Answer:
Explanation:
4Li + O₂ = 2Li₂O.
4 mole 1 mole
3.25 g Li = 3.25 / 7
= .464 moles
3.5 g of O₂ = 3.5 / 32 mole
= .11 mole
.11 mole of O₂ will react with .44 mole of Li as per the equation above
but Li available is .464 which is in excess .
Hence O₂ is in short supply for given mass of Li .
Hence O₂ is the limiting reagent .
What is the composition of a universal indicator?
Answer:
The main universal indicator is in the form of a solution and are thymol blue , methyl red , bromothymol blue and phenolphthalein this mixture is important because each component loses or gains protons depending upon the acidity of the solution being tested .
maybe this mighr help u
Which of the following cell organelles is NOT found in BOTH plant and animal cells?
O cells membrane
O cell wall
O ribosomes
O cytoplasm
MULTIPLE CHOICE QUESTION
When the frequency increases, the waves
become?
Shorter
Longer
Answer:
Shorter
Explanation:
As a wavelength increases in size, its frequency, and energy (E) decrease. From these equations, you may realize that as the frequency increases, the wavelength gets shorter. As the frequency decreases, the wavelength gets longer. There are two basic types of waves: mechanical and electromagnetic.
How does a computer's ability to perform so many calculations in a very short time affect how people communicate (pls help)
Answer:
A computer's ability to perform so many calculations in a very short time affects how people communicate by stopping them from talking actually. We no longer talk verbally. We don't go out and socialize, we always talk from the phone or text. We have lost our inner touch with talking.
Explanation:
Scientists examine fossils from three different animals. They determine that all three animals share similar structures and
record their observations as follows
• Animal A and animal B have somewhat similar structures
• Animal A and animal C have very similar structures
• Animal B and animal C have very similar structures
The scientists use the similarities to determine the order in which the fossils should appear in the fossil record. Based on the
scientists' observations, which order is the most reasonable?
ABC
ACB
С, В, А
В, А С
Answer:
C,B,A
Explanation:
C has the most similar structure
B has the second most similar structure
A has the least similair structure
Based on the scientists' observations, the order which is the most reasonable is C,B,A.
What are observations?Observations are defined as a set of statements or facts which are recorded while conducting an experiment.Observations are made through sensing changes in the variables of the experiment.
It is specifically defined as an act of knowing or recording the changes in the variables of the experiment.Recording observations holds importance as recording observations avoid the experiment to be repeated over and over again.
It is important to note down observations so that the testing of hypothesis is made easier.There are four types of observations .Observations need to be descriptive and must be written in complete sentences and should include all the numerical data of the experiment.
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Help me with this question
Answer:
your cool
Explanation:
owa owa owa owa owa bob
If 21.00 mL of a 0.68 M solution of C6H5NH2 required 6.60 mL of the strong acid to completely neutralize the solution, what was the final pH at the equivalence point
Answer:
pH = 2.46
Explanation:
Hello there!
In this case, since this neutralization reaction may be assumed to occur in a 1:1 mole ratio between the base and the strong acid, it is possible to write the following moles and volume-concentrations relationship for the equivalence point:
[tex]n_{acid}=n_{base}=n_{salt}[/tex]
Whereas the moles of the salt are computed as shown below:
[tex]n_{salt}=0.021L*0.68mol/L=0.01428mol[/tex]
So we can divide those moles by the total volume (0.021L+0.0066L=0.0276L) to obtain the concentration of the final salt:
[tex][salt]=0.01428mol/0.0276L=0.517M[/tex]
Now, we need to keep in mind that this is an acidic salt since the base is weak and the acid strong, so the determinant ionization is:
[tex]C_6H_5NH_3^++H_2O\rightleftharpoons C_6H_5NH_2+H_3O^+[/tex]
Whose equilibrium expression is:
[tex]Ka=\frac{[C_6H_5NH_2][H_3O^+]}{C_6H_5NH_3^+}[/tex]
Now, since the Kb of C6H5NH2 is 4.3 x 10^-10, its Ka is 2.326x10^-5 (Kw/Kb), we can also write:
[tex]2.326x10^{-5}=\frac{x^2}{0.517M}[/tex]
Whereas x is:
[tex]x=\sqrt{0.517*2.326x10^{-5}}\\\\x=3.47x10^-3[/tex]
Which also equals the concentration of hydrogen ions; therefore, the pH at the equivalence point is:
[tex]pH=-log(3.47x10^{-3})\\\\pH=2.46[/tex]
Regards!
B) Which of these is NEVER an example of freshwater? A) Pacific Ocean B) Okefenokee Swamp Mississippi River Lake Pontchartrain.
Answer:
Lake pontchartrain
Explanation:
What is the mass of 2 moles of nitrogen gas, N2?
Answer:
28g
Solution. Hence, 2 moles of nitrogen atoms weigh 28g.
Which is not true of the cell theory?
which is NOT true about the cell theory?
A:all living organisms are composed of cells
B:all cells have a nucleus, which acts like the brain of the cell
C:all cells come preexisting living cells
D:the cell is the most basic part of a living organism
Answer this express as a chemical equation
Answer:
Pb(No3)2+2Nacl_PbCl2+2NaNO3
PLEASE HELP WORTH 100 POINTS !!!!!
Answer: Imidogen
Explanation: I just looked it up.
Answer:
Imidogen
Explanation:
What are the coefficients that would correctly balance this equation?
____Zn + ____K2CrO4 → ____K + ____ZnCrO4
1, 2, 1, 2
2, 1, 2, 1
1, 1, 2, 1
1, 2, 3, 1
Answer:
Explanation:
1,2,1,2
Answer:
b
Explanation:
How many grams do 4.5 moles of oxygen atoms weigh
Answer:
71.99100
Explanation:
The mass of oxygen equal to one mole of oxygen is 15.998 grams and the mass of one mole of hydrogen is 1.008 g. 15.998*4.5 = 71.99100
Hayley woke up to a hot and humid day but knows it is going to cool off later. What should she expect the weather to be like tonight?
Answer:
It will most likely rain because cool air cannot hold as much moisture as warm air.
Explanation:
I did the quiz !! :)
I really hope this helps!!!!!!!!!!!! :)
In a thin layer chromatography experiment, a plate of length 9.3 cm was used and a horizontal line was made at 1.45 cm above the bottom of the plate. After running the experiment (developing and drying), a spot was observed at 5.6 cm from the bottom of the plate, and the solvent front was 7.7 cm from the bottom of the plate. What is the Rf value
Answer: The [tex]R_f[/tex] value is 0.664
Explanation:
Distance travelled by solvent front = (7.7-1.45)cm = 6.25 cm
Distance travelled by unknown = (5.6-1.45) cm = 4.15 cm
The retention factor or the [tex]R_f[/tex] value is defined as the ratio of distance traveled by the unknown to the distance traveled by the solvent front.
[tex]R_f=\frac{\text {distance travelled by unknown}}{\text {distance travelled by solvent}}[/tex]
[tex]R_f=\frac{4.15}{6.25}=0.664[/tex]
Thus the [tex]R_f[/tex] value is 0.664
If 4.52g of the precipitate is formed, how many grams of sodium chloride reacted?
The question is incomplete, the complete question is;
AgNO3(aq)+NaCl(aq)→AgCl(s)⏐↓+NaNO3(aq)
1- If 4.52g of the precipitate is formed, how many grams of sodium chloride reacted?
Answer:
1.8 g
Explanation:
Given the equation;
AgNO3(aq)+NaCl(aq)→AgCl(s)↓+NaNO3(aq)
We can see that the reaction is 1:1 Hence, 1 mole of sodium chloride yielded 1 mole of the precipitate(AgCl).
If this is so,
Number of moles of precipitate formed = 4.52g/143.32 g/mol
Number of moles of precipitate formed = 0.0315 moles
Hence, 0.0315 moles of precipitate was formed by 0.0315 moles of NaCl
Therefore;
Mass of NaCl reacted = 0.0315 moles * 58.5 g/mol = 1.8 g
An average bushel of apples has a mass of 10 kg and contains 5 dozen apples.
What would be the average mass of 6 apples?
Answer:
Average mass of 6 apple = 1 kg
Explanation:
Given:
Average mass of 5 dozen apple = 10 kg
Find:
Average mass of 6 apple
Computation:
Average mass of 6 apple = [Average mass of 1 apple] x [6 apple]
Average mass of 6 apple = [10/(12 x 5)] x [6]
Average mass of 6 apple = 1 kg
0.254g lead(ii)ethanoate, on adding excess K2CrO4 solution, gave 0.130g of lead(ii)chromate precipitate. what is the percentage composition of Pb in the organic salt? (O = 16, Cr = 52, Pb = 207).
Answer:
32.8%
Explanation:
All of the Pb⁺² species precipitated as lead(II) cromate, PbCrO₄ (we know this as excess K₂CrO₄ was used).
First we convert 0.130 g of PbCrO₄ into moles, using its molar mass:
0.130 g ÷ 323 g/mol = 4.02x10⁻⁴ mol PbCrO₄There's 1 Pb⁺² mol per PbCrO₄ mol, so in total 4.02x10⁻⁴ moles of Pb⁺² were in the ethanoate sample.
We convert those 4.02x10⁻⁴ moles of Pb into grams:
4.02x10⁻⁴ mol * 207 g/mol = 0.083 g PbFinally we calculate the percentage composition of Pb:
0.083 g Pb / 0.254 g salt * 100% = 32.8%can you help me please
how many grams are there in 3400 moles of tetranitrogen dicarbide?
Explanation:
molar mass of tetranitrogen dicarbide S4N4= 4×32+4×14
128+56
184 g/mol
no.of moles =given mass/ molar mass
3400= given mass / 184
3400×184 =given mass.
625600 g
GIVING 28 POINTS AWAY PLEASE HELP ME WITH BOTH QUESTIONS ASAP!!
Answer: D
Explanation: for question 2 the answer is D and for 3 it is A. That is very easy and the muscular systen has nothing to do with breathing.
Answer:
2: d
3: b
i think, im not too sure
if anybody could help with this question i would appreciate it
its not college level but i dont know how to change the grade level
Answer:
D. Liquid
Explanation:
It's mercury given the density and mercury's a metal that is liquid at room temperature
Which of these materials are insulators? Select the THREE (3) that apply.
aluminum can
wool
rubber
iron nail
copper wire
plastic
Answer:
wool ,rubber and copper wire should be correct
what happened to Jodys
father
Answer:
Jody's father was bitten by a poisonous snakes name rattle snake
In order for heat to flow there must be... *
A. identical tempatures
B. a difference in tempatures
C. a difference in altitude
D. an electrical current present
Answer:
B. a difference in temperatures.
Explanation:
Conduction involves the transfer of electric charge or thermal energy due to the movement of particles. When the conduction relates to electric charge, it is known as electrical conduction while when it relates to thermal energy, it is known as heat conduction.
In the process of heat conduction, thermal energy is usually transferred from fast moving particles to slow moving particles during the collision of these particles.
Also, thermal energy is typically transferred between objects that has different degrees of temperature and materials (particles) that are directly in contact with each other but differ in their ability to accept or give up electrons.
In order for heat to flow there must be a difference in temperatures.
This ultimately implies that, the driving force responsible for heat to flow is a difference in temperature between the points from which heat originates and where heat is received.
Additionally, the higher the temperature difference, the greater would be the heat flow; which is usually from a high temperature level to a low temperature level.
CuCl2(aq) + Na3PO4(aq) =>?
Net ionic equation
The number of moles of molecules in a 12.0-gram sample of Cl2 is equal too?
Answer:
0.3529moles
Explanation:
no of moles =mass ÷molar mass
molar mass =17+17
=34
12÷34
=0.3529moles
According to the mole concept, the number of moles of molecules in a 12.0-gram sample of Cl₂ is equal to 0.169 moles.
What is a mole?
Mole is defined as the unit of amount of substance . It is the quantity measure of amount of substance of how many elementary particles are present in a given substance.
It is defined as exactly 6.022×10²³ elementary entities. The elementary entity can be a molecule, atom ion depending on the type of substance. Amount of elementary entities in a mole is called as Avogadro's number.
It is widely used in chemistry as a suitable way for expressing amounts of reactants and products.For the practical purposes, mass of one mole of compound in grams is approximately equal to mass of one molecule of compound measured in Daltons. Molar mass has units of gram per mole . In case of molecules, where molar mass in grams present in one mole of atoms is its atomic mass.Number of moles is mass/molar mass= 12/70.90=0.169 moles.
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2) A common "rule of thumb" -- for many reactions around room temperature is that the
rate will double for each ten degree increase in temperature. Does the reaction you hav
studied seem to obey this rule.
The question is incomplete. The complete question is :
A common "rule of thumb" for many reactions around room temperature is that the rate will double for each ten degree increase in temperature. Does the reaction you have studied seem to obey this rule? (Hint: Use your activation energy to calculate the ratio of rate constants at 300 and 310 Kelvin.)
Solutions :
If we consider the activation energy to be constant for the increase in 10 K temperature. (i.e. 300 K → 310 K), then the rate of the reaction will increase. This happens because of the change in the rate constant that leads to the change in overall rate of reaction.
Let's take :
[tex]$T_1=300 \ K$[/tex]
[tex]$T_2=310 \ K$[/tex]
The rate constant = [tex]$K_1 \text{ and } K_2$[/tex] respectively.
The activation energy and the Arhenius factor is same.
So by the arhenius equation,
[tex]$K_1 = Ae^{-\frac{E_a}{RT_1}}$[/tex] and [tex]$K_2 = Ae^{-\frac{E_a}{RT_2}}$[/tex]
[tex]$\Rightarrow \frac{K_1}{K_2}= \frac{e^{-\frac{E_a}{RT_1}}}{e^{-\frac{E_a}{RT_2}}} $[/tex]
[tex]$\Rightarrow \frac{K_1}{K_2}= e^{-\frac{E_a}{R}\left(\frac{1}{T_1}-\frac{1}{T_2}\right)}$[/tex]
[tex]$\Rightarrow \ln \frac{K_1}{K_2}= - \frac{E_a}{R} \left(\frac{1}{T_1} -\frac{1}{T_2} \right)$[/tex]
[tex]$\Rightarrow \ln \frac{K_2}{K_1}= \frac{E_a}{R} \left(\frac{1}{T_1} -\frac{1}{T_2} \right)$[/tex]
Given, [tex]$E_a = 0.269$[/tex] J/mol
R = 8.314 J/mol/K
[tex]$\Rightarrow \ln \frac{K_2}{K_1}= \frac{0.269}{8.314} \left(\frac{1}{300} -\frac{1}{310} \right)$[/tex]
[tex]$\Rightarrow \ln \frac{K_2}{K_1}= \frac{0.269}{8.314} \times \frac{10}{300 \times 310}$[/tex]
[tex]$\Rightarrow \ln \frac{K_2}{K_1}= 3.479 \times 10^{-6}$[/tex]
[tex]$\Rightarrow \frac{K_2}{K_1}= e^{3.479 \times 10^{-6}}$[/tex]
[tex]$\Rightarrow \frac{K_2}{K_1}= 1$[/tex]
∴ [tex]$K_2=K_1$[/tex]
So, no this reaction does not seem to follow the thumb rule as its activation energy is very low.
Which of the following statements would be an argument against multiculturalism?
(Click all that apply.)
A) Canadians are a mixture of people from various cultural, religious, racial, and ethnic origins. This mixture helps in relations with other countries.
B) Many cultural and ethnic groups have helped build Canada. We should encourage people to preserve their heritage; their traditions are part of Canadian history.
C) Canadians will learn tolerance through being in contact with other cultures. Multiculturalism can help to eliminate discrimination and prejudice.
D) The Canadian government should not spend citizens' tax dollars on multiculturalism. Our taxes are already too high.
Answer:
D
Explanation: