Answer:
A. because salt : Na and Cl, not C
A student was performing a separation of a mixture of organic compounds. The final step of the process involved a filtration of the analyte from an aqueous solution. After drying the filtered solid for a very short period time, they took the melting point of the compound. The measured melting point range of the compound was 106 – 113.8 0C, while the literature melting point of the compound was 122.3 0C. The above scenario is a very common one in organic labs.
1. Do you think their sample was pure?
2. If not, then what do you think could be the source of error.
3. How do you think this error can be minimized?
Answer:
1) No
2) The solvent contaminated the analyte
3) The solvent should be evaporated properly before washing and drying the analyte
Explanation:
During separation of organic compounds, solvents are used. These solvents are able to contaminate the analyte and lead to a large difference in melting point of solids obtained.
However, the error can be minimized by evaporating the solvent before washing, drying and melting point determination of the solid.
Based on the visible cell structures, which of the following statements is true?
All of the cells are plant cells.
All of the cells have chloroplasts.
All of the cells are animal cells.
All of the cells have a nucleus.
What is the correct 1 letter code for the amino acid sequence Glutamic Acid-Histadine-Tyrosine Select one: a. E-H-Y b. G-H-T c. Q-H-T d. E-H-T
Answer:
a. E-H-Y
Explanation:
A group of three nucleotides is called a codon that codes for a specific amino acid in the protein. There are 20 essential amino acids present in human body and are required in the diet.
Each amino acid is given a one-letter code that makes the study of amino acid sequences easy. One letter code for the given amino acid sequence Glutamic Acid-Histidine-Tyrosine is E-H-Y in which E is code for Glutamic Acid, H is a code for Histidine, and Y is a code for Tyrosine.
Hence, the correct answer is "a. E-H-Y".
What is the Kc equilibrium-constant expression for the following equilibrium? S8(s) + 24F2(g) 8SF6(g)
Answer:
[tex]Kc=\frac{[SF_6]^8}{[F_2]^2^4}[/tex]
Explanation:
Hello.
In this case, for the undergoing chemical reaction:
[tex]S_8(s) + 24F_2(g) \rightleftharpoons 8SF_6(g)[/tex]
We consider the law of mass action in order to write the equilibrium expression yet we do not include S8 as it is solid and make sure we power each gaseous species to its corresponding stoichiometric coeffient (24 for F2 and 8 for SF6), thus we obtain:
[tex]Kc=\frac{[SF_6]^8}{[F_2]^2^4}[/tex]
Best regards!
I need help plzzz this is for today please help
Answer:
4. Water from upland areas often carries sediment and pollutants. The marshy land and plants in estuaries filter these pollutants out of the water. The plants in estuaries help prevent shoreline erosion. Estuaries also protect inland areas from flooding and storm surges.
5. Dredging impacts marine organisms negatively through entrainment, habitat degradation, noise, remobilization of contaminants, sedimentation, and increases in suspended sediment concentrations.
Explanation:
The farther you go in to the ocean, the more salinity it contains. The closer you are to freshwater, the less salinity it contains. This can happen in estuaries, and estuaries are almost like brackish waters.
Hope this helps you!
Be sure to answer all parts.
Write a balanced equation for each reaction. Do not include states of matter to your equation.
H2 + O2 H20
Answer:
2H₂ + O₂ → 2H₂O
Explanation:
Chemical equation:
H₂ + O₂ → H₂O
Balance chemical equation:
2H₂ + O₂ → 2H₂O
Step 1:
H₂ + O₂ → H₂O
Left hand side Right hand side
H = 2 H = 2
O = 2 O = 1
Step 2:
H₂ + O₂ → 2H₂O
Left hand side Right hand side
H = 2 H = 4
O = 2 O = 2
Step 3:
2H₂ + O₂ → 2H₂O
Left hand side Right hand side
H = 4 H = 4
O = 2 O = 2
What is the percent error for the experiment if the actual density is
2.49g/mL but the experimental value is 1.47 g/mL?
Answer:
The answer is 40.96%Explanation:
The percentage error of a certain measurement can be found by using the formula
[tex]P(\%) = \frac{error}{actual \: \: number} \times 100\% \\ [/tex]
From the question
actual density = 2.49g/mL
error = 2.49 - 1.47 = 1.02
We have
[tex]p(\%) = \frac{1.02}{2.49} \times 100 \\ = 40.96385542...[/tex]
We have the final answer as
40.96 %Hope this helps you
CHEMISTRY!! 50 POINTS!
There are 5.5 L of a gas present at -38.0 C. What is the temperature if the volume of the gas has changed to 1.30 L?
Answer:
The answer to this question is 33.8
State Hess' law of constant heat summation.
(b) Calculate the enthalpy of formation of CH4 from the following data:
i) C(s) + O2(g) → CO2(g); ∆H = -393.7 kJ/mol
ii) H2(g) + 1⁄2 O2(g) → H2O(l); ∆H = -285.8 kJ/mol
iii) CH4(g) + 2 O2(g)→ CO2(g) + 2H2O(l); ∆H = -890.4 kJ/mol
Answer:
-74.6 kj/mol
Explanation:
you can see the answer at the pic
How many of the 7 traits of living things have
Answer:
What do you mean by this?
Explanation:
Plz answer me will mark as brainliest
Explanation:
Valves
Blood capillaries
If 5.00g of iron metal is reacted with 0.950g of Cl2 gas, how many grams of ferric chloride (FeCl3) will form?
Answer:
1.45g of FeCl3
Explanation:
The equation of the reaction is given as;
2Fe + 3Cl2 --> 2FeCl3
2 mol of Fe reracts with 3 mol of Cl2 to form 2 mol of FeCl3
Upon converting to mass using;
Mass = Number of moles * Molar mass
( 2 * 55.85 = 111.7g ) of Fe reacts with ( 3 * 71 = 213g ) of Cl2 to form ( 2 * 162.2 = 324.4g) of FeCl3
Cl2 is the limiting reactant as it determines how much of FeCl3 is formed
213g of Cl2 = 324.4g of FeCl3
0.950g of Cl2 = x
x = (0.950 * 324.4 ) / 213
x = 1.45g of FeCl3
If 200.00 mL of a solution of sugar and water contains 0.0025 moles of sugar, what is the concentration of the solution in units of moles per unit volume? Round decimals to the nearest thousandth where applicable. Do not include trailing zeros in decimal answers (e.g., 0.05 instead of 0.050).
Answer:
0.013 mol/L
Explanation:
Molarity, which is molar concentration or moles per unit volume, can be calculated using the formula:
M = n/V
Where; M = Molar concentration of solution
n = number of moles of solute
V = Volume of solvent
n = 0.0025 moles of sugar
V = 200.00mL of solution
Since 0.001L = 1mL
200mL = 0.200L
Therefore, M = n/V
M = 0.0025/0.200
M = 0.0125 mol/L
Round up to the nearest thousandth ~ 0.013mol/L
Question 11
4 pts
Using the formula 2H202 --> 2H2O + O2, if 7.30 moles of peroxide are
decomposed, how many moles of oxygen will be formed?
Answer:
3.65 mol O₂
Explanation:
Step 1: RxN
2H₂O₂ → 2H₂O + O₂
Step 2: Define
Given - 7.30 mol H₂O₂
Solve - x mol O₂
Step 3: Stoichiometry
[tex]7.30 \hspace{3} mol \hspace{3} H_2O_2(\frac{1 \hspace{3} mol \hspace{3} O_2}{2 \hspace{3} mol \hspace{3} H_2O_2} )[/tex] = 3.65 mol O₂
What does chemical equations and chemical formulas have in common?
Answer:
Chemical symbols refer to chemical elements only. They do not necessarily refer to atoms of that element, but also to ions.
Explanation:
find the frequency factor at 273 k for the decomposition of nitrogen dioxide, which has the reaction: 2no2(g) → 2no(g) + o2(g) the activation energy of the reaction is 111 kj/mol and the rate constant is 1.0 x 10-22 s-1. round to two decimal places.
Answer:
0.17 s⁻¹
Explanation:
Step 1: Given data
Temperature of the reaction (T): 273 KActivation energy (Ea): 111 kJ/molRate constant (k): 1.0 × 10⁻²² s⁻¹Ideal gas constant (R): 8.314 × 10⁻³ kJ/mol.KFrequency factor (A): ?Step 2: Calculate the frequency factor
We will use the Arrhenius equation.
ln k = lnA - (Ea/R).(1/T)
lnA = ln k + (Ea/R).(1/T)
lnA = ln 1.0 × 10⁻²² s⁻¹ + [(111 kJ/mol)/(8.314 × 10⁻³ kJ/mol.K)].(1/273K)
A = 0.17 s⁻¹
In chemistry, one often uses a unit of charge known as the Faraday, F, which has the magnitude of the charge of 1 mole of electrons. How many faradays of charge does that correspond to
Answer:
1 Faraday
Explanation:
This question seeks to test proper understanding of Faraday's second law of electrolysis which states when the same quantity electricity passes through a solution of different electrolytes, the mass of the substance deposited is directly proportional to there chemical equivalence.
This law hints at the charges of ions being the chemical equivalence and also been represented as the unit for the quantity of electricity in faraday, F. Hence, a metal with the charge of 1+ can be displaced by 1F (which is equal to 96, 500 coloumbs). This charge also represents one molecule of electron, thus 1 faraday corresponds to one mole of electrons.
NOTE: It should be noted that a metal with the charge of 2+ can be displaced by 2F and so on.
Four grams of hydrogen react completely with 32 grams of oxygen. Based on the law of conservation of mass how many grams of water will be produced
Se producirán 36 gramos de agua
Explicación: Ya que en una reacción química no puede descubrir ningún cambio en masa total de las sustancias que en ella intervienen, pues en una reacción química ni se gana ni se pierde masa.
Which of the following evidence supports the theory of plate tectonics
Answer:
seafloor spreading
Explanation:
i took the test
What can you infer about the likely occurrence of the other isotopes in each of the
above elements? Explain your reasoning.
Answer:
Most common has the same or closest mass because it is closer to the original’s mass.
Explanation:
I got it from the answer key
Read more here:
https://brainly.com/question/1598931
True or False: Particles that are moving faster have a higher temperature
Answer:
true
Explanation:
I'm not sure why cause I dont know how to explain but it's TRUE
Answer:
True
Explanation:
The particles moving faster in a substance the hotter it gets.
A scientist discovers remnants of an organism on a slide under his microscope. He can only identify a few components: a large vacuole, ridged cell wall, and a chloroplast. Was the organism prokaryotic or eukaryotic? How do you know?
Answer:
Eukaryotic (a plant cell)
Explanation:
The presence of a chloroplast indicates that the cell has membrane-bound organelles. This is not a feature of prokaryotic cells - only eukaryotic cells. Therefore, the cell is eukaryotic. The presence of a large vacuole, chloroplast, and rigid cell wall suggests its a plant cell as plant cells are the only eukaryotes with these features.
How can a shoreline be destroyed by a Hurricane?
Answer:
costal erosion
Explanation:
can cause erosion
Answer:
The water piles up with nowhere to go but onto land when it gets to the coast. The rising water, called storm surge, can submerge low-lying areas and towns along the coast. Combined with the crashing waves of the storm, the storm surge can cause demolishing docks, houses, roads, and erode beaches.
Explanation:
Please answer !! For chemistry
Answer:
a. is the correct answer
Explanation:
Consider the reaction of zinc metal with hydrochloric acid:
Zn(s) + 2 HCl(aq) → ZnCl2(aq) + H2(g).
If 29.39 × 1024 atoms of zinc completely reacted with hydrochloric acid, how many moles of hydrochloric acid must have reacted?
Do NOT include units in your entry. Report your answer with 3 SFs.
______________________ moles of HCl
Answer:
6.054×10²⁵
Explanation:
1)find number of moles of zinc
2)multiply the mole of zinc with 2
3)use the formula mol = number of particle/ avogadro constant
Total, 97.64 moles of hydrochloric acid (HCl) must have reacted.
To determine the number of moles of hydrochloric acid (HCl) that reacted, we first need to find the molar ratio between zinc (Zn) and hydrochloric acid (HCl) from the balanced chemical equation:
Zn(s) + 2 HCl(aq) → ZnCl₂(aq) + H₂(g)
From the equation, we see that 1 mole of Zn will reacts with 2 moles of HCl.
Given that 29.39 × 10²⁴ atoms of zinc reacted, we need to convert this quantity to moles. We can do this by using Avogadro's number:
1 mole of any substance = 6.022 × 10²³ atoms
Number of moles of zinc reacted = (29.39 × 10²⁴ atoms) / (6.022 × 10²³ atoms/mol)
Number of moles of zinc reacted ≈ 48.82 moles (rounded to 3 significant figures)
Now, using the molar ratio from the balanced equation, we can determine the number of moles of hydrochloric acid (HCl) that reacted:
Number of moles of HCl reacted = 2 × Number of moles of zinc reacted
Number of moles of HCl reacted ≈ 2 × 48.82 moles
≈ 97.64 moles
Therefore, approximately 97.64 moles of hydrochloric acid (HCl) must have reacted.
To know more about hydrochloric acid here
https://brainly.com/question/14519330
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When 435 J of heat is added to 3.4 g of olive oil that's at 21 Deg C, it's
temperature increases to 85 Deg C. Calculate the specific heat of Olive oil? Show work
Answer:
k Nishant
Explanation:
i don't know sorry but u can search in google
If the density of aluminum is 2.7g/ml, what is the volume of 12.0g?
Answer:
The answer is 4.44 mLExplanation:
The volume of a substance when given the density and mass can be found by using the formula
[tex]volume = \frac{mass}{density} \\ [/tex]
From the question we have
[tex]volume = \frac{12}{2.7} \\ = 4.4444444....[/tex]
We have the final answer as
4.44 mLHope this helps you
Which number represetns a coefficient?
2
3
4
7
Which of the following is NOT a strong electrolyte?
:
Answers:
Na2SO4
KI
CaCl2
LiOH
C6H1206
Answer:
C6H1206
Explanation:
C6H12O6 is a monomer of carbohydrates also known as glucose, so it is not an electrolyte at all.
In the combustion of hydrogen gas, hydrogen reacts with oxygen from the air to form water vapor. hydrogen+oxygen⟶water If you burn 58.9 g of hydrogen and produce 526 g of water, how much oxygen reacted?
Answer:
[tex]m_{O_2}=467gO_2[/tex]
Explanation:
Hello.
In this case, for the reaction:
[tex]2H_2+O_2\rightarrow 2H_2O[/tex]
The correct way to compute the oxygen that reacted is by considering the mass of hydrogen, 58.9 g, its molar mass, 2.02 g/mol, the 2:1 mole ratio between hydrogen and oxygen and the atomic mass of that gaseous oxygen 32.00 g/mol; therefore we use the following stoichiometric procedure:
[tex]m_{O_2}=58.9gH_2*\frac{1molH_2}{2.02gH_2}*\frac{1molO_2}{2molH_2} *\frac{32.00gO_2}{1molO_2} \\\\m_{O_2}=467gO_2[/tex]
The same result could have been obtained by using the mass of water since the law of conservation of mass is obeyed here.
Best regards!