Answer: endothermic
Explanation: A chemical reaction or physical change is endothermic if heat is absorbed by the system from the surroundings.
Avogadro’s number is the number of particles in one mole of a pure substance, true or false?
Answer: The answer is true.
Explanation: Avogadro's number is a mole, which concludes that this statement is true.
What foods have peroxides?
Answer: Wheat flour, edible oil, egg white, lettuce preservative, meat or poultry marinade, vegetable antibacterial wash.
Explanation:
hydrogen peroxide is used as a bleaching agent in some food
I hope this helped
7.8 L =mLDimensional AnalysisRatio:ProportionFormula MethodmLХLx mL=IImL11
answer and explanation
1 L = 1000 mL
and so to determine 7.8L we can o the calculation as follows
x mL = 1000 mL/ 1 L x 7.8 L/1 = 7800 mL/1 = 7800 mL
A certain gas has a volume of 195 mL at 20°C and 1.00 atm. What is the its volume in mL at60°C and 600 mm Hg?
To solve this question we will assume that the moles of gas do not change and that the gas behaves like an ideal gas.
For an ideal gas we have that its behavior will be according to the following equation:
\(PV=nRT\)Where,
P is the pressure of the gas, in atm
V is the volume of the gas, in liters
n are the moles of the gas
T is the temperature of the gas, in Kelvin
R is a constant, 0.08206 atm.L/mol.K
We have for this gas two states, an initial state (1) and a final state (2), so for each state we can apply the ideal gas law, we will have:
Initial state:
\(\begin{gathered} P_1V_1=nRT_1 \\ nR=\frac{P_1V_1}{T_1} \end{gathered}\)Final state:
\(\begin{gathered} P_2V_2=nR_T_2 \\ nR=\frac{P_2V_2}{T_2} \end{gathered}\)Since nR are constants, we can equate both equations:
\(\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}\)For each state the conditions of pressure, volume and temperature will be:
P1=1.00atm
V1=195mL = 0.195L
T1=20°c = 293.15K
P2= 600mmHg=0.79atm
T2=60°C=333.15K
V2=Unknown
We clear V2 and replace the known data:
\(V_2=\frac{P_1V_1}{T_1}\times\frac{T_2}{P_2}\)\(\begin{gathered} V_2=\frac{1atm\times0.195L}{293.15K}\times\frac{333.15K}{0.79atm} \\ V_2=\frac{1\times0.195\times333.15}{293.15\times0.79}L \\ V_2=0.280L=280mL \end{gathered}\)Answer: The final volume of the gas will be 280mL
10. What is the mass of 2.6 moles of Ag?
O 2.4 x 10-2 g
O 2.9 g
O 280 g
O 1.6 x 1024 g
Answer: 280 g
Explanation:
Hydrogenation is a chemical reaction between hydrogen gas and another substance. Hydrogenation of vegetable oils takes place in the presence of a metal catalyst. What kind of catalyst is this?
The catalyst used in the hydrogenation of vegetable oils is a transition metal, commonly nickel, which facilitates the addition of hydrogen atoms to the unsaturated carbon-carbon double bonds in the oil molecules, resulting in a solid product with improved stability and shelf life.
Hydrogenation is a chemical reaction where hydrogen gas (H2) is combined with another substance, often to convert unsaturated molecules into saturated ones. In the case of vegetable oils, hydrogenation is employed to turn liquid oils into solid fats, such as margarine or shortening. This process enhances the stability, shelf life, and melting point of the oils.
The catalyst used in the hydrogenation of vegetable oils is typically a metal, often a transition metal. Common catalysts include nickel, palladium, platinum, and sometimes even rhodium. These metals facilitate the addition of hydrogen atoms to the unsaturated carbon-carbon double bonds found in the vegetable oil molecules. Nickel, being relatively inexpensive and effective, is the most commonly used catalyst in this process.
During the hydrogenation reaction, the vegetable oil is heated and mixed with hydrogen gas. The metal catalyst is introduced, and its presence accelerates the reaction, allowing the hydrogen atoms to be added to the oil molecules efficiently. The result is a product with a higher percentage of saturated fatty acids, leading to its solid state at room temperature.
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If the electronnegavity difference between elements A and X is 0.8, the bond in AX will most likely be what?
Answer:
Polar covalent bond
Explanation:
When the electronegativity difference between two elements A and X is 0.8, the bond AX formed will most likely be a polar covalent bond.
A polar covalent bond is one whose electronegativity difference is between 0.5 and 2.1.
In such a bond type, we have heteronuclear species with one of the species having a higher electronegativity value.
When electronegativity difference is less than 0.5, a non-polar covalent bond forms. If the value is greater than 2.1, an ionic bond will form.how to sold equation with periodic table of elements?
Answer:
6w6288shbdmdkdhckcncjciicjcididjdn dmxixisk ddjdidjjd
Explanation:
dnnxjxkxjxjndnfncjcshndnsbsnnsnssbsnsnsnsndndndnx
Transpiration is when a plant releases water vapor through its stomata, which are pours in its leaves and stems. What other process in the water cycle is this most similar to? explain your reasoning.
In addition to respiration, a process known as guttation involves the loss of liquid water from a plant's healthy leaf or stem, mostly through water stomata.
What is the transpiration process?The physiological loss of water . water of water vapor, mostly from the stomata of leaves, but also by evaporation first from surfaces of leaf tissue, flowers, and stems, is known as transpiration.
Why is transpiration necessary to plants?Additionally, by providing evaporative cooling, vegetation transpiration makes a major contribution to the energy balance of the leaf. Additionally, transpiration speeds up the movement of nutrients and water from roots to the shoots. Transpiration occurs when water vapor leaves a plant through the stomata.
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HELP!!! >_<
Instructions: Write and balance molecular equations for the following reactions between aqueous solutions. You will need to decide on the formulas and phases of the products in each of the cases.
Question: An aqueous solution of barium nitrate is mixed with an aqueous solution of potassium phosphate.
Balanced chemical equation:
\(3 Ba(NO3)2 (aq) + 2 K3PO4 (aq) ----- > 6 KNO3 (aq) + Ba3(PO4)2(s)\)
What is double-displacement reaction?
In an aqueous solution, a double-displacement reaction takes place when the positive and negative ions of two ionic compounds exchange positions to form two completely different compounds.
Chemical formula for :
Barium nitrate---> Ba(NO3)2 (aq)
Pottasium Phosphate = K3PO4 (aq)
Reaction between these two is a type of double displacement type reaction in which ions are exchanged , forming
Pottasium Nitrate -----> KNO3 (aq)
Barium Phosphate -----> Ba3(PO4)2 (s)
(aq) means the phase is aqueous and (s) means phase is solid or the compound precipitated out .
Now, writing the molecular formula using the above data , we get:
\(Ba(NO3)2 (aq) + K3PO4 (aq) ------ > KNO3 (aq) + Ba3(PO4)2 (s)\)
A equation is called balanced when number of chemical species are same on both sides of the equation .
Here, in product side there are 3 Ba and 2 (PO4) and only 1 Ba and 1 PO4 in reactant side to balance this let's multiply
2 with K3PO4 on reactant side and ,
3 with Ba(NO3)2 on reactant side
The equation thus becomes:
\(3 Ba(NO3)2 (aq) + 2 K3PO4 (aq) ------ > KNO3 (aq) + Ba3(PO4)2 (s)\)
Now,
There are 6 K atoms on reactant side to balance this let's multiply 6 with KNO3 in product side by doing so we also balanced NO3.
Consequently, the balanced chemical equation is
3 Ba(NO3)2 (aq) + 2 K3PO4 (aq) ----- > 6 KNO3 (aq) + Ba3(PO4)2(s)
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Consider the following reaction:
2H2(g) + O2(g) → 2 H₂O(g)
-
How many liters of H₂ are required to produce a total of 2 moles
of H₂O at STP?
89.4 L
67.2 L
44.8 L
22.4 L
44.8 liters of H₂ are required to produce a total of 2 moles of H₂O at STP. Therefore, option C is correct.
What is stoichiometry ?The term stoichiometry is defined as the determination of the proportions in which elements or compounds react with one another.
The rules followed in the identification of stoichiometric relationships are based on the laws of conservation of mass and energy and the law of combining weights or volumes.
The balanced reaction is:
2 H₂ + O₂ → 2 H₂O
By reaction stoichiometry, the following amounts of moles of each compound participate in the reaction:
H₂ - 2 moles
O₂- 1 mole
H₂O - 2 moles
The STP conditions refer to the standard temperature and pressure, which values are 0 °C and 1 atmosphere as a reference values for gases. In these conditions 1 mole of any gas occupies an approximate volume of 22.4 liters.
For calculate the number of moles of O₂ required, you can observe the stoichiometry of the reaction. By reaction stoichiometry 2 moles of H₂O are produce by 2 moles of H₂.
Then, you can apply the following rule of three:
if by definition of STP conditions 1 mole of H₂ occupies a volume of 22.4 liters, 2 moles occupy how much volume?
volume = (2 moles× 22.4 L)/ 1 L
= 44.8 L
Thus, 44.8 liters of H₂ are required to produce a total of 2 moles of H₂O at STP, option C is correct.
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the heat of fusion of butane is 80.3 j/g. how much heat is needed to melt 25.0 g of butane? question 47 options: 105.3 j 3.21 j 80.3 j 2.01 x 103 j
The heat needed to melt 25.0 g of butane is 2.01 x 10³ J
To find the amount of heat needed to melt 25.0 g of butane with a heat of fusion of 80.3 J/g, you can use the following equation:
Heat needed = (mass of butane) × (heat of fusion)
Step 1: Identify the mass of butane and the heat of fusion.
Mass of butane = 25.0 g
Heat of fusion = 80.3 J/g
Step 2: Multiply the mass of butane by the heat of fusion.
Heat needed = (25.0 g) × (80.3 J/g)
Step 3: Calculate the heat needed.
Heat needed = 2007.5 J
Rounding to the appropriate significant figures, the closest answer is 2.01 x 10³ J. Therefore, 2.01 x 10³ J of heat is needed to melt 25.0 g of butane.
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WILL VOTE BEST & GIVE 25 POINTS - PLEASE ANSWER
Your mom needs some pills from the Walgreens pharmacy for her diabetic medication. If one of the
pills weighs 650mg and the technician weighs exactly 15.6g of pills, how many pill were dispensed
and placed into the pill bottles. Show all work with units.
Answer:
24 pills
Explanation:
650 mg/1000 = 0.65 g
(There are 1000 mg in one g)
15.6g/0.65g=24
Why is it usually not possible to recrystallize a liquid substance? Select an answer and submit. For keyboard navigation, use the up/down arrow keys to select an answer. a. liquids have too much kinetic energy b. liquids transition to gases easier than to solids c. liquids have high potential energy d. liquids at room temperature do not readily transition into solids or crystals e. all of the above
Liquids at room temperature do not readily transition into solids or crystals (Option D) is why is it usually not possible to recrystallize a liquid substance.
Why is it usually not possible to recrystallize a liquid substance?Recrystallization involves dissolving a solid in a suitable solvent and then allowing it to cool and reform into crystals. However, liquids do not readily form crystals at room temperature because their molecules are disordered and lack the organized arrangement necessary for crystal formation.
Additionally, liquids may have insufficient intermolecular forces to hold the crystal lattice together. Therefore, recrystallizing a liquid substance is usually not possible.
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using the chemical equation from the previous problem (question 4), identify the spectator ions:- Phosphide ion- Phosphite ion - Barium ion - Phosphate ion - Sulfate ion - Sulfite ion - Beryllium ion - Ammonium ion - Sulfide ionThe equation is 2(NH4)3PO4+3BaS=3(NH4)2S+Ba3(PO4)2
Ammonium ion (NH4+) and Phosphate ion (PO4^3-) are the spectators ions.
In the given chemical equation, 2(NH4)3PO4 + 3BaS → 3(NH4)2S + Ba3(PO4)2, the spectator ions are those that appear in both the reactants and products of the reaction, but do not undergo any chemical change. In this case, the ammonium ion (NH4+) and phosphate ion (PO43-) are spectator ions. They appear in both the reactant (NH4)3PO4 and product NH4)2S and Ba3(PO4)2 respectively.
However, the phosphide ion (P3-), phosphite ion (PO33-), sulfate ion (SO42-), sulfite ion (SO32-), and beryllium ion (Be2+) are the ions involved in the chemical reaction. These ions react with each other and result in the formation of new compounds.
It is essential to identify the spectator ions in a chemical equation to determine the actual reactants and products involved in the reaction. This information is crucial in determining the stoichiometry of the reaction and calculating the amount of product formed or reactant consumed, Thus, identifying the spectator ions helps in the accurate representation of the chemical reaction and its various aspects.
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how many elements are in 2CaCO3 pls help
In 2CaCO3 there are 3 elements
I hope that helped you! If you have any further questions comment down below or message me! Good luck!
ph before and after sulphuric acid is added
Answer:
added to what? base? if its added to base then it will increase in pH. H2S04(sulphuric acid is strong) so the pH is ard 3
Someone help me please! I will mark brainliest if it’s right!
Answer:
a) compound
b)element
c)mixture
d)compound
Explanation:
can waves travel through empty space? why?
Answer:
Elctromagnetic waves can travel through empty space.
Explanation:
Waves that may pass through matter or empty space are known as electromagnetic waves. The electromagnetic field, like the other basic fields, penetrates the whole universe, including the region we refer to as empty space. There are no fields in space. The medium through which electromagnetic waves travel is called the electromagnetic field.
what is a significant figure of 0.502 ?
What happens when a chemical hand warmer is unwrapped and starts to work?
A. A physical change absorbs thermal energy.
B. A chemical reaction absorbs thermal energy.
C. A physical change releases thermal energy.
D. A chemical reaction releases thermal energy.
Answer: D. A chemical reaction releases thermal energy.
Explanation:
Hope this helps! <3 :)
If the following elements were involved in redox reactions, which noble-gas configuration would they most likely attain?
Appropriate elements to their respective bins. ( He OR Ne OR Ar OR Kr ); for { Li, Al, O, P, K, Se, Sr }
The elements would most likely attain a noble-gas configuration of He, Ne, Ar, or Kr. The appropriate elements for their respective bins are Se would gain two electrons to attain a noble-gas configuration of Kr. Sr would lose two electrons to attain a noble-gas configuration of Kr.
Noble gases are the most stable elements because their outermost electron shells are fully occupied, which is what the other elements aim to achieve. Noble gas configuration is the electron configuration of noble gases, which are the most stable elements. The electron configuration of the nearest noble gas is achieved by adding or removing electrons from the atom. Each of the seven periods in the periodic table corresponds to a specific block of the periodic table. The 1s block is called the first period, the 2s2p block is the second period, and so on.
The elements Li, Al, O, P, K, Se, and Sr belong to different blocks of the periodic table, so they each have different electron configurations.
The electron configurations of Li, Al, O, P, K, Se, and Sr are 1s2 2s1, [Ne] 3s2 3p1, [He] 2s2 2p4, [Ne] 3s2 3p3, [Ar] 4s1, [Ar] 3d10 4s2 4p4, and [Kr] 5s2, respectively.
To achieve a noble-gas configuration, these elements would lose or gain electrons as follows: Li would lose one electron to attain a noble-gas configuration of He. Al would lose three electrons to attain a noble-gas configuration of Ne. O would gain two electrons to attain a noble-gas configuration of Ne.
P would gain three electrons to attain a noble-gas configuration of Ar. K would lose one electron to attain a noble-gas configuration of Kr.
Se would gain two electrons to attain a noble-gas configuration of Kr. Sr would lose two electrons to attain a noble-gas configuration of Kr.
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(First to answer gets some good) Order the following components of the universe from largest to smallest: Moon, planet,universe,star,galaxy,nebula,comet!
Answer:
Universe, galaxy, solar system, star, planet, moon and asteroid.
Explanation:
You're welcome!
Polar bonds share electrons _______.
Why are xrays used to probe the crystal structure of a material
Answer:
Because X-rays have wavelengths similar to the size of atoms
X rays are used to probe the crystal structure of a material because this have same wavelength as atoms of crystal have.
What are x rays?X rays are the type of electromagnetic radiations and it is produced when the fast moving electron collide with the target anode and sudden deceleration takes place.
X rays have the high energy so that it easily penetrate in any crystal molecule as they also have same wavelength as atoms of the crystals have.
Hence due to high energy and same wavelength was of atoms of crystal it is used to probe the crystal.
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What is a daughter element
Answer:
The element formed when a radioactive element undergoes radioactive decay. The latter is called the parent. The daughter may or may not be radioactive.
Explanation:
hope this helps
whic solvent ration gave the best separatoin of the pigments why was that the case
The solvent ratio that provided the best separation of pigments depends on the specific pigments and their solubility characteristics. Different pigments have varying degrees of solubility in different solvents, so the ideal solvent ratio for separation will vary.
The best solvent ratio for separating pigments depends on their solubility properties. Pigments can have different solubilities in various solvents due to differences in their molecular structures and intermolecular interactions. Some pigments may be more soluble in polar solvents, while others may be more soluble in nonpolar solvents.
When selecting a solvent ratio for pigment separation, it is important to consider the desired outcome. If the goal is to achieve a broad separation of pigments, a solvent system with a moderate polarity, such as a mixture of polar and nonpolar solvents, might be suitable. This combination can provide a balance between solubility and selectivity, allowing for the separation of a wide range of pigments.
However, if the objective is to achieve a specific separation of pigments with similar solubility characteristics, a solvent ratio that is more polar or nonpolar might be preferred. This choice can enhance the resolution between closely related pigments by exploiting their different solubilities in the solvent system.
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Neutral atoms & charged atoms has
equal number of electrons
Answer:
wrong.
Explanation: charged atoms have have more electrons than neural because they charge it . a neural atom has eaqual number of electrons and neutrons.
hope this helps(^人^)
Researchers ohtained a savide of statisfics for systolic blood pressure show a mean of 132 mmtte and a stardiard deviation of 33, while the heart rates have a mean of 99 bcim and a standiard deviafion of 27 Question 24 (3 polnts) One patient had a systolic blood pressure of 204mmHg. Find the z-score associated with this blood pressure value. Show your work in order to recelve partial credit. Question 25 (3 points) Question 25 (3 points) The same patient had a heart rate of 52bpm. Find the z-score associated with this patient's heart rate. Show your work in order to recelve partiai credit. Question 26 (2 points) Which of these values is more unusual relative to the other patients in the sample this individual's systolic blood pressure or their heart rate? Explain your rensoning.
The more unusual the value is relative to the other values in the dataset .In this case, the z-score for the systolic blood pressure is 2.18, while the z-score for the heart rate is -1.74. Since the absolute value of the z-score for the systolic blood pressure is larger than that of the heart rate, it can be concluded that the systolic blood pressure value is more unusual relative to the other patients in the sample as compared to the patient's heart rate value.
Question 24Given: Mean systolic blood pressure = 132 mm
Hg; standard deviation of systolic blood pressure = 33;
Systolic blood pressure of patient = 204 mmHg
.The formula to calculate z-score = `(x - μ) / σ`
Where, `x` is the value of the variable,
`μ` is the mean of the variable,
`σ` is the standard deviation of the variable
.Substituting the values, we getz-score = `(204 - 132) / 33 = 2.18`
Therefore, the z-score associated with the systolic blood pressure value of 204 mmHg is 2.18
. Question 25
Given: Mean heart rate = 99 bpm;
standard deviation of heart rate = 27;
Heart rate of patient = 52 bpm.
The formula to calculate z-score = `(x - μ) / σ
`Where, `x` is the value of the variable,
`μ` is the mean of the variable,
`σ` is the standard deviation of the variable.
Substituting the values, we getz-score = `(52 - 99) / 27 = -1.74
`Therefore, the z-score associated with the heart rate of 52 bpm is -1.74.
Question 26
Z-score can be used to compare two different data sets. The absolute value of the z-score shows how many standard deviations the value is away from the mean. Hence, the larger the absolute value of the z-score, the more unusual the value is relative to the other values in the dataset.In this case, the z-score for the systolic blood pressure is 2.18, while the z-score for the heart rate is -1.74. Since the absolute value of the z-score for the systolic blood pressure is larger than that of the heart rate, it can be concluded that the systolic blood pressure value is more unusual relative to the other patients in the sample as compared to the patient's heart rate value.
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Scientists Discuss time and how old the Earth is. How do they measure the idea
of time so long ago if they were not around to measure it with the technology we
have today? (Minimum 3 COMPLETE Sentences)
The following is the introduction to a special e-publication called Determining the Age of the Earth (click the link to see a table of contents). Published earlier this year, the collection draws articles from the archives of Scientific American. In the collection, this introduction appears with the title, “Stumbling Toward an Understanding of Geologic Timescales.”