Answer:In chemistry, a lone pair refers to a pair of valence electrons that are not shared with another atom in a covalent bond and is sometimes called an unshared pair or non-bonding pair. Lone pairs are found in the outermost electron shell of atoms. They can be identified by using a Lewis structure.
1. A student mixes two liquids together and notices that a white solid has formed
at the bottom of the container.
What can the student conclude?
1. A precipitate has formed.
2. A physical change has occurred.
3. A chemical reaction has occurred.
4. A chemical change has occurred.
Answer:
3. A chemical reaction has occured
A student mixes two liquids together and notices that a white solid has formed at the bottom of the container which means precipitate has formed.
What is precipitation reaction ?
Precipitation is the process of creating an insoluble compound in chemistry by either reacting two salts or altering the temperature to alter the solubility of the compound. Additionally, the solid that results from a precipitation reaction is referred to as "precipitate."Precipitation can be a sign that a chemical reaction has taken place, but it can also happen if the concentration of a solute is higher than its solubility. The process of small, insoluble particles aggregating together or forming an interface with a surface, such as the container wall or a seed crystal, is known as nucleation, and it occurs before precipitation.Precipitation is the process of transforming a liquid into a solid. A precipitant is a chemical that gives rise to a solid in a liquid solution. The term "precipitate" refers to the resulting solid. In the event that the molecule size of the insoluble compound is tiny or there is deficient gravity to attract the strong to the lower part of the compartment, the hasten might be equitably dispersed all through the fluid, shaping a suspension. Any process that separates the precipitate from the solution's liquid portion, known as the supernatant, is referred to as sedimentation. Centrifugation is a common technique for sedimentation. A "flower" is a powder that forms after the precipitate has been recovered.
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PLEASE HELP No links or fake answers or ill report you and every question you have ever answered to getnur acc deleted. I have no idea how to shower these. Ty if you help and I will give brainliest and like and 5 stars. xx
Answer:
!dk bestie i tried to do it but i cant maybe someone else can figure it or they already did :( anyway i hope you have a amazing day luv <3
The pH of tomato juice is 4, thus tomato is a (an) _______________ substance
Answer:
Acidic
Explanation:
pH from 0-6.9 are acidic substances
pH of 7 are neutral
pH above 7 to 14 are badic substances
Answer: Acidic
Explanation:
PH of 1-6 is considered acidic.
PH of 7 is neutral.
PH of 8-14 is considered basic (alkaline)
Why does the moon have a stronger gravitational effect on the earth then the sun?
Explanation:
The tidal forces of the Moon are much stronger than the Sun's because it is so much closer to our planet, causing a much greater variation in the gravitational force from one location to another. The Sun's gravitational force, on the other hand, varies much less because the Sun is so far.
Please mark me has brainliest1. Cierta muestra fue diluida así: 1 mL MP se agrega 4mL de agua, luego se extrae 0,5 mL y se lleva a 5 mL y de esta última se obtiene 0,2 y se añade 1,3 de diluyente. Calcule la dilución total.
Answer:
1/375
Explanation:
Primero se debe calcular el factor de dilución para cada dilución seriada. Para ello, se divide el volumen de muestra entre el volumen final de la solución diluida.
1) 1 mL en 1 mL + 4 mL = 5 mL
D1 = 1 mL/5 mL = 1/5
2) 0,5 mL en 5 mL
D2 = 0,5 mL/5 mL = 1/10
3) 0,2 mL en 0,2 mL + 1,3 mL = 1,5 mL
D3 = 0,2 mL/1,5 mL = 2/15
La dilución total se calcula como el producto de las diluciones seriadas realizadas:
DT = D1 x D2 x D3 = 1/5 x 1/10 x 2/15 = 1/375
Which of the following is a TRUE statement?
a.
A molecule always has three types of elements present
b.
Compounds always include the elements hydrogen and sodium
c.
Compounds include things we use in our everyday lives
d.
All elements prefer to hang out with other elements and form molecules
Answer:
b
Explanation:
Viruses are not considered organisms, because they lack many of the characteristics of living things. A virus is essentially a string of genetic material in
a protein coat. Some viruses contain DNA, while others, called retroviruses, contain RNA. One example of a retrovirus is HIV, which causes AIDS
How is RNA different from DNA? Choose the 2 statements that apply
A. DNA and RNA use different sets of nitrogen bases.
B
DNA has 1 strand of genetic material while RNA has 2 strands
C. DNA contains deoxyribose sugar and RNA contains ribose sugar,
D. DNA and RNA are proteins
Answer:
well, I think the answer is C
The difference between RNA and DNA are:
A. DNA and RNA use different sets of nitrogen bases.
C. DNA contains deoxyribose sugar and RNA contains ribose sugar.
What are RNA and DNA?DNA and RNA, both are genetic materials, but DNA is double-stranded and RNA is single-stranded.
DNA is present in all animals and plants, and RNA is present in viruses and bacteria.
Both are made up of nitrogenous bases and sugar.
Thus, the correct options are A and C.
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How many grams are in 0.35 moles of C2H4? please show dimensional analysis
Answer:
9.8g
Explanation:
Using periodic table find molar mass of C and H:
C=12.01g/mol
H=1.008g/mol
Molar mass of C2H4=(12.01)2+(1.008)4=28.03g/mol
Using molar mass times moles of the chemical to find the mass in 0.35 moles of c2h4:
28.03 x 0.35=9.8grams
1. Which functional group is found in an ester? (1 point)
Answer:
2nd one
Explanation:
Fact!
_____________Makes the particles of the solvent and the solute move around more and come in contact more often. More contact, more opportunity for dissolving.
Answer:
Solvation
Explanation:
Solvation is the name of the process in which the particles of the solute are surrounded by the particles of the solvent molecules and they together mix together to form a solution.
In order words, it is a process of the surrounding solute particles with the solvent particles in order to form a solutions. When the water is the solvent, the process is known as hydration.
It only occurs when the particles of the solvent and solute are in contact with each other and the opportunity for the dissolving process is more when more is the contact between the particles.
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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A form of energy that is related to its temperature...
nuclear energy
thermal energy
potential energy
kinetic energy
Answer:
Kinetic Energy
Explanation:
Temperature and Kinetic Energy are directly proportional.
how humans can improve the negative aspects of soil use FULL SENTENCES 50 POINTS PLEASE HELP
Answer:
Using diverse nutrient sources can help maintain soil health. Manure and compost add organic matter as well as an array of nutrients, but using just compost or manure to meet the nitrogen needs of the crop every year can result in excessive phosphorus levels in the soil.
The shape of the directly sunlit portion of the Moon as viewed from
Earth
your answer:
lunar phases
how many moles of water is 5.02 x 10 18 molecules of water
Answer:
8.334×10^-6 moles
Explanation:
a mole is 6.023×10^23
5.02×10^18 ÷ 6.023×10^23=8.33×10^-6
so there are 8.33×10^-6 moles of water in 5.02x10^18 molecules of water
The number of moles of water in which 5.02 × 10¹⁸ molecules of water is present is 8.33 × 10⁻⁶.
What is moles?
Moles is a unit which is used to tells about the quantity of any substance, in one moles of any substance 6.023 × 10²³ number of atoms of that substances are present.
In 1 mole of water = 6.023 × 10²³ number of molecules of water is present
So, number of 5.02 × 10¹⁸ molecules of water present in how many moles will be calculated as:
Required moles = 5.02 × 10¹⁸ / 6.023 × 10²³ = 8.33 × 10⁻⁶
Hence, required moles is 8.33 × 10⁻⁶.
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why a dipole develops in a molecule
Answer:
Dipole interactions occur when partial charge form within a molecule because of the uneven distribution of electrons.polar molecules align so that the positive end of one molecule interacts with the negative end of another molecule.
Answer: Uneven distribution of electrons in a
Molecule.
Explanation: Q. What’s the dipole-dipole interaction ?
SOL.-
CONCEPT-
Dipole-dipole Forces -
Intermolecular interactions are necessary for the stability of the molecule. There are many types of intermolecular forces, and dipole-dipole forces are part of these forces them.
Dipole-dipole forces, also known as dipole-dipole interactions. The electrostatic forces between two permanent polar molecules is known as dipole- dipole force. Generally, the positive side of one molecule is attracted to the negative side of another molecule. The two molecules come closer, and add for increasing the stability of the substance. This type of interaction is different from a regular ionic bond or a covalent bond because there is no transfer or sharing of electrons.
Causes of a Dipole-dipole Interaction-
Dipole-dipole interaction arises due to the unlike distribution of electrons in a molecule. The electrons are assembled at one end of the molecule. Thus, the molecule get a partially negative charge at one end and a partial positive charge at the another end. That process making them polar. Generally, two polar molecules with opposite nature charges will attract one another.
Diagram-
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pleaaseeee help im failing so bad3
I used a stick of (vegan) butter as our example of thinking about how temperature changes the properties of something when it is wamer or cooler.
1. What is something else you could use to describe how temperature affects the properties of when it is warmer or cooler? How does this change whether it is warm or cold. Describe it.
explain why copper 2 oxide is a base although it does not turn litmus paper to blue
Answer:
See explanation
Explanation:
Copper II oxide is a base but not an alkali. An alkali is a soluble base. Since Copper II oxide is not soluble in water then it is not an alkali.
Let us recall that the change of colour of litmus with an alkali requires the presence of water. In the absence of water, solid Copper II oxide does not turn red litmus paper blue.
The ability to turn red litmus paper blue is commonly observed with alkalis and Copper II oxide is not an alkali.
Also recall that since Copper II oxide is not soluble, hydroxide ions are absent hence Copper II oxide does not turn red litmus paper blue.
How many Zn atoms are there in 4.65 moles of Zn?
atoms
Submit Answer
Retry Entire Group
9 more gra
Which of the following is an indication that a substance has undergone a chemical change?
A.
No new product has been formed.
B.
The color of the substance has not changed.
C.
The original constitute has not changed.
D.
The molecular structure has changed.
Answer:
D.
Hope it helps!!!!!!!!!
Which of the following accurately describes the orbital path of most planets in our solar system?
The orbital path is in a perfect circle.
The orbital path looks circular.
The orbital path is in a large elliptical shape.
The orbital path varies greatly from planet to planet.
What is the chemical formula for this?
Answer:
-OOH
Explanation:
This forms an acid if it comes in contact with a metal
Answer:
HO2; Hydroperoxyl
Explanation:
Since there are two oxygen molecules, and one hydrogen molecule, it can be classified as a hydroperoxyl molecule.
It is an inorganic compound with the following characteristics
Covalent compound (O,H are nonmetals) Valence of O (O must form an octet): 6 Valence of H: 1 Total valence electrons: 13 Molar mass: 33.01 g/molThe pressure in a Red Rider BB gun cartridge is 1.5 atm. If the rifle was at 25 °C prior to firing, what is the temperature change of the cartridge after firing if the cartridge reaches standard air pressure of 1.0 atm?
Answer:
–99 °C
Explanation:
From the question given above, the following data were obtained:
Initial pressure (P₁) = 1.5 atm
Initial temperature (T₁) = 25 °C
Final pressure (P₂) = 1 atm
Change in temperature (ΔT) =?
Next, we shall determine the final temperature. This can be obtained as follow:
Initial pressure (P₁) = 1.5 atm
Initial temperature (T₁) = 25 °C + 273 = 298 K
Final pressure (P₂) = 1 atm
Final temperature (T₂) =?
P₁/T₁ = P₂/T₂
1.5 / 298 = 1 / T₂
Cross multiply
1.5 × T₂ = 298
Divide both side by 1.5
T₂ = 298 / 1.5
T₂ = 199 K
Converting 199 K to °C, we have:
T(°C) = T(K) – 273
T₂ = 199 – 173
T₂ = –74 °C
Finally, we shall determine change in temperature. This can be obtained:
Initial temperature (T₁) = 25 °C
Final temperature (T₂) = –74 °C
Change in temperature (ΔT) =?
ΔT = T₂ – T₁
ΔT = –74 – 25
ΔT = –99 °C
Thus, the change in the temperature is –99 °C
what element has 5 protons, 7 electrons, and 6 neutrons
Answer: Boron
Explanation: lol
Answer:
Boron. (What kind of name is that?????????????)
Explanation:
A projectile is projected with an initial velocity of 40 m/s at a 45o angle to the horizontal. , calculate the total time travelled.
Answer:
5.77 s
Explanation:
From the question,
The total time travelled by the projectile = Time of flight (T)
T = 2usinθ/g............ Equation 1
Where T = Time of Flight of the projectile, u = Initial velocity, θ = Angle of projection to the horizontal, g = acceleration due to gravity
Given: u = 40 m/s, θ = 45°
Constant: g = 9.8 m/s²
Substitute these values into equation 1
T = 2(40)sin(45°)/9.8
T = 80sin(45°)/9.8
T = 80×0.7071/9.8
T = 5.77 s
An experiment was conducted to see which metal pot would be better for cooking food quickly. The table below shows how quickly small pieces of wax melted during the experiment.
Type of metal
Time for the wax to melt (seconds)
Aluminum
27
Bronze
45
Copper
15
Steel
80
The following statement was made after the data were examined: “Copper pots are the best pots for cooking food quickly.” Which term best describes this statement?
conclusion
hypothesis
procedure
result
Answer:
Conclusion.....hope this helps
Answer:
conclusion
Explanation:
help? It would honestly mean a lot :(
Answer:
1 1
5 2
6 1
8 3
10 3
6 3
9 3
13 3
Explanation:
First of you add the subscripts (the little numbers after the letters) and multiply the big numbers before the letters together to get the number of atoms
For Example:
O= 1 atom
Si{2}= 2 atoms
Mg{5}C{6}= 11 atoms
3Na{2}= 6 atoms
O(SiNa){2}= OSi{2}Na{2}= 5 atoms
Each Capital letter is a new Element
For Example:
O = 1 Element
NaSi = 2 Elements
An atom of a certain element has 19 protons, 19 electrons, and a mass number of 39. This element is very reactive. How many neutrons are in this atom?
Record your answer and fill in the bubbles on your answer document. Be sure to use the correct place value.
Answer:
There are 20 neutrons in this atom.
Explanation:
The figure shows a nutrition label. How much energy does this food contain?
Answer:
i need help with that too.
Explanation: