Answer:
The most important use of liquid crystals is in displays because the molecules of a liquid crystal can control the amount, color, and direction of vibration of the light that passes through them. hope that helps love!
Which balanced equation represents an oxidation-reduction reaction?
Answer:
Oxidation states are used in chemistry solutions. It is a bond in which electron transfers easily from one nucleus to another nucleus.
Explanation:
Oxidation-reduction reactions have some rules.The oxidation state is 0 at an uncombined bond.The bond of oxidation reduction is +1 in alkeli metal. The bond in two metal is +2The oxidation reduction state at helogens is -1. It does not happened always.The oxygen bond in oxidation and reduction is -2. The sum of the oxidation state is equal to the compound charges.In this process the changes occur for any elements. Redox could be occur. Its oxidized and reduction reaction can be seen in this process.How are scientific questions answered?
O A. By predicting a solution to the question
O B. By reading books about the question
O C. By asking other scientists what they think
D. By observing and measuring the physical world
Answer:
D
Explanation:
Scientists always perform tests and observe and measure in the physical world to prove their points or answer their questions.
Which group is in the leftmost column on the periodic table?
alkali metals
a.pex
yes
Difference between rapid combustion and spontaneous combustion.
Answer: The difference between rapid combustion and spontaneous combustion...
Explanation:
Rapid combustion is a form of combustion, otherwise known as a fire, in which large amounts of heat and light energy are released, which often results in a flame.Whereas spontaneous combustion is the ignition of organic matter (e.g. hay or coal) without apparent cause, typically through heat generated internally by rapid oxidation.
In 1982, the United States government changed the way it minted pennies. Before 1982, pennies were made of 95% copper and 5% tin. Now they are made of 97.5% zinc coated with copper. Because they weigh different amounts (have different masses) and are still the same item, they make a good model for studying isotopes.
4. What do the two kinds of pennies represent in this exercise?
5. How do the pennies differ? How do isotopes differ?
6. What do the pennies have in common? What do isotopes have in common?
Step 3: Measure Solubility in Cold Water
10
0
-10
80
100 m
60
-40
20
Temperature of the water to the nearest degree:
ANSWER IS 2°C. !!!
Answer:
2 degrees celcius
Explanation:
pls help asap pls !!
Answer:
basic solution.
Explanation:
has a pH of 12.
it turns clear indicator pink.
it contains hydroxide ions which conduct electricity
Which of he following is a secondary alkanol?
a. CH3CH2CH2OH
b. CH3CH2CH2CH2OH
c. C(CH3)3OH
d. CH3CH(OH)CH3
Answer: Thus [tex]CH_3CH(OH)CH_3[/tex] is a secondary alkanol.
Explanation:
Alkanol are compounds which contains carbons bonded by single bonds and contains hydroxy (-OH) as functional group.
Primary alkanol are those compounds which contain hydroxyl group attached a carbon which is further attached to a single carbon atom. Example: [tex]CH_3CH_2CH_2OH[/tex] and [tex]CH_3CH_2CH_2CH_2OH[/tex]
Secondary alkanol are those compounds which contain hydroxyl group attached to a carbon which is further attached to two more carbon atoms.Example: [tex]CH_3CH(OH)CH_3[/tex]
Tertiary alkanol are those compounds which contain hydroxyl group attached to a carbon which is further attached to three more carbon atoms. Example: [tex]C(CH_3)_3OH[/tex]
Thus [tex]CH_3CH(OH)CH_3[/tex] is a secondary alkanol.
Which statement best describes how an ionic bond forms?
The transfer of electrons forms strong bonds between ions.
The sharing of electrons forms strong bonds between ions.
The transfer of electrons results in attractive forces between molecules.
The sharing of electons results in attractive forces between molecules.
Answer:
The answer is option A
Explanation:
The question states,'which statement best describes how an ionic bond forms. The correct option is A. Ionic bonds are formed as a result of complete transfer of electrovalence electrons from one atom to another. The atom that donate the electron become a positively charged ion while the atom that received the atom become a negatively charged ion.
Brainliest is greatly appreciated
Answered by: Skylar
6/8/2020
10:05 AM (Eastern Time)
Answer:
A!!!!
Explanation:
5.6 × 1012 / 3.5 × 109 = A × 10B
Answer:
B= 17649.28/A
Explanation:
Which of the following is an example of frontier research?
A. Investigating how organisms are made of cells.
B. Testing the electrical resistance of different materials.
C. Discovering the nature of dark matter.
D. Researching how animals on the Great Plains interact.
Answer:
B. Testing the electrical resistance of different materials.
Explanation:
An example of frontier research is " Testing the electrical resistance of different materials".
What is frontier research?A frontiers Research Topic offers researchers the chance to present various viewpoints, approaches, and findings on a new or developing topic in a forum monitored by experts in the area but also published in a complete open-access journal.
What is electrical resistance?Electrical resistance towards the current stream within an electrical circuit is measured by resistance. The Greek letter omega (ω) stands for ohms, which are used to evaluate resistance.
Therefore, the correct answer will be an option (B).
To know more about frontiers Research and electrical resistance
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Calcium carbonate, when heated, forms calcium oxide and carbon dioxide. 100grams of calcium carbonate will produce 56grams of calcium oxide. How many grams of carbon dioxide will it produce? Show working out
Answer:
It will produce 44 grams of carbon dioxide
Explanation:
Step 1: Data given
MAss of CaCO3 = 100 grams
Molar mass of CaCO3 = 100.09 g/mol
Mass of CaO produced = 56 grams
Molar mass of CaO = 56.08 g/mol
Step 2: The balanced equation
CaCO3 → CaO + CO2
Step 3: Calculate moles CaCO3
Moles CaCO3 = mass CaCO3 / molar mass CaCO3
Moles CaCO3 = 100 grams / 100.09 g/mol
Moles CaCO3 = 1.00 moles
Step 4: Calculate moles CaO
Moles CaO = 56 grams / 56.08 g/mol
Moles CaO = 1.00 moles
Step 5: Calculate moles CO2
For 1 mol CaCO3 we'll have 1 mol 1 mol CaO and 1 mol CO2
Step 6: Calculate mass CO2
Mass CO2 = moles CO2 * molar mass CO2
Mass CO2 = 1.00 moles * 44.0 g/mol
Mass CO2 = 44 grams
It will produce 44 grams of carbon dioxide
Of the choices below, which one is not an ionic compound?
A) PCl5
B) MoCl6
C) RbCl
D) PbCl2
E) NaCl
Answer: [tex]PCl_5[/tex] is not an ionic compound.
Explanation:
An ionic compound is defined as the compound which is formed when electron gets transferred from one atom to another atom. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
Thus [tex]MoCl_6[/tex], [tex]RbCl[/tex], [tex]PbCl_2[/tex] and [tex]NaCl[/tex] are all ionic compounds.
Covalent compound is defined as the compound which is formed by the sharing of electrons between the atoms forming a compound. These are usually formed when two non-metals react.
Thus [tex]PCl_5[/tex] is a covalent compound as both Phosphorous and chlorine are non metals.
PCl₅ is not an ionic compound. Ionic or electrovalent compounds are formed
through the transfer of electrons in a chemical reaction. Metals and non-
metals mostly form ionic compounds.
Covalent bonding on the other involves the sharing of electrons between
two elements. Non-metals are mostly involved in this type of reaction.
PCl₅ possesses a covalent bond and not ionic as electrons are shared
between two non metals which are phosphorus and chlorine.
Read more on https://brainly.com/question/957239
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^)
1.Mitch weighs out 67 grams of potassium (K) to make a buffer. How many moles of potassium did Dr. Hellman weigh out?
2.Which statement is NOT true about a reaction rate?
Group of answer choices
Increases with increase in reactant concentration
Increases with increasing temperature
Is the speed at which product is formed
Is the rate at which reactant is used up
All of the answers are true
3.Which statement is NOT true about a catalyst?
Group of answer choices
Are not used up during a reaction
Increases the rate of the reaction
Lowers the energy of activation
Biological catalysts are called enzymes
Are used up during a reaction
Answer:
1. 1.72 moles of potassium.
2. All of the answers are true
3. Are used up during a reaction
Explanation:
Recall that the number of moles is obtained from;
Number of moles= Mass of potassium/ molar mass of potassium
Mass of potassium= 67 g
Molar mass of potassium= 39 gmol-1
Number of moles of K= 67 g/ 39 gmol-1
Number of moles = 1.72 moles of potassium.
2. When we look at all the options, we will realize that all the options are true. The rate of reaction doubles for each 10°C rise in temperature, increasing reactant concentration increases particle collision and ultimately increases the rate of reaction. Rate of reaction deals with rate of disappearance of reactants or rate of appearance of products.
3. Catalysts remain unchanged in a chemical reaction because they do not actually participate in the reaction. Hence they are not used up in any chemical reaction.
What is chemical potential energy?
Answer:
It is the energy that is stored in bonds that hold particles together
Explanation:
What is the temperture at which all molecular movements stop called
Answer:
Absolute Zero
Explanation:
at 0 Kelvin, nothing can move and entropy reaches 0
Answer:
absolute zero
Explanation:
How many liters of hydrogen gas is produced from 3.712 g of magnesium with 104.2ml of 1.385 mol/L HCL (aq) at SATP? Please show your work and explain it. I really need help with this question, it's on one of my quizzes.
Answer:
[tex]V=1.61L[/tex]
Explanation:
Hello,
In this case, the undergoing chemical reaction is:
[tex]Mg+2HCl\rightarrow MgCl_2+H_2[/tex]
Next, we compute the reacting moles of each reactants:
[tex]n_{Mg}=3.712gMg*\frac{1molMg}{24.305 gMg}=0.153molMg[/tex]
[tex]n_{HCl}=1.385\frac{molHCl}{L}*0.1042L=0.144molHCl[/tex]
Then, as magnesium and hydrohloric acid are in a 1:2 molar ratio 0.153 moles of magnesium will completely react with 0.306 moles of hydrochloric acid yet we only have 0.144 moles, therefore, limiting reactant is hydrochloric acid. Thus, we compute the produced moles of hydrogen:
[tex]n_{H_2}=0.144molHCl*\frac{1molH_2}{2molHCl} =0.072molH_2[/tex]
Finally, we use the ideal gas equation with T=298K and 1atm (STP conditions) to compute the liters of hydrogen gas:
[tex]PV=nRT\\\\V=\frac{nRT}{P}=\frac{0.072mol*0.082\frac{atm*L}{mol*K}*273K}{1atm}\\ \\V=1.61L[/tex]
Best regards.
Use the drop-down menus to complete the statements
Answer:
First one: group
Second one: period
Third one: number of valence electrons
Last one: increases
In an electrolytic cell, which ion would migrate
through the solution to the negative electrode?
(1) a chloride ion
(3) a bromide ion
(2) a silver ion
(4) a fluoride ion
Answer:
Silver ion
Explanation:
In an electrolytic cell, the positive ions known as the cations migrate to the negative electrode, the cathode where they accept electrons to become discharged as neutral atoms. Also, the negative ions known as the anions migrate to the positive electrode, the anode, where they give up their electrons to become discharged as neutral atoms.
From the question above, the only positive ion among the options given is the silver ion, Ag+, therefore, it is the correct option.
An acid is added to water, and a new equilibrium is established. What is the system after the acid is added? A. pH w = 1 x 10-14 B. pH w -14 C. pH > pOH and Kw = 1 x 10-14 D. pH > pOH and Kw > 1 x 10-14
Answer:
C. pH > pOH; Kw = 1.0 * 10^-14
Explanation:
The ion product of water, Kw = [H+]*[OH-] = 1.0 * 10^-14. It is a constant.
When an acid or base is added to water, its ion product does not change as it a constant. However, the relative concentrations of H+ ions and OH- ions will change depending on whether an acid or base is added to water.
When an acid is added to water, the concentration of H+ ions increases while that of OH- ions decreases, and vice versa.
Therefore, in the above situation where an acid is added to water, pH > pOH; Kw = 1.0 * 10^-14
A balloon containing helium gas expands from 230 mL to 860 mL as more helium is added. What was the initial quantity of helium present if the expanded balloon contains 3.8 × 10-4 mol, assuming constant temperature and pressure? Which of the variables are known?
Answer and Explanation:
For computing the initial quantity of helium we have to apply the law of ideal gas which is shown below:
[tex]pV=nRT\[/tex]
[tex]n=\dfrac{pV}{RT}[/tex]
Now we have to compute the ratio between the initial and the final numbers of moles which is
[tex]\dfrac{n_1}{n_2}=\dfrac{\dfrac{p_1V_1}{RT_1}}{\dfrac{p_2V_2}{RT_2}}[/tex]
The statement defines that
[tex]T_1=T_2,~p_1=p_2.[/tex]
Therefore
[tex]\dfrac{n_1}{n_2}=\dfrac{V_1}{V_2}[/tex]
[tex]\dfrac{n_1}{3.8\times10^{-4}}=\dfrac{230}{860}\iff\\\\ n_1=\dfrac{3.8\times10^{-4}\times230}{860}[/tex]
[tex]\boxed{n_1\approx1.0\times10^{-4}~mol}[/tex]
And, the variables are known is starting volume and ending gas quantity
Answer:
beginning volume and ending quantity of gas
Explanation:
Why does an ultraviolet light cause paint to fade
Answer:
There are light absorbing color bodies called chromophores that are present in dyes. Ultraviolet rays are one of the causes of fading because they can break down chemical bonds and fade the color in objects.
How many moles of gas are contained in 22.41 liters at 101.325 kPa and 0ᴼC? (Note: use Ideal Gas Law, PV = nRT) a 2.5 mole b 1.5 mole c 1.0 mole d 2.0 mole
Answer:
Therefore, 1.00 mole of the gas is present in the container.
Explanation:
The following data were obtained from the question:
Volume (V) = 22.41L
Temperature (T) = 273K
Pressure (P) = 101.325 kPa
Gas constant (R) = 8.31 L.kPa/mol.K.
Number of mole (n) =...?
The number of mole of the gas in the container can obtained by applying the ideal gas equation as illustrated below:
PV = nRT
Divide both side by RT
n = PV /RT
n =101.325 x 22.41 / 8.31 x 273
n = 1.00 mole.
Therefore, 1.00 mole of the gas is present in the container.
Answer:
1 mole of gas is contained in 22.41 liters at 101.325 kPa and 0ᴼC
Explanation:
Ideal gases are a simplification of real gases that is done to study them more easily. It is considered to be formed by point particles, do not interact with each other and move randomly. It is also considered that the molecules of an ideal gas, in themselves, do not occupy any volume.
The pressure, P, the temperature, T, and the volume, V, of an ideal gas, are related by a simple formula called the ideal gas law:
P*V = n*R*T
where P is the gas pressure, V is the volume that occupies, T is its temperature, R is the ideal gas constant, and n is the number of moles of the gas.
In this case:
P= 101.325 kPa= 1 atmV= 22.41 Ln=?R= 0.082 [tex]\frac{atm*L}{mol*K}[/tex]T= 0°C= 273 °KReplacing:
1 atm*22.41 L=n* 0.082 [tex]\frac{atm*L}{mol*K}[/tex]*273 K
Solving:
[tex]n=\frac{1 atm*22.41 L}{0.082\frac{atm*L}{mol*K} *273 K}[/tex]
n=1 mole
1 mole of gas is contained in 22.41 liters at 101.325 kPa and 0ᴼC
The diagram shows the setup of an experiment. The observations of the experiment are listed in the table below the diagram. A beaker filled three-fourths with a liquid labeled colorless silver nitrate solution is shown. A small strip is shown inside the beaker. The strip is labeled copper strip. The title of the image is Experimental Setup. Experimental Observations Observation Description 1 Copper strip became thinner 2 Gray particles were deposited on the edge of the strip Which of the following is the correct explanation for one of the given observations? (4 points) Observation 2 is a result of nitrate ions moving into the solution. Observation 2 is a result of silver ions moving into the solution. Observation 1 is a result of copper atoms losing two electrons. Observation 1 is a result of silver atoms losing one electron.
Answer:
The answer is Observation 1 is a result of copper atoms losing two electrons.
Explanation:
The electrons result in the color change of the copper strip, causing the gray particles to join onto the metal.
Answer:
C
Explanation:
Observation 1 is a result of the copper atoms losing two electrons. It came out as the right answer.
How will you test for the gas which is liberated when hcl reacts with an active metal ?
Ill give the brainliest answer to whoever helps me with this equation
Answer: The percent yield for the [tex]NaBr[/tex] is, 86.7 %
Explanation : Given,
Moles of [tex]FeBr_3[/tex] = 2.36 mol
Moles of [tex]NaBr[/tex] = 6.14 mol
First we have to calculate the moles of [tex]NaBr[/tex]
The balanced chemical equation is:
[tex]2FeBr_3+3Na_2S\rightarrow Fe_2S_3+6NaBr[/tex]
From the reaction, we conclude that
As, 2 moles of [tex]FeBr_3[/tex] react to give 6 moles of [tex]NaBr[/tex]
So, 2.36 moles of [tex]FeBr_3[/tex] react to give [tex]\frac{6}{2}\times 2.36=7.08[/tex] mole of [tex]NaBr[/tex]
Now we have to calculate the percent yield for the [tex]NaBr[/tex].
[tex]\text{Percent yield}=\frac{\text{Experimental yield}}{\text{Theoretical yield}}\times 100[/tex]
Experimental yield = 6.14 moles
Theoretical yield = 7.08 moles
Now put all the given values in this formula, we get:
[tex]\text{Percent yield}=\frac{6.14mol}{7.08mol}\times 100=86.7\%[/tex]
Therefore, the percent yield for the [tex]NaBr[/tex] is, 86.7 %
The nickname __________ was given to people from southern states that supported reconstruction laws that helped African Americans.
A. "copperhead"
B. "scalawag"
C. "carpetbagger"
D. "Radical Republican"
is the study of the natural world through observation and experimentation.
Answer:
YES
Explanation:
The systematic study of the structure and behavior of the physical and natural world through observation and experiment.
The correct answer is either a or d. Can anyone explain which one it is and why? CH3C ≡ CCH2CH2Cl is named: a. 1-chloro-3-pentyne b. 5-chloro-2-pentene c. 1-acetylenyl-3-chloropropane d. 5-chloro-2-pentyne
Answer: The IUPAC name of [tex]CH_3C\equiv CCH_2CH_2Cl[/tex] is 5-chloro-2-pentyne
Explanation:
1. First select the longest possible carbon chain. For the number of carbon atom, we add prefix as 'meth' for 1, 'eth' for 2, 'prop' for 3, 'but' for 4, 'pent' for 5, 'hex' for 6, 'sept' for 7, 'oct' for 8, 'nona' for 9 and 'deca' for 10.
2. The longest possible carbon chain should contain all the bonds and functional groups.
3. The numbering is done in such a way that the carbon containing the functional group or substituent gets the lowest number.
4. The naming of alkane is done by adding the suffix -ane, alkene by adding the suffix -ene, alkyne.
Thus the IUPAC name of [tex]CH_3C\equiv CCH_2CH_2Cl[/tex] is 5-chloro-2-pentyne
