Answer:
Extending DNA strands to match samples
Consider a buffer made by adding 132.8 g of NaC₇H₅O₂ to 300.0 mL of 1.17 M HC₇H₅O₂ (Ka = 6.3 x 10⁻⁵) What is the pH of this buffer?
Answer:
pH = 1.62
Explanation:
We can solve this problem using Henderson-Hasselbach's equation:
pH = pKa + log[tex]\frac{[A^-]}{[HA]}[/tex]Where
pKa = -log(Ka) = 4.20[A⁻] = [NaC₇H₅O₂][HA] = [HC₇H₅O₂]Now we convert 132.8 g of NaC₇H₅O₂ into moles, using its molar mass:
132.8 ÷ 144.11 g/mol = 0.921 molesThen we calculate [NaC₇H₅O₂]:
0.921 moles / 300.0 mL = 0.003 MNow we can proceed to calculate the pH of the solution:
pH = 4.20 + log[tex]\frac{0.003}{1.17}[/tex]pH = 1.62A 36.6-mol sample of Co represents how many atoms?
Answer:
2.20 x 10²⁵ atoms
Explanation:
Atoms of CO= 36.6-mol sample
From Avogadro's constant, which is
(6.022 × 10^ 23 atoms per mole)
Then
Number of atoms=[ 6.022 × 10^ 23 atoms/mole] × [36.6-mol]
= 2.20 x 10²⁵ atoms
Hence, number of atom is 2.20 x 10²⁵ atoms
The different unit cell types have a different packing efficiency. The simple cubic has the least efficient packing and the face-centered cubic has the most efficient packing (sometimes the face-centered cubic is called cubic closest packing). You can determine what percent of the unit cell is occupied by (1) determining the volume of the whole unit cell and (2) determining the volume of the occupied space by the atoms in the unit cell. Remember that the volume of a cube is V
Answer:
The answer is "52.8".
Explanation:
Please find the graph file in the attachment.
They have the atoms in 8 corners with one unit cell in an one so mesh (SCC).
Atoms throughout the corner contribute [tex]\frac{1}{8}[/tex]to both the cell unit
Atom number per SCC unit cell, [tex]Z = (8 \times \frac{1}{8}) = 1[/tex]
Let 'r' become the atom's radius. [tex]r = 3.43\times 10^{-8}\ \ cm[/tex]
We can see from the diagram that edge length [tex]AB = a = 2r[/tex]
[tex]Packing\ efficiency = \frac{(1 \ atom \ Volume \times Z)}{Volume \ of \ unit\ cell \times 100}\\\\[/tex]
[tex]= \frac{\frac{4}{3}\times \pi \times r^3 \times 1}{a^3 \times 100}\\\\=\frac{\frac{4}{3}\times \pi \times r^3 \times 1}{(2r)^3 \times 100} \\\\=\frac{\frac{4}{3}\times \pi \times( 3.43\times 10^{-8}cm)^3 \times 1}{(2\times 3.43\times 10^{-8}cm)^3 \times 100}\\\\= 52.8 \%[/tex]
Hey can someone pls help me answer these questions? It should be easy maybe. It’s just science. The question just won’t to know where you would put the arrow above to show the motion of the plates. Where would I put it?
Why do we test for free chlorine in drinking water?
Answer:
The presence of free chlorine in drinking water is correlated with the absence of most disease-causing organisms, and thus is a measure of the potability of water
Calculate the value of the equilibrium constant for the following system, where the concentrations of reactants and products are: [NO]=1.2x10^-3M , [NO2]=1.5x10-^1M , [N2O]=2.4x10^-3M
Answer:
The equilibrium constant is 2.08x10⁵
Explanation:
Based on the reaction:
3NO ⇄ N₂O + NO₂
The equilibrium constant, k, is defined as:
k = [NO₂] [N₂O] / [NO]³
Where the [] is the molarity in equilibrium of each specie.
Computing te values of the problem:
k = [1.5x10⁻¹M] [2.4x10⁻³M] / [1.2x10⁻³M]³
k = 2.08x10⁵
The equilibrium constant is 2.08x10⁵
Which of the following limits a population's growth?
Answer:
hereeee
Explanation:
Limitations to population growth are either density-dependant or density-independent. Density-dependent factors include disease, competition, and predation. Density-dependant factors can have either a positive or a negative correlation to population size.
Answer: environmental factors
Explanation:
Which is the limiting reactant?
Answer:
Explanation:
The limiting reactant (or limiting reagent) is the reactant that gets consumed first in a chemical reaction and therefore limits how much product can be formed.
I NEED HELP WITH THIS ASAPP
Need help is label a warm area or is b Orr are they both warm
Answer:
your image is a blavk screen so we cant tell
Explanation:
PLZ HELP ME ASAP!!!!(I WILL ALSO MARK BRAINLIEST!!!)
(True or False) A cold front often signals sunny warm weather.
Please help:
An object rolled 15m/s for 3 seconds. How far did it roll?
How saliva works as a buffering agent?
Answer:
The carbonic acid/bicarbonate buffer is the major buffer in stimulated saliva, with bicarbonate acting mainly to neutralize acids produced by bacteria when they digest sugars in the mouth or acids from the stomach. The concentration of the bicarbonate ion depends largely on the salivary flow rate.
Explanation:
Basta Yan sagut ko eh
Answer:
The carbonic acid/bicarbonate buffer is the major buffer in stimulated saliva, with bicarbonate acting mainly to neutralize acids produced by bacteria when they digest sugars in the mouth or acids from the stomach. The concentration of the bicarbonate ion depends largely on the salivary flow rate
Explanation:
What is the name of the compound Cd(MnO4)2?
A
cadmium manganate
B.
cadmium manganite
C.
cadmium permanganate
O
D.
admium permanganite
When you are riding a bicycle at night, your bicycle's reflectors help people in cars see your bicycle how do bicycle reflectors work
A. They are made of a special material that gives off its own light
B. They are hooked up to batteries that allow them to produce light
C. They bounce light back from other sources
D. They are coverd with paint that glows in the dark
Although the Devil's Finger Fungus looks much like a plant, it is classified
in the kingdom Fungi. Which is a characteristic of fungi that is not found
in organisms of the plant kingdom?
Select one:
О
Their cells have a nucleus
O
They are heterotrophic
O
Their cells have cell walls
о
The are multicellular
Answer:
O the multicellular
Explanation:
sana nakatulong
Given all properties are present in both plant kingdom as well as on fungi kingdom species.
What are cells?Cells are the functional and fundamental unit of any organism which may be they are from plants and animals.
In the fungi kingdom and plant kingdom, both species will have nucleus in their cells and they also have multi cells in their structure only except yeast and it belongs from fungi family. Cell are covered by the cell walls and they both are heterotrophic in nature.
Hence given all properties are present in both species.
To know more about fungi kingdom, visit the below link:
https://brainly.com/question/10878050
What is the vapor pressure of an aqueous solution that has a solute mole fraction of 0.1000? The vapor pressure of water is 25.756 mmHg at 25 °C.
Answer:
χsolvent = 1.0000 - 0.1000 = 0.9000
Use Raoult's Law:
Psolution = (χsolvent) (P°solvent)
x = (0.900) (25.756)
x = 23.18 mmHg (to four sig figs)
The vapor pressure of an aqueous solution is x = 23.18 mmHg (to four sig figs)
χsolvent = 1.0000 - 0.1000 = 0.9000
Use Raoult's Law:
P solution = (χsolvent) (P°solvent)
x = (0.900) (25.756)
x = 23.18 mmHg (to four sig figs)
What is an aqueous solution?An aqueous answer is one in which the solvent is liquid water. that is, solute (dissolved) ions and molecules are surrounded by water molecules and integrated into the network of bonds within the water. The dissolved species then spread in the course of the water.
A solution wherein water is the solvent is called an aqueous solution. although water is an exceptional solvent, now not the whole thing dissolves comfortably in the water.
Aqueous' in a chemical equation suggests that the cloth dispersed in water (an answer in water). As an example, when we pour sodium hydroxide answer into dilute hydrochloric acid, we get an aqueous solution of sodium chloride. The liquid is used to signify the formation of liquid materials in response.
Learn more about the aqueous solution here: https://brainly.com/question/19587902
#SPJ2
Why are diamonds unevenly distributed on Earth?
Soil forms only in places where rock particles are deposited.
Soil forms only in places where larger rocks are broken into smaller rocks.
Soil forms only within the Earth under heavy pressure.
Soil forms in the air and is then deposited mainly in places that get a lot of rain.
Answer:
Why aren't diamonds found evenly distributed on Earth? Diamonds are only formed under specific conditions that involve geological processes, such as volcanic activities and plate movements. Since these conditions and processes only take place in certain areas, you can only find diamonds in these special places.
Explanation:
What was the purpose of letting the transformed cells sit in LB for a few minutes before spreading them onto the plates?
A. This allows time for the cells to express the antibiotic resistance gene
B. This allows the cells to take up the plasmid after the heat shock procedure
C. This allows time for the cells to warm up before plating
D. This allows cells time to start glowing green
Answer: D
Explanation:
What is the formal charge on the phosphorus in the PO43- polyatomic ion?
Answer:
P has a formal charge of 0
Explanation:
Essentially P is in the middle of that ion, and its valence electrons are being used with the 4 Os. Hope that makes sense or helps at least. There's good videos that talk about how this works but I can't link them in brainly
Iron is obtained by reaction of hematite (Fe2O3) with carbon monoxide. From the balanced reaction below, how many grams of iron is produced when 24.6 mol of hematite is used up in the reaction?
Fe2O3 + 3CO ® 2Fe + 3CO2
Answer: 2755.2 g of [tex]Fe[/tex] will be produced from 24.6 mol of haematite.
Explanation:
The balanced chemical equation is:
[tex]Fe_2O_3+3CO\rightarrow 2Fe+3CO_2[/tex]
According to stoichiometry :
1 mole of [tex]Fe_2O_3[/tex] produce = 2 moles of [tex]Fe[/tex]
Thus 24.6 moles of [tex]Fe_2O_3[/tex] will produce=[tex]\frac{2}{1}\times 24.6=49.2moles[/tex] of [tex]Fe[/tex]
Mass of [tex]Fe=moles\times {\text {Molar mass}}=49.2moles\times 56g/mol=2755.2g[/tex]
Thus 2755.2 g of [tex]Fe[/tex] will be produced from 24.6 mol of haematite.
Be sure to answer all parts. For an aqueous solution of sodium chloride (NaCl), determine the molarity of 4.05 L of a solution that contains 195 g of sodium chloride. M Determine the volume of this solution that would contain 4.63 moles of sodium chloride. L Determine the number of moles of sodium chloride in 25.35 L of this solution. mol
Answer:
[tex]0.824\ \text{M}[/tex]
[tex]5.62\ \text{L}[/tex]
[tex]20.89\ \text{mol}[/tex]
Explanation:
Molar mass of NaCl = 58.44 g/mol
Mass of NaCl = 195 g
Volume of solution = 4.05 L
Molarity of solution is
[tex]\dfrac{195}{4.05}\times \dfrac{1}{58.44}=0.824\ \text{M}[/tex]
The molarity of the solution is [tex]0.824\ \text{M}[/tex]
Moles of NaCl = 4.63 mol
Volume is given by
[tex]\dfrac{4.63}{0.824}=5.62\ \text{L}[/tex]
The volume of the solution that contains the required amount NaCl is [tex]5.62\ \text{L}[/tex]
Volume of solution = [tex]25.35\ \text{L}[/tex]
Moles of solution is given by
[tex]0.824\times 25.35=20.89\ \text{mol}[/tex]
The number of moles of NaCl is [tex]20.89\ \text{mol}[/tex].
In what direction does thermal energy transfer?
Answer:
Either direction
Explanation:
If you cook food it would go from cold to hot. If you were to put a drink in the fridge it would go from hot to cold. So it is either direction.
Why is a rotting apple a reaction in which energy is neither absorbed nor released?
A. The chemical energy in the reactants is almost equal to the chemical energy in the products.
B. The chemical energy in the reactants is much greater than the chemical energy in the products.
C. The chemical energy in the reactants is much less than the chemical energy in the products.
( don’t send links, I won’t click them)
Vishwanath had some money. he spent 3 upon 4 part of money to buy goods for his birthday,1 upon 5 part of money give to his sister and the rest of Rs.40 to mother how much did he have at first
Answer:
The correct answer is - 800.
Explanation:
Given:
Total amount = ? or assume x
spend in buying birthday item = 3/4 of x
given to sister = 1/5 of x
remaining to mother = 40
solution:
the remaning amount = x- (3x/4+x/5) = 4=
=> x- 19x/20 = 40
=> x = 20*40
=> x = 800
thus, the correct answer is = 800
10. Which of the following group of colors of the visible light is listed from
lowest to highest frequency?
A. Blue, green, red
C. Red, violet, green
B. Green, blue, red
D. Red, green, violet
Answer:
The correct answer is - D. Red, green, violet.
Explanation:
Visible light is the spectrum of light that can be seen by the naked eyes of humans without any equipment. This spectrum has various frequency light that helps us see things in color. The frequency of light ranges between seven different colors in which violet has the highest frequency and red has the lowest.
The different frequencies are as follows:
color frequency
red (limit) 1.77
red 1.91
orange 2.06
yellow 2.14
green 2.25
cyan 2.48
blue 2.75
violet (limit) 3.10
On this basis of this the group of colors of the visible light is listed from
lowest to the highest frequency - Red, green, violet
What do we call a large group of wind turbines used to generate electricity?
1)Wind Pack
2)Wind Mill
3) Wind Farm
4) Wind Plant
Answer:
your answer is 3 hope this helps you
Answer:
A wind farm
Explanation:
another word is a wind park
12. How many moles of atoms are present in 154 g of Na2O?
A) 2.48 mol
B) 7.45 mol
C) 51.3 mol
D) 0.827 mol
Answer:
[tex]\boxed {\boxed {\sf A. \ 2.48 \ mol \ Na_2O}}[/tex]
Explanation:
We are asked to convert an amount in grams to moles. To do this, we use the molar mass. This is the number of grams in one mole of a substance. It is the same value numerically as the atomic mass on the Periodic Table, however the units are grams per mole, not atomic mass units.
Look up the molar masses for the individual elements.
Sodium (Na): 22.9897693 g/mol Oxygen (O): 15.999 g/molLook back at the formula: Na₂O. Notice there is a subscript of 2 after sodium. This means there are 2 atoms of sodium in every molecule, so we have to multiply sodium's molar mass by 2 before adding oxygen's.
Na₂O: 2(22.9897693 g/mol)+ 15.999 g/mol = 61.9785386 g/molSet up a ratio using the molar mass.
[tex]\frac {61.9785386 \ g \ Na_2O}{1 \ mol \ Na_2O}[/tex]
Multiply by the given number of grams.
[tex]154 \ g \ Na_2O*\frac {61.9785386 \ g \ Na_2O}{1 \ mol \ Na_2O}[/tex]
Flip the ratio so the grams of sodium oxide can cancel each other out.
[tex]154 \ g \ Na_2O*\frac {1 \ mol \ Na_2O}{61.9785386 \ g \ Na_2O}[/tex]
[tex]154 *\frac {1 \ mol \ Na_2O}{61.9785386 }[/tex]
[tex]\frac {154}{61.9785386 } \ mol \ Na_2O[/tex]
[tex]2.48473106141 \ mol \ Na_2O[/tex]
The original measurement of grams given has 3 significant figures, so our answer must have the same. For the number we calculated, that is the hundredth place.
2.48473106141The 4 in the thousandth place tells us to leave the 8.
[tex]2.48 \ mol \ Na_2O[/tex]
There are 2.48 moles of sodium oxide in 154 grams, so choice A is correct.
A ________________________ can be at the top of a food chain.
Answer:
ap.ex predat0rs
Explanation:
lave
Use the drop-down menus to identify the parts of a
wave.
A
B:
C
D
Answer:
Use the drop-down menus to make your selections.
What is the difference between wave A and wave B?
✔ Wave A has higher amplitude than wave B.
What is the difference between wave C and wave D?
✔ Wave C has a lower frequency than wave D.
Explanation: