Answer:
Physical changes can be classified as reversible or irreversible. Melting is an example of a reversible physical change.
Explanation:
How many grams of solid sodium acetate should be added to 2.00 L of 0.184 M acetic acid solution to prepare a buffer with a pH of 4.140
pH = pKa + log [NaAc]/[HAc]
4.140 = 4.74 + log x
log x = -0.60
x = [NaAc]/[HAc] = 0.25
moles HAc = 1.50 L x 0.287 mol/L = 0.431 moles
moles NaAc = 0.25 x 0.431 = 0.1078 moles NaAc
grams NaAc = 0.108 x 80 g/mole = 8.64 grams
A sample of gas is at 78.0 oC. You want to change the volume of the gas from 1.60 L to 0.425 L under constant pressure. What must you do to the temperature of the gas
Answer:
the rule is V1/T1= V2/T2
so we convert the T1 from °c to kelvin
78+273.15= 351.15 k
1.60/351.15 = 0.425/T2
4.55 ×10-³ = 0.425/T2
then T2 = 93.40 kelvin
hence, we should decrease the temperature
una pieza de hierro de 25cm3 tiene una masa de 195g cual es su densidad?
Answer:
Pretend you are a TV producer. Think of ideas for new TV shows. Your objective is to create ideas that will be successful, regardless of whether this is quality programming or not. Think of an idea of a copy. Explain the basics of what this show will be like and what show it is copying. Explain why you feel this show will be popular. Think of an idea of a spin-off. Explain the basics of what this show will be like and what show it is spinning off from. Explain why you feel this show will be popular. Think of an idea for a TV show that falls into one of the genre categories listed in the genre chart. Describe the basics of the show and how it falls under the genre’s expectations for characters, plots, and aesthetics. Explain why you feel this show will be popular.
How many moles are present in 1.39 grams of carbon?
C
R. F. M (Relative Formula Mass) of C=12
12g of C=1 mole
1.39g of C=(1*1.39)/12
=0.1158 moles
What is the name of the zone of life on earth ?
a . atmosphere
b . biosphere
c . lithosphere
d . magnetosphere
Answer:
B. Biosphere
Explanation:
Describe the difference between accuracy and precision. How do these two concepts relate to the idea of significant digits?
Answer:
Accuracy of a measured value refers to how close a measurement is to the correct value. The uncertainty in a measurement is an estimate of the amount by which the measurement result may differ from this value. Precision of measured values refers to how close the agreement is between repeated measurements.
Explanation:
is isopropyl alcohol the same as hydrogen peroxide
Answer:
Unlike isopropanol, hydrogen peroxide is not a type of alcohol. You might recognize its chemical formula, H2O2, as being similar to that of water (H2O). The difference is that hydrogen peroxide has two oxygen atoms instead of one. That one extra oxygen atom makes it a strong oxidizer.
33. Which element in Period 5 of the Periodic Table
is a transition element?
A) Sr
B) Ag C) Sb
D) Xe
Silver or Ag is the transition element present in period 5 of the periodic table.
What is periodic table?
Periodic table is a tabular arrangement of elements in the form of a table. In the periodic table, elements are arranged according to the modern periodic law which states that the properties of elements are a periodic function of their atomic numbers.
It is called as periodic because properties repeat after regular intervals of atomic numbers . It is a tabular arrangement consisting of seven horizontal rows called periods and eighteen vertical columns called groups.
Elements present in the same group have same number of valence electrons and hence have similar properties while elements present in the same period show gradual variation in properties due to addition of one electron for each successive element in a period.
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Unless otherwise instructed, you may use the periodic table in the Chemistry:
question.
What is the molar mass of ammonia (NH,)?
o 15 g/mol
o 17 g/mol
42 g/mol
43 g/mol
Answer:
17 g/Mol
Explanation:
To determine the molar mass of any compound, you have to add up the molar masses of every atom that make up the respective compound. In this case NH3 equals one nitrogen atom and three hydrogen atoms.
What does that mean? Ammonia's molar mass will be the sum of the molar mass of one nitrogen atom and 3 times the molar mass of a hydrogen atom.
Peroindic table:
N=14.0067 g/mol.
H=1.00794 g/mol
(i will give brainliest)
The following image shows what happens when the particles in a certain state occupy a space. What is the state of the substance that is occupying the space and how do you know?
A. The substance is a gas because the particles are spreading out to fill the space of the container.
B. The substance is a liquid because the particles inside are taking the shape of the container.
C. The substance is a mixture of a gas and a liquid because the particles are filling the space of the container.
D. The substance is a solid because the particles inside the box have a definite shape.
Answer:
A
Explanation:
The substance is a gas because the particles far randomly arranged and far apart from each other. This happens because when a substance is a gas, particles have weak attraction to each but a lot more kinetic energy which means the they move around all the time spreading out to fill the container. If it was a solid, then all the particles would be very close together and have a fixed position and if it was a liquid then the particles would be fairly close and moving around each other but as we can see in the diagram, all the particles are far apart confirming that it is a gas.
Answer:
the answer is A beacause the other person is right :)
Explanation:
please give them brainliest
Every magnet must have what at its ends?
O A. A positive charge and a negative charge
B. A positive charge and a north pole
C. A north pole and a south pole
D. A south pole and another south pole
Answer:
one end is the north pole and the other is the south pole.
Explanation:
a north pole will attract a south pole; the magnets pull on each other. But the two north poles will push each other away. ... A compass is a tiny magnet balanced on a point so it can turn freely.
Que pasa si a una taza de arena le pongo espuma y lo agito por 10 minutos?
Answer:
Conversion of energy
Explanation:
Shaking the sand is a form of kinetic energy. The friction of the sand particles rubbing against each other converts the kinetic energy to heat energy. Some of the kinetic energy also converts into the energy of sound waves, which you can hear while you shake the sand.
In a crystal of an ionic compound, each cation is surrounded by a number of what?
Answer:In a metal, atoms readily lose electrons to form positive ions (cations). These ions are surrounded by delocalized electrons, which are responsible for conductivity.
Explanation:
Due to the structure of ionic compounds, in a crystal of an ionic compound, each cation is surrounded by a number of oppositely-charged anions.
What are ionic compounds?Ionic compounds are compounds that are composed of oppositely charged ions held together by strong electrostatic forces of attraction.
The ions present in an ionic compound are the positively-charged ions known as cations and the negatively-charged ions known as anions.
Each of the oppositely-charged ions are attracted to each other.
Therefore, in a crystal of an ionic compound, each cation is surrounded by a number of oppositely-charged anions.
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moles
Calculate the number of moles of 3.00 g of boron tribromide,
what chemical properties does soap have that makes it a good cleaning agent?
Answer:
Soap is an excellent cleanser because of its ability to act as an emulsifying agent. An emulsifier is capable of dispersing one liquid into another immiscible liquid. This means that while oil (which attracts dirt) doesn't naturally mix with water, soap can suspend oil/dirt in such a way that it can be removed.
Soap acts as a cleaner because of its ability to act as an emulsifying agent. A soap molecule has a polar head and a nonpolar tail. Soap consists of a carbon chain where one end attracts oil and the other attracts water.
What is the cleaning action of soap?Most of dirt can be described as oily in nature as oil does not dissolve in water. The molecule of soap consists of sodium salts of long-chain carboxylic acids. In soaps, the chain of carbon atoms dissolves in the oil, and the ionic or polar end of the soap molecule dissolves in water.
The soap molecules produce structures known as micelles. In micelles, one end faces the oil droplet, and the other end which is ionic in nature faces outside. Therefore, soap can form an emulsion in water and supports in dissolving the dirt when we wash our clothes.
Soap can be described as a kind of molecule in which both ends have different properties. The hydrophilic end dissolves water and is attracted to it whereas the hydrophobic end is dissolved in hydrocarbons and is water repulsive in nature.
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Silver, Chromium and Copper are these type of elements _____
Answer:
Group 11
Explanation:
Group 11, by modern IUPAC numbering, is a group of chemical elements in the periodic table, consisting of copper (Cu), silver (Ag), and gold (Au).
Answer:
silver, chromium and copper are metal type of element
is this correct? ...
what do you mean by blood pressure is 130 19 mm of HG
Answer:
Hypertension stage 1 is 130-139 mm of HG
In your own words, explain why it is necessary to include only one chain-terminating/ synthesis-terminating nucleotide in each well of the electrophoresis instrument.
Answer: DNA sequencing methods employ chain termination nucleotides. Furthermore, if two chain-terminating nucleotides are employed in the same well, determining which strand is ended by which dideoxynucleotide will be impossible.
(its my own words, but i did search it to get this answer, hope it helps!)
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what is the function of the digestive system? why is it important to the body?
The digestive system is made up of the gastrointestinal tract—also called the GI tract or digestive tract—and the liver, pancreas, and gallbladder. The GI tract is a series of hollow organs joined in a long, twisting tube from the mouth to the anus. The hollow organs that make up the GI tract are the mouth, esophagus, stomach, small intestine, large intestine, and anus. The liver, pancreas, and gallbladder are the solid organs of the digestive system.
The small intestine has three parts. The first part is called the duodenum. The jejunum is in the middle and the ileum is at the end. The large intestine includes the appendix, cecum, colon, and rectum. The appendix is a finger-shaped pouch attached to the cecum. The cecum is the first part of the large intestine. The colon is next. The rectum is the end of the large intestine.
Digestion is important because your body needs nutrients from food and drink to work properly and stay healthy. Proteins, fats, carbohydrates, vitamins NIH external link, minerals NIH external link, and water are nutrients. Your digestive system breaks nutrients into parts small enough for your body to absorb and use for energy, growth, and cell repair.
Proteins break into amino acidsFats break into fatty acids and glycerolCarbohydrates break into simple sugarsEach part of your digestive system helps to move food and liquid through your GI tract, break food and liquid into smaller parts, or both. Once foods are broken into small enough parts, your body can absorb and move the nutrients to where they are needed. Your large intestine absorbs water, and the waste products of digestion become stool. Nerves and hormones help control the digestive process.
What is the theoretical yield of sodium chloride when 8.3 g of sodium is reacted with 4.5 g of chlorine? 2Na(s) + Cl2(g) → 2NaCl(s)
The theoretical yield of sodium chloride when 8.3 g of sodium react with 4.5 g of chlorine is 3.30 g
We'll begin calculating the masses of Na and Cl that reacted and the mass of NaCl produced from the balanced equation.
2Na + Cl₂ —> 2NaClMolar mass of Na = 23 g/mol
Mass of Na from the balanced equation = 2 × 23 = 46 g
Molar mass of Cl₂ = 2 × 35.5 = 71 g/mol
Mass of Cl₂ from the balanced equation = 1 × 71 = 71 g
Molar mass of NaCl = 23 + 35.5 = 58.5 g/mol
Mass of NaCl from the balanced equation = 2 × 58.5 = 117 g
SUMMARY
From the balanced equation above,
46 g of Na reacted with 71 g of Cl₂ to produce 117 g of NaCl
Next, we shall determine the limiting reactant.From the balanced equation above,
46 g of Na reacted with 71 g of Cl₂
Therefore,
8.3 g of Na will react with = (8.3 × 71)/46 = 12.81 g of Cl₂
From the calculation made above, we can see that a higher amount (i.e 12.81 g) of Cl₂ than what was given (i.e 4.5 g) is needed to react completely with 8.3 g of Na.
Therefore, Cl₂ is the limiting reactant and Na is the excess reactant
Finally, we shall determine the theoretical yield of NaCl by using the limiting reactant (i.e Cl₂)From the balanced equation above,
71 g of Cl₂ reacted to produce 117 g of NaCl.
Therefore,
4.5 g of Cl₂ will react to produce = (4.5 × 117)/71 = 3.30 g of NaCl
Thus, the theoretical yield of NaCl produced is 3.30 g
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Answer:
The correct answer is 7.4 g NaCl
Explanation:
How are traits inherited?
Please explain thoroughly
inherited traits are passed from parent to offspring according to the rules of Mendelian genetics. Most traits are not strictly determined by genes, but rather are influenced by both genes and environment
HELP!!!
Water boils in an open pot at 100 °C, but in a pressure cooker it can boil at 116 °C.
Describe what happens to the gas particles inside the pressure cooker as the pressure increases.
Explain whether the diagram Francisco drew is correct for the water particles in an open pot at 100 °C as well as those in the pressure cooker at 116 °C.
Identify which water particles have more energy, those in the open pot or those in the pressure cooker.
Explain why Francisco should use a pressure cooker to warm the jars of vegetables. Include a description of the behavior of the gaseous and liquid particles in the pressure cooker in your explanation.
PLEASE GIVE ME AN ANSWER TO EACH ONE IF YOU CAN.
Answer:
A pressure cooker looks like a regular pot but has a modified lid that locks on over a rubber gasket to create a seal. The cooker works by raising the temperature of boiling water, thereby speeding up the time it takes to boil, braise, or steam. To use a pressure cooker, you put the food in the pot with some liquid-usually a minimum of 2 cups to build up sufficient steam pressure. Once the lid is locked in place and the cooker is set on high heat, steam develops in the pot and can’t escape. The trapped steam increases the atmospheric pressure inside the cooker by 15 pounds per square inch (psi), or 15 pounds above normal sea-level pressure. At that pressure, the boiling point of water is increased from 212°F to 250°F. This higher temperature is what cooks food faster. Once the cooker has reached full pressure, usually indicated by a gauge or pop-up rod on the lid, a release valve opens, letting out steam in a regulated flow to maintain a constant temperature inside the pot.
Explanation:
According to Newton's law of universal gravitation, how are mass and
gravitational force related?
A. Mass and gravitational force are the same.
B. An increase in mass is a decrease in force.
C. An increase in mass is an increase in force.
O D. Mass and gravitational force are not related.
Explanation:
Since the gravitational force is directly proportional to the mass of both interacting objects, more massive objects will attract each other with a greater gravitational force. So as the mass of either object increases, the force of gravitational attraction between them also increases.
what is the ka for 0.03M Solution of HClO4 for 1.90 PH value.
A) 7.2x10^-3
B) 8.27x10^-3
C) 8.27x10^-4
D) 6.27x10^-4
(I keep getting 5x10^-3 when I round all the values to 2 decimal places but it’s not in the options)
A student conducts an experiment to separate water into hydrogen and oxygen through a chemical reaction as shown below.
H Hydrogen gas Orygengu rises in this test tube test tube.
2 H2O --> 2H2 + O2
As a result the student collects 28.0 g of hydrogen and 224.0 g of oxygen. How many grams of water did the student originally start with?
The amount, in grams, of water, that the student originally started with would be 252 g
From the balanced equation of the reaction, the ratio of H2O to H2 is 1:1. Thus for every 1 mole of water that is separated, 1 mole of H2 is produced.
Recall that: mole = mass/molar mass
Mole of 28.0 g H2 produced = 28/2
= 14 moles
Equivalent mole of H2O would, therefore, be 14 moles.
Mass of 14 moles H2O = mole x molar mass
= 14 x 18
= 252 g
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why does reducing solute particle size increase the speed at which the solute dissolves in water .
Because it has less surface area. This can be applied to something like cooking potatoes. Cooking a larger potato will take longer than a small potato.
TRUE or FALSE the term “anti-inflammatory” likely means “against inflammation”
Answer:
True
ANTI MEANS AGAINST
Explanation:
identify ALL equations that involve Pressure(Minimum 2)
Answer:
p=F/A.Explanation:
What is the molar mass of an unknown gas with a density of 3.35 g/L at 1.00 atm and 25.0 °C
Answer:
[tex]\implies \sf D = \dfrac{PM}{RT}[/tex]
[tex]\implies \sf 3.35= \dfrac{1 \times M}{ \frac{1}{12} \times 298}[/tex]
[tex]\implies \sf 3.35= \dfrac{12\times M}{ 298}[/tex]
[tex]\implies \sf 3.35 \times 298= 12\times M[/tex]
[tex]\implies \sf 998.3= 12\times M[/tex]
[tex]\implies \sf M = \dfrac{998.3}{12} [/tex]
[tex]\implies \bf M = 83.1917 \: \frac{g}{mol} [/tex]