_{reactants}}{\Delta_{time}}[/tex] or [tex]Rate=\frac{\Delta_{products}}{\Delta_{time}}[/tex]
[tex]S_{products}-S_{reactants}[/tex] gives the entropy change for the reaction.
[tex]\Delta H-T\Delta S[/tex] gives Gibbs free energy.
[tex]PV=nRT[/tex] is the ideal gas equation.
Final answer:
Chemical kinetics equation for reaction rates and how rates of reactions depend on reactant and product concentrations.
Explanation:
Reaction rates in chemical kinetics are described by the equation: rate = k[A]m[B]n , where k is the rate constant, m and n are exponents determined experimentally, and m+n is the reaction order.
The rate of a chemical reaction can be expressed as the change in concentration of reactants or products over time. In general, the rate of reaction depends on the concentration of reactants or products involved in the reaction.
For a net forward reaction under rapid equilibrium conditions, the rate equation can be derived and expressed in terms of concentrations of reactants and products.
What is the empirical formula for
C12H10O
The empirical formula is Diphenyl ether. 2-Phenylphenol, or o-phenylphenol.
For the empirical formula of a compound, you need to find the simplest, whole-number ratio of the elements present in the compound. The given molecular formula is C12H10O.
1. Determine the number of moles for each element:
Carbon (C): 12 moles
Hydrogen (H): 10 moles
Oxygen (O): 1 mole
2. Find the simplest, whole-number ratio by dividing each mole value by the smallest number of moles (which is 1 in this case):
C: 12 moles / 1 = 12
H: 10 moles / 1 = 10
O: 1 mole / 1 = 1
So, the empirical formula is Diphenyl ether. 2-Phenylphenol, or o-phenylphenol.
Using the equation, what is the mass of lithium nitride is produced from 12.26 L of ammonia?
Answer:
19.2g
Explanation:
The equation of the reaction is;
Li3N(s) +3H2O(l) ---->NH3(g) +3LiOH(aq)
From Avogadro's law we know that 1 mole of any gas occupies a volume of 22.4 L under standard conditions.
It is also clear from the equation that 1 mole of lithium nitride produces 1 mole of ammonia occupying 22.4L volume
Hence;
1 mole of Lithium nitride yields 22.4 L of ammonia
x moles of lithium nitride yields 12.26L of ammonia
x= 12.26×1/22.4
x= 0.55 moles of lithium nitride
Molar mass of lithium nitride= 34.83 g/mol
Mass of lithium nitride = number of moles × molar mass
Mass of lithium nitride= 0.55 moles × 34.83 g/mol
Mass of lithium nitride = 19.2g
Answer:
The mass of lithium nitride that produces 12.26 L of ammonia is 19.053 g
The mass of lithium hydroxide produced is 39.3 g
Explanation:
Water and Lithium nitride combine to form ammonia and lithium hydroxide the equation for the reaction being;
Li₃N(s) + 3H₂O(l) → NH₃ (g) + 3LiOH (aq)
That is 1 mole of lithium nitride combines with 3 moles of water molecules to form 1 mole of ammonia gas plus 3 moles of lithium hydroxide
Whereby the volume of ammonia produced is 12.26 L, we have at STP
PV = nRT
Therefore, n = PV/RT
Where:
P = Pressure = 1 atm
V = Volume = 12.26 L
R = Universal gas constant = 0.08205 L·atm/(mol·K)
T = Temperature = 273.15 K
Plugging the values in gives;
n = (1×12.26)/(0.08205×273.15) = 0.547 moles
Since 1 mole of lithium nitride forms 1 mole of NH₃, 0.547 mole will be required to produce 0.547 moles of NH₃ and 3×0.547 or 1.64 moles of LiOH
Molar mass of Li₃N = 34.83 g/mol
Molar mass of LiOH = 23.95 g/mol
Since mass = Number of moles × molar mass, we have;
Mass of Li₃N = 0.547 × 34.83 = 19.053 g
Mass of LiOH = 1.64 × 23.95 = 39.3 g
Therefore;
The mass of lithium nitride that produces 12.26 L of ammonia = 19.053 g
The mass of lithium hydroxide produced = 39.3 g.