Answer:
2.4g of NaClO must be added
Explanation:
To find the pH of a buffer we must use H-H equation:
pH = pKa + log [A⁻] / [HA]
Where pH is the pH of the buffer, 7.35
pKa of the HClO buffer is 7.54
[A⁻] could be taken as moles of NaClO
And [HA] moles of the weak acid: 500mL = 0.500L * (0.1mol/L) = 0.05 moles
Replacing:
pH = pKa + log [A⁻] / [HA]
7.35 = 7.54 + log [A⁻] / [0.05moles]
0.6457 = [A⁻] / [0.05moles]
0.03228 moles = Moles of NaClO we need to make the pH = 7.35 buffer.
To convert these moles to grams we use the molar mass of NaClO (74.44g/mol):
0.03228 moles * (74.44g/mol) =
2.4g of NaClO must be added
The radius of Pt atom in an fcc structure is 0.1386 nm. Pt has atomic mass of 195.09 g/mol. Calculate the density of this fcc structure. The Avogadro’s number NAis 6.022 x 1023 per mole
Answer:
21.51g/cm³
Explanation:
To answer this question we need to know that, in 1 unit FCC cell:
Edge length = √8 * R
Volume = 8√8 * R³
And there are 4 atoms per unit cell
The mass of the 4 atoms of the cell, in grams, is:
4 atom * (1mol / 6.022x10²³atom) * (195.09g / mol) = 1.2958x10⁻²¹g
Volume in cm³:
0.1386nm * (1x10⁻⁷cm / 1nm) = 1.386x10⁻⁸cm
Volume = 8√8 * (1.386x10⁻⁸cm)³
Volume = 6.02455x10⁻²³cm³
And density, the ratio of mass and volume, is:
1.2958x10⁻²¹g / 6.02455x10⁻²³cm³ =
21.51g/cm³
‘ASAP’What do the different categories of hurricanes represent?
O Air density
O Humidity
O Pressure
O Wind speeds
Answer:
Sorry I do not know the answer but I do know its not c (pressure)
Explanation:
I took a quiz with that question and I got it wrong my other guess is air density though
Answer:
Wind Speeds
Explanation:
im awnsering late cuz i need pointsss
a compound has a molecular formular of C12H24O6.What is the compound's empirical formula
Answer:
The empirical formula for C12 H24 O6 is C2 H4 O.
Answer:
We are given the formula of the compound:
C12H24O6
The empirical formula of a molecular formula is the lowest whole number ratio between the number of atoms of each element
The ratio of C to H to O in the given formula is :
12 : 24 : 6
we notice that all 3 of the numbers have 6 in common. Dividing all three of the numbers by 6, we get:
2 : 4 : 1
Hence, the ratio of Carbon to Hydrogen to Oxygen in the empirical formula of the given compound is 2 : 4 : 1 ,
Empirical Formula = C2H4O
4. This is low wet land.
A. swamp
B. island
C. desert
D. peninsula
5. Japan is one of these.
A. island
B. peninsula
C. swamp
D. desert
Answer:
swap
Explanation: because it is a low wet land
Answer:
4. swamp
5. Island
Plz mark brainliest:)
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
plsss help!!!!! I'll give u brainlest and 10 points
Answer:
I would say it is true
Explanation:
A liquid has a volume of 62.7 mL and a density of 2.59 g/mL. What is its mass? (show all work)
Answer:
162.4
Explanation:
The formula for mass is density* volume so 62.7 multiplied by 2.59 equals 162.393. then you round so your anwser would be 162.4
what does celery, a wooden spoon, and oil/gasoline have in common?
Answer:
All of them are organic compounds which have carbon as their main atom in the structure.
Explanation:
Hello.
In this case, since organic chemistry is the study of all the compounds having the carbon atom as their main atom, all the vegetables, animals, an in general, living things are composed by lipids, proteins, and other organic substances with this feature. Moreover, wood-based materials are mainly composed by lignin which is an organic polymer also having carbon as the main atom. In addition, oil and gasoline are organic chemical compounds with a lot of applications in daily life which also contain carbon atoms in their structure.
In such a way, a celery, a wooden spoon, and oil/gasoline have the carbon atom in common as their main atom in their chemical structures.
Best regards.
Use the periodic table to identify the chemical symbol or name for each element below.
zirconium:
zr
rhenium:
re
: As
: K
tin:
yttrium:
: Yb
Answer:
zirconium is Zr
rhenium is Re
As is arsenic
K is potassium
tin is Sn
yttrium is Y
ytterbium is Yb
Explanation:
With the help of the periodic table, the identification of the chemical symbol or name for each element is represented as follows:
Zirconium: Zr. Rhenium: Re. Arsenic: As.Potassium: K.Tin: Sn. Yttrium: Y. Ytterbium: Yb. What are the chemical elements?Chemical elements may be defined as any type of substance that cannot be further decomposed into simpler substances through the utilization of other ordinary chemical processes or external factors. These elements possess specific physical as well as chemical properties distinctly.
In the modern periodic table, each element is arranged on the basis of its increasing atomic number. Each element possesses its unique symbol, atomic mass, and physical properties like boiling points, melting points, density, etc.
Therefore, with the help of the periodic table, the identification of the chemical symbol or name for each element is well represented above.
To learn more about the Periodic table, refer to the link:
https://brainly.com/question/15987580
#SPJ2
____ KClO3 = ____ KCl + ____ O2
Answer:
2KCIO3=2KCI+3O2
Explanation:
1. equalize right side O with left side O- Right side we have 3 and left only 2 so we add 3 in front(on left side)(3*2=6 O on both sides)
2.we add 2 on right side so now we have 6 O on left and 6 O on right and 2KCI
3.Add 2 on right side KCI so on both sides we got 2 KCI
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
i’m so lost please help
C=4
D=-19
Explanation:
2exp-25/5exp-7= 4exp-19
8. Why is the magnetic force considered to be a noncontact force?
Answer:
Magnetic forces are non contact forces; they pull or push on objects without touching them. Magnets are only attracted to a few 'magnetic' metals and not all matter. Magnets are attracted to and repel other magnets.
Hope this helps!!!
Explanation:
Level 1 01 Which correctly pairs the outside particles with their charge? A. Electrons: Positive B. Protons: Positive C. Neutrons: Neutral D. Electrons: Negative
Answer:
D. Electrons: Negative.
Explanation:
Hello, happy to help you today!
In this case, by considering the Bohr's atomic model in which atom is composed by a nuclei containing both protons and neutrons which are positively and neutrally charged respectively and surrounding electrons assembled in orbits or levels of energy which are negatively charged in order to provide a balance to the atom, the correct statement is: D. Electrons: Negative. Also consider the Bohr's model on the attached picture.
My best regards to you!
using this chemical might discolour equipment and surfaces
Answer: do not know how to answer this
Explanation:
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".
________ and ________ fibres are obtained from animals
Answer:
Explanation:
Silk and wool
Answer:
silk and wool fibers are obtained from animals
Explanation:
good luck :)
The initial pressure of a mixture of C6H6 and an excess of H2 in a rigid vessel is 1.21 atm. A catalyst is introduced. After the reaction reaches completion, the temperature is restored to its initial value. The final pressure in the vessel is 0.839 atm. What was the mole fraction of C6H6 in the original mixture
Answer:
mole fraction of C6H6 = 0.613 atm
Explanation:
The equation for this reaction is :
[tex]C_6H_6 _{(g)} + 3H_2_{(g)} \to C_6H_{12}_{(g)}[/tex]
Initial P₁ P₂ 0
Final 0 P₂ -P₁/2 P₁
After completion of the reaction;
P₁ + P₂ = 1.21 atm ----- (1)
P₂ - P₁/2 + P₁ = 0.839 atm
P₂ + P₁/2 = 0.839 atm ----- (2)
Subtracting (2) from (1); we have:
P₁/2 = 0.371
P₁ = 0.742 atm
From(1)
P₁ + P₂ = 1.21 atm
0.742 atm + P₂ = 1.21 atm
P₂ = 1.21 atm - 0.742 atm
P₂ = 0.468 atm
Thus, the partial pressure of C6H6 = 0.742 atm
∴
Partial pressure = Total pressure × mole fraction of C6H6
mole fraction of C6H6 = Partial pressure / Total pressure
mole fraction of C6H6 = 0.742 atm / 1.21 atm
mole fraction of C6H6 = 0.613 atm
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
magnesium: atomic number
Answer:
Magnesiums atomic number is 12
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A student asks why the ashes from a fire have a much lower mass than the wood that was burned.
Which is the correct answer to the student’s question?
Gases are released into the air.
Atoms in the wood are destroyed.
Heat causes the molecules to change color.
Water inside the wood solidifies.
(I am not in college)
"Calculate the pH of an aqueous solution at 25°C that is (a) 0.15 M in HCl. 0.82 (b) 3.7 M in HNO3. -0.57 (c) 6.9 × 10−4 M in HClO4."
Answer:
See explanation
Explanation:
The pH of a solution is defined as the negative logarithm of hydrogen ion concentration.
For HCl
pH= - log[0.15] = 0.82
For HNO3
pH= -log[3.7] = -0.57
For HClO4
pH= - log [6.9 × 10^-4] = 3.16
Calculate the following quantity: molarity of a solution prepared by diluting 49.16 mL of 0.0270 M ammonium sulfate to 525.00 mL.
Answer:
2.528x10⁻³M
Explanation:
Molarity is an unit of concentration used in chemistry. Is defined as the moles of solute per liter of solution.
To find the molarity of the solution we need to determine the moles of ammonium sulfate present in the initial 49.16mL solution and, with total volume, we can find the molarity, thus:
Moles ammonium sulfate:
49.16mL = 0.04916L * (0.0270 moles / L) =
1.327x10⁻³moles ammonium sulfate
These moles are present in 525.0mL = 0.525L. Thus, molarity of the solution will be:
1.327x10⁻³moles ammonium sulfate / 0.525L =
2.528x10⁻³MThe reaction between HCl and KOH results in an increase in temperature in the solution. Select the correct statement from the list below.
a) this is an endothermic reaction
b) this is a phase change reaction
c) this is a vaporization reaction
d) this is an exothermic reaction
Answer:
d) this is an exothermic reaction.
Explanation:
The reaction between HCl and KOH results in an increase in temperature in the solution. Select the correct statement from the list below.
a) this is an endothermic reaction . NO. This would cause a decrease in the temperature of the solution.
b) this is a phase change reaction . NO. All the species remain in the aqueous phase.
c) this is a vaporization reaction . NO. All the species remain in the aqueous phase.
d) this is an exothermic reaction. YES. The reaction releases heat, so it is exothermic.
Which statement best demonstrates how data from a global positioning system (GPS) can be used to lessen the effects of a
wildfire? (1 point)
GPS data can be used by people to quickly evacuate an area because of a wildfire
GPS data can be used by scientists to predict weather patterns that can lead to a wildfire
GPS data can be used by firefighters to identify the boundaries of a wildfire
GPS data can be used by first responders to calculate the safest route to a wildfire
Answer: here is your answer
Explanation: You are visiting your Grandmother and notice that she is eating a balanced diet, taking vitamins, getting the proper amount of sleep and is not overweight. Despite her healthy lifestyle, she appears run down and tired. You realize that it's due to her lack of physical activity. Write a convincing letter to your grandma explaining the benefits of participating in regular physical activity.
To vaporize/condense a substance, does the substance have to absorb or release heat?
Answer: it would release heat because the thermal energy it absorbed to become a gas. so it would release heat. hope this helps :)
Explanation:
2. What is the purpose of subscripts?
3. What is the difference between monatomic and polyatomic ions?
4. How do the names of monatomic anions end?
5. When are Roman numerals used in cation names ?
2. Chemical formulas are used to describe the types of atoms and their numbers in an element or compound. The atoms of each element are represented by one or two different letters. When more than one atom of a specific element is found in a molecule, a subscript is used to indicate this in the chemical formula.
3. The main difference between monatomic and polyatomic ions is that monatomic ions are composed of single atoms whereas polyatomic ions are composed of two or more atoms per ion.
4. These are nonmetal elements which have accepted extra electrons. These ions are relatively few in number and are listed below. Monatomic anions are named by taking the root of the element name and applying an -ide ending. Other important simple anions.
5. This is indicated by assigning a Roman numeral after the metal. The Roman numeral denotes the charge and the oxidation state of the transition metal ion. For example, iron can form two common ions, Fe2+ and Fe3+. To distinguish the difference, Fe2+ would be named iron (II) and Fe3+ would be named iron (III).
__________ have the lowest ionization energies of the groups listed
PLZ HELP I'LL AWARD BRAINLIEST
Answer: have the lowest ionization energies of the groups listed
PLZ HELP I'LL AWARD BRAINLIEST
Explanation:
What is another term for the limbic system?:
A. primitive brain
B. logical brain
C. gender center
D. memory center
Answer:
a
Explanation:
because the sytem it si locate at the bothe side
What is the volume of 11.2 g of O2 at 7.78 atm and 415 K?
Answer:
1.53 L
Explanation:
Step 1: Given data
Mass of oxygen (m): 11.2 gPressure (P): 7.78 atmTemperature (T): 415 KIdeal gas constant (R): 0.0821 atm.L/mol.KStep 2: Calculate the moles (n) corresponding to 11.2 g of oxygen
The molar mass of oxygen is 32.00 g/mol.
11.2 g × (1 mol/32.00 g) = 0.350 mol
Step 3: Calculate the volume of oxygen
We will use the ideal gas equation.
P × V = n × R × T
V = n × R × T / P
V = 0.350 mol × (0.0821 atm.L/mol.K) × 415 K / 7.78 atm
V = 1.53 L