what is science and important of science
science is all about the nature.
it is the study of squaring knowledge
In the reduction of 4-tert-butylcyclohexanone with sodium borohydride, the major product has the tert-butyl group in the equatorial position and the alcohol in the ________ position.
Answer:
Axial position
Explanation:
In the reduction of 4-tert-butylcyclohexanone with sodium borohydride, the major product has the tert-butyl group in the equatorial position and the alcohol in the axial position.
The reason for this is that, axial bonds are parallel to each other. If substituents are larger than hydrogen, they experience a greater steric crowding in axial compared to the equatorial position. Therefore, many substituted cyclohexane compounds prefer a conformation in which the larger substituents are in equatorial position.
Cobalt has an atomic number of 27 and atomic mass of 59. How many neutrons does cobalt have? 
A. 32
B. 31
C. 30
D. 33
Answer:
32
Explanation:
59-27
In this lab you will need to prepare solutions using dilutions. Starting with the stock 0.300 M NaOH solution, how would you prepare a 0.100 M NaOH solution (using 0.300 M NaCl as the diluent)
Answer:
1/3 dilution : 1 volume of stock solution + 2 volumes of diluent
Explanation:
Concentrated solution = 0.300 NaOH
Diluted solution = 0.100 NaOH
The dilution factor is : 0.100/0.300 = 1/3
Thus, we have to dilute three times the stock solution. For this, we take 1 volume of stock solution and then we add 2 volumes of diluent. As result, we will have 1 volume of stock solution in a total of 3 volumes. For example, we take 1 mL of 0.300 NaOH and then we add 2 mL of diluent (0.300 NaCl). The final concentration after dilution will be:
Cd = 0.300 M x 1 mL/3 mL = 0.100 M
HELP ME FAST
How many moles are in 325 g of MgCO3?
0.161 moles
0.269 moles
1.98 moles
3.85 moles
Answer:
3.85
Explanation:
Calculate molar mass, starting with each element, then find grams per mole, then convert.
WILL GIVE BRAINLIEST TO FIRST ANSWER
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Answer: A Molecular Approach, 2/e. Mole ratio. 2 mol C4H10 : 13 mol O2 : 8 mol CO2 : 10 mol H2O. ❖ 2 molecules of C4H10 react ... of aluminum and 73.15 g of sulfur are combined to form aluminum sulfide according to the equation:.
Explanation:
what is the pH of a 2.58 x 10^-6 M solution of an acid?
Answer:
5.59Explanation:
The pH of a solution can be found by using the formula
[tex]pH = - log [ {H}^{+} ][/tex]
From the question we have
[tex]ph = - log(2.58 \times {10}^{ - 6} ) \\ = 5.58838[/tex]
We have the final answer as
5.59Hope this helps you
A 50.00 g sample of a compound containing only carbon, hydrogen, and oxygen was partially analyzed. The sample contained 24.66 g carbon, and 3.43g of hydrogen. The molecular weight of the compound was determined to be 146.0 amu. Determine emperical the molecular formula of the compound
Answer:
1. Empirical formula => C₂H₃O
2. Molecular formula => C₆H₉O₃
Explanation:
From the question given above, the following data were obtained:
Mass of compound = 50 g
Mass of Carbon = 24.66 g
Mass of Hydrogen = 3.43 g
Molecular weight of compound = 146.0 amu
Empirical formula =?
Molecular formula =?
Next, we shall determine the mass of oxygen in the compound. This can be obtained as follow:
Mass of compound = 50 g
Mass of C = 24.66 g
Mass of H = 3.43 g
Mass of O =?
Mass of O = mass of compound – ( mass of C + mass of H)
= 50 – (24.66 + 3.43)
= 50 – 28.09
= 21.91 g
1. Determination of the empirical formula.
Mass of C = 24.66 g
Mass of H = 3.43 g
Mass of O = 21.91 g
Divide by their molar mass
C = 24.66 / 12 = 2.055
H = 3.43 / 1 = 3.43
O = 21.91 / 16 = 1.369
Divide by the smallest
C = 2.055 / 1.369 = 2
H = 3.43 / 1.369 = 3
O = 1.369 / 1.369 = 1
Therefore, the empirical formula of the compound is C₂H₃O
2. Determination of the molecular formula.
Molecular weight of compound = 146.0 amu
Empirical formula => C₂H₃O
Molecular formula =?
Molecular formula = [C₂H₃O]ₙ = molecular weight
Thus,
[C₂H₃O]ₙ = 146
[(12×2) + (3×1) + 16]n = 146
[24 + 3 + 16]n = 146
43n = 146
Divide both side by 43
n = 146 / 43
n = 3
Molecular formula = [C₂H₃O]ₙ
Molecular formula = [C₂H₃O]₃
Molecular formula = C₆H₉O₃
If an aqueous solution of ___________ is added to a mixture of barium nitrate and silver nitrate, the barium ion will precipitate, but the silver ion would remain in solution.
Answer:
sodium fluoride
Explanation:
When we add sodium fluoride to a solution of a given mixture, we get barium fluoride from Ba, which would be an insoluble salt, and silver fluoride from Ag, which would be a soluble salt.
The solubility rule will be used to determine the barium salt that forms as a precipitate and leaves Ag+ salt in the solution.
From the following equations, we will see that the precipitate is formed in Ba but Ag remains dissolved in the solution.
[tex]Ba(NO_3)_2{(aq)} + 2NaF_{(aq)} \to BaF_{2(s)} +2NaNo_{3(aq)}[/tex]
[tex]AgNo_{3(aq)} +NaF_{(aq)} \to AgF_{(aq)} + NaNO_{(aq)}[/tex]
Why did the model of the atom change?
A. New materials became available to build better models.
B. The structure of atoms changed over time.
C. Scientists did not like the original model.
D. Experiments provided new evidence about the atom.
Which represents a balanced chemical equation?
Answer:
C
Explanation:
Reactant part has 2 Mg and 2 O, product part has 2 Mg and 2 O
which of these is inorganic 1) leaf 2) earthworms 3) minerals 4) bacteria
Answer:
Bacteria
Explanation:
THIS NOT MY WORK. its for my sister. HELP HER
Answer:
Your answer will be b(molten material from the outer core makes its way to the surface of earth)
Explanation:
Answer:
C
Explanation:
I'm pretty sure molten material comes from the inner core. I think you can search up this though, try to find where molten material comes from. Goodluck!
If in Part II, you mixed (carefully measured) 25.0 mL of 0.81 M NaOH with 65.0 mL of 0.33 M HCl, which of the two reagents is the limiting reagent for heat of reaction
Answer:
NaOH is the limiting reactant.
Explanation:
Hello there!
In this case, according to the given information, it turns out firstly necessary to write out the chemical reaction between NaOH and HCl:
[tex]NaOH+HCl\rightarrow NaCl+H_2O[/tex]
Thus, since they react in a 1:1 mole ratio; we can now calculate the moles of each substance by using their volumes and molarities:
[tex]n_{NaOH}=0.0250L*0.81mol/L=0.02025molNaOH\\\\n_{HCl}=0.0650L*0.33mol/L=0.02145molHCl[/tex]
Now, since NaOH is in a fewer proportion, we infer just 0.02025 moles of HCl are consumed so that 0.0012 moles of this acid remain unreacted; in such a way, we infer that the NaOH is the limiting reactant for this reaction.
Regards!
1. What happens when like charges are brought closer to each other?
A chemist must dilute of aqueous silver perchlorate solution until the concentration falls to . He'll do this by adding distilled water to the solution until it reaches a certain final volume. Calculate this final volume, in liters. Round your answer to significant digits
The given question is incomplete, the complete question is:
A chemist must dilute 54.1 mL of 20.2 M aqueous silver perchlorate (AgC102) solution until the concentration falls to 3.00 M. He'll do this by adding distilled water to the solution until it reaches a certain final volume. Calculate this final volume, in liters. Round your answer to 3 significant digits.
Answer:
The correct answer is 0.364 L.
Explanation:
A solution is made less concentrated by diluting it with a solvent. There is no change in the number of moles when more solvent is added to the solution. In case, if the solution is diluted from V1 to V2, a change is noticed in the molarity of the solution based on the given equation,
M1V1 = M2V2
In the given case, the V1 or the volume of the original solution is 54.1 ml, M1 or the molarity of the original solution is 20.2 M.
The M2 or the molarity of the diluted solution is 3.00 M, there is a need to find the V2 or the volume of the diluted solution.
Now by putting the values in the equation we get,
= 20.2M * 54.1 ml = 3.0 M * V2
V2 = 364.27 ml
It is known that 1000 ml is equivalent to 1L, therefore, 1 ml = 0.001 L
Now, the value of V2 will be,
= 364.27 * 0.001 L = 0.36427 L or 0.364 L
100 grams of iron (Fe) reacts with sulfuric acid (H2SO4) in the following equation.
Fe + H2SO4 Fe2(SO4)3 + H2
36. The number of grams of iron (III ) sulfate [Fe2(SO4)3] that will be produced is __ grams.
a
275
b
357
b
b357
Answer:
2Fe +3 H2SO4 Fe2(SO4)3 + 3H2
2*56g. 3*98g➔400g. +6g
we have
2*56 g of Fe gives 400g of iron (III ) sulfate
now
100g of Fe gives=400/112*100=357g of iron (III ) sulfate
[tex]\:[/tex]
B is your answer.!
RISD-QSA-SCI-CHEM-Units 7-12 Question: 1-1
A sample of 0.0255 mol potassium hydroxide, KOH, was dissolved in water to yield 10.0 mL of solution. What is the molarity of the solution?
Answer:
0.02.55M
Explanation:
Concentration = moles/ volume(L)
10mL= 0.01L
Concentration (M)= 0.0255 mol / 0.01L
Concentration (M)= 0..255M
Which of the following density formulas have been rearranged correctly? pls help i have no idea what i’m doing
1. v = m/d
2. m = d/v
3. v = md
4. m = v/d
Answer:
v = m/d
Explanation:
To know which option is correct, we shall rearrange the the formula of density. This can be obtained as follow:
The density of a substance is defined as the mass per unit volume of the substance. Mathematically, it is expressed as:
Density (d) = mass (m) / volume (v)
d = m/v
Make m the subject
d = m/v
Cross multiply
m = dv
Next, made v the subject
d = m/v
Cross multiply
dv = m
Divide both side by d
v = m/d
SUMMARY:
From the density formula (i.e d = m/v) we obtained:
m = dv
v = m/d
Therefore, option v = m/d gives the correct answer to the question.
In a different titration, a 0.7529 g sample of a mixture of solid C6H5COOH and solid NaCl is dissolved in water and titrated with 0.150 M NaOH. The equivalence point is reached when 24.78 mL of the base solution is added. Calculate each of the following.
a. The mass, in grams, of benzoic acid in the solid sample
b. The mass percentage of benzoic acid in the solid sample
Answer:
a. 0.4539g benozic acid
b. 60.29% of benzoic acid in the solid sample
Explanation:
The benzoic acid reacts with NaOH as follows:
C6H5COOH + NaOH → C6H5COONa + H2O
Where 1 mole of the acid reacts per mole of NaOH
The NaCl doesn't react with NaOH
To solve this question we must find the moles of NaOH added = Moles of benzoic acid. With the moles of the acid and its molar mass (C6H5COOH = 122.12g/mol) we can find the mass of the acid and its mass percentage:
a. Moles NaOH = Moles Benzoic acid:
24.78mL = 0.02478L * (0.150mol / L) = 0.003717 moles Benozic acid
Mass benzoic acid:
0.003717 moles Benozic acid * (122.12g / mol) = 0.4539g benozic acid
b. Mass percentage is:
0.4539g / 0.7529g * 100 = 60.29% of benzoic acid in the solid sample
How many atoms in total are there in 7.35 mol of magnesium oxide (MgO)
molecules?
Answer:
4.42 x 10^24
Explanation:
Determine the spec gravity of 500 mL alcohol if the density is 0.79g/ml
Answer:
S.G = 0.79.
Explanation:
Hello there!
In this case, according to the given information in the problem, it turns out possible for us to calculate the specific gravity of this alcohol by simply dividing its density, 0.79 g/mL by that of the water, 1 g/mL just as a reference for us to work with:
[tex]S.G=\frac{\rho _{alc}}{\rho _w}[/tex]
Thus, we plug in the densities to obtain:
[tex]S.G=\frac{0.79g/mL}{1g/mL}\\\\S.G=0.79[/tex]
Which is dimensionless as g/mL is cancelled out due to its presence on both top and bottom of the previous formula.
Regards!
What is a definition for ergonomics?
When an aqueous solution of sodium phosphate (Na3PO4) and an aqueous solution of magnesium sulfate (MgSO4) are mixed, a precipitate forms. Write the chemical formula of the precipitate.
Answer: The chemical formula of this precipitate is [tex]Mg_{3}(PO_{4})_{2}[/tex].
Explanation:
An equation which depicts the chemical reaction of substances in the form of chemical formulas is called a chemical equation.
For example, chemical equation for an aqueous solution of sodium phosphate [tex](Na_{3}PO_{4})[/tex] and an aqueous solution of magnesium sulfate [tex](MgSO_{4})[/tex] are mixed, a precipitate forms is as follows.
[tex]3MgSO_{4}(aq) + 2Na_{3}PO_{4}(aq) \rightarrow Mg_{3}(PO_{4})_{2}(s) + 3Na_{2}SO_{4}(aq)[/tex]
Here, trimagnesium phosphate is the precipitate. The chemical formula of this precipitate is [tex]Mg_{3}(PO_{4})_{2}[/tex].
Thus, we can conclude that the chemical formula of this precipitate is [tex]Mg_{3}(PO_{4})_{2}[/tex].
a student adds 0.5 moles of solute to enough water to form 500 ml of solution what is the concentration of the solution he made
Answer: The concentration of solution made by the student is 1 M.
Explanation:
Molarity is defined as the amount of solute expressed in the number of moles present per liter of solution. The units of molarity are mol/L.
The formula used to calculate molarity:
[tex]\text{Molarity of solution}=\frac{\text{Number of moles of solute}\times 1000}{\text{Volume of solution (mL)}}[/tex] .....(1)
Given values:
Moles of solute = 0.5 moles
Volume of solution = 500 mL
Plugging values in equation 1:
[tex]\text{Molarity of solution}=\frac{0.5\times 1000}{500}\\\\\text{Molarity of solution}=1M[/tex]
Hence, the concentration of solution made by the student is 1 M.
How many moles of O2 did you produce the 8.31 moles of H2O
the equation is not present.
A toy helicopter takes off and moves 2 m up and then 2 m back down. What
is the displacement of the helicopter?
A. 0 m
B. 2 m down
C. 2 m up
D. 4 m
Answer:
0m
Explanation:
2m up - 2m down =0m
What is the wavelength of a light of frequency 7.21 x 1014 Hz?
O A. 237 nm
B. 721 nm
C. 416 nm
O D. 628 nm
The wavelength of the light having a frequency of 7.21×10¹⁴ Hz is 416 nm (Option C)
How do I determine the wavelength of light?Wavelength and frequency are related to the velocity of a wave according to the following formula:
Velocity (v) = wavelength (λ) × frequency (f)
v = λf
With the above formula, the wavelength of the light can be obatined. Details below.
From the question given above, the following data were obtained:
Frequency (f) = 7.21×10¹⁴ HzVelocity of light (v) = 3×10⁸ m/sWavelength (λ) = ?Velocity (v) = wavelength (λ) × frequency (f)
3×10⁸ = wavelength × 7.21×10¹⁴
Divide both sides by 7.21×10¹⁴
Wavelength = 3×10⁸ / 7.21×10¹⁴
Wavelength = 416×10⁻⁹ m
Multiply by 10⁹ to express in nm
Wavelength = 416×10⁻⁹ × 10⁹
Wavelength = 416 nm
Thus, we can conclude that the wavelength is 416 nm (Option C)
Learn more about wavelength:
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What do all fossil fuels have in common?
O A. They are all liquids.
OB. They all contain crude oil.
O C. They all produce nitrogen as a combustion product.
O D. They are all nonrenewable energy sources.
Answer:
Your answer would be D, they are all non-renewable energy sources. Hope this helps!
Answer:
D. They are all nonrenewable energy sources.
solution of alcohol and water
[tex]\huge\mathsf{\red{\underline{\underline{Answer}}}}[/tex]
[tex]{\green{\dashrightarrow}}[/tex]When you mix the rubbing alcohol with water, the latter's molecules make hydrogen bonds with the water molecules. The alcohol dissolves in the water to form a homogenous solution, so you cannot distinguish the alcohol and the water anymore.