Answer: 6
Explanation:
You would need 6
Which substance has Delta.Hf defined as 0 kJ/mol? H2O (s) Ne (l) F2 (g) CO2 (g)
Answer:
F2 (g)
Explanation:
Edg 2021
Answer:
F2 g
Explanation:
Kristy finds the mass of an object to be 20 grams and the volume to be 10 mL. What is the density of the object? (don't send me links, just give a straight answer)
You have 100 mL of a solution of benzoic acid in water; the amount of benzoic acid in the solution is estimated to be about 0.30 g. The distribution coefficient of benzoic acid in diethyl ether and water is approximately 10. Calculate the amount of acid that would be left in the water solution after four 20-mL extractions with ether.
Answer:
0.00370 g
Explanation:
From the given information:
To determine the amount of acid remaining using the formula:[tex]\dfrac{(final \ mass \ of \ solute)_{water}}{(initial \ mass \ of \ solute )_{water}} = (\dfrac{v_2}{v_1+v_2\times k_d})^n[/tex]
where;
v_1 = volume of organic solvent = 20-mL
n = numbers of extractions = 4
v_2 = actual volume of water = 100-mL
k_d = distribution coefficient = 10
∴
[tex]\dfrac{(final \ mass \ of \ solute)_{water}}{0.30 \ g} = (\dfrac{100 \ ml}{100 \ ml +20 \ ml \times 10})^4[/tex]
[tex]\dfrac{(final \ mass \ of \ solute)_{water}}{0.30 \ g} = (\dfrac{100 \ ml}{100 \ ml +200 \ ml})^4[/tex]
[tex]\dfrac{(final \ mass \ of \ solute)_{water}}{0.30 \ g} = (\dfrac{1}{3})^4[/tex]
[tex]\dfrac{(final \ mass \ of \ solute)_{water}}{0.30 \ g} = 0.012345[/tex]
Thus, the final amount of acid left in the water = 0.012345 * 0.30
= 0.00370 g
The relationship between the volume and mass of an element is
Answer:
Density
Explanation:
The mass of an element is the average weight that the isotope of the particular element contains. Its characteristic indicates the amount of substance present in an element.
However, the volume of an element on the other hand is the mole of an element that is contained in a room temperature.
The relation joining both the mass and volume of an element is density.
This is because density showcase the relationship between the mass of an element to space in occupies in terms of volume.
It is given by the formula:
Density = mass/volume
How much heat is evolved in converting 1.00 mol of steam at 160.0 ∘C to ice at -55.0 ∘C? The heat capacity of steam is 2.01 J/(g⋅∘C) and of ice is 2.09 J/(g⋅∘C).
Answer:
the heat capacity of steam is 2.01 J/(g⋅∘C) and of ice is 2.09 J/(g⋅∘C). 1. See answer.
Why all mushrooms cannot be eaten?
Explanation:
The toxins present are secondary metabolites produced by the fungus. Mushroom poisoning is usually the result of ingestion of wild mushrooms after misidentification of a toxic mushroom as an edible species. ... The safety of eating wild mushrooms may depend on methods of preparation for cooking.
how many molecules are there in 75.0 grams of phosphorus trichloride plzz helpp
Answer:
Explanation:
55
Choose true or false
1. Acetone cannot be used as a solvent because the Grignard reagent will react with its carbonyl, instead of reacting with the planned synthesis carbonyl.
2. Tetrahydrofuran is not a suitable solvent for the Grignard reaction because his oxygen may form complexes with the Mg, deactivating the Grignard.
3. Phenol can be used as a solvent in Grignard reaction as long as is anhydrous and moisture is kept out of the system with a drying tube with drierite.
4. Syringes are used in the Grignard experiment to avoid mixing all the reagents.
5. We use syringes to inject the reagents through a septum preventing moisture to enter the system.
Explanation:
Grignard reagent reacts with ketones. Upon chemical reaction of acetone and Grignard reagent there will be formation of tertiary alcohol.
1). So the statement, acetone cannot be used as a solvent because the Grignard reagent will react with its carbonyl, instead of reacting with the planned synthesis carbonyl is true.
2). Tetrahydrofuran is not a suitable solvent for the Grignard reaction because his oxygen may form complexes with the Mg, deactivating the Grignard is a false statement.
3). Phenol can be used as a solvent in Grignard reaction as long as is anhydrous and moisture is kept out of the system with a drying tube with drierite is false statement.
4). Syringes are used in the Grignard experiment to avoid mixing all the reagents is false statement.
5). We use syringes to inject the reagents through a septum preventing moisture to enter the system is true statement.
Match the description with either a dehydration reaction or a hydrolysis reaction.
1. Water is used to split a compound into two parts.
2. Water is a product in this reaction.
3. Synthesis reaction
4. Decomposition reaction
Answer:
1) Hydrolysis
2)Dehydration
3)Dehydration
4)Hydrolysis
Explanation:
Hydrolysis is the chemical breakdown of substances by water and depends on the chemistry, solubility, pH, and the oxidation–reduction (Eh or redox) potential of compound
https://www.sciencedirect.com/topics/earth-and-planetary-sciences/hydrolysis
With hydrolysis water will be a reactant, not a product, and is associated with breaking down substances. Hence 1 and 4 being a Hydrolysis reaction.
Dehydration on the other hand, is defined as :
In a dehydration reaction, either a hydroxyl group from one molecule combines with a hydrogen atom from the other molecule, or two hydrogen atoms from one molecule combine with an oxygen atom on the other molecule. In either case, water is released, and the two molecules are joined together.
https://www.albert.io/blog/dehydration-synthesis-ap-biology-crash-course/
Therefore it is associated with creating a bond of sorts, and water is a product, which is why 2 and 3 are dehydration.
Hope this helps!
The matching of the description with either a dehydration reaction or a hydrolysis reaction is as follows:
Water is used to split a compound into two parts: Hydrolysis reaction. Water is a product in this reaction: Dehydration reaction.Synthesis reaction: Dehydration reaction.Decomposition reaction: Hydrolysis reaction. What is a Dehydration reaction?A Dehydration reaction may be defined as a type of chemical reaction that significantly involves the elimination or removal of water from the reactant molecules. In this type of reaction, water is definitely one of the products.
Hydrolysis reaction is just opposite to the dehydration reaction. It is also known as hydration reaction. It is a type of decomposition reaction that involves water as reactant. It is a type of chemical reaction in which a molecule of water stimulates and breaks one or more chemical bonds in the entire reaction.
Therefore, the matching of the description with either a dehydration reaction or a hydrolysis reaction is well described above.
To learn more about Hydrolysis reactions, refer to the link:
https://brainly.com/question/4352413
#SPJ2
A sample of a gas at 15°C and 2.50 atm pressure has a volume of 4.5 L. The pressure is lowered to 0.85 atm and the volume decreases to 2.5 L. What is the final temperature of the gas in K.
[tex]P_{1} = \text{2.50 atm}[/tex]
[tex]T_{1} = 15^{\circ}\text{C + 273 = 288 K}[/tex]
[tex]V_{1} = \text{4.5 L}[/tex]
[tex]P_{2} = \text{0.85 atm}[/tex]
[tex]V_{2} = \text{2.5 L}[/tex]
Unknown:[tex]T_{2}[/tex]
Solution:[tex]\dfrac{P_{1}V_{1}}{T_{1}} = \dfrac{P_{2}V_{2}}{T_{2}}[/tex]
[tex]T_{2} = T_{1} \times \dfrac{P_{2}}{P_{1}} \times \dfrac{V_{2}}{V_{1}}[/tex]
[tex]T_{2} = \text{288 K} \times \dfrac{\text{0.85 atm}}{\text{2.50 atm}} \times \dfrac{\text{2.5 L}}{\text{4.5 L}}[/tex]
[tex]\boxed{T_{2} = \text{54.4 K}}[/tex]
[tex]\\[/tex]
#ILoveChemistry
#ILoveYouShaina
How is the enthalpy of reaction shown in this potential energy diagram?
Answer:
as the difference of the energy of the reactants and the energy of the products
In the given potential energy diagram, the energy of product at higher level and energy of reactant at lower level. The for this reaction will be positive. So, the enthalpy of reaction is defined as the difference of the energy of the reactants and the energy of the products.
I hope this helps!
Copper sulfate is made of one copper (Cu) atom, one sulfur (S) atom, and four oxygen (O) atoms. Write the chemical formula correctly.
explain how you would find the solubility of a solute
Answer:
Solubility indicates the maximum amount of a substance that can be dissolved in a solvent at a given temperature. Such a solution is called saturated. Divide the mass of the compound by the mass of the solvent and then multiply by 100 g to calculate the solubility in g/100g .
Solubility of solute:
Solubility is the ability of a solid, liquid, or gaseous chemical substance (referred to as the solute) to dissolve in solvent (usually a liquid) and form a solution.The solubility of a given solute in a given solvent typically depends on temperature. For many solids dissolved in liquid water, solubility tends to correspond with increasing temperature.To calculate the solubility in g/100g:
Divide the mass of the compound by the mass of the solvent and then multiply by 100 g.For example:Solubility of NaNO₃=[tex]\frac{21.9g*100g}{25 g} =87.6[/tex]
Learn more:
brainly.com/question/18735192
Who was the first person to suggest the existence of atoms?
Answer:
Democritus first introduced the idea of the atom almost 2500 years ago.
Answer:
B. Democritus
Explanation:
Aluminum metal reacts with oxygen gas in a combination reaction that forms a product that coat the metal preventing it from further oxidation. Which of the following is the correct balanced equation for the reaction?
a. Al(s) + 302(g) → 2903(s).
b. 2Al(s) + O2(g) → 2A10(s).
c. AI(s) + O2(g) → AIO (s).
d. 4Al(s) + 3O2(g) →2Al2O3.
e. 3Al(s) + O2 → Al3O2.
Answer:
d. 4 Al(s) + 3 O₂(g) → 2 Al₂O₃(s)
Explanation:
Aluminum metal reacts with oxygen gas in a combination reaction that forms a product that coats the metal preventing it from further oxidation: aluminum oxide. Aluminum is a cation with charge 3+ (Al³⁻) and oxide is an anion with charge 2- (O²⁻). Thus, the neutral compound aluminum oxide has the chemical formula Al₂O₃. The unbalanced chemical equation is:
Al(s) + O₂(g) → Al₂O₃(s)
We can balance using the trial and error method. First, we will balance O atoms by multiplying Al₂O₃ by 2 and O₂ by 3.
Al(s) + 3 O₂(g) → 2 Al₂O₃(s)
Finally, we get the balanced equation by multiplying Al by 4.
4 Al(s) + 3 O₂(g) → 2 Al₂O₃(s)
9. The formular for finding the area
of an object is
A. Length + Width
B. Length - Width
C. Length : Width
D. Length x Width
E. 2 (Length + Width)
ans
Answer:
D. length × width
Explanation:
eg. 30 cm(length) × 20cm(width) = 600cm²
The specific heat capacity of liquid ethanol is 2.42 J/gºC.
How many joules of heat must be absorbed by 0.463 g ethanol to change its temperature from 51.6 °C to 82.4 °C?
Show work to receive credit.
Which two properties are explained by the pool-of-shared-electrons model for metals?
A. low vapor pressure, high melting point
B. malleability, conductivity
C. high melting point, conductivity
D. low vapor pressure, malleability
Answer:
Actually the answer is B Malleability, conductivity
Explanation:
Why is specific activity used as a measurement of enzyme purity, but the turnover number cannot be used for this purpose?
Answer:
See explanation
Explanation:
Specific activity of an enzyme is defined as a measure of the rate of reaction between enzyme and substrate.
In the study of enzyme kinetics, specific activity is particularly regarded to be the amount of substrate converted by the enzyme per milligram of protein per unit of time. It is thus a reliable measure of enzyme activity per milligram of total protein.
On the other hand, the turnover number is defined as a measure of the number of conversions achieved by a substrate molecule in one second at a particular active site depending on the specific enzyme concentration.
Since specific activityof the enzyme is the ratio of the enzyme activity to enzyme concentration, then specific activity can be used as a measurement of enzyme purity.
For the balanced chemical reaction
>
C4H2OH + 602 > 4CO2 + 5H20
if you want to make 100 molecules of CO2, how many molecules of O2 will you need? Answer with a number only.
ITS
Answer:
150
Explanation:
C₄H₂OH + 6O2 → 4CO2 + 5H₂OWe can find the equivalent number of O₂ molecules for 100 molecules of CO₂ using a conversion factor containing the stoichiometric coefficients of the balanced reaction, as follows:
100 molecules CO₂ * [tex]\frac{6moleculesO_2}{4moleculesCO_2}[/tex] = 150 molecules O₂150 molecules of O₂ would produce 100 molecules of CO₂.
PLSSS HELP MEEEEEEEE
It takes 5 seconds for a wave with a wavelength of 0.4 m to travel past you.
What is the frequency of the wave?
A. 2.0 Hz
B. 0.2 Hz
C. 5 Hz
D. 2.5 Hz
Answer:
A
Explanation:
frequency is the product of time and wave length
Answer:
(B) 0.2Hz
Explanation:
took the test and it for sure was not 2.0Hz
aluminum chloride and bubbles of hydrogen gas are produced when metallic aluminum is placed in hydrochloride acid. what is a balanced equation for this reaction?
Answer:
AlCl3 + HCl ===> AlCl4 +H-
3CaCl2 + 2AlF3 --> 3CaF2 + 2AlCl3 3CaCl2 + 2AlF3 --> 3CaF2 + 2AlCl3 How many grams of CaF2 will form from 36.5 grams of AlF3?
Answer:
32.1 g
Explanation:
3CaCl₂ + 2AlF₃ → 3CaF₂ + 2AlCl₃
First we convert 36.5 g of AlF₃ into moles, using its molar mass:
36.5 g ÷ 133.34 g/mol = 0.274 mol AlF₃
Then we convert 0.274 moles of AlF₃ into moles of CaF₂, using the stoichiometric coefficients of the reaction:
0.274 mol AlF₃ * [tex]\frac{3molCaF_2}{2molAlF_3}[/tex] = 0.411 mol CaF₂
Finally we convert 0.411 moles of CaF₂ into grams, using its molar mass:
0.411 mol * 78.07 g/mol = 32.1 g
A company manufacturing KMnO4 wants to obtain the highest yield possible. Two of their research scientists are working on a technique to increase the yield.
Both scientists started with 50.0 g of manganese oxide (MnO2).
What is the theoretical yield of potassium permanganate when starting with this 50.0 g MnO2?
The equation for the production of potassium permanganate is as follows:
2 MnO2 + 2 KOH + O2 → 2 KMnO4 + H2
You must show all work to receive full credit.
Answer:
[tex]m_{KMnO_4}=90.9gKMnO_4[/tex]
Explanation:
Hello there!
In this case, according to the given chemical equation for the reaction for the production of potassium permanganate, we can see a 2:2 mole ratio of this product to the starting manganese (II) oxide, which means, we can calculate the theoretical yield of the former via stoichiometry:
[tex]m_{KMnO_4}=50.0gMnO_2*\frac{1molMnO_2}{86.94gMnO_2}*\frac{2molKMnO_4}{2molMnO_2} *\frac{158.034gKMnO_4}{1molKMnO_4} \\\\m_{KMnO_4}=90.9gKMnO_4[/tex]
Regards!
Describe the buffer capacity of the acetic acid buffer solution in relation to the addition of both concentrated and dilute acids and bases. Reference the results in Data Tables 1,2,3, and 4 in your answer.
Answer:
The more concentrated acetic acid buffer has a better buffer capacity because requires more moles of acid or base to change the pH than a more diluted acetic acid buffer.
Explanation:
Buffer capacity is defined as the moles of an acid or base that are needed to change the pH of a buffer in 1 unit.
A more concentrated solution of acetic buffer contains more moles of the acid per liter of solution. A solution that contains more moles of the acetic ion or the acetic acid requires more moles of base or acid to change the pH, that means:
The more concentrated acetic acid buffer has a better buffer capacity because requires more moles of acid or base to change the pH than a more diluted acetic acid buffer.
Question 26 (1 point)
What is the number of electrons shared between the atoms
in an 12 molecule?
Оа
7
Ob
2.
Ос
8
Od
4
Question 27 1 point)
Answer:
obviously 2 is the answer
b. The following reaction takes place in a basic solution. (7 points)
MnO4–(aq) + NO2–(aq) MnO2(s) + NO3–(aq)
The half-reactions (balanced only for atoms) are the following:
MnO4– + 2H2O MnO2 + 4OH–
NO2– + 2OH– NO3– + H2O
Use the following steps to finish balancing the equation.
i. Balance each half-reaction for charge. (2 points)
ii. Multiply each half-reaction by the correct number in order to balance charges for the two half-reactions. (2 points)
iii. Add the equations and simplify to get a balanced equation. (2 points)
iv. How can you tell from this equation that the reaction occurred in a basic solution? (1 point)
Answer: The final equation has hydroxide ions which indicate that the reaction has occurred in a basic medium.
Explanation:
Redox reaction is defined as the reaction in which oxidation and reduction take place simultaneously.
The oxidation reaction is defined as the reaction in which a chemical species loses electrons in a chemical reaction. It occurs when the oxidation number of a species increases.
A reduction reaction is defined as the reaction in which a chemical species gains electrons in a chemical reaction. It occurs when the oxidation number of a species decreases.
The given redox reaction follows:
[tex]MnO_4^-(aq)+NO_2^-(aq)\rightarrow MnO_2(s)+NO_3^-(aq)[/tex]
To balance the given redox reaction in basic medium, there are few steps to be followed:
Writing the given oxidation and reduction half-reactions for the given equation with the correct number of electronsOxidation half-reaction: [tex]NO_2^-+2OH^-\rightarrow NO_3^-+H_2O+2e^-[/tex]
Reduction half-reaction: [tex]MnO_4^-+2H_2O+3e^-\rightarrow MnO_2+4OH^-[/tex]
Multiply each half-reaction by the correct number in order to balance charges for the two half-reactionsOxidation half-reaction: [tex]NO_2^-+2OH^-\rightarrow NO_3^-+H_2O+2e^-[/tex] ( × 3)
Reduction half-reaction: [tex]MnO_4^-+2H_2O+3e^-\rightarrow MnO_2+4OH^-[/tex] ( × 2)
The half-reactions now become:
Oxidation half-reaction: [tex]3NO_2^-+6OH^-\rightarrow 3NO_3^-+3H_2O+6e^-[/tex]
Reduction half-reaction: [tex]2MnO_4^-+4H_2O+3e^-\rightarrow 2MnO_2+8OH^-[/tex]
Add the equations and simplify to get a balanced equationOverall redox reaction: [tex]3NO_2^-+2MnO_4^-+H_2O\rightarrow 3NO_3^-+2MnO_2+2OH^-[/tex]
As we can see that in the overall redox reaction, hydroxide ions are released in the solution. Thus, making it a basic solution
Describe the three freezing points. Is there a relationship between the amount of solute in the solution and the freezing temperature
Answer:
The three freezing points will all be slightly different. It is given that a water solution has a freezing point of zero degrees Celsius, so water would have a freezing temperature below that. Salt will lower the freezing point, the more that is added.
Explanation:
f(x) = -x2+x+6
x
-2
a
-1
4
0
b
1
6
2
c с
do
11 11 11
Cross primary components of vascular tissue are the xylem and phloem. These two tissues transport fluid and nutrients internally. There are also two meristems associated with vascular tissue: the vascular cambium and the cork cambium. All the vascular tissues within a particular plant together constitute the vascular tissue system of that plant.
Question 8 (5 points)
(08.02 MC)
A 10 M concentrated stock solution of NaCl was used to prepare 5 liters of diluted 1 M solution. Which of the following statements is true about
the
process used to achieve this required dilution? (5 points)
O a
The volume of stock solution used was less than 0.4 liters.
Oь
The volume of stock solution used was more than 5 liters.
Ос
The volume of the solvent used was less than 0.4 liters.
Od
The volume of the solvent used was less than 5 liters.
Answer:
d . The volume of the solvent used was less than 5 liters.
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to calculate the volume of the stock (initial) solution by using the following equation:
[tex]M_1V_1=M_2V_2[/tex]
Thus, we solve for, V1, which stands for the aforementioned volume of stock solution:
[tex]V_1=\frac{M_2V_2}{M_1}[/tex]
Then, we plug in to obtain:
[tex]V_1=\frac{5L*1M}{10M}\\\\V_1=0.5L[/tex]
Now, since the final volume was 5 L, we can infer that the volume of solvent is 4.5 L and that of the stock solution 0.5 L for a total of 5 L of diluted solution; therefore, the correct reasoning is d . The volume of the solvent used was less than 5 liters.
Regards!
Answer:
The volume of the solvent is less than 5
Explanation:
