Answer:
a) [tex]V_1=5ul[/tex]
b) [tex]v=20ul[/tex]
Explanation:
From the question we are told that:
initial Concentration [tex]C_1=50mg/ml[/tex]
Final Concentration [tex]C_2=10mg/ml[/tex]
Final volume needs [tex]V_2 =25ul[/tex]
Generally the equation for Volume is mathematically given by
[tex]C_1V_1=C_2V_2[/tex]
[tex]V_1=\frac{C_1V_1}{C_2}[/tex]
[tex]V_1=\frac{10*25}{50}[/tex]
[tex]V_1=5ul[/tex]
Therefore
The volume of buffer needed is
[tex]v=V_2-V_1\\\\v=25-5[/tex]
[tex]v=20ul[/tex]
Choose the compound below that contains at least one polar covalent bond, but is nonpolar.
a. SiF4
b. SeF4
c. HCl
d. ICl3
e. Both SiF4 and ICl3 are nonpolar and contain a polar covalent bond.
Answer:
HCl contain a polar covalent bond because H is more electropositive than Cl and Cl is more electronegative than H, resulting in a dipole moment
4) Calculate the percentage by
mass of oxygen in Pb(NO3)2
A) 193
B20
145
Answer:
im getting 331.23
Explanation:
Element Number Mass Percet Composition
O 6 16.00 28.9828819853274
N 2 14.01 8.45937867946744
Pb 1 207.21 62.5577393352051
Convert 1.16 mol of calcium cyanide, Ca(CN)2, to mass.
what is wrong with the statement? "because there are no common factors in the molecular formula, k2co3 is also the empirical formula of potassium carbonate"
The empirical formula is the same as the molecular formula because the ratio of atoms in the compound correspond to the number of atoms of each element in the compound.
The empirical formula of a compound shows the ratio of atoms of each element in the compound while the molecular formula shows the number of atoms of each element in the compound.
For the compound, K2CO3, the empirical formula is the same as the molecular formula because the ratio of atoms in the compound correspond to the number of atoms of each element in the compound. It has nothing to do with common factors.
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Pure silver has a brilliant white metallic luster. How many moles of silver, Ag, are in 7.54 × 1023 atoms of silver?
The number of moles of silver, Ag, that are in 7.54 × 10²³ atoms of silver is 1.25 moles
From the question,
We are to determine the number of moles of silver, Ag, that are present in 7.54 × 10²³ atoms of silver
From the formula
[tex]Number\ of\ moles =\frac{Number\ of\ atoms}{Avogadro's\ constant}[/tex]
Avogadro's constant = 6.022 × 10²³ atoms mol⁻¹
and
From the given information
Number of silver atoms = 7.54 × 10²³ atoms
Putting the parameters into the formula, we get
Number of moles of silver present = [tex]\frac{7.54\times 10^{23} }{6.022\times 10^{23}}[/tex]
Number of moles of silver present = 1.2520757 moles
Number of moles of silver present ≅ 1.25 moles
Hence, the number of moles of silver, Ag, that are in 7.54 × 10²³ atoms of silver is 1.25 moles
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Which condition is usually associated with low air pressure systems?
Answer:
clouds and precipitation that minimize temperature changes throughout the day
Explanation:
What is the job of cellular respiration?
Answer:
to break down sugar in the presence of oxygen to release energy in the form of ATP
Explanation: i just finished this chapter of the class
30 points!!!!
2K + 2H2O → 2KOH + H2
This reaction shows which detail about potassium and hydrogen?
Hydrogen is more reactive than potassium.
Potassium and hydrogen form ionic bonds.
Potassium is more reactive than hydrogen.
Potassium and hydrogen form covalent bonds
Answer:
2K + 2H2O → 2KOH + H2
So Hydrogen is more reactive than pottasium .
According to law of conservation of matter, 2 moles of potassium react with water to produce 1 mole of hydrogen gas.So, 2 moles of potassium produce 1 mole of hydrogen gas.Answer:
A
Explanation:
Hydrogen is more reactive than potassium.
Which combination of reagents used in the indicated order with benzene will give m-nitropropylbenzene? a. 1) CH3CH2CH2Cl/AlCl3, 2) HNO3/H2SO4 b. 1) HNO3/H2SO4, 2) CH3CH2CH2Cl/AlCl3 c. 1) CH3CH2CH2Cl/AlCl3, 2) HNO3/H2SO4, 3) Zn/HCl d. 1) HNO3/H2SO4, 2) CH3CH2CH2Cl/AlCl3, 3) Zn/HCl
Answer:
1) HNO3/H2SO4, 2) CH3CH2CH2Cl/AlCl3
Explanation:
Benzene is a stable aromatic compound hence it undergoes substitution rather than addition reaction.
When benzene undergoes substitution reaction, the substituent introduced into the ring determines the position of the incoming electrophile.
If I want to synthesize m-nitropropylbenzene, I will first carry out the nitration of benzene using HNO3/H2SO4 since the -nitro group is a meta director. This is now followed by Friedel Craft's alkykation using CH3CH2CH2Cl/AlCl3.
Which phenomena does wind cause?
A)tides and waves
B)deep currents and tides
C)waves and surface currents
D)surface currents and deep currents
HELP PLEASE ILL GIVE OUT BRAINLIEST
The phenomena which wind causes are waves and surface currents.
What are surface currents?
Surface currents are caused by winds which blow over the ocean water and result in creation of waves. Surface currents are horizontal streams of water which are capable of flowing thousands of kilometers and can reach great depths.
Surface currents play a major role in determining the climate all over the world. They are influenced by three major factors 1) overall global wind patterns 2)rotation of earth 3)shape of ocean basins . When a surface current collides with the land it changes the direction of currents.
Because of surface currents the global climate has warmer water from equator to the cooler parts of the ocean as they transfer heat energy.
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what happens if we mix vitamin c and d together
we can get rid of scurvy as well as rickets ......
What is always true about lenses?
Answer: They all bend light.
i don't know much about lenses so i hope this helps! :)
convert 8.4 • 10^16 molecules of CO2 to moles
Answer:
0.00000000000000084
Explanation:
When comparing Be2 and H2:
I. Be2 is more stable because it contains both bonding and antibonding valence electrons.
II. H2 has a higher bond order than Be2.
III. H2 is more stable because it only contains 1s electrons.
IV. H2 is more stable because it is diamagnetic, whereas Be2 is paramagnetic
a. II,III,IV
b.II,III
c.III only
d.I,II
e.III,IV.
Answer:
The answer is "Option b".
Explanation:
H2 does have bond energy of 1, while Be2 has a covalent bond of zero. Be2 has eight electrons, each of which dwells in a distinct orbital. As just a result, four of them are linked molecular orbitals and two are antibonding molecular orbitals, respectively. As just a result, this molecule is unstable. This chemical orbital, with a bond order of 1, has just two electrons. As a result, it is a very solid substance. H2's bond length is higher than Be2's. Since it only has one electron, H2 is more stable than that of other compounds.
Define atomic numbers and mass numbers
Answer:
1). Atoms of each element contain a characteristic number of protons. In fact, the number of protons determines what atom we are looking at (e.g., all atoms with six protons are carbon atoms); the number of protons in an atom is called the atomic number.
2) In contrast, the number of neutrons for a given element can vary. Forms of the same atom that differ only in their number of neutrons are called isotopes.
3) Together, the number of protons and the number of neutrons determine an element’s mass number: mass number = protons + neutrons. If you want to calculate how many neutrons an atom has, you can simply subtract the number of protons, or atomic number, from the mass number.
How can a redox reaction be identified?
O A. Atoms have rearranged.
O B. Protons have been transferred.
.
O
C. lons are present in solution.
D. Oxidation states have changed.
Answer:
'Oxidation states have changed.'
Explanation:
Redox Reactions can be identifiable by a change in oxidation number/states of two of the atoms in the reaction. Any reaction in which no oxidation numbers/state change is not a redox reaction.
increasing temperature increases:
1:Enthalpy
2:Free Energy
3:Entropy
4:Specific heat
Answer:
2 :free energy
Explanation:
I hope it is fine answer for you ☺️☺️☺️
LAST ATTEMPT! Covalent compound naming ! !!
Answer:
Name the non-metal furthest to the left on the periodic table by its elemental name.
Name the other non-metal by its elemental name and an -ide ending.
Use the prefixes mono-, di-, tri-.... to indicate the number of that element in the molecule.
im prolly wrong
in a test trial, using 6% extra strength bleach at room temperature, 100.0 mL of oxygen gas was produced in 2.03 seconds. Calculate the average reaction rate for the oxygen gas.
The average reaction rate for oxygen gas is 49.26 mL/s
The average reaction rate of a substance refers to the speed at which a reaction occurs and therefore products are formed. In the reaction presented, oxygen gas is the product.
Moreover, the average reaction rate can be expressed in mL per second or mL/s, and the formula to calculate it is:
Product in mL/seconds
Let's calculate the reaction rate:
100 mL/ 2.03 s = 49.26 mL/sLearn more about oxygen in: https://brainly.com/question/1506082
PLEASE HELP ME!! sue tomorrow:(
Answer:
If you are looking for the answer, for the question.
Earthquakes trigger tsunamis when the seismic activity causes the land along fault lines to move up or down
What is the empirical formula for a compound that is comprised of 54.0% sodium, 8.50% boron, and 37.5% oxygen by mass
Answer:
Sodium metaborate: sodium+boron+oxygen= NaBO 2.
The formula can be written also as Na 2O·B
Explanation:
26. Which group in the periodic table contains
an element that can form a blue sulfate
a
compound?
(1) 1
(2)
(3) 11
(4) 17
Answer:
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Answer:
Option (3) 11
Explanation:
Elements in Group 11 of the periodic table are called Noble Metals.Noble metals have high resistance to oxidation and low chemical reactivity.Noble metal includes Gold (Au), Silver (Ag), Copper (Cu).Copper forms a blue sulfate when reacts with Sulphuric Acid.Formula of Copper Sulfate : CuSO4.Since, Copper belongs to the Group 11 elements of the periodic table hence, option (3) is the right answer.For more information:
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What test was used to identify hydrogen gas? Write a balanced equation to represent the test?
How many moles is 7.78 x 1024
formula units of MgCl2?
How many moles is 7.78 x 1024
formula units of MgCl2?
answer: 7966.72
Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, there are 0.49moles of MgCl[tex]_2[/tex] in 7.78 x 10²⁴atoms of MgCl[tex]_2[/tex] .
What is mole?The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity of amount of substance. It measure the number of elementary entities of a given substance that are present in a given sample. There are so many formula for calculating mole.
we know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number
mole =given number of atoms ÷ 6.022×10²³(Avogadro number)
given number of atoms of MgCl[tex]_2[/tex]= 7.78 x 10²⁴
Substituting the values
mole= 7.78 x 10²⁴÷ 6.022×10²³
mole = 0.49moles of MgCl[tex]_2[/tex]
So, there are 0.49moles of MgCl[tex]_2[/tex] in 7.78 x 10²⁴atoms of MgCl[tex]_2[/tex] .
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Please write out the balanced chemical equations for the following
reactions.
**Ensure you write the states of the reactants and products.**
• zirconium chloride reacts with scandium dichromate
Answer: Super idol
Explanation:
chinese malapoks
An hibernating bear accumulates 25 kg of a triglyceride (846 g/mol) comprising the following fatty acids: C16, C17 and C18∆9. How many grams of β-hydroxybutyrate (104 g/mol) can the bear produce from this triglyceride during its hibernation?
The quantity of β-hydroxybutyrate the bear can produce
during hibernation is 3,073.30grams.
Hibernation is defined as the period of less activity by animals to conserve energy to survive coarse weather conditions.
A typical example of an animal that hibernates is the bear.
From the question, a bear is able to accumulate 25kg (25000grams) of triglyceride.
To calculate quantity of β-hydroxybutyrate that would be produced from 25kg triglyceride;
846g of triglyceride = 104grams of β-hydroxybutyrate
25000g of triglyceride = x grams
(Cross multiple to solve for x grams)
X = 104 × 25000/846
[tex]x = \frac{104 \times 25000}{846} [/tex]
[tex]x = \frac{2600000}{846} [/tex]
[tex]x = 3073.30grams[/tex]
Therefore, the quantity of β-hydroxybutyrate the bear can produce during hibernation is 3,073.30grams.
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In order to complete the reaction of hexyl magnesium bromide with acetone, what next step needs to be done.
a. Fractional Distillation.
b. Vacuum filtration.
c. Aqueous workup.
d. Crystallization.
Answer:
Aqueous workup.
Explanation:
The reaction of hexyl magnesium bromide with acetone yields a tertiary alcohol. There is an organic phase and an aqueous phase.
Aqueous workup is the process of recovering the pure tertiary alcohol from the organic phase of the system.
Hence, in order to complete the reaction of hexyl magnesium bromide with acetone, aqueous workup is required.
Element X has an electron configuration of 2-8-2. This element will combine with the oxide ion to form a compound with the formula
How many oxygen atoms are there in 0.25 mole of CO2?
Answer:
It is known that 1 mol of a molecule contains 6.023×1023 6.023 × 10 23 number of molecules. So, 0.25 moles of CO2 C O 2.
The correct option for the given question about Mole Concept is Na / 2 atom of oxygen.
What is mole?In chemistry, a mole is a unit. A mole of a substance is the mass of the substance containing precisely 12 gram of the same number of atoms as 12C.The mole is the SI unit used to measure a substance's quantity. It has the symbol mol.
How to solve this question?
In 1 mole number of molecules of CO₂ = Na (Avagadro Number)
In 0.25 mole number of molecules of CO₂ = 0.25 × Na molecules
In 1 molecule number of oxygen atom = 2 atom
In 0.25 × Na molecules number of oxygen atom = 2 × 0.25 × Na atom
In 0.25 × Na molecules number of oxygen atom = 0.5 × Na atom
So in 0.25 mole of CO₂ number of oxygen atom = Na / 2 atom
Thus we can conclude that in 0.25 mole of CO₂ number of oxygen atom will be Na / 2, where Na is Avagadro Number.
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An analytical chemist is titrating of a solution of benzoic acid with a solution of . The of benzoic acid is . Calculate the pH of the acid solution after the chemist has added of the solution to it. Note for advanced students: you may assume the final volume equals the initial volume of the solution plus the volume of solution added.
The question is incomplete. The complete question is :
An analytical chemist is titrating 148.9 mL of a 1.100 M solution of benzoic acid [tex]$HC_6H_5CO_2$[/tex] with a 0.3600 M solution of KOH. The [tex]pK_a[/tex] of benzoic acid is 4.20. Calculate the pH of the acid solution after the chemist has added 232.0 mL of the KOH solution to it. Note for advanced students: you may assume the final volume equals the initial volume of the solution plus the volume of KOH solution added.
Solution :
Number of moles of [tex]$C_6H_5OCOOH$[/tex] [tex]$=148.9 \ mL \times \frac{L}{1000\ mL} \times \frac{1.100 \ mol}{L}$[/tex]
= 0.16379 mol
Number of moles of NaOH added [tex]$=232.0 \ mL \times \frac{L}{1000\ mL} \times \frac{0.3600 \ mol}{L}$[/tex]
= 0.08352 mol
ICE table :
[tex]C_6H_5OCOOH \ \ \ + \ \ \ OH^- \ \ \ \rightarrow \ \ C_6H_5OCOO^- \ \ \ \ + \ \ H_2O[/tex]
I (mol) 0.16379 0.08352 0
C (mol) -0.08352 -0.08352 +0.08352
E (mol) 0.08027 0 0.08352
Total volume = (148.9 + 232) mL
= 380.9 mL
= 0.3809 L
Concentration of [tex]$C_6H_5OCOOH, [C_6H_5OCOOH]$[/tex] [tex]$=\frac{0.08027 \ mol}{0.3809 \ L}$[/tex]
= 0.211 M
Concentration of [tex]$C_6H_5OCOO^- , [C_6H_5OCOO^-] =\frac{0.08352 \ mol}{0.3809 \ L}[/tex]
= 0.219 M
[tex]pK_a[/tex] of [tex]C_6H_5OCOOH = 4.20[/tex]
According to Henderson equation,
[tex]$pH = pK_a + \log \frac{[C_6H_5OCOO^-]}{[C_6H_5OCOOH]}[/tex]
[tex]$=4.20 + \log \frac{0.219}{0.211}$[/tex]
= 4.22
Therefore, the pH of the acid solution is 4.22
