Answer:
P value is commonly used. The prevalent use of P values to summarize the results of research articles could result from the increased quantity and complexity of data in recent scientific research.
Explanation:
`Pb(NO3)2 (aq) + LiBr(aq) →
Answer:
PbBr2 + LiNO3
And goodluck
When 0.28g of a basic oxide, MO, is reacted with 250cm3 of 0.05moldm–3 hydrochloric acid the excess acid required 50cm3 of 0.05moldm–3 sodium hydroxide solution for neutralisation. Which one of the following is the relative atomic mass of M?
A 12
B 28
C 40
D 56
the answer is C but i have no idea how!
mol of excess acid: 50 cm ³x 0.05 M = 2.5 mlmol
mol of acid reacted: (250 cm³ x 0.05 M) - 2.5 mlmol = 10 mlmol = 10 x 10⁻³ mol
MM (molar mass) MO = mass : mol = 0.28 : 10 x 10⁻³ = 28
MM MO = Ar M + Ar O
28 = Ar M + 16
Ar M = 12
I think the answer is A
In order to maintain a sodium chloride (NaCl) concentration similar to ocean water, an aquarium must contain 4.7 g NaCl per 100 g of water. What is the percent by mass of NaCl in the solution?
Answer:
0.047
Explanation:
mass percent is part/whole mass
The table compares the frequency of some unknown electromagnetic waves,
Comparison of Frequency
Electromagnetic Wave Frequency (hertz)
1014 Hz
1010 Hz
1020 Hz
106 Hz
Which electromagnetic wave has the
longest wavelength?
Wave W
Wave X
Wave Y
Wave Z
Answer:
Wave X
Explanation:
because the lower the frequency, the longer the wave length
Answer:
Wave X is the correct answer. Hope it helps!
Explanation:
A gold bar is contain 3.0 mol of gold, how many atoms of gold are in the bar
Answer:
18.066 x 10^23 atoms of Au
Explanation:
ONE mole = 6.022 x 10^23 particles
3 x 6.022 x 10^23
How much energy does a 445 nm wave of light have? (The speed of light in a
vacuum is 3.00 x 108 m/s, and Planck's constant is 6.626 x 10-34 J•s.)
Answer:
A
Explanation:
To calculate questions like this, you need to make use of the equation below:
E = hν
E is the energy, h is Planck's constant, and ν is the frequency.
Also, another important formula you need for this question is the following:
ν = c / λ
ν is the frequency, c is the speed of light, and λ is the wavelength.
Therefore, E = hν = hc/λ.
Also remember to convert nm wavelength to meters.
To answer the question, E = hc/λ = ((6.626*10^-34 J•s)(3*10^8 m/s))/(4.45*10-7 m) = 4.42 • 10^-19 J = A
Glycolysis is an example of:
A.
Aerobic metabolism
B.
Anabolic metabolism
C.
A net reductive process
D.
Fermentation
Answer:
glycolysis is an example of aerobic metabolism option A is the correct answer of given statement
Which of the following items is NOT a compound?
Which picture shows a pattern of stars? (2 points)
Group of answer choices
the moon in the sky
Public Domain
two children watching a shooting star
© Choreograph / iStock 2018
the sun setting in Ottawa, Canada
a line connecting five stars together
Answer:
A line connecting five stars together
Explanation:
Constellations or patterns (same thing) are made up of stars. The stars form shapes, but there is not really lines in the sky. We have to draw the lines with our head or take a picture of it and draw lines on it. Some patterns are: the big dipper, the small dipper etc. Last but not least, just some random info about the constellations.. zodiac signs have their own constellations. Here is a list of the zodiacs to their constellations:
•Leo (the Lion)
•Aquarius (the Water Bearer)
•Gemini (Twins)
•Cancer (Crab)
•Aries (Ram)
•Scorpio (Scorpion)
•Taurus (Bull)
•Sagittarius (Archer)
•Capricorn (Sea Goat)
•Pisces (Fishes)
•Libra (Scales)
•Virgo (V-i-r-g-i-n: Maiden)
Of the following substances, only______ has London dispersion forces as the only
intermolecular force.
HCI
O Kr
O CH3OH
NH3
O H₂S
Answer:
HCI
Explanation:
thats the sorrect one
brainly me bro pls pls
i need 4 brainly im willing to brainly me
A 3.00 laqueous solution of koh contains 195 g of koh. The solution has the density of 1.29 g/ml
For a 3.00 aqueous solution of Koh contains 195 g of Koh. The solution has a density of 1.29 g/ml and is mathematically given as
molarity = 1.16L
molarity of solution = 0.946M
percentage concentration = 5%
What is molarity?
Generally, the equation for molarity is mathematically given as
molarity = no of moles/ volume in liters
no of mol = 195/56.1
no of mol = 3.48
molarity = 3.48/3.00
molarity = 1.16L
therefore,
mass = 1.29 g/ml x 3000mL
mass = 3.87kg/mL
mass of solute is
= 3.87-0,195
= 3.675
molarity of solution
= 3.48/3.675
molarity of solution = 0.946M
In conclusion, the percentage concentration is
= 195/3870 x100
percentage concentratio = 5%
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3. A metal tank contains three gases: oxygen, helium, and nitrogen. If the partial pressures of the three
gases in the tank are 35.0 atm of O2, 5.0 atm of N, and 25.0 atm of He, what is the total pressure
inside of the tank?
this homework assignemnt is confusing can someone please help.
Answer: Heyya, the answer is 0.8539gH2. Pls mark brainliest
Explanation:
How many grams of oxygen can be prepared by the decomposition of 12 grams of mercury oxide?
A 104.5 mL intravenous (IV) solution contains 5.10 g of glucose (C6H12O6). What is the molarity of this solution? The molar mas of glucose is 180.16 g/mol.
Answer:
Molarity=0.271M
Explanation:
molarity=moles/volume
moles=5.10/180.16
=0.0283 moles
volume=0.1045L
Molarity=0.0283/0.1045
=0.271M
Sulfur and fluorine react in a combination reaction to produce sulfur hexafluoride: S(g) + 3F2(g) ->SF6(g) If 50 g S is allowed to react as completely as possible with 105.0g F2(g), how many grams ofn SF6 can we get?
The quantity of SF6 that we can get is = 228.2g
Calculation of product formationThe quantity of S that reacted = 50g
The quantity of F2(g)that reacted = 105.0g
Therefore the quantity of SF6 that will be produced = ?
But molar mass of sulphur = 32g/mol
molar mass of SF6(g)= 146.06 g/mol
If 32g of S = 146.06 g of SF6
50 g of S = x
Make X the subject of formula,
X = 50×146.06/32
X = 7303/32
X = 228.2g of S
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Compare the boiling points of alcohol, ethers and alkanes and explain one reason for the difference
Alcohols have higher boiling points than do ethers and alkanes of similar molar masses.
What is meant by Boiling Point ?The temperature at which the vapor pressure of a liquid equals the pressure surrounding the liquid is called the boiling point of the substance.
Approximately boiling point of Ethanol: 78.4°C, ether: 34.6°C, ethanes: 68°C
The reason for the difference is that it takes more energy to separate alcohol molecules then it does to separate alkane molecules and ether molecules.
The OH group in alcohol allows molecules to engage in hydrogen bonding.
Therefore Boiling point are in the order ;
Alcohol > alkane > ethers
To know more about Boiling Point
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which is the best definition of resistance
would the water in a pond or the water in a full bathtub have more thermal energy? Explain why.
All of the following use subjective scoring EXCEPT:
A. Diving
B. Figure Skating
C. Archery
D. Gymnastics
Answer:
Archery
Explanation:
Archery is scored based on point values assigned to the rings on the target.
In which of these systems is the entropy decreasing?
a liquid cooling
air escaping from a tire
snow melting
salt dissolving in water
Answer:
a liquid cooling
Explanation:
Liquid cooling results in liquid (more disorder) turning to solid (less disorder).
Entropy describe disorder in our system. Going from more disorder to less disorder decreases entropy.
Rest of the options increase entropy b/c gas escaping from tire releases gas from confined shape to vast environment, snow melting turns solid (order) into liquid (less order), and salt dissolving turns solid into liquid form.
According to the ideal gas law, what
will be the volume of 0.25 mol of
nitrogen at 0.82 atm pressure and
57°C temperature?
Explanation:
Ideal Gas Law
PV = n R T
V = n R T / P n = moles R = gas constant = .082057 L atm / ( K mol)
T is in Kelvin
V = .25 moles * .082057 * (273.15 + 57) K / .82 atm = 8.3 moles
( two Sig Dig)
For the following H30 concentration list the pH and the OH concentration in
Molarity) (5 points each, 10 points total)
[H30*]= 1.4*105 M
pH=
[OH]=
Answer:
[H3O+] = 1.4*10^-5 M
pH = 4.85
[OH-] = 7.08*10^-10
Explanation:
As pH is a measure of hydronium H3O concentration, simply substitute [H3O+] into the following equation:
pH = -log[H+]
pH = -log(1.4*10^-5)
pH = 4.853871...
Round to 2-3 sig figs due to only being given data with 2 significant figures
pH = 4.85
One method to get to [OH-] is to turn pH into pOH and then use inverse functions to get [OH-]
pH + pOH = 14
4.85 + pOH = 14
pOH = 9.15
Then to get [OH-] from pOH:
pOH = -log[OH-]
9.15 = -log[OH-]
-9.15 = log[OH-]
10^(-9.15) = [OH-]
7.07945784 * 10^-10 = [OH]
Round based on given significant figures again:
7.08*10^-10 = [OH-]
(Feel free to add any questions & I'll be sure to reply if clarification is needed)
[H₃O]=1.4 x 10⁻⁵
pH = 5 - log 1.4
pOH = 9 + log 1.4
[OH⁻] = 1 x 10⁻¹⁴ : 1.4 x 10⁻⁵ = 7.14 x 10⁻¹⁰
Substances in a fire extinguisher help prevent air from reaching a burning material. Why would this be a good way to fight a fire?
Answer:
because of the substance contained in a fire extingudher it woulfnt start a fire.
A person wishes the heat pot of freshwater from 20°C to 100°C in order to boil water for pasta they calculate that their pot holds 2 kg of water and that they would need to apply 669,440 Joules of heat energy to produce the desire temperature change are the person calculations correct?defend your answer and demonstrate all relevant calculation
Q=mcΔt
669440 = 2.10³ x 4.184 x (100-20)
669440 = 669440 √ (correct)
If there are 9.02x103 amu of copper in a sample, how many copper atoms are there in
the sample?
Answer:
Average atomic mass = 63.62 amu
Explanation:
Average atomic mass is the weighted average of the individual isotopes.
And thus the weighted average =
(0.6917×63+0.3083×65)⋅amu = ?? amu.
Note that we have not accounted for the less massive copper isotopes that would decrease this mass to the accepted value of
63.55 amu.
Hope this helps! Good luck!
What are the three main organic things found in healthy soil? (Select three.)
Answer:
Organic matter is composed of living things (plant roots and organisms), dead things (recent plant and animal residue), and very dead things (highly decomposed material, or humus).
Explanation:
hope this helps if not let me know have a great day
The beakers on the left and right both contain the same amount of HCL (liquid) and the same mass of calcium carbonate (solid). In which beaker will the reaction rate be the greatest?
A) The reaction rate will be highest in beaker 1 because there is a larger surface area of calcium carbonate.
B) The reaction rate will be highest in beaker 2 because there is a larger surface area of calcium carbonate.
C) The reaction rate will be highest in beaker 1 because there is a smaller surface area of calcium carbonate.
D) The reaction rate will be highest in beaker 2 because there is a smaller surface area of calcium carbonate
Answer:
B
Explanation:
Smaller pieces results in a larger surface area, therefore the answer is beaker B.
A farmer buys a new plot of land on which to grow crops. The land he buys is very flat. The farmer's main concern with this plot of land is wind erosion because certain seasons are very windy in this area. He has a large budget for the project, but he does not want to spend a lot of time or money maintaining any erosion control method that he installs.
Which method of erosion control is probably most suitable for the farmer to use?
A. contour plowing
B. buffer strips
C. terracing
D. windbreak
There are 11 runners in a race. Medals are awarded for 1st, 2nd, and 3rd place. In how many different ways can the medals be awarded? 330 990 110 165
Answer:
990
Explanation:
