Answer:
See explanation
Explanation:
Science as a body of knowledge seeks to understand the processes that occur in nature so as to offer plausible explanations to those processes as well as redesign nature for our benefit.
Hence, science is an inquiry into nature with the aim to improve the life of the general population of the world.
Chemistry is the study of matter and the changes that matter undergoes. Chemistry lies at the very foundation of science since changes in matter is the basis for the processes that occur in nature.
Hence, chemistry plays a critical role in understanding nature as well as amending nature to improve the living condition of the world's rapidly growing population.
g 0.500 L of a solution with a concentration of 0.25 M is needed. To prepare this solution, a stock solution with a concentration of 1.25 M is prepared. What volume of the stock solution is needed to create the desired solution
Answer:
0.1 L
Explanation:
From the question given above, the following data were obtained:
Concentration of stock solution (C₁) = 1.25 M
Volume of diluted solution (V₂) = 0.5 L
Concentration of diluted solution (C₂) = 0.25 M
Volume of stock solution needed solution (V₁) =?
The volume of the stock solution needed can be obtained as follow:
C₁V₁ = C₂V₂
1.25 × V₁ = 0.25 × 0.5
1.25 × V₁ = 0.125
Divide both side by 1.25
V₁ = 0.125 / 1.25
V₁ = 0.1 L
Therefore, the volume of the stock solution needed is 0.1 L
Determine the molarity of the sodium ions when 78.0 g Na2S is dissolved in water for a final volume of 1.0 L.
Answer:
[Na⁺] = 1.99 M
Explanation:
Na₂S is a ionic salt that can be dissociated.
Dissociation equation is:
Na₂S → 2Na⁺ + S⁻²
1 mol of sodium sulfide can give 2 moles of sodium cation.
We convert moles of salt: 78 g . 1mol / 78.06 g = 0.999 moles
As ratio is 1:2, after dissociation we have (0.999 . 2) = 1.998 moles of Na⁺
Molarity is a type of concentration.
It indicates moles of solute in 1 L of solution and in this case, we have 1 L as final voulme.
Moles of Na⁺ are 1.998 moles. Then molarity (mol/L) is:
M =1.99 mol/L
What is the largest number
(of a single species) a specific area can support?
A. Population
B. Unlimited factor
C. Carrying capacity
D. Niche
Answer:
carrying capacity
Explanation:
Thus, the carrying capacity is the maximum number of individuals of a species that an environment can support. Population size decreases above carrying capacity due to a range of factors depending on the species concerned, but can include insufficient space, food supply, or sunlight.
Calculate the moles of H3PO4 that reacted (8). Consult the coefficients in the balance chemical reaction to obtain the mole ratio. Show your calculation here.
Answer:
The number of moles of H₃PO₄ that reacted is 0.000343 moles
Note: Some data is missing. Data from the attachment is used for the calculationsinnthe explanation below.
Explanation:
The reaction is a neutralization reaction between NaOH and H₃PO₄. The equation of the reaction is given as follows:
3 NaOH + H₃PO₄ ---> Na₃PO₄ + 3 H₂O
The molarity of the NaOH solution is 0.238 mol/L.
Average volume of NaOH used during the titration to arrive to endpoint = (4.6 + 3.9 + 4.5) mL / 3 = 4.33 mL
Molarity is defined ratio of the number of moles of solute to the volume of solution. Mathematically, molarity = number of moles/volume in Litres
Number of moles of NaOH reacted = 0.238 mol/L × (4.33mL × 1 L/1000 mL)
Number of moles of NaOH = 0.00103 moles
From the equation of the reaction, 3 moles of NaOH reacts with 1 mole of H₃PO₄
0.00103 moles of NaOH will react with 0.00103 x 1/3 moles of H₃PO₄ = 0.000343 moles of H₃PO₄.
Therefore, number of moles of H₃PO₄ that reacted is 0.000343 moles
Name the following aldehyde PLEASE PLEASE HELP
Answer:
Explanation:
Answer is D 2,5-dimethylheptanal
You should accern the lowest possible number close to the parent name
Increasing the temperature of a chemical reaction usually increases greatly the rate of the reaction. The most iportant reason for this is that increasing the temperature increases: _______.
A) the collision frequency
B) the probability factor
C) the fraction of collisions with energy greater than Bact
D) the energy of activation.
E) the amount of heat released in the reaction
Answer:
the fraction of collisions with energy greater than Eact
Explanation:
The activation energy of a reaction stands as a sort of energy barrier between reactants and products. It is only reactants that possesses energy greater than the activation energy that can be converted from reactants to products.
When the temperature of the system is increased, more particles acquire energy greater than the activation energy. Hence, the fraction of collisions with energy greater than the activation energy increases so the rate of reaction increases likewise.
An aqueous solution contains 0.29 M of benzoic acid (HA) and 0.16 M of sodium benzoate (A-). If the pH of this solution was measured to be 4.63, calculate the pKa of benzoic acid g
Answer:
pKa = 4.89.
Explanation:
We can solve this problem by using the Henderson-Hasselbach equation, which states:
pH = pKa + log [tex]\frac{[A^-]}{[HA]}[/tex]
In this case [A⁻] is the concentration of sodium benzoate and [HA] is the concentration of benzoic acid.
We input the given data:
4.63 = pKa + log [tex]\frac{0.16}{0.29}[/tex]
And solve for pKa:
pKa = 4.89
Under certain conditions, the substance mercury(II) oxide can be broken down to form mercury and oxygen. If 32.2 grams of mercury(II) oxide react to form 29.8 grams of mercury, how many grams of oxygen must simultaneously be formed
Explanation:
This is a decomposition reaction. Firstly, you will want to write the chemical equation out and balance it.
[tex]2Hg_2O->4Hg+O_2[/tex] (The -> is supposed to be an arrow, sorry!)
We see that there's only 1mol of Oxygen made in the products, we can do some simple math to solve for the amount of grams of Oxygen produced according to the amount of the reactant (Hg2O).
[tex]32.2gHg_2O*\frac{1molHg_2O}{417.18gHg_2O}*\frac{1molO_2}{2molHg_2O}*\frac{32gO_2}{1molO_2}[/tex]
I want to break this down, just in case:
The 417.18gHg2O is the molecular mass of the molecule (so I doubled Hg and added 16 to it to get this number).
As we can see in the chemical equation, 1mol Hg2O produces 2mol O because Oxygen is a diatomic molecule (so there will always be two of it when it's by itself).
And finally, in 1mol O2 there are 32g of O2.
** When you do math like this, always make sure that all of your units cancel out except for the units you're looking for. For example, here we're looking for the grams of Oxygen, so after everything else cancels out, we should only have grams O2.
So, 1.23gO2 should be your answer.
I don’t want to fail help
I need correct answer if u don’t know I will report
When the researcher compiled information which research method did they most likely utilize?
a) documentary
b) survey
c) participant observation
d) case study
Answer:
a
Explanation:
documentary is best researcher!.
A sample of 10.6 g of KNO3 was dissolved in 251.0 g of water at 25 oC in a calorimeter. The final temperature of the solution was 21.5 oC. What is the molar heat of solution of KNO3
Answer:
36.55kJ/mol
Explanation:
The heat of solution is the change in heat when the KNO3 dissolves in water:
KNO3(aq) → K+(aq) + NO3-(aq)
As the temperature decreases, the reaction is endothermic and the molar heat of solution is positive.
To solve the molar heat we need to find the moles of KNO3 dissolved and the change in heat as follows:
Moles KNO3 -Molar mass: 101.1032g/mol-
10.6g * (1mol/101.1032g) = 0.1048 moles KNO3
Change in heat:
q = m*S*ΔT
Where q is heat in J,
m is the mass of the solution: 10.6g + 251.0g = 261.6g
S is specififc heat of solution: 4.184J/g°C -Assuming is the same than pure water-
And ΔT is change in temperature: 25°C - 21.5°C = 3.5°C
q = 261.6g*4.184J/g°C*3.5°C
q = 3830.87J
Molar heat of solution:
3830.87J/0.1048 moles KNO3 =
36554J/mol =
36.55kJ/mol
43 mg = [?]g
A. 0.043 g
B. 4.3 g
C. 4300 g
D. 43,000 g
Answer:
Option A (0.043 g) is the correct answer.
Explanation:
Given:
= 43 mg
As we know,
[tex]1 \ mg = \frac{1}{1000} \ g[/tex]
then,
⇒ [tex]43 \ mg = \frac{43}{1000} \ g[/tex]
[tex]= 0.043 \ g[/tex]
Thus, the above is the correct alternative.
The volume of a single tantalum atom is 1.20×10-23 cm3. What is the volume of a tantalum atom in microliters?
Answer:
1.20x10⁻²⁰μL
Explanation:
1cm³ is equal to 1milliliter. As we must know, 1milliliter = 1000 microliters, 1000μL. To convert the 1.20x10⁻²³mL we need to use the conversion factor: 1mL = 1000μL.
The volume of tantalum in μL is:
1.20x10⁻²³mL * (1000μL /1L) = 1.20x10⁻²⁰μL
The following statements either define or are closely related to the terms periodic law, period, or group. Match the terms to the appropriate statements.1. This is a vertical arrangement of elements in the periodic table. 2. This is a horizontal arrangement of elements in the periodic table. 3. The properties of the elements repeat in a regular way as the atomic numbers increase. 4. Element 19 begins this arrangement in the periodic table 5. The chemical properties of elements 12, 20, and 38 demonstrate this principle.
Answer:
Please find the complete solution in attached file.
Explanation:
Periodic law is the the properties of the elements that repeat in a regular way as the atomic numbers increase.
What is periodic table?Periodic chart organized collection of all chemical elements arranged roughly according to increasing atomic weight. The periodic recurrence of several features in the elements was originally identified by Dmitry I. Mendeleyev in 1869.
1. This is a vertical arrangement of elements in the periodic table group
2. This is a horizontal arrangement of elements in the periodic table period
3. The properties of the elements repeat in a regular way as the atomic numbers increase periodic law
4. Element 19 begins this arrangement in the periodic table period
5. The chemical properties of elements 12, 20, and 38 demonstrate this principle. periodic law
Therefore, periodic law is the the properties of the elements that repeat in a regular way as the atomic numbers increase.
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When sodium chloride, NaCl , dissolves in water, the solution contains ___________________ in addition to the water solvent. The partial charges in water help dissolve the compound as the hydrogen end of water is attracted to the ____________ and the oxygen end is attracted to the _______________
Answer:
sodium ions and chloride ions
chloride ion
sodium ion
Explanation:
Ionic substances are composed of ions. When you dissolve an Ionic substance in water, the ions that compose the substance together with water molecules are present in solution.
Hence, when sodium chloride is dissolved in water, sodium ions and chloride ions are released in solution.
Water has a dipole moment. Hence, the chloride ions are attracted to hydrogen (the positive end of the dipole) while sodium ions are attracted to oxygen (the negative end of the dipole).
This is how the solid is dissolved in water.
When sodium chloride, NaCl , dissolves in water, the solution contains sodium and chloride ions in addition to the water solvent. The partial charges in water help dissolve the compound as the hydrogen end of water is attracted to the chloride ions and the oxygen end is attracted to the sodium ions.
What molecules are soluble in water?Those molecules in which positive ion as well as negative ion is present, will show solubility in water.
Sodium chloride (NaCl) is an ionic compound, which dissociates into sodium ion and chloride ion in the water. As in the water H⁺ ions are present which get attracted towards the chloride ions (Cl⁻) and hydroxide ion (OH⁻ ion) get attracted towards the sodium ions (Na⁺) and show complete dissolution.
Hence correct answers are sodium and chloride ions, chloride ion and sodium ion.
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Which 2 resonance forms destablize the carbocation intermediate if bezonitrile undergoes chlronation at the ortho or para positions
The question is incomplete, the complete question is shown in the image attached
Answer:
A and B
Explanation:
The electrophilic substitution of arenes yields a cation intermediate. The positive charge of the cation is delocalized over the entire ring.
The -CN group directs incoming electrophiles to the ortho/para position. The resonance structures for the chlorination of benzonitrile are shown in the question.
Recall that -CN is an electron withdrawing group. The resonance forms that destablize the carbocation intermediate are those in which the -CN group is directly attached to the carbon atom bearing the positive charge as in structures A and B.
How many molecules of C 2H 5Br will be present if you had 4.52 g of this compound?
What is the phase of water at 0.25 atm and 0°C?
Water
(liquid)
Pressure (atm)
0.5-
0.25
Ice
(solid)
Water vapor
(gas)
0
000
Temperature (°C)
O A. Gas
O B. Solid and gas
O C. Solid and liquid
D. Solid
Water is in the solid phase at 0.25 atm and 0°C.
In what phase is water at 25?A pressure of 50 kPa and a temperature of 50 °C correspond to the “water” region—here, water exists only as a liquid. At 25 kPa and 200 °C, water exists only in the gaseous state.
What phase is water in at 0 C?Under standard atmospheric conditions, water exists as a liquid. But if we lower the temperature below 0 degrees Celsius, or 32 degrees Fahrenheit, water changes its phase into a solid called ice.
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Determine whether methylcyclohexane contains a chiral center. _____ How many different substituents do you count at atom
Answer:
methylcyclohexane does not possess a chiral center
Explanation:
A molecule is said to possess a chiral center if one or more of the atoms in the molecule is bonded to four different atoms or groups.
If we look at methylcyclohexane, none of the carbon atoms in the molecule is bonded to four different atoms or groups hence the molecule contains no chiral centers and will not exhibit optical isomerism.
So, methylcyclohexane has a plane of symmetry thus it is an achiral molecule.
The number of mol of oxygen in 2.5 mol of caffeine
Answer:
5.0molO
Explanation:
To find the moles of oxygen in 2.5 moles of caffeine, we will first research caffeine's molecular formula: C8H10N4O2. From the molecular formula, we can see there are 2 oxygen atoms in every 1 molecule of C8H10N4O2.We can therefore multiply by the following mole ratio to get the moles of oxygen.
2.5molC8H10N4O2×2molO/1molC8H10N4O2 = 5.0molO.
What is the name of this molecule?
Explanation:
here is your answer
hope this will help you
How many moles are in the number of molecules below? I only need to know the 5th question.
Answer:
11
1. 6.02×10 23
this is the answer Hope it helps you
compound of aspartame is a dipeptide that is often used as a sugar substitute which functional groups are present
Answer:
Carboxyl, primary amine, amide, ester, and phenyl.
Explanation:
The functional groups present in the compound of aspartame are carboxyl, primary amine, amide, ester, and phenyl. Aspartame is an artificial non-saccharide sweetener which is 200 times sweeter than sucrose. This aspartame is commonly used as a sugar substitute in many foods and beverages. It has the trade names such as NutraSweet, Equal, and Canderel.
Wine goes bad soon after opening because the ethanol dissolved in it reacts with oxygen gas to form water and aqueous acetic acid , the main ingredient in vinegar. Calculate the moles of acetic acid produced by the reaction of of ethanol. Be sure your answer has a unit symbol, if necessary, and round it to significant digits.
Answer:
The answer is "It takes 1,70 mol of ethanol".
Explanation:
To make acetic acid, we must first write the balanced reaction that occurs of ethanol with oxygen
The response is balanced:
[tex]CH_3CH_2OH+O_2\to CH_3COOH+H_2O[/tex]
1 mol of ethanol creates 1 mol of According the equilibrium Ethanol moles, therefore, required 1.70 mol of water = 1.70 mol
The density of aluminum is 2.7 g/cm3.
Part A
What is its density in kilograms per cubic meter?
Express your answer in kilograms per cubic meter to two significant figures.
Answer:
2700 kg/m³
Explanation:
First let's convert 2.7 g/cm³ to kg/cm³, keeping in mind that 1 kilogram equals 1000 grams:
2.7 g/cm³ * [tex]\frac{1kg}{1000g}[/tex] = 0.0027 kg/cm³Finally we need to convert 0.0027 kg/cm³ to kg/m³, keeping in mind that 1 meter equals 100 centimeters, as follows:
0.0027 kg/cm³ * [tex](\frac{100cm}{1m} )^3[/tex] = 2700 kg/m³The answer is 2700 kg/m³.
Name two natural sources of esters.
Answer:
"Esters are widespread in nature and are widely used in industry. In nature, fats are in general triesters derived from glycerol and fatty acids. Esters are responsible for the aroma of many fruits, including apples, durians, pears, bananas, pineapples, and strawberries."
Explanation:
Indicate type of chemical reactions for 2Mgl2+MN(SO3)2=2MgSO3+Mnl4
Answer:
double decomposition reaction
Calculate the mass of water produced when 1.57g of butane reacts with excess oxygen
Explanation:
So, first you will want to write the balanced chemical equation for this reaction.
Butane = [tex]C_4H_{10}[/tex]
[tex]2C_4H_{10}+13O_2=>10H_2O+8CO_2[/tex]
^ This ends up being your balanced chemical equation. Now, you can do the math!
[tex]1.57gC_4H_{10}*\frac{1molC_4H_{10}}{58.12gC_4H_{10}}*\frac{10molH_2O}{2molC_4H_{10}}*\frac{18gH_2O}{1molH_2O}[/tex]
After plugging this into a calculator, your final mass of water should be:
2.43gH2O
How many hydrogen atoms are in 3.90 mol of ammonium sulfide?
Answer:
First, the number of ammonium sulfide molecules should be calculated:
N = NA × n,
where NA - the Avogadro number, n - number of moles.
N (ammonium sulfide) = 6.022 × 1023 × 8.5 mol = 51.187 × 1023.
The moelcular formula of ammonium sulfide is (NH4)2S. It means that each molecule contains 8 hydrogen atoms.
As a result, 8.5 mol of (NH4)2S contain:
51.187 × 1023 × 8 = 41 × 1024 hydrogen atoms.
Answer: 41 × 1024 hydrogen atoms
Suppose, in an experiment to determine the amount of sodium hypochlorite in bleach, you titrated a 23.92 mL sample of 0.0100 M K I O 3 with a solution of N a 2 S 2 O 3 of unknown concentration. The endpoint was observed to occur at 13.80 mL . How many moles of K I O 3 were titrated
Answer:
2.39x10⁻⁴ moles
Explanation:
As the problem asks us the number of moles of KIO₃ that were titrated, all that is required of us is to calculate how many moles of KIO₃ are there in 23.92 mL of a 0.0100 M solution (All moles in the samples are titrated).
We can do so by using the definition of molarity:
Molarity = moles / litersconverting 23.92 mL ⇒ 23.92 / 1000 = 0.02392 L
moles = 0.0100 M * 0.02392 Lmoles = 2.39x10⁻⁴ moles15. You are interested in separating 4-methylbenzoic acid from 1,4-dimethoxybenzene using a procedure similar to the extraction procedure we used in lab. You plan to use sodium bicarbonate instead of sodium hydroxide. a) Show the reaction between salicylic acid and sodium bicarbonate. Label the acid, base, conjugate acid, conjugate base. b) Give the pKa values of the acid and conjugate acid. c) Which base will work better, sodium hydroxide or sodium bicarbonate
Solution :
a). The separation of 4-methylbenzoic acid from 1,4-dimethoxybenzene will work but it will result in lower recovery.
In the reaction of acid-base to form a sodium 4 - methoxy benzoate, that is soluble in the water, 4-methoxy benzoic acid reacts with the sodium bicarbonate to give sodium 4-methoxybenzoate as well as carbonic acid.
b). The pKa for the 4-methoxybenzoic acid is [tex]4.46[/tex], and that of carbonic acid is [tex]6.37[/tex]
c). The Keq for the reaction is [tex]10(6.37 - 4.46) = 101.91[/tex]
Therefore, the equilibrium lies to the right and also the reaction favors the products and the separation works.
But the recovery will be low when compared to the extraction with Sodium hydroxide as the strong base will drive the equilibrium further to the right position, thus neutralizing all the acids virtually. And the weak base will partially neutralize the acid.
