You are attempting the reduction of quinone with sodium borohydride. After adding the 0.05 g of NaBH4 you note that the solution remains yellow. Following the procedure, you continue to add increments of 0.05 g NaBH4. You note that the yellow color remains even after the addition of 0.10 g of extra NaBH4. Several students around you are experiencing a similar problem. Propose a cause for this and suggest a solution.
Answers
Answer:
When benzoquinone reacts with sodium borohydride, which is yellow in color, white and colorless hydroquinone is formed.
Explanation:
The reaction described below should occur. However, even as we add more sodium borohydride, the color stays yellow. This implies that the solution must contain unreacted benzoquinone. Furthermore, NaBH4 is a kind of hydride (H-), and the reaction starts with the addition of hydride.
The acid oxygen is protonated once more to produce a neutral primary alcohol. As sodium borohydride is a reducing agent, adding more will not cause the benzoquinone to react with it, increasing the amount of NaBH4 will not affect the color of the benzoquinone.
Often, benzoquinone is very vulnerable to solid minerals, acids, and alkalis, causing it to condense and decompose.
Related Questions
The strength of an acid is affected by the polarity of the bond connected to the acidic hydrogen. The more highly polarized this bond, the more easily the hydrogen is ionized. Electronegative atoms or groups of atoms present in the structure of an acid can act to withdraw electrons and produce additional polarization. Two common groups of acids to which this principle can be applied are oxoacids and carboxylic acids. In the latter group, the length of the hydrocarbon chain in a carboxylic acid has very little effect on acid strength Longer chains may slightly diminish acidity. Bases act as hydrogen ion acceptors because of the unshared electron pass in their structure. Any group present in a base that withdraws electrons makes these electron pairs less available to accept a hydrogen ion. In contrast, any group that can act as an electron donating group such as hydrocarbon groups (usually represented as II) can increase the base strength. Thus, the addition of electronegative atoms or groups of atoms to the structure of a base decreases the base strength and electron donating groups increase base strength. Many common weak bases are derivatives of ammonia, in which H atom(s) of NH_2 are replaced with other groups.
Arrange the following oxoacids in order of decreasing acid strength. Rank from strongest to weakest acid.
1. HBrO
2. HClO
3. HClO2
4. HClO3
Answers
Answer:
The answer is "[tex]\bold{HClO_3 > HClO_2 >HClO > HBrO}[/tex]"
Explanation:
We arrange oxoacids to decrease the intensity of acids in this question. Or we may conclude all this from strongest to weakest acids they order oxoacids, that's why above given order is correct.
Which of these is a disadvantage of wind energy?
a. it is renewable.
0
b. it reduces greenhouse gas emissions.
0
c. it is abundant.
0
d. it reduces bird and bat populations
Answers
Answer: d
Explanation: took the test got it right
How many moles of water are produced from burning 80 moles of
methane in excess oxygen?
Answers
Answer:
160 mol H₂O
Explanation:
Step 1: Write the balanced complete combustion reaction
CH₄ + 2 O₂ ⇒ CO₂ + 2 H₂O
Step 2: Establish the appropriate molar ratio
According to the balanced equation, the molar ratio of CH₄ to H₂O is 1:2.
Step 3: Calculate the moles of water formed from 80 moles of methane
We will use the previously established molar ratio.
80 mol CH₄ × 2 mol H₂O/1 mol CH₄ = 160 mol H₂O
3. Calculate the average atomic mass of sulfur if 95.00% of all sulfur atoms have
a mass of 31.972 amu, 0.76% has a mass of 32.971u and 4.22% have a mass of
33.967u.
Answers
Answer:
Average atomic mass = 32.057 u
Explanation:
Average atomic mass = Σ(isotope × abundance)
Average atomic mass = (0.95 × 31.972) + (0.0076 × 32.971) + (0.0422 × 33.967)
Average atomic mass = 32.057 u
In 2-3 sentences, explain how objects in our solar system planets acquired the mass to become planets.
Answers
The sun contained 99% of the available matter and the rest matter formed smaller clumps inside the spinning disk. These clumps gained enough mass which lead to their gravity shaping them into spheres becoming planets.
What are planets?A planet can be described as a large, rounded astronomical body that is neither a star nor its remnant. The theory of planet formation is the nebular hypothesis, which tells that an interstellar cloud collapses out of a nebula to generate a young protostar orbited by a protoplanetary disk.
The planet grows in this disk by the accumulation of material driven by gravity and this process is known as accretion. Our solar system has at least eight planets that rotate around an axis tilted with respect to its orbital pole.
All planets possess an atmosphere, although that of Mercury is tenuous. The Solar System planets create magnetic fields apart from Venus and Mars, and all planets except Venus and Mercury have natural satellites.
Learn more about planets, here:
https://brainly.com/question/15268075
#SPJ2
Which halogens are gases at STP?
Answers
As the atomic number increases, the reactivity of the halogens decreases. Fluorine and chlorine exist as gases at room temperature, while bromine is a liquid, and iodine is a solid.
Answer:
As the atomic number increases, the reactivity of the halogens decreases. Fluorine and chlorine exist as gases at room temperature, while bromine is a liquid, and iodine is a solid.
SSA PRACTICE QUESTION
Mandy wanted to see if a new
environmentally-friendly pesticide will
prevent insect damage to tomato plants.
After making a hypothesis, she conducts
her experiment. She treats five tomato
plants with traditional pesticide and five
with the new pesticide. Mandy also
leaves five plants untreated as a control.
She makes careful notes of how she set
up her experiment and then records her
data about all of the plants. Why is it
important for Mandy to record her
procedures and data accurately?
Answers
Answer:
The correct answer is - so that other scientists can replicate the experiment and make sure the results are correct or to check accuracy.
Explanation:
The data and procudres are required to be recorded or noted correctly so the experiment and research can be replicate and tested for the accuracy of the experiment by other scientist and researcher.
Mandy also need to note procedure, data, variables and other data correctly for the testing the accuracy and replication of the experiment. The replication is essential to check if every thing is correct and result are error free.
Pls help with the question.
Answers
Answer:
2 L
Explanation:
From the question
Applying boyles law,
PV = P'V'....................... Equation 1
Where P = Initial pressure, P' = Final Pressure, V = Initial Volume, V' = Final Volume.
make V' the subject of the equation
V' = PV/P'.................... Equation 2
Givne: V = 5 L, P = 500 mmHg, P' = 1240 mmHg
Substitute these values into equation 2
V' = (5×500)/1240
V' = 2500/1240
V' = 2 L
What is created when an acid is mixed with a base?
Answers
Answer:
If you mix equal amounts of a strong acid and a strong base, the two chemicals essentially cancel each other out and produce a salt and water. Mixing equal amounts of a strong acid with a strong base also produces a neutral pH (pH = 7) solution.
You are given 19.2 liters of H3PO4. How many moles do you have?
Answers
Answer:
Explanation:
Do a quick conversion: 1 grams H3PO4 = 0.010204583427424 mole using the molecular. How many grams H3PO4 in 1 mol? You can view more details on each measurement unit: molecular weight of H3PO4 or mol This. The formula weight is simply the weight in atomic mass units of all the atoms in a given formula.
A] 1 N2 + 3 H2 → 2 NH3
1. How many moles and grams of ammonia can be made from 6.3 moles of H2 ?
2. How many moles and particles of ammonia can be made from 2.5 moles of N2 ?
3. How many moles is 425 g of ammonia? How many moles and grams of N2 are needed to make it?
4. How many moles and grams and liters of H2 are needed to make 10 moles of ammonia?
Answers
I haven't done these in some time, so I'm not sure if they are 100% right.
1) 6.3 moles of H2( 2 mol of NH3 / 3 mol of H2)= 4.2 mol of NH3
6.3 moles of H2( 2 mol of NH3/ 3 mol of H2)(17.04 g of NH3/1 mol NH3)= 71.57 g of NH3
2) 2.5 moles of N2(2 mol of NH3/1 mol of N2)= 5 moles of NH3
2.25 moles of N2(2 mol of NH3/ 1 mol of N2)(6.02x10^23 particles/ 1 mol of NH3)= 3.01x10^24 particles of NH3
3) 425 g of NH3(1 mol of NH3/17.04 g NH3)= 24.9 moles of NH3
425 g of NH3(1 mol of NH3/17.04 g of NH3)(1 mol of N2/2 mol of NH3)(28.02 g of N2/1 mol N2)= 349 g of N2
425 g of NH3(1 mol of NH3/17.04 g of NH3)(1 mol of N2/2 mol of NH3)= 12.5 mol of N2
4) 10 moles NH3(3 moles of H2/2 moles of NH3)= 15 moles H2
10 moles NH3(3 mol of H2/2 mol of NH3)(2.02 g of H2/1 mol of H2)= 30.3 g of H2
30.3 g = .0303 liters of H2
How did you spend your Easter?
Answers
Answer:
I didn't do anything, we don't celebrate lol I hope you had fun though!
Explanation:
What is the relative atomic mass of an element
whose isotopic composition is 90% of 20x and 10% of 22x
Answers
Answer:
20.2 amu.
Explanation:
Let A represent isotope ²⁰X
Let B represent isotope ²²X
From the question given above, the following data were obtained:
For Isotope A (²⁰X):
Mass of A = 20
Abundance (A%) = 90%
For Isotope B (²²X):
Mass of B = 22
Abundance (A%) = 10%
Relative atomic mass (RAM) =?
The relative atomic mass (RAM) of the element can be obtained as follow:
RAM = [(Mass of A × A%)/100] + [(Mass of B × B%)/100]
RAM = [(20 × 90)/100] + [(22 × 10)/100]
RAM = 18 + 2.2
RAM = 20.2 amu
Thus, relative atomic mass (RAM) of the element is 20.2 amu
How many grams of carbon disulfide will be produced if .012
kg of sulfur reacts with carbon?
Answers
Answer:
14.25g
Explination:
I found this answer on quizlet titled, "Chem Quizlet" by jamie_barbara
pls help with 1 question (15 ponts)
What happens in the circulatory system?
Answers
Select all of the answers that apply.
Which of the following characteristics must an air mass have?
It flows as one unit.
It has different temperatures but uniform humidity.
It must be 1,000 miles or more in size.
It must form over a low-pressure area.
It has a uniform temperature and humidity.
Answers
Explanation:
it has different temperature but uniform humidity
hope it will help you
write the molecular formula of sodium nitroprusside.
Answers
Answer:
Explanation: Sodium Nitroprusside, whose molecular formula is • 2H2O, and whose molecular weight is 297.95. Dry sodium nitroprusside is a reddish-brown powder, soluble in water.
Write a word equation and a skeleton equation for the chemical reaction.
A. Solid iron reacts with aqueous copper(ii) nitrate to produce solid copper and aqueous iron(ii) nitrate.
Answers
2 C4H10 + 13O2 -------> 8CO2 + 10H2O
a) What is the mole ratio between butane and oxygen gas?
b) What is the mole ratio between water and oxygen gas?
c) How many moles of water formed?
d) How many moles of butane burned?
e) How many grams of butane burned?
f) How much oxygen was used up in moles?
g) How much oxygen was used up in grams?
Answers
Answer:
A. 2 : 13
B. 10 : 13
C. 10 moles of water, H₂O.
D. 2 moles of butane, C₄H₁₀
E. 116 g of butane, C₄H₁₀
F. 13 moles of oxygen, O₂
G. 416 g of oxygen, O₂
Explanation:
The equation for the reaction is given below:
2C₄H₁₀ + 13O₂ —> 8CO₂ + 10H₂O
A. Determination of the mole ratio between butane and oxygen gas.
Mole of butane, C₄H₁₀ = 2 moles
Mole of oxygen, O₂ = 13 moles
Mole ratio of butane and oxygen = 2 : 13
B. Determination of the mole ratio between water and oxygen gas
Mole of the water, H₂O = 10 moles
Mole of oxygen, O₂ = 13 moles
Mole ratio of water and oxygen = 10 : 13
C. Determination of the moles of water formed.
From the balanced equation above,
10 moles water, H₂O were produced.
D. Determination of the moles of butane burned.
From the balanced equation above,
2 moles of butane, C₄H₁₀ were burned.
E. Determination of the mass of butane burned.
Molar mass of C₄H₁₀ = (12×4) + (10×1)
= 48 + 10 = 58 g/mol
Mole of C₄H₁₀ = 2 moles
Mass of C₄H₁₀ =?
Mass = mole × molar mass
Mass of C₄H₁₀ = 2 × 58
Mass of C₄H₁₀ = 116 g
Thus, 116 g of butane, C₄H₁₀ were burned.
F. Determination of the number of mole of oxygen used.
From the balanced equation above,
13 moles of oxygen, O₂ were used.
G. Determination of the mass of oxygen used.
Molar mass of O₂ = 2 × 16 = 32 g/mol
Mole of O₂ = 13 moles
Mass of O₂ =?
Mass = mole × molar mass
Mass of O₂ = 13 × 32
Mass of O₂ = 416 g
Thus, 416 g of oxygen, O₂ were used.
Explain the term mole ratio in your own words When would you use this term ?
Answers
Answer:
A mole ratio is the ratio between the amounts in moles of any two compounds involved in a chemical reaction.
Mole ratios are used as conversion factors between products and reactants in many chemistry problems.
Explanation:
What are the two types of bonding we have studied?
a. Metallic and covalent
b. Covalent and ionic
c. lonic and metallic
d. Molecular and metallic
Answers
Answer:
B: Covalent bond and Ionic bond
During a solar eclipse, explain what would an observer
on the Moon see on the surface of the Earth?
Answers
Answer:
It getting darker
Explanation:
This is because the light isn't hitting the earth as much, making it darker. They might also see more city lights than before. Hope this helps! plz mark as brainliest!
how much carbon is in CO2 if the sample contains 48 g of oxygen remember the ratio of carbon to oxygen is 12 g of 32 g
18g
24g
12g
20g
Answers
Answer: 24g
Explanation:
Suppose that Laser A were to shine a beam of light straight into the left side of Prism A, and Laser B were to shine an identical beam of light straight into the left side of Prism B. Which prism would refract the light more? (Assume the sides of the two prisms are sloped the same.)
Answers
Answer:
Prism B
Explanation:
Which sample contains the greatest number of atoms. A sample of Ca that contains 3.40×1024 atoms or a 1.76 mole sample of Be?
The sample of _____ contains the greatest number of atoms.
Answers
Answer:
The sample of __Ca___ contains the greatest number of atoms
Explanation:
As we know,
1 mole [tex]= 6.022*10^{23}[/tex] molecular entities (Can be atom, ions or molecules)
Number of atoms in 1.76 mole sample of Be
[tex]= 6.022*10^{23} *1.76\\= 1.059 * 10^{24}[/tex]
The sample of __Ca___ contains the greatest number of atoms
Help me pls I put 49 point( every single point that I have) pls help me
Answers
Answer:
see below
Explanation:
1) chem rxn compound molecule covalent ions ionic
2) 2 hydrogen one oxygen H2O covalent
3) is always liq
4
In the Hatom , what is the correct order (arrangement) of energy levels
Answers
Use average bond enthalpies (linked above) to calculate the enthalpy change for the following gas-phase reaction. CO(g) + Cl2(g) COCl2(g) To analyze the reaction, first draw Lew To analyze the reaction, first draw Lewis structures for all reactant and product molecules. ΔHreaction = ------ kJ Draw the reaction using separate sketchers for each species. Separate multiple reactants and/or products using the + sign from the drop-down arrow. Separate reactants from products using the → symbol from the drop-down menu. Remember to include nonbonding valence electrons in your Lewis structures. To analyze the reaction, first draw Lewis structures for all reactant and product molecules. Draw the reaction using separate sketchers for each species. Separate multiple reactants and/or products using the + sign from the drop-down arrow. Separate reactants from products using the → symbol from the drop-down menu. Remember to include nonbonding valence electrons in your Lewis structures. To analyze the reaction, first draw Lewis structures for all reactant and product molecules. Draw the reaction using separate sketchers for each species. Separate multiple reactants and/or products using the + sign from the drop-down arrow. Separate reactants from products using the → symbol from the drop-down menu. Remember to include nonbonding valence electrons in your Lewis structures.
Answers
Answer:
ΔHreaction (KJ) = - 78 KJ
The value may vary in relation to the source of the bond enthalpy data.
Bond enthalpies used (From a table of bond enthalpies )
Bond KJ/ mol
C≡O 1080
C-Cl 330
C=O 741
Cl-Cl 243
Explanation:
CO(g) + Cl2(g) → COCl2(g)
1) Lewis structures
Valence electrons
C 4
O 6
Cl 7
Reactants
CO(g)
In the case of CO, carbon has a negative charge and oxygen a positive charge.
Cl2(g)
Products
COCl2(g)
_______________________
ΔHreaction (KJ) = ∑ n* ΔH ( reactants) - ∑ n* ΔH (product)
ΔHreaction (KJ) = (ΔHC≡O + ΔHCl-Cl) - ( ΔHC=O + 2* ΔHC-Cl)
Replacing the values
ΔHreaction (KJ) = (1080 + 243) - ( 741 + 2* 330)
ΔHreaction (KJ) = 1323 - 1401
= - 78 KJ
what statement is the best description of a chemical bond
Answers
Answer:
A chemical bond holds atoms together.
help ill mark brainlist !!! (no bots or links)
at a subduction zone, a very low and deep point forms on the surface of the crust. what is this low point called?
A ) Rift
B ) Valley
C ) Ridge
D ) Trench
Answers
Answer:
The trench.
Explanation:
A region where this process occurs is known as a subduction zone, and its surface expression is known as an arc-trench complex.