HELP ME OUT PLS!!!!!!!!!
All stars begin their life in a
O black hole
O main sequence
O protostar
O nebula
Answer:
nebula
Explanation:
I am well informed
Which mixture would be easiest to separate based on the size of the particles?
A.
oil and water
B.
vinegar and water
C.
sand and gravel
D.
sugar and water
Answer:
i believe sand and gravel because you can sift the sand
Explanation:
Determine the empirical formula of a compound containing 48.38 grams of carbon, 8.12 grams of hydrogen, and 53.5 grams of oxygen
As with most stoichiometry problems, it is necessary to work in moles. The ratio of the moles of each element will provide the ratio of the atoms of each element.
Get the mass of each element by assuming a certain overall mass for the sample (100 g is a good mass to assume when working with percentages).
Remeber that percentages are a ratio multiplied by 100. You must convert percentages back to their decimal value before working with them.
(.4838) (100 g) = 48.38 g C
(.0812 ) (100 g) = 8.12 g H
(.5350) (100 g) = 53.38 g O
Convert the mass of each element to moles of each element using the atomic masses.
(48.38 g C) (1 mol/ 12.10 g C) = 4.028 mol C
(8.12 g H) (1 mol/ 1.008 g H) = 8.056 mol H
(53.38 g O) (1 mol/ 16.00 g O) = 3.336 mol O
Find the ratio or the moles of each element by dividing the number of moles of each by the smallest number of moles.
Use the mole ratio to write the empirical formula.
Consider the following reaction where Kc = 55.6 at 698 K.
H2(g) + I2(g) 2HI(g)
A reaction mixture was found to contain 2.29×10-2 moles of H2(g), 3.80×10-2 moles of I2(g) and 0.254 moles of HI(g), in a 1.00 liter container.
Is the reaction at equilibrium?
If not, what direction must it run in order to reach equilibrium?
The reaction quotient, Qc, equals
.
The reactionfill in the blank 2
A. must run in the forward direction to reach equilibrium.
B. must run in the reverse direction to reach equilibrium.
C. is at equilibrium.
Answer:
B
No the reaction is not at equilibrium
The reaction must run to the left (reactants) to reach equilibrium
Qc = 74.14
Explanation:
Qc = (0.254)^2 / ((2.29 x 10-2)(3.8 x 10-2))
Qc = 74.14
74.14 > 55.6
Qc > Kc
When the Northern Hemisphere is tilted ________the Sun, the sunlight is _________ direct than it is in the Southern Hemisphere. (Select all that apply.)
Group of answer choices
away from; more
toward; less
toward; more
away from; less
Answer:
away from, less
Explanation:
sun is further away from the northern hemisphere so receives less light
What is the molarity of a solution made by adding 1.565 moles of
PbNO3 to 0.500 L?
300. M
31.3 M
3.13 M
1.56 M
Answer:
3.13M
Explanation:
Using the Molaitry equation ( M = n/v ) just plug numbers in and solve.
Which of the following are true about photosynthesis and cellular respiration. (Select all that apply.)
The products of one process are the reactants of the other.
The relationship between them enables life to survive as we know it.
They both happen only in plants.
They both take place in human cells.
Answer:
2 and 4 are the best answers
Explanation:
Answer:
A and B
Explanation:
Took the k12 test.
What is the pH of
0.000519 M NaOH?
The pH of the sodium hydroxide (NaOH) solution at the given concentration of 0.000519 M is determined as 10.72.
What is pH of solution?
The pH of a solution is defined as the logarithm of the reciprocal of the hydrogen ion concentration [H+] of the given solution.
Concentration of the basic solution, [OH⁻] = 0.000519
pOH = -log[OH⁻]
pOH = -log[0.000519]
pOH = 3.28
pH of the solutionpH + pOH = 14
pH = 14 - pOH
pH = 14 - 3.28
pH = 10.72
Thus, the pH of the sodium hydroxide (NaOH) solution at the given concentration of 0.000519 M is determined as 10.72.
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Question 4 of 15
The types of radiation produced by alpha, beta, and gamma decay differ in
many ways. Which characteristic do they all have in common?
A. The ability to treat cancer
B. The ability to cause cancer
C. The ability to trace the movement of chemicals
D. The ability to damage human tissue
Answer:
D. The ability to damage human tissue
please give me brainliest.
is mixing water and glue a chemical or physical change?
Answer:
physical
Explanation:
because it would still remain as a liquid. if you were to add borax or something to it, then it would be a chemical change.
Reactivity Series
Iron, tin and zinc all react with dilute hydrochloric acid to produce hydrogen.
Plan an experiment to determine the order of reactivity of iron, tin and zinc.
You are provided with powdered samples of the metals and common laboratory apparatus.
Answer:
Measuring electode potential
Explanation:
Make an electrode of all of them and measure standard reductive potential metals with lower srp will be more reactive
The metals which are placed above the hydrogen in the reactivty series can produce hydrogen gas with HCl. The order of reactivity of given metals is as follows: Zinc > iron > tin.
What is reactivity series?The reactivity series of elements or the activity series can be defined as the arrangement of metals in descending order according to their reactivities.
The metals placed at the top of the activity series are strong reducing agents and can be readily oxidized. These metals readily tarnish/corrode. The reducing ability becomes weaker while moving down the reactivity series.
The electropositivity of the elements decreases as we move down in the reactivity series of metals. All metals which are placed above hydrogen in the activity series can able to release hydrogen gas upon reacting with dilute HCl.
Therefore, the metals Iron, tin, and zinc release hydrogen gas when they react with the HCl. The order of reactivity is according to their reduction potential which is Zinc > iron > tin.
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Which type of covalent bond is the least stable?
A.Covalent bonds
B.Double bonds
C.Single bonds
D.Triple Bonds
Answer:
D because: A Triple bond is when three pairs of electrons are shared between two atoms in a molecule. It is the least stable out of the three general types of covalent bonds.
What is the process of photosynthesis
Answer:
Photosynthesis is the process by which plants use sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar
A manometer measures 450 torr of pressure in a container with 0.500-L sample of carbon dioxide, CO2. The gas is compressed to a volume of 0.100 L. What is the new pressure reading in the manometer?
Let's see
Apply boyles law
P1V1=P2V2450(0.5)=0.1P_2225=0.1P_2P_2=2250Torrcalculate the concentration of HCL
the concentration of HCI
solution:[tex]mass \: formula \: of \: hci = 1 + 35.5[/tex]
[tex] = 36.5[/tex]
[tex]mass = relative \: formula \: mass \times amount[/tex]
[tex] = 36.5 \times 0.125[/tex]
[tex] = 4.56g | {dm}^{3} [/tex]
hence, the concentration of HCI is 4.56g/dm3.
If the actual yield for a substance is 39.487g but the theoretical yield is 38.000g, what is
the percent yield?
a. 2%
b. 96%
c. 50%
d. 104%
Answer:
b. 96%
Explanation:
Which of these activities would a Forensic toxicologist NOT preform?
a. Determine the chemical
makeup of alcohol
b. Determine if drugs played a role in an accident.
c . Determine if drugs played a role in a perpetrator actions.
d. Determine if a person died of natural causes or a poison.
Answer:
A
Explanation:
because I know it from doing a test
a pharmaceutical company wants to extract an ingredient from pomace supplied by a certain food processing plant. which process is the most efficient with the lowest environmental impact
A. Catalyst extraction
B. High pressure, high temperature water extraction
C. Organic solvent extraction
D. Enzyme extraction
Answer: high pressure, high temperature water extraction
Explanation:
Answer:
C). high pressure, high temperature water extraction
Explanation:
PLEASE QUICKLY HELP:)
which entry-level job would give you the best experience for a career in the lodging sector?
Choose one answer correctly!
A. Hostess
B. Réservation agent
C. Sever
D. Tour guide
Answer:
i think Hostess but id K a lodging sector is an The hospitality industry encompasses a wide range of services and activities such as lodging, restaurants, food services, and convention centers. The lodging sector consists of hotels, motels, resorts, and bed and breakfasts.
Explanation:
calculate, a can of chicken broth contains 450 mg of sodium chloride in 240.0g of broth. What is the percent by mass of sodium chloride in the broth?
Answer:
The percent by mass of sodium chloride in the broth is 0.1875 %
Explanation:
Our first step is transforming the sodium chloride figure from mg to g
450mg x 1g/1000 mg= 0.45g
Now, we must calculate the percentage by using the following formula:
0.45g / 240g x 100= 0.1875%
Henceforth, we can conclude that the percentage by mass of sodium chloride in the broth is 0.1875%
The per cent by mass of sodium chloride in the broth is 0.1875 %
What is per cent by mass?The mass per cent of a component of a compound is the percentage ratio of the mass of the component by the total mass of the compound. The formula is mass per cent = (mass of component / total mass of compound) × 100.
Given data:
Mass of sodium chloride =450 mg = 0.45g
Now, we must calculate the percentage by using the following formula:
[tex]\frac{0.45gX 100}{240g }[/tex]
= 0.1875%
Hence, we can conclude that the percentage by mass of sodium chloride in the broth is 0.1875%
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Name the following ketone:
o
CH3CCH3
Answer: the answer is A
Explanation:
just finished this on acellus
Acetone is the name of the following compound and can also be referred to as 2-propanone.
What is a ketone?ketone, any of a class of organic compounds characterized by the presence of a carbonyl group in which the carbon atom is covalently bonded to an oxygen atom.
Acetone, an organic compound, is chemically described as [tex]CH_3COCH_3[/tex], and can also be referred to as 2-propanone.
Acetone is a hydrocarbon derivative, more specifically a ketone in its simplest form because of its particular functional group.
Hence, acetone is the name of the following compound and can also be referred to as 2-propanone.
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Which characteristic of an outermost shell is required for an atom to not need any electrons?
1 electron
more than 2 electrons
more than 21 electrons
a full
Answer:
A full.
Explanation:
An electron needs to have a full octet do not need any more electrons. So the correct option is D.
What is a valence shell?
The s and p electrons in the outermost shell are valence electrons. Core electrons are those found in the inner shell. Valence electrons are little subatomic particles that we come across as we examine and investigate an element's atom. We can trace the valence electrons and forecast the sorts of bonds with the aid of Lewis structures.
The majority of valence electrons are negatively charged particles, and they are all grouped in various orbitals or shells. Additionally, these electrons are in charge of how atoms interact with one another and create chemical bonds.
However, not every electron belongs to an atom. A chemical bond or molecule can only be created by the electrons that are found in the outermost shell. Valence electrons are the name given to this sort of electron.
Therefore the correct option is D.
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Determine the longest wavelength of light required to remove an electron from a sample of potassium metal, if the binding energy for an electron in K is 1.76 × 103 kJ/mol. A. 113 nm B. 885 nm C. 68.0 nm D. 147 nm E. 387 nm
Answer:
The wavelength of light is 68 nm.
Explanation:
Given data:
Binding energy of electron = 176 × 10³ Kj/ mol or (1.76× 10⁶ j/mol)
Wavelength of light require to remove the electron = ?
...................................................
Explanation:
I honestly don't understand why you post useless questiond
Help, will mark brainiest if the answer is correct(explanation is preferred but not needed).
Answer:
See graph below
Explanation:
For this graph of acid-base (strong) the equivalence is just ph = 7
the only solid figure that has two circular bases is a
Cylinder
Cylinder A cylinder is a solid figure with two parallel congruent circular bases.
Answer:
Cylinder
Explanation:
A cylinder is a solid figure with two parallel congruent circular bases.
Ammonia is a gas for which reliable analytical methods are available to determine its concentration in other gases. To measure flow in a natural-gas pipeline, pure ammonia gas is injected into the pipeline at a constant rate of 72.3 kg/min for 12 min. Five miles downstream from the injection point, the steady-state ammonia concentration is found to be 0.382 wt %. The gas upstream from the point of ammonia injection contains no measurable ammonia. How many kilograms of natural gas are flowing through the pipeline per hour?
amount of ammonia injected:
72.3 kg/min x 12 min = 867.6 kg
ammonia concentration = 0.382%
[tex]\tt 0.382\%=\dfrac{mass~amonia}{mass~ammonia+mass~natural~gas}\times 100\%\\\\0.00382=\dfrac{867.6}{867.6+mass~natural~gas}\\\\mass~natural~gas=226,252.88~kg/12min=1131264.4~kg/h[/tex]
What is the electrical conductivity of Copper and Glass?
Please help
Answer:
Table of Resistivity and Conductivity at 20°C
Material ρ (Ω•m) at 20 °C Resistivity σ (S/m) at 20 °C Conductivity
Deionized water 1.8×105 5.5×10−6
Glass 10×1010 to 10×1014 10−11 to 10−15
Explanation:
Table of Resistivity and Conductivity at 20°C
Material ρ (Ω•m) at 20 °C Resistivity σ (S/m) at 20 °C Conductivity
Deionized water 1.8×105 5.5×10−6
Glass 10×1010 to 10×1014 10−11 to 10−15
Which substance will hold its shape?
plasma
liquid
gas
solid
Answer:
solid
Explanation:
plasma = no
liquid= shapes is container it is in
gas = shaped to container also
A lab technician determines the boiling point elevation of an aqueous solution of a nonvolatile, nonelectrolyte to be 1.12 C. What is the solution’s molality?
Answer:
2.19m
Explanation:
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