Answer:
c. Voltmeter
Explanation:
PLATO LIVES MATTER
10 things you should never do while making a measurement in chemistry
Answer:
Measure at the top of the meniscus
Hold the container (it is unsteady)
Explanation:
I'm really, really, sorry. I took chemistry in 6th grade and I'm in 8th, and I don't remember the entire list. This is all I could think of.
What kind of mixture is sometimes difficult to distinguish form a compound? Why?
Answer:
In a heterogeneous mixture, the parts of the mixture are noticeably different from one another. In a homogeneous mixture, the substances are so evenly distributed that it is difficult to distinguish one substance in the mixture from another.
What color change is exhibited by phenolphthalein during a titration of aqueous acetic acid with aqueous sodium hydroxide ? a. colorless to pink b. pink to colorless c. no color change d. yellow to blue e blue to yellow
The color change exhibited by phenolphthalein during a titration of aqueous acetic acid with aqueous sodium hydroxide is pink to colorless.
An indicator is an organic dye which changes color in acidic, basic and neutral medium.
Phenolphthalein is an example of an indicator. When aqueous acetic acid is titrated against aqueous sodium hydroxide, the indicator may be added to the basic solution.
Phenolphthalein has a pink color in a basic medium. As the acid is added gradually, the solution turns colorless at end point.
Hence, the color change exhibited by phenolphthalein during a titration of aqueous acetic acid with aqueous sodium hydroxide is pink to colorless.
Learn more: https://brainly.com/question/2728613
Potassium hydroxide has the chemical formula KOH. It feels slippery and is used in cleaning liquids. Based on this description, potassium hydroxide is most likely a(n) A acid. B base. с neutral solution. D pH indicator.
Answer:
it should be a base
Explanation:
this is because solutions such as bleach are usually slippery on the hands, and mostly bases are in cleaning solutions
help, Look at the model below. Explain what is correct and/or incorrect about the model based on scale, proportion, and quantity.
How many different E2 products are expected in the reaction of 3-bromo-1,1-dimethylcyclohexane with NaOCH2CH3?
A) only 1
B) 2
C) 3
D) 4
What mass of 2-naphthol would have to be ingested by each rat in a sample set of rats in order to kill half the population of rats? Assume each rat weighs 230 g. Show your calculations for full credit.
Answer:
303.6 mg
Explanation:
Given that:
The lethal dose [tex]LD_{50}[/tex] = 1320 mg/kg
The weight of the rat = 230 g
The lethal dose is the dose of a substance likely to cause death. SO a lethal dose of 50 will cause the death of 50% of the sample of test animals.
Therefore;
The mass of 2-naphthol that would have been ingested by each rat in a sample set of rats in order to kill half the population of rats will be equal to:
[tex]=\dfrac{LD_{50}}{1000} \times wt \ of \ rat[/tex]
[tex]=\dfrac{1320}{1000}\times 230[/tex]
= 303.6 mg
Compound Y has a distribution coefficient of 4.0 when extracted from water with chloroform, with Y being more soluble in chloroform. How many 10.0 mL chloroform extractions would be required to extract at least 95% of Y from a 50.0 mL aqueous solution of water?
For the extraction of at least 95% of Y in water, 3 extractions are to be performed.
Distribution coefficient can be defined as the ratio of the concentration of solute in an organic solvent to water.
Distribution coefficient = [tex]\rm \dfrac{concentration\;in\;solvent}{concentration\;in\;water}[/tex]
For the first extraction, the concentration in organic solvent = X per 10 mlConcentration in water = 100-X per 50 ml
Distribution coefficient = [tex]\rm \dfrac{\frac{X}{10} }{\frac{100-X}{50} }[/tex]
4 = [tex]\rm \dfrac{\frac{X}{10} }{\frac{100-X}{50} }[/tex]
4 = [tex]\rm \dfrac{50X}{1000-X}[/tex]
4000 - 4X = 50X
X = 74.1 %
Thus, after the first extraction, the amount of Y extracted is 74.1%.
We have to extract at least 95% of Y. Thus, the second extraction is performed.
Remaining y = 100 - 74.1Remaining y = 25.9%
The concentration in organic solvent = X per 10 ml
Concentration in water = 25.9 -X
Distribution coefficient = [tex]\rm \dfrac{\frac{X}{10} }{\frac{25.9-X}{50} }[/tex]
4 = [tex]\rm \dfrac{\frac{X}{10} }{\frac{25.9-X}{50} }[/tex]
4 = [tex]\rm \dfrac{50X}{259-X}[/tex]
1036 - 4X = 50X
X = 19.2%
Thus, after the second extraction the amount of Y extarcted = first extraction + second extraction
The amount of Y extracted = 74.1 + 19.2 %
The amount of Y extracted = 93.3%
To reach at least 95% extraction, the third extraction has to be performed.The remaining Y for third extraction = 100 - 93.3
The remaining Y for the third extraction = 6.7%
Concentration in water = 100 - 6.7
Distribution coefficient = [tex]\rm \dfrac{\frac{X}{10} }{\frac{6.7-X}{50} }[/tex]
4 = [tex]\rm \dfrac{\frac{X}{10} }{\frac{6.7-X}{50} }[/tex]
4 = [tex]\rm \dfrac{50X}{67-X}[/tex]
268 - 4X = 50X
X = 5.0%
The total extraction after third extraction = 93.3 + 5%
The total extraction after third extraction = 98.3%.
Thus for the extraction of at least 95% of Y in water, 3 extractions are to be performed.
For more information about the distribution coefficient, refer to the link:
https://brainly.com/question/13599982
What is the hydroxide concentration of a solution with a poH of 2? Is this solution acidic, basic or neutral?
An isotope of the element fluorine has 9 protons and 10 neutrons. What is the name of this isotope?
fluorine
Answer:
fluorine atom
Explanation:
A river and all of its tributaries make up a(n) _________.
Answer:
A river and its tributaries make up a watershed (aka river system or drainage basin)
Pls mark me as brainliest
Answer:
river system
Explanation:
a river and all its tributaries make up a river system
What is the ground-state electron configuration for the Mn4 ion and is it paramagnetic or diamagnetic?
Answer:
[Ar]3d4 is the ground-state electron configuration for the Mn4 ion
but i don't know whether it is paramagnetic or daimagnetic
Muscles in a kangaroo’s legs work because of the cells that make up the muscle. Which component of cell theory does this best illustrate?
( science )
Answer:
cells are a basic unit of structure and function all things
Tumu’s class was given an assignment to feature a scientist that contributed to the development of the cell theory. The class decided to use images to feature the scientist of their choice.
Which image would Tumu most likely use in his assignment to feature Rudolf Virchow?
the magnified shapes of cells in a piece of cork
the different cells that make up a plant leaf
the types of cells at work in the human body
the way root cells reproduce to increase root length
Answer:
The types of cells at work in the human body
Explanation:
Rudolf Virchow was a German physician who is known as the father of modern pathology. He contributed to the development of the cell theory by concluding that all cells come from preexisting cells. This led to the conclusion that diseases occur at the cellular level, which allowed scientists to diagnose diseases more accurately.
Considering that Virchow analyzed human cells, the image that Tumu would be most likely to use in his assignment is the one of the types of cells at work in the human body.
Answer:
D the way root cells reproduce to increase root length
Explanation:
Have a good day!
Is iron man made or natural
Answer:
Iron is natural. Paper is man-made
Explanation:
Answer:
iron
Explanation:
A solution of acetic acid is prepared in water by adding 11.1 g of sodium acetate to a volumetric flask and bringing the volume to 1.0 L with water. The final pH is measured to be 5.25. What are the concentrations of acetate and acetic acid in solution? (Assume that the temperature of the solution is 25 degrees Celsius)
Answer:
Molarity acetate: 0.1353M
Molarity acetic acid: 0.0418M
Explanation:
When in solution you have a weak acid (Acetic acid) and its conjugate base (sodium acetate) a buffer is produced. The pH of this buffer is obtained using the H-H equation:
pH = pKa + log [A⁻] / [HA]
Where pH is pH of the solution = 5.25
pKa is pKa of acetic buffer = 4.74
[A⁻] is molarity of acetate ion - Molar mass sodium acetate: 82.03g/mol-:
11.1g * (1mol / 82.03g) = 0.1353moles A⁻ / 1.0L = 0.1353M
And [HA] are moles of acetic acid.
Solving for HA:
5.25 = 4.74 + log [0.1353] / [HA]
0.51 = log [0.1353] / [HA]
3.236 = [0.1353] / [HA]
[HA] = 0.1353M / 3.236
[HA] = 0.0418M
no question................................
Answer:
ok
Explanation:
A) Earlier you were told that of all of the 14 solutes you will be studying, the only one that is not appreciably ionized in water is aqueous ammonia. What does this statement imply about the equilibrium point of the reaction involving aqueous ammonia/ammonium hydroxide?B) Use your results and conclusions from part (a) to explain why a complicated name like Aqueous ammonia/ammonium hydroxide is used for this solution?
Answer:
Throughout the overview section following portion, the description and according to particular circumstance is defined.
Explanation:
As per the question,
⇒ [tex]NH_3(aq)+H_2O\leftrightarrow NH_4+(aq)+OH-(aq)[/tex]
A weak basis seems to be NH3. It serves as a base since the aqueous solution or phase is protonated. But NH3 +, just becoming a weak base, is therefore deprotonated into form NH3, and therefore also 90% of ammonia becomes found throughout NH3 state in aqueous solution.⇒ [tex]NH_3+(aq) \leftrightarrow NH_3(aq)+H+(aq)[/tex]
However, it is also available in NH3 form throughout the aqueous solution much of the moment.
Does MgO have a structure like that of NaCl or ZnS? If the density of MgO is 3.58g/cm3, estimate the radius (in centimeters) of the O2â anions and of the Mg2+ cations.
Answer:
The radius of O^2- is 1.5*10^-8 cm and the radius of
Mg ^2+ is 6.2*10^-9 cm
Explanation:
Face centered cubic : 1/8 atoms on each edges + 1/2 atoms on each face
= [tex]\frac{1}{8}* 8 + \frac{1}{2}*6[/tex] = 4 effective atoms
MgO have a structure like NaCl forms a lattice of FCC.
density of the lattice = [tex]\frac{ z.M}{a^3*Na}[/tex]
z : no of atoms
M: mass of the atoms
a: radius of the atom
Na: Avogadro's number
a^3(radius) = [tex]\frac{ 4*40.3}{3.58*6.022*10^23}[/tex]
a^3 = 7.477 * 10^-23 cm^3
a = 4.21 * 10^-8 cm
Now calculating the anionic(ra O^2-) and cationic (rc Mg^2+)
in Fcc a = 2[tex]\sqrt{2} ra[/tex]
ra = 1.5*10^-8 cm
a = 2ra + 2rc
rc = a/2 -ra
rc = 6.2*10^-9 cm
The radius of O^2- is 1.5*10^-8 cm and the radius of Mg ^2+ is 6.2*10^-9 cm
Redox reactions stand for oxidation/reduction reactions. True or false: an oxidation reaction is always paired with a reduction reaction.
Answer:
The answer is: true
Explanation:
In redox reactions, the half-reactions of oxidation and reduction always occur simultaneously in pair.
The oxidation half-reaction involved the lost of electrons from a reduced substance (A) to form a oxidized substance (A⁺):
A ⇒ A⁺ + e-
In contrapossition, during the reduction half-reaction the oxidized substance (B⁺) gains electrons to form the reduced subtance (B):
B⁺ + e- ⇒ B
The overall redox reaction is obtained by the addition of the two half-reactions:
A ⇒ A⁺ + e-
B⁺ + e- ⇒ B
-----------------
A + B⁺⇒ A⁺ + B
The electrons gained by B are provided by A, which lost the same number of electrons. Thus, the oxidation/reduction reactions are paired.
How many liters of blood does a human body have
Answer:
20000
Explanation:
The autoignition of both ethanol and octane occurs at 363 oC. Which gas sample contains the gas molecules that have a greater average kinetic energy
Answer:
See explanation
Explanation:
At the same temperature, the average kinetic energy of gases depends on the molecular mass of the gas. Hence, given a particular temperature, lighter molecules travel faster on the average than heavier molecules.
Considering ethanol and octane, The molar mass of ethanol is 46.07 g/mol while the molar mass of octane is 114.23 g/mol. Hence, ethanol has a greater average kinetic energy than octane at the same temperature.
Microwave ovens use microwaves with a wavelength of 0.12 meters. How much energy does this wave have? 2 x 10-20 10 mm FI
Answer:
E = 165.75×10⁻²⁶ J
Explanation:
Given data:
Wavelength = 0.12 m
Energy of wave = ?
Solution:
Formula:
E = h c/λ
c = 3×10⁸ m/s
h = 6.63×10⁻³⁴ Js
Now we will put the values in formula.
E = 6.63×10⁻³⁴ Js × 3×10⁸ m/s / 0.12 m
E = 19.89×10⁻²⁶ J.m / 0.12 m
E = 165.75×10⁻²⁶ J
Which of the two forces is greater the force on the firefly or the force on the bus explain your answer please I really need help please
It’s due today please
Answer: The force on the firefly
The unfortunate firefly hitting the bus does not change the velocity of the bus very much. Technically there is a change, but it's so very small and miniscule that it barely registers. To any casual observer not paying very close attention, they don't notice anything at all. So effectively the force on the firefly is a lot greater since the firefly got the worst end of the deal.
So in short, we look at the velocity of each object and see which velocity changed the most. In this case, the firefly's velocity changed from whatever speed it was flying to 0 when it stops flying all together. That's why the force is greater on the bug.
What effect does a high carbon level have on the deep ocean? Why might it be important to keep an eye on the deep ocean carbon levels? What could that one number tell you about the cycle as a whole?
High concentrations of carbon dioxide make it harder for marine animals to respire (to extract oxygen from seawater). This, in turn, makes it harder for these animals to find food, avoid predators, and reproduce. Low concentrations of oxygen can have similar effect
Becay the Ocean's Carbon Balance. The idea seemed simple enough: the more carbon dioxide that people pumped into the atmosphere by burning fossil fuels, the more the oceans would absorb. ... Water trapped at the surface would become saturated, at which point, the ocean would slow its carbon uptake.
what is the iupac name of CH3-CH2CH(CH3)CH2-COOH
Answer:
Butanoic acid.
Explanation:
What is chemical weathering
Explanation:
Chemical weathering is caused by rain water reacting with the mineral grains in rocks to form new minerals (clays) and soluble salts. These reactions occur particularly when the water is slightly acidic.
1. When waves go from one place to another, they transport
A. amplitude
C. frequency
B. wavelength
D. energy
Urgent help me please answer it if you know it
What is the acceleration of a car moving at the same speed and in the same direction?
Answer:
if it ain't changing direction the acceleration isn't being affected