Answer:
2nd option is the correct answer of this question
Answer:
yes it is b
Explanation:
The dependent variable in an experiment
A.never changes
B.will vary according to the temperature
C.shows changes during the experiment.
D.is always the larger value.
Answer:
C
Explanation:
I need help plzzzzzz
Tris is a molecule that can be used to prepare buffers for biochemical experiments. It exists in two forms: Tris (a base) and TrisH (an acid). The MW of Tris base is 121.14 g/mol; the MW of TrisH is 157.6 g/mol (the extra weight is due to the Cl- counterion that is present in the acid). The Ka of the acid is 8.32 X 10-9. Assume that you have TrisH in solid form (a powder), unlimited 1M HCl, 1 M NaOH and distilled water. How would you prepare 1 L of a 0.02 M Tris Buffer, pH?
Solution :
For the reaction :
[tex]$\text{TrisH}^+ + H_2O \rightarrow \text{Trish}^- + H_3O^+$[/tex]
we have
[tex]$Ka = \frac{[\text{Tris}^- \times H_3O]}{\text{Tris}^+}$[/tex]
[tex]$=\frac{x^2}{0.02 -x}$[/tex]
[tex]$=8.32 \times 10^{-9}$[/tex]
Clearing [tex]$x$[/tex], we have [tex]$x = 1.29 \times 10^{-5} \text{ moles of acid}$[/tex]
So to reach [tex]$\text{pH} = 7.8 (\text{pOH}= 14-7.8=6.2)$[/tex], one must have the [tex]$\text{OH}^-$[/tex] concentration of the :
[tex]$\text{[OH}^-]=10^{-pOH} = 6.31 \times 10^{-7} \text{ moles of base}$[/tex]
So we can add enough of 1 M NaOH in order to neutralize the acid that is calculated above and also adding the calculated base.
[tex]$\text {n NaOH}=1.29 \times 10^{-5}+6.31 \times 10^{-7}$[/tex]
[tex]$= 1.35 \times 10^{-5} \text{ moles}$[/tex]
Volume NaOH [tex]$= 1.35 \times 10^{-5} \text{ moles} \times \frac{1000 \text{ mL}}{1 \text{ mol}} = 0.0135 \text{ mL}$[/tex]
Tris mass [tex]$H^+ = 0.02 \text{ mol} \times 157.6 \text{ g/mol}=3.152 \text{ g}$[/tex]
Now to prepare the said solution we must mix:
[tex]$3.152 \text{ g Tris H} + 0.0135 \text{ mL NaOH} \ 1 M$[/tex] gauge to 1000 mL with water.
Where did the zebra mussels originally come from? Plz help
Answer:
The zebra mussel is a fresh and brackish water bivalve mollusk. It feeds on plankton and suspended organic matter. It is listed 100 most damaging invasive alien species in the world of the International Union for Conservation of Nature
Zebra mussels are an invasive, fingernail-sized mollusk that is native to fresh waters in Eurasia. Their name comes from the dark, zig-zagged stripes on each shell. Zebra mussels probably arrived in the Great Lakes in the 1980s via ballast water that was discharged by large ships from Europe
Explanation:
hope this helps
Answer:
Eurasia
Explanation:
it about chemical change
Answer:
Steps 3 and 4 :)
What document, signed by the district attorney, authorizes the search of a building for the purpose of collecting evidence at a crime scene?
Answer:
A search warrant is a document that is signed by the district attorney, and authorizes the search of a building for the purpose of collecting evidence at a crime scene.
When 9.00 g C6H12O6 burns with excess oxygen, how many grams
of CO2 will be made?
- 0.44 g
- 6.6 g
- 2.2 g
- 13.2 g
Question 6 of 10
Which law of motion states that an object's acceleration is directly related to
the net force applied and inversely related to the mass of the object?
O A. Newton's law of inertia
O B. Newton's second law
Ο Ο Ο
C. Newton's third law
OD. Newton's first law
Strontium chlorate is mixed with ammonium phosphate
Explanation:
Please, if I may ask, what is the exact question?
Which choice best describes the properties of potassium (K), based on its position on the periodic table of elements?
A.
a nonreactive metal
B.
a highly reactive metal
C.
a nonreactive nonmetal
D.
a highly reactive nonmetal
Answer:
B
Explanation:
Metals are found on the left side of the table and nonmetals the right, (K) is on the very left column meaning it is highly reactive
The option which best describes the properties of potassium (K), based on its position on the periodic table of chemical elements is: B. a highly reactive metal.
Alkali metals can be defined as the monovalent chemical elements that are found in Group IA of the periodic table.
Generally, these group of chemical elements readily lose their single (one) valence electron to form ionic compounds with non-metals. Some examples of alkali metal are:
Lithium (L).Sodium (Na).Potassium (K).Potassium (K) being an alkali metal with a single (one) valence electron in its outermost shell is considered to be highly reactive with other chemical elements, especially halogens because of its position on the periodic table of chemical elements.
In conclusion, Potassium (K) is a highly reactive metal based on its position on the periodic table of chemical elements.
Read more: https://brainly.com/question/24143069
What is a good example of food waste that can be added to compost?
O oil
O chicken breast
O eggshells
Oyogurt
A proposed mechanism for one of the pathways for the destruction of ozone in the atmosphere is: step 1: O3 NO NO2 O2 step 2: NO2 O NO O2 (a) Identify the molecularity of each step in the mechanism. step 1 _________ step 2 _________ (b) Write the equation for the net reaction. Use the smallest integer coefficients possible. If a box is not needed, leave it blank.
Answer:
See explanation
Explanation:
The destruction of ozone is a non-elementary reaction. This means that it does not take place in a single reactive encounter. The reaction rather takes place is a sequence of steps called the reaction mechanism.
We can see that in the overall reaction, ozone is reduced to ordinary oxygen thus the ozone layer is depleted by this reaction. It is a two step reaction as shown.
Both steps (1) and (2) are bimolecular. The equation of the net reaction is shown in the image attached.
What is Molecule made off?
a) Electrons
b) Protons
c) Atoms
d) Nuclei
Answer:
C) Atoms
Explanation:
Hope that helped :)
A gas exerts a pressure of 4.1 atm at 300K. What is the pressure of the gas at 1010K?
Answer: 10
Explanation: 10 + 4.1 = 10
A gas exerts a pressure of 4.1 atm at 300K. Therefore, 13.1 atm is the pressure of the gas at 1010K.
What is pressure?The force delivered perpendicularly to an object's surface per unit volume over which this force is dispersed is known as pressure. The pressure as compared to the surrounding air is known as gauge pressure.
Pressure is expressed using a variety of units. Some of these come from dividing a unit of force by an area unit the traditional pressure measurement with in imperial and U.S. is the pound-force every square inch, whereas the SI pressure measurement, also called the pascal, becomes a newton per square meter.
P₁/T₁=P₂/T₂
4.1/300=P₂/1010
P₂ =13.1 atm
Therefore, 13.1 atm is the pressure of the gas at 1010K.
To know more about pressure, here:
https://brainly.com/question/29341536
#SPJ2
Which is an appropriate layering process for a compost pile?
O a layer of pine needles, a layer of paper napkins, some soil, and some water
O a layer of paper napkins, a layer of grass clippings, some soil, and some water
O a layer of dried leaves, a layer of cheese, some soil, and some water
O a layer of grass clippings, a layer of fruit scraps, some soil, and some water
Answer: O a layer of grass clippings, a layer of fruit scraps, some soil, and some water
Explanation:
The compost pile is made up of decomposing organic materials that are obtained from dead and decaying vegetable or plant matter, animal materials like dung, dead skins and others. The decomposition is done by the soil microbes that recycle the matter into nutrients that are absorbed by the plants. All the components of the compost pile are degradable and completely converted into organic matter. The grass clipping and fruit scraps mixed with soil and water can be easily decomposed by the soil microbes easily.
The appropriate layering process for a compost pile would be: a layer of grass clippings, a layer of fruit scraps, some soil, and some water and the correct option is option 4.
This layering process ensures a balanced mix of nitrogen-rich "green" materials (such as grass clippings) and carbon-rich "brown" materials (such as fruit scraps).
The addition of soil introduces microorganisms necessary for decomposition, and water provides moisture for the composting process.
The layering of different materials promotes proper airflow and creates an optimal environment for the decomposition of organic matter, resulting in the formation of nutrient-rich compost.
Thus, the ideal selection is option 4.
Learn more about Layering, here:
https://brainly.com/question/30005642
#SPJ6
Can someone help me with this? And provide an explanation on how they found their answer? Using conversion factors. I'm confused :(
You have used 3.0×102 L of distilled water for a dialysis patient. How many gallons of water is that?
Answer:
This would be 63 gallons :)
Explanation:
The Volume of water = 2.4 × 10² L
The Volume of water in gal = ?
The solution: We know that one gal is equal to 3.785 litter.
So in conclusion, 2.4 × 10²L × 1 gal / 3.785 L
2.4 × 10²L × 0.264 gal. L⁻¹
0.634 × 10² gal
Hopefully this helps :3
63 gal
PLEASE HELPPPP!!!!!!!!!!!!
Answer:
Largest: Mg
Smallest: Cl
Explanation:
help school so annoying
Answer:
I think its scenario 2 Guitar strings
Explanation:
"You move your fingers and arm to play the guitar! This energy was stored in the molecules inside your muscles and now is being used to move your fingers which, in turn, transfers energy to the strings of the guitar. Now the strings are vibrating, having kinetic energy,"
I searched this up, if you answer requires an explanation put this in your own words.
Hotter things have more energy than colder things. this is science middle school
Answer:
true
Explanation:
Hotter things have more heat energy than colder things. That's because the atoms or molecules move around faster in hot things (red, right) than they do in cold things (blue, left). ... The more heat you supply, the faster the molecules move and the further apart they get.
Answer: Depends on the situation.
Explanation: Hotter things do have more energy than colder things. But, if the mass of the colder thing is bigger, it really depends. If the colder thing have way more particles than the hotter thing, the colder thing may have more energy.
4.2g of cerium reacted with oxygen to form 5.16g of an oxide of cerium. Find
the simplest formula of this oxide*
ASAP plz
Answer:
CeO₂
Explanation:
Hello!
In this case, since we are given the mass of both cerium and the cerium oxide, we can first compute the moles of cerium and the moles of oxygen as shown below:
[tex]n_{Ce}=4.2gCe*\frac{1molCe}{140.12gCe}=0.03molCe\\[/tex]
[tex]m_O=5.16g-4.2g=0.96gO\\\\n_O=0.96g*\frac{1molO}{16.0gO} =0.06molO[/tex]
Now, we simply divide each moles by 0.03 as the fewest moles in the formula to obtain the simplest formula (empirical formula) of this oxide:
[tex]Ce=\frac{0.03}{0.03}=1\\\\O =\frac{0.06}{0.03}=2[/tex]
Thus, the formula turns out:
[tex]CeO_2[/tex]
Regards!
Identify the scientist associated with each major contribution to the development of atomic theory. He discovered the electron. He discovered periodic changes in properties of elements when they are listed in order of their atomic weights. He experimented with the deflection of cathode rays by a magnetic field. He carried out experiments, using gold foil, that measured the scattering of positively charged alpha particles by heavy atoms. He proposed that atoms are the basic units of matter. He proposed the model of the atom had most of its mass concentrated in a very small nucleus. He proposed that in a chemical reaction, atoms are neither created nor destroyed. Answer Bank
Answer:
He discovered the electron- J.J Thompson
He discovered periodic changes in properties of elements when they are listed in order of their atomic weights- Dimitri Mendeleev
He experimented with the deflection of cathode rays by a magnetic field- J.J Thompson
He carried out experiments, using gold foil, that measured the scattering of positively charged alpha particles by heavy atoms- Ernest Rutherford
He proposed that atoms are the basic units of matter- John Dalton
He proposed the model of the atom had most of its mass concentrated in a very small nucleus- Ernest Rutherford
He proposed that in a chemical reaction, atoms are neither created nor destroyed-John Dalton
Explanation:
J.J Thompson was the discoverer of the electrons. He also worked hard to show that they were negatively charged particles after he experimented with them using a magnetic field. He named them cathode rays.
Dimitri Mendeleev found that, when all the known chemical elements were arranged in order of increasing atomic weight, the resulting table displayed a recurring pattern, or periodicity, of properties within groups of elements(Encyclopedia Britannica).
Ernest Rutherford demonstrated by experiment using a thin gold foil and alpha particles that the atoms are composed of a positive massive core called the nucleus.
John Dalton proposed that matter is composed of atoms. Also, in a chemical reaction, atoms are neither created nor destroyed.
What heats the mantle?
Answer:
Fire
Explanation:
How many significant figures
are in this number?
3 x 10^6
9. ______________ Consists of the Sun and everything that orbits the Sun
10. ______________ A celestial body that orbits a star
11. ______________ The force that pulls all objects with mass toward one another
12. ______________ Located between the orbits of Mars and Jupiter
Answer:
9.solar system
10.comet
11.gravity
12.earth and saturn
You have a 5M stock solution of NaCl (Formula Weight: 58.44g/mole), a 0.25M stock solution of glucose (Formula Weight; 180.156g/mole), and a bottle of solid Tris base (Formula Weight: 121.1g/mole). How would prepare (be specific) 250mL of a single solution containing 150mM Tris, 25mM glucose, and 150mM NaCl. g
Answer:
4.54g of Tris base,25mL of the 0.25M stock solution of glucose and 7.5mL of the 5M stock solution of NaCl must be added and complete the volume in a volumetric flask to 250.0mL
Explanation:
To prepare the single solution we need to find the moles of each solute (Tris, glucose and NaCl) from the stock solutions anf the solid:
Moles Tris:
0.250L *(0.150mol / L) = 0.0375moles Tris * (121.1g/mol) = 4.54g of Tris base must be added
Moles glucose:
0.250L * (0.025mol/L) = 6.25x10⁻³mol glucose * (1L / 0.25mol) = 0.025L = 25mL of the 0.25M stock solution of glucose must be added
Moles NaCl:
0.250L * (0.150mol / L) = 0.0375mol NaCl * (1L / 5mol) = 0.0075L =
7.5mL of the 5M stock solution of NaCl
You must add:
4.54g of Tris base,25mL of the 0.25M stock solution of glucose and 7.5mL of the 5M stock solution of NaCl must be added and complete the volume in a volumetric flask to 250.0mL
Which distinguishes chemical changes from physical changes?
Answer:
In a chemical reaction, there is a change in the composition of the substances; in a physical change there is a difference in the appearance, smell, or simple display of a sample of matter without a change in composition.
Explanation:
In terms of environmental impact, what’s the difference between natural gas, coal, and biomass
Answer:
Fossil fuels release carbon dioxide into the atmosphere. Coal has the approximate chemical formula CH. ... Natural gas is the best fossil fuel in terms of energy output per unit carbon dioxide emitted. Biomass is renewable because a new crop can be grown after each harvest, and biomass is a low carbon fuel.
Explanation:
Answer:
Explanation:
Coal has the approximate chemical formula CH.
Natural gas is the best fossil fuel in terms of energy output per unit carbon dioxide emitted.
Biomass is renewable because a new crop can be grown after each harvest, and biomass is a low carbon fuel.
A sample of aluminum, which has a specific heat capacity of , is dropped into an insulated container containing of water at and a constant pressure of . The initial temperature of the aluminum is . Assuming no heat is absorbed from or by the container, or the surroundings, calculate the equilibrium temperature of the water. Be sure your answer has significant digit
Answer:
The answer is below
Explanation:
A 21.0 g sample of aluminum, which has a specific heat capacity of 0.897 J g '°C ', is dropped into an insulated container containing 200.0 g of water at 25.0 °C and a constant pressure of 1 atm. The initial temperature of the aluminum is 90.1 °C Assuming no heat is absorbed from or by the container, or the surroundings, calculate the equilibrium temperature of the water. Be sure your answer has 3 significant digits.
Solution:
The amount of heat lost or gained by a substance is given by the formula:
Q = mcΔT
Where Q is the heat lost or gained, m is the mass of the substance, ΔT is the temperature change.
The law of conservation of energy states that energy cannot be created or destroyed but can be transferred.
Therefore the heat lost by aluminum = heat gained by water
[tex]Q_{lost}=Q_{gained}\\\\m_ac_a\Delta T_a=m_wc_w\Delta T_w\\\\m_a= mass \ of\ aluminium = 21g,c_a=specific\ heat\ capacity\ of\ aluminum\\=0.897\ J/g^oC, \Delta T_a=90.1^oC-x,x=equilibrum\ temperature\\m_w= mass \ of\ water = 200g,c_w=specific\ heat\ capacity\ of\ water\\=4.184\ J/g^oC, \Delta T_w=x-25^oC\\\\ hence:\\\\21*0.897*(90.1-x)=200*4.184*(x-25)\\\\1697.2137-18.837x=836.8x-20920\\\\838.8x+18.387=1697.2137+20920\\\\857.187x=22617.2137\\\\x=26.4^oC[/tex]
Does anyone know how to create algae in a water bottle
Practice Problem Website: https://www3.nd.edu/~smithgrp/structure/workbook.html
1. Click on Do the problems
2. Click on the number for the practice problem to be completed
3. Click on IR
Example of problem 1 from the website:
Formula: C3H5BrO2
IR Peaks:
1717 nm—Strong peak indicates a carbonyl group C=O
2571-2670 nm- medium peak indicates sp3 hybrid C-H.
3067 nm --- Broad medium peak indicates OH group, specifically in a carboxylic acid (Would not be a carboxylic acid without the carbonyl peak as well)
Complete the following problems: 3, 5, 7, 8, 12, 13, 27, 32, 38, and 40.
Be as accurate as possible. I am looking for the frequency and molecular formula to make sense with the functional group you think is represented.