Answer:
Close to the calculated endpoint of a titration - Partially open
At the beginning of a titration - Completely open
Filling the buret with titrant - Completely closed
Conditioning the buret with the titrant - Completely closed
Explanation:
'Titration' is depicted as the process under which the concentration of some substances in a solution is determined by adding measured amounts of some other substance until a rection is displayed to be complete.
As per the question, the stopcock would remain completely open when the process of titration starts. After the buret is successfully placed, the titrant is carefully put through the buret in the stopcock which is entirely closed. Thereafter, when the titrant and the buret are conditioned, the stopcock must remain closed for correct results. Then, when the process is near the estimated end-point and the solution begins to turn its color, the stopcock would be slightly open before the reading of the endpoint for adding the drops of titrant for final observation.
Please help with all 3 parts!
Answer:
1:Part A.
[tex]\bold{42.2 g C_{12}H_{22}O_{11} \:in \:528 g H₂O}[/tex]
Mass Percent=[tex]\bold{\frac{Mass\: of \:Solute}{Mass\: of \:Solution}×100\%}[/tex]
=[tex]\frac{42.2}{528}*100\%=\bold{\underline{7.99\: or \:8\%}}[/tex]
Part B.
[tex]\bold{198\:m g\: C_{6}H_{12}O_{6} \:in\:4.71 g\: H₂O}[/tex]
mass of solute: 198mg
mass of solvent :4.71g=4710g
Mass Percent=[tex]\bold{\frac{Mass\: of \:Solute}{Mass\: of \:Solution}×100\%}[/tex]
=[tex]\frac{198}{4710}*100\%=\bold{\underline{4.20\%}} [/tex]
Part C.
[tex]\bold{8.85 g NaCl \:in \:190 g\: H₂O}[/tex]
Mass Percent=[tex]\bold{\frac{Mass\: of \:Solute}{Mass\: of \:Solution}×100\%}[/tex]
=[tex]\frac{8.85}{190}*100\%=\bold{\underline{4.66\%}}[/tex]
Answer:
It will help you !!!!!!!!!!
why is repetition important in science?
Answer:
the repetition principle is important in scientific research, because the observational indexes are random variables,which requires a certain amount of samples to reveal their changing regularity
Which best describes a scientist who solves a new problem using something already learned?
creative
curious
observant
skeptical
Answer:
The answer should be Skeptical
The first step of electrophilic aromatic substitution involves the formation of the arenium ion intermediate.
a. True
b. Fasle
Answer:
True
Explanation:
Aromatic compounds undergo substitution rather than addition reactions because the aromatic structure is maintained.
Electrophilic aromatic substitution begins with attack of the electrophile on the aromatic ring to yield a delocalized intermediate called the arenium intermediate. Loss of hydrogen from this intermediate yields the final product.
How many milliliters of 0.204 Mol KMnO4 are needed to react with 3.24 g of iron(II) sulfate, FeSO4? The reation is as folows. 10FeSO4(aq) + 2 KMnO4(aq) = 5Fe2(SO4)3(aq) + 2MnSO4(aq) + K2SO4(aq) + 8H2O(l)
Answer:
Explanation:
nFeSo4=3.36/152
nkmno4=1/5nFeSO4
V=17.68 ml
uses of rare or inert gases
Explanation:
noble gases are useful let's take for instance helium which is used in balloons. they are used to form inert atmosphere and they are used also to deter chemical reaction.
Select all of the following statements that represent the differences between a voltaic cell and an electrolytic cell. Group of answer choices The electrodes will change in mass for only the electrolytic cell Reduction happens at the cathode for only the electrolytic cell The redox reaction is spontaneous for only voltaic cell Electrode with the lowest reduction potential is reduced in an electrolytic cell A potential is generated when the voltaic cell runs
Answer:
The electrodes will change in mass for only the electrolytic cellElectrode with the lowest reduction potential is reduced in an electrolytic cellA potential is generated when the voltaic cell runsThe following statements represent the differences between a voltaic cell and an electrolytic cell -
The redox reaction is spontaneous for only voltaic cell potential is generated when the voltaic cell runsThe process occurs spontaneously in the voltaic cells due to chemical reactions.electrolytic cell electrical energy is needed for the chemical reactions to occur.A potential is generated by a chemical reaction and for electrolytic cells, a potential is needed.
there is definitely an exchange of mass in a voltaic cellthe species with lower reduction potential always gets reduced and in any electrochemical cell reduction occurs at the cathode.The following statements represent the differences between a voltaic cell and an electrolytic cell -
The redox reaction is spontaneous for only voltaic cell potential is generated when the voltaic cell runsThus, The following statements represent the differences between a voltaic cell and an electrolytic cell -
The redox reaction is spontaneous for only voltaic cell potential is generated when the voltaic cell runsLearn more:
https://brainly.com/question/3614785
How to prepared sodium chloride solution.
Explanation:
Dissolve 93.52g of NaCl in about 400mL of distilled water, then add more water until final volume is 800mL. If starting with a solution or liquid reagent: When diluting more concentrated solutions, decide what volume(V2) and molarity (M2) the final soluble should be.
tính ΔH° của phả ứng sau ở 200°C
CO+1÷2O=CO2
ΔH°
number is equal to 6022 x 10^23
Answer:
The Avogadro's number
Explanation:
the number is 6.02214x10 to the 23 power
explain in details how triacylglycerol have an advantage over carbohydrates as stored fuel
Answer:
As stored fuels, triacylglycerols have two significant advantages over polysaccharides such as glycogen and starch. The carbon atoms of fatty acids are more reduced than those of sugars, and oxidation of triacylglycerols yields more than twice as much energy, gram for gram, as that of carbohydrates.
Explanation:
HELP! How is the mass number of an atom calculated?
A - total number of electrons
B - total number of protons
C - protons plus neutrons
D - electrons plus neutrons
The density of a gas cannot be measured.
True
False
Answer:
False
Explanation:
Answer:
False
Explanation:
Hydrogen is manufactured on an industrial scale by this sequence of reactions:
CH4(g) + H2O(g) ⇆ CO(g) + 3H2(g)
CO(g)+ H2O(g) ⇆ CO(g) + H2(g)
The net reaction is:
CH4(g) + H2O(g) ⇆ CO(g) + 4H2(g)
Write an equation that gives the overall equilibrium constant K in terms of the equilibrium constants K1 and K2.
Answer:
[tex]K=K_1*K_2\\\\K=\frac{[H_2]^3[CO_2][H_2]}{[CH_4][H_2O][H_2O]}[/tex]
Explanation:
Hello there!
In this case, for the given chemical reaction, it turns out firstly necessary to write the equilibrium expression for both reactions 1 and 2:
[tex]K_1=\frac{[CO][H_2]^3}{[CH_4][H_2O]} \\\\K_2=\frac{[CO_2][H_2]}{[CO][H_2O]}[/tex]
Now, when we combine them to get the overall expression, we infer these two are multiplied to get:
[tex]K=K_1*K_2\\\\K=\frac{[CO][H_2]^3}{[CH_4][H_2O]} *\frac{[CO_2][H_2]}{[CO][H_2O]}\\\\K=\frac{[H_2]^3[CO_2][H_2]}{[CH_4][H_2O][H_2O]}[/tex]
Regards!
Carboxylic acid derivatives undergo hydrolysis to make carboxylic acids.
a. True
b. False
Answer:
TRUE
Explanation:
All carboxylic acid derivatives have in common the fact that they undergo hydrolysis (a cleav- age reaction with water) to yield carboxylic acids. with hydroxide ion to yield a carboxylate salt and an alcohol. The carboxylic acid itself is formed when a strong acid is subsequently added to the reaction mixture.
PLS MARK BRAINLIEST
how do elasticity ang flexibility differ?
Answer:
the object will regain its original form as soon as the deforming force is removed. ... Flexibility means the object is just easily deformed, and will stay that way.
Explanation:
An equilibrium mixture of PCl5(g), PCl3(g), and Cl2(g) has partial pressures of 217.0 Torr, 13.2 Torr, and 13.2 Torr, respectively. A quantity of Cl2(g) is injected into the mixture, and the total pressure jumps to 263.0 Torr at the moment of mixing. The system then re-equilibrates. The chemical equation for this reaction is
Answer:
p'PCl3 = 6.8 torr
p'Cl2 =26.4 torr
p'PCl5 =223.4 torr
Explanation:
An equilibrium mixture of PCl5(g), PCl3(g), and Cl2(g) has partial pressures of 217.0 Torr, 13.2 Torr, and 13.2 Torr, respectively. A quantity of Cl2(g) is injected into the mixture, and the total pressure jumps to 263.0 Torr at the moment of mixing. The system then re-equilibrates. The chemical equation for this reaction is
PCl3(g) + Cl2(g) ---> PCl5(g)
Calculate the new partial pressures after equilibrium is reestablished. [in torr]
pPCl3
pCl2
pPCl5
Step 1: Data given
Partial pressure before adding chlorine gas:
Partial pressure of PCl5 = 217.0 torr
Partial pressureof PCl3 = 13.2 torr
Partial pressureof Cl2 = 13.2 torr
A quantity of Cl2(g) is injected into the mixture, and the total pressure jumps to 263.0 Torr at the moment of mixing
Step 2: The equation
PCl3(g)+Cl2(g) ⇔ PCl5(g)
Step 3: The expression of an equilibrium constant before adding chlorine gas
Kp = pPCl5 / (pPCl3 * pCl2)
Kp = 217.0 / (13.2 * 13.2)
Kp = 1.245
Step 4: The expression of an equilibrium constant after adding chlorine gas
Partial pressure of PCl5 = 217.0 torr
Partial pressure of PCl3 = 13.2
Partial pressure of Cl2 = TO BE DETERMINED
Step 5: The total pressure of the system
Ptotal = pPCl5 + pPCl3 + pCl2
263.0 torr = 217.0 torr + 13.2 torr + pCl2
pCl2 = 263.0 - 217.0 -13.2 = 32.8 torr
Step 6: The initial pressure
The equation: PCl3(g)+Cl2(g) ⇔ PCl5(g)
pPCl3 = 13.2 torr
pCl2 = 32.8 torr
pPCl5 = 217.0 torr
Step 7: The pressure at the equilibrium
p'PCl3 = (13.2 -x) torr
p'Cl2 = (32.8 - x) torr
p'PCl5 = (217.0 + x) torr
Step 8: The equilibrium constant
'Kp = p'PCl5 / (p'PCl3 * p'Cl2)
1.245 = (217.0+x) / ((13.2-x)(32.8-x)
x = 6.40 torr
p'PCl3 = 13.2 -6.40 = 6.8 torr
p'Cl2 = 32.8 - 6.40 =26.4 torr
p'PCl5 = 217.0 + x) 6.4 = 223.4 torr
c6h5-c=o-ch3 + br2/oh
Explanation:
here's the molecule you were looking for
How does a smoke detector utilize radiation?
A. Beta radiation creates a stead stream of electrons. When the stream is broken by smoke particles, it sets off the alarm.
B. Alpha radiation ionizes the air. When smoke interacts with the ionized particles it causes the alarm to sound.
C. Gamma radiation creates a stead stream of electrons. When the stream is broken by smoke particles, it sets off the alarm.
D. Beta radiation ionizes the air. When smoke interacts with the ionized particles it causes the alarm to sound.
Hypercalcemia sign and symptoms severe symptoms
Answer:
Hypercalcemia can cause stomach upset, nausea, vomiting and constipation. Bones and muscles. In most cases, the excess calcium in your blood was leached from your bones, which weakens them. This can cause bone pain and muscle weakness.
Some symptoms are:
Fatigue, bone pain, headaches.
Nausea, vomiting, constipation, decrease in appetite.
Forgetfulness.
Lethargy, depression, memory loss or irritability.
Muscle aches, weakness, cramping and/or twitches.
Compounds such as butane and isobutane that have the same molecular formula but differ in the order in which the atoms are connected are called ____________
a. trans isomers
b. cis isomers
c. conventional isomers
d. constitutional isomers
Answer:
One compound, called n-butane, where the prefix n- represents normal, has its four carbon atoms bonded in a continuous chain. The other, called isobutane, has a branched chain. Different compounds that have the same molecular formula are called isomers.
Answer:
d. constitutional isomers
Explanation:
i hope it will help
What is the formula for the compound made from mercury (II) and the nitrate ion.
Answer:
Hg(NO3)2
Explanation:
Hg occurs both as Hg(I) and Hg(II) but nitrate is -1, not -2 We NORMALLY use the smallest set of subscripts but in the case of Hg(I) compounds, most of them are dimeric. Hg2Cl2, Hg2(NO3)2, etc. Note that there also is a mercury(II) nitrate; i.e., Hg(NO3)2. Therefore, although the empirical formula for mercury(I) nitrate is HgNO3, the molecular formula is Hg2(NO3)2 anf I was always encouraged to write the molecular formula instead of the empirical formula.
Hope this helps! Feel free to shoot me any questions <3
Identify the compound with ionic bonds.
CO
H2O
Ne
KCl
O2
Answer:
CO =Coordinate Covalent Bond ,H2O = Water , NE= Nickel or Neon ,KCL=Potassium Chloride and O2 = Water
Explanation:
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C2H5MgBr + PCl3 ra chất gì
Answer:
C2H5P
is the right answer
Do the tests performed to identify DNA exclude the presence of RNA?
DNA and RNA can also be ISOLATED from the same biological sample.
So the answer is no, both DNA and RNA are together.
Answer:
so the answer is no
both DNA and RNA are together.
Explanation:
DNA and RNA can also be ISOLATED from the same. biological sample
cuales son las caracteristicas de el livermorio
Answer:
Livermorium is a radioactive, artificially produced element about which little is known. It is expected to be a solid and classified as a metal. It is a member of the chalcogen group. Livermorium has four isotopes with known half-lives, all of which decay through alpha decay
Gimme the sandmeyer's reaction!!!
Explanation:
HERE IS YOUR ANSWER.....
What is the source of energy stored by ATP in cells?
Answers
A.
oxidation of biological compounds
B.
reduction of biological compounds
C.
synthesis of biological compounds
D.
polymerization of biological compounds
Answer:
I think C (synthesis of biological compounds
Explanation:
have a nice day
· Acids are not safe to be used, but our stomach secretes hydrochloric acid. What would happen if the stomach does not carry out this task? Mark them brainlist
The Bohr effect:_____.
a. explains through the Bohr model of the atom why Fe2+ will bind O2 in heme but Fe3+ will not.
b. contributes to binding of O2 by hemoglobin in lungs and release of O2 from hemoglobin in tissues.
c. applies to both myoglobin and hemoglobin.
d. relates [H+] to [CO2].
Answer:
b. contributes to binding of O2 by hemoglobin in lungs and release of O2 from hemoglobin in tissues.
Explanation:
The Bohr effect is a phenomenon described by Christian Bohr. Is an affinity that binds oxygen and hemoglobin and is inversely related to the concentration of carbon dioxide. As CO2 reacts with water and an increase in CO2 results in a decrease in blood ph.