The best design for this experiment is to number the items from 1 to 1,200 and then choose random numbers in the table of random digits (second option).
How to use a table of random digits?These tables are used to randomly assign items or subjects into groups when experimenting. The best way to use these tables are:
Give each item or participant a number.Take a lot at the table and choose a number.If this number is the same that the number assigned to an item or participant classify it in the first group.Keep selecting.Based on this, for this experiment the steps are:
Number the items from 1 to 1,200. Identify numvers in the table.Assign the first 400 items to the process 1 group. Repeat the process for the other two groups.Learn more about experiments in: https://brainly.com/question/11256472
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Answer:
b. Number each item from 1 to 1,200. Reading from left to right from a table of random digits, identify 800 unique numbers from 1 to 1,200. Assign the items with labels in the first 400 numbers to the process 1 group. Assign the items with labels in the second 400 numbers to the process 2 group. Assign the remaining items to the process 3 group.
Explanation:
Statistics A edg. 2023
PLEASE HELP, will give brainliest
Answer:
See below
Explanation:
(NH4)2SO4 Molar weight (from periodic table)
(N =14 H4 = 4 ) * 2 = 36
S = 32 O4 = 64 TOTAL = 132 gm/mole
N % = ( 2*14) / 132 = 21.2% molar mass = 28 gm
H % = (2 *4) / 132 = 6% molar mass = 8 gm
S % = 32/132 = 24.2 % molar mass = 32 gm
O % = (64) / 132 = 48.5% molar mass = 64 gm
____________is not an effect of heat
a. Expansion
b. Change of state
c. Contraction
d. Chemical change
Answer:
c. contraction
Explanation:
Heating will cause substances to expand, or change their state (like solid to liquid) or it may be a chemical reaction.
How much 5. 90 m naoh must be added to 480. 0 ml of a buffer that is 0. 0215 m acetic acid and 0. 0275 m sodium acetate to raise the ph to 5. 75?
Buffers are the solution that resists the change in pH. 1.39 ml of 5.90 M sodium hydroxide must be added to raise the pH to 5.75.
What is Henderson–Hasselbalch equation?Henderson–Hasselbalch equation is used to determine the pH of the buffer by the equilibrium concentration of the acid and the conjugate base.
Moles of acetic acid are calculated as:
[tex]0.480 \times 0.0215 = 0.01032[/tex]
Moles of sodium acetate are calculated as:
[tex]0.480 \times 0.0275 = 0.0132[/tex]
The total number of moles is = 0.02352
Now, using the Henderson–Hasselbalch equation:
[tex]\rm pH = \rm pKa + log \dfrac{[Acetate]}{[Acetic\; acid]}[/tex]
Given,
pH = 5.75
pKa = 4.74
Substituting values in the above equation:
[tex]\begin{aligned} 5.75 &= 4.74 +\rm log \rm \dfrac{[Acetate]}{[Acetic\; acid]}\\\\10.2329 &= \rm \dfrac{[Acetate]}{[Acetic\; acid]}\end{aligned}[/tex]
Solving further:
[tex]\begin{aligned} 10.2329 &= 0.02352 - \rm \dfrac{[Acetic\; acid]}{[Acetic\; acid]}\\\\11.2329\; \rm [Acetic \; acid] &= 0.02352 \\\\&= 0.002093\end{aligned}[/tex]
Moles of acetate is calculated as:
0.02352 moles - 0.002093 moles = 0.021427 moles
Initial moles of acetate were 0.0132, added moles of acetate by the addition of the sodium hydroxide resulted in, 0.021427 - 0.0132 = 0.00822 moles of sodium hydroxide.
Volume is calculated as:
[tex]0.00822 \;\rm moles \times \dfrac{1\;\rm L}{5.90\;\rm M} = 0.00139 L[/tex]
Therefore, 1.39 mL of 5.90M of sodium hydroxide is added.
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How many moles of nh3 is needed to react with. 824 mol nh3
1.648 moles of ammonia will be required to produce 0.824 moles of nitrogen gas.
What are moles?Mole is a very important unit of measurement that chemists use. A mole of something means you have 602,214,076,000,000,000,000,000 of that thing, like how having a dozen eggs means you have twelve eggs.
According to the reaction, 1 mole of nitrogen gas is produced by 2 moles of ammonia.
Then, 0.824 moles of nitrogen gas will be produced by:
1.648 moles of ammonia will be required to produce 0.824 moles of nitrogen gas.
Hence, 1.648 moles of ammonia will be required to produce 0.824 moles of nitrogen gas.
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cold winter morning, a PHS student measured the air pressure in her
be 1.5 atm. The tire was warmed to 15°C and the new pressure was
tm. If the volume didn't change, what was the initial temperature in
re in degrees Celsius?
Find the initial temperature in Kelvin, then convert to Celsius
9°C
3,4°C
26°C
2°C
2. A 2.5 mol SAMPLE OF OXYGEN GAS (O2) INCREASES TO 3.2 mol
FROM AN INITIAL PRESSURE OF 720 mmHg. THE VOLUME
CHANGES FROM 34 L TO 45 L, AND THE TEMPERATURE
INCREASES FROM 25°C TO 45°C, WHAT IS THE FINAL PRESSURE
OF THIS GAS?
696.32 mmHg is the final pressure of the gas.
What is an ideal gas equation?The ideal gas equation, pV = nRT, is an equation used to calculate either the pressure, volume, temperature or number of moles of a gas.
Given data:
[tex]P_1[/tex] = 720 mmHg
[tex]P_2[/tex] = ?
[tex]n_1[/tex] = 2.5 mol
[tex]n_2[/tex] = 3.2 mol
[tex]V_1[/tex] = 34 L
[tex]V_2[/tex] = 45 L
Formula
Combined gas law
[tex]\frac{P_1 V_1}{n_1} = \frac{P_2 V_2}{n_2}[/tex]
[tex]P_2[/tex] = 696.32 mmHg
Hence, 696.32 mmHg is the final pressure of the gas.
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In a nuclear fission reaction, a freely moving neutron is introduced to a nuclear fuel, such
as uranium-235. What happens next?
O A. The neutron breaks apart.
B. Heat is released by the neutron.
O C. A neutron is absorbed by an atom's nucleus. .
O D. The nucleus becomes unstable.
In a nuclear fission reaction, a freely moving neutron is introduced to a nuclear fuel, then a neutron is absorbed by an atom's nucleus.
What is nuclear fission?Nuclear fission is a process in which an unstable nuclei will convert into stable nuclei after releasing the energy in the form of particles.
When we introduce a freely moving neutron to the nuclear fuel of uranium-235 nuclei then this introduced neutron was absorbed by the nuclei and makes the nuclei more unstable. Then this unstable nuclei will convert into two nuclei in the addition of three neutrons.
Hence, a neutron is absorbed by an atom's nucleus.
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HELP PLEASE I BEG OF YOU
Identify three different alloys in your home. Describe how each alloy is used and why the properties of the alloy make it suitable for that application.
Answer:
Iron - Nails, Utencils, Appliances
Copper - Wiring
Aluminiem - Roofing, Ducting
8x-47+19=24[tex]8x-47+19=24[/tex]
the outermost layer of earth's atmosphere is
Answer: Exosphere
Explanation:
Answer:
exosphere
Explanation:
the outermost layer of earth's atmosphere is called exosphere
Identify the most important type(s) of interparticle forces present in the solid c2h6
Intermolecular forces are the forces present between the molecules. The London dispersion forces are the strongest interparticle forces present in the ethane.
What is LDF?London dispersion forces are the intermolecular forces are the temporary forces present between the induced dipole formed by the electrons occupied in the atom.
The electrons of the atom are distributed symmetrically and are dispersed just as the light in quanta. In ethane molecule ionic, and hydrogen forces are absent and only LDF and dipole-dipole are present.
Therefore, LDF and dipole-dipole are the intermolecular forces that are present in ethane.
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Which of the following statements is correct?
Lithium is a metal, Titanium is a nonmetal
Magnesium and Helium are gases.
Copper and Argon conduct electricity,
Calcium is malleable, Sulfur is not malleable.
Answer:
The 4th statement. Because sulfur is not malleable.
Answer:
d
Explanation:
renata developed a hair dye additive that is guaranteed to cover grey hair. she granted the right to use this additive to a major hair collor manufacturer, and renata now recives a
What Renata has granted to the manufacturer of the colored hair dye is called a patent.
What is a patent?A patent is a right given to a manufacturer to be the sole producer of a product for a given period of time. Usually, the patent has to last for a given number of years after which the technology becomes commonplace.
Hence, what Renata has granted to the manufacturer of the colored hair dye is called a patent.
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The definition of the acceleration states that an object accelerates when it
Answer: Acceleration and velocity
Explanation:
Newton's second law says that when a constant force acts on a massive body, it causes it to accelerate, i.e., to change its velocity, at a constant rate. In the simplest case, a force applied to an object at rest causes it to accelerate in the direction of the force.
Answer:
Moving with changing velocity
Explanation:
the resultant force acting on it is not zero
hence
The increase in boiling point from CH4, SiH4, GeH4 to SnH4 is caused by the increase in strength of which type of intermolecular force?
Methane (CH4) with the smallest atomic size, would have the lowest boiling point.
What is Boiling point ?It is the temperature at which the pressure exerted by the surroundings upon a liquid is equaled by the pressure exerted by the vapour of the liquid; under this condition, addition of heat results in the transformation of the liquid into its vapour without raising the temperature.
CH₄, SiH₄, GeH₄, SnH₄ are very similar. They are all in the same group and their molecular geometry is a tetrahedral.
They have covalent bonds. The key difference: The number of protons and electrons.
These are non-polar molecules, so there are no ionic bonds. There are no H bonded to a F, N or O, so there is no hydrogen bonds.
Dipole induced dipole forces (AKA London dispersion forces) dictate the boiling points of these atoms. It is the attraction between atoms that dictate how easily they can disperse.
The electrons in an atom are constantly moving due to their repulsion of each other. However, if one electron has moved and the other has not, it is temporarily charged.
The biggest molecule will have the highest boiling point. The more protons and electrons, the stronger the effect.
Therefore, Methane (CH4) with the smallest atomic size, would have the lowest boiling point.
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students mixed two liquids in a beaker and listed their observations
> Liquid 1 was colorless
> Liquid 2 was colorless
> The mixture of liquids 1 and 2 formed a colorless solution
> small, solid particles formed and fell to the bottom of the beaker
based on these observations, which statement contains the best evidence that a chemical reaction occurred?
A. There is a change in shape
B. there is a change in volume
C. the two liquid mix into a solution
D. the two liquids made a new substance
The two liquids made a new substance.
What is a physical and chemical change?A chemical change results from a chemical reaction, while a physical change is when matter changes forms but not chemical identity.
A chemical change occurs when some substances are transformed into different substances, with different nature and properties. In this case when both liquids are mixed a solid is formed. This is an example of a change of state of the liquids reactants to the solid product, which has properties and characteristics different from that of the initial liquids of the mixture which is called a chemical change.
Hence, option D is correct.
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You need to make an aqueous solution of 0.194 M potassium acetate for an experiment in lab, using a 125 mL volumetric flask. How much solid potassium acetate should you add
To prepare 0.194 M potassium acetate, add 2.379895 g of potassium acetate to a 125 mL volumetric flask and fill with water to the mark.
Define molarity of a solution.Molarity (M) is the amount of a substance in a certain volume of solution. Molarity is defined as the moles of a solute per litres of a solution.
The following data were obtained from the question:
Molarity of potassium acetate = 0.194 M
Volume of solution = 125 mL
Mass of potassium acetate =?
Next, we shall convert 125 mL to L. This can be obtained as follow:
1000 mL = 1 L
Therefore,
125 mL = 0.125 L
Thus, 125 mL is equivalent to 0.125 L.
Next, we shall determine the number of moles of potassium acetate in the solution. This can be obtained as follow:
Molarity of potassium acetate = 0.194 M
Volume of solution = 0.125 L
Moles of potassium acetate =?
Molarity = [tex]\frac{mole}{Volume}[/tex]
Cross multiply
Mole of potassium acetate = 0.194 M × 0.125
Mole of potassium acetate = 0.02425 mole
Finally, we shall determine the mass of potassium acetate
Molar mass of potassium acetate= 98.14 g/mol
Mass of potassium acetate =?
Mole = [tex]\frac{mass}{Molar mass}[/tex]
Mass of potassium acetate =0.02425 × 98.14
Mass of potassium acetate = 2.379895 g
Thus, to prepare 0.194 M potassium acetate, add 2.379895 g of potassium acetate to a 125 mL volumetric flask and fill with water to the mark.
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How many moles of nacl are needed to make 5.2l of a 2m solution
Answer:
10.4 moles
Explanation:
n / 5.2 = 2 M
n = 10.4 moles
How many molecules are in 22g of NaOh
Answer:
40
Explanation:
because NaOH makes 40 grams.
Write the reaction for the weak base co32- in water
The weak base carbonate reacts with the water forming bicarbonate and the hydroxide ion.
What is a weak base?The weak bases are given as the compounds that have the inability to get completely dissociated in water.
The carbonate is given as the weak base, as in water it remains constituted in the form of a bond with oxygen.
The reaction of water with the carbonate ion is given as:
[tex]\rm CO_3^{2-}\;+\;H_2O\;\rightleftharpoons HCO_3^-\;+\;OH^-[/tex]
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Which state or states of matter have fixed volume but not a fixed shape? (HELP FAST)
Answer:
liquid
Explanation:
A solid is defined as substance with a set volume and form. A liquid is defined as substance with a set volume but no fixed form. A gas is substance that does not have a definite volume or shape. Plasma, like a gas, has no set volume or shape.
Plssssss helpppppp
Consider a beaker half-filled with water there’s a balloon stretched over the opening and nothing can leak out. What would happen if you placed the beaker/balloon apparatus on a hot plate and let the water come to a boil?
Answer:
The balloon will expand
Explanation:
Steam needs more space than the equivalent wt amount of liquid
What happens when a hydrogen atom is added to a bromothymol blue molecule? (Will give brainliest)
Hydrogen atom is added denotes to something
H+ or H_3O+ is released inside solutionSo the
solution becomes acidicHence.
Bromothymol blue will turn yellow
Helpp me plsss I don't understand this
Take the cuttings from the trees and place them around in different enviornements, if the trees grow up to be the expected size in a different eviornement then the the scientists' claim is correct.
I didn't understand at first either, the question is worded a little strangly, but I believe this should answer the question that was asked.
If 3. 5 grams of ni are reacted with excess oxygen to form nickel oxide unser standard state conditions, what is the entropy change for the reaction?
Entropy Change is the measure of the randomness of the thermodynamic system. The entropy change for the reaction is -49.3 J/K.
What is the change in entropy?Entropy change is the ratio of the heat transfer of the system to the absolute temperature of the system.
The entropy of nickel = 182.1 J/mol. K
The entropy of oxygen = 205.0 J/mol. K
The entropy of nickel oxide = 37.99 J/mol. K
Entropy change is calculated as:
[tex]\begin{aligned}\Delta \rm S &= 2(37.99)-2(182.1)-205\\\\&= 75.98 - 364.2 - 205\\\\&= -493.22 \end{aligned}[/tex]
Therefore, -49.3 J/K is the entropy change.
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4Fe + 3O2 → 2Fe2O3
Iron combines with oxygen to form rust. Given the chemical reaction, how many grams of iron(Fe) would produce 10 g of rust(Fe2O3)?(molar mass of iron= 55.85; molar mass of rust= 159.69g)
A) 6.99
B) 29.9
C) 69.9
D) 9.99
6.99 grams of iron (Fe) would produce 10 g of rust (Fe2O3) when iron combines with oxygen to form rust.
How to calculate mass?The mass of a substance can be calculated as follows:
According to this question, iron combines with oxygen to form rust as follows:
4Fe + 3O2 → 2Fe2O3
First, we convert the mass of rust to moles as follows:
moles of Fe2O3 = 10g/159.69 = 0.063moles
4 moles of Fe produces 2 moles of Fe2O30.063 moles of Fe2O3 will be produced by 0.125 moles of Fe.Next, convert moles of Fe to mass as follows:
mass of Fe = 0.125 × 55.85 = 6.99g
Therefore, 6.99 grams of iron (Fe) would produce 10 g of rust (Fe2O3) when iron combines with oxygen to form rust.
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How are seeds beneficial to humans or the environment give me a good Reason!!
Answer:Seeds are great sources of fiber. They also contain healthy monounsaturated fats, polyunsaturated fats and many important vitamins, minerals and antioxidants. When consumed as part of a healthy diet, seeds can help reduce blood sugar, cholesterol and blood pressure
Explanation:
Answer:
Seeds grow plants wherever they fall is in the right condition and can be used as a sort of food for humans
Explanation:
If you want to prepare 2.00 L of a 0.800 M NaNO_3 solution from a NaNO_3 stock solution that is 1.5 M in concentration, how many mL of the stock solution must you start with
1066.7 ml of the stock solution must start with, preparing 2.00 L of a 0.800 M NaNO3 solution.
What is volume?Volume is the space occupied by a three-dimensional object.
By the formula [tex]\rm M_1V_1= M_2V_2[/tex]
M1 is the initial molarity, 1.5 M
M2 is the final molarity, 0.800 M
V1 is the initial volume
V2 is the final volume, 2.00 L
Putting the values in the equation
[tex]\rm 1.5\;M \times V_1= 0.800\;M \times 2.00\;L\\\\V_1 = \dfrac{ 0.800\;M \times 2.00\;L}{1.5\;M} = 1066.7\;ml[/tex]
Thus, the initial volume is 1066.7 ml
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what is the kc expression of H2(g)+Cl2(g)-2HCL(g)
Answer:The equilibrium constant (kc) for the reaction 2HCl(g) =H2(g)+Cl2 (g) is 4×10^-34 at 25°C.
Explanation:
The topics covered by the study of thermodynamics include:.
Answer:
a. energy changes during heating.
b. energy changes during chemical reactions.
c. color changes during chemical reactions.
d. Both (a) and (b)
Explanation:
The answer is D.Both (a) and (b)