Answer:
math si hard
Explanation:
The mole fration of ethanol and water in a sample of rectified spirit which contains 95% of ethanol by mass is 0.8 and 0.11.
How do we calculate mole fraction?Mole fraction of any substance will be calculated by dividing the moles of that substance from the total moles of the solution.
Moles (n) will be calculated as:
n = W/M, where
W = given mass
M = molar mass
Given that 95% of ethanol by mass is present in the sample, so 95g of ethanol is present in 100g of solution.
Mass of solvent (water) = 100 - 95 = 5g
Moles of water = 5g / 18g/mol = 0.27mol
Moles of ethanol = 95g / 46g/mol = 2.06mol
Mole fraction of water = 0.27 / (0.27+2.06) = 0.11
Mole fraction of ethanol = 2.06 / (0.27+2.06) = 0.8
Hence required mole fraction of water & ethanol is 00.11 and 0.8 respectively.
To know more about mole fraction, visit the below link:
https://brainly.com/question/1601411
#SPJ2
help please need now
Answer:
it is second one
Explanation:
thanks
The two most common isotopes of argon (Ar) are argon-36 and argon-40. Given that the average atomic mass is 39.95, what can be said about the relative abundance of each isotope? Which is more common and how do you know? No calculation is necessary. I am looking for a simple written response.
Answer:
Argon-40
the reason this is abundent is because this is a more common isotope
Explanation:
Forces are measured in
Newton
Watt
Mass
Grams
Answer:
A
Explanation:
Force can also be described intuitively as a push or a pull. A force has both magnitude and direction, making it a vector quantity. It is measured in the SI unit of newtons and represented by the symbol F.
Which process occurs in a fission nuclear reactor?
Nuclei combine.
Nuclei split apart.
Neutrons combine.
Neutrons split apart.
Answer:
Nuclear fission/ split apart
Explanation:The process of splitting a nucleus is called nuclear fission and is used in nuclear power reactors. Fission is another word for splitting.
Hope this helps! brainlyeast would only be necessary if this helped you thanks! :) have a good day!
Answer:
The correct answer is B. Nuclei split apart
Explanation:
EDGE2022
How many grams of potassium sulfate should be weighed to prepare 100 ppm of potassium in 250mL of solution if the purity of the salt is 98.7%?
Answer:
R=0.0564g K2SO4
Common human behavior that seems to be programmed or directed by genes or hormones?
Answer:
There's a lot...lying...rolling eyes...aggression...mating...parenting...sadness...basically alot
Explanation:
A block of metal has a mass of 85g and a volume of 6.35mL. What is the density?
Answer:
13.39
Explanation:
Density is g/mL divide the grams by the mL
How many atoms of H are in 11 moles of H2O
Answer:
1.325×10²⁵
Explanation:
1 mole of H2O has 2 mole of H atom
11 mole of H20 has 22 mole of H atom
we know
1 mole=6.023×10²³ atom
hence 22mole H =22×6.023×10²³
=1.325×10²⁵
List the official SI units
Answer:
The seven SI base units, which are comprised of:
Length - meter (m)
Time - second (s)
Amount of substance - mole (mole)
Electric current - ampere (A)
Temperature - kelvin (K)
Luminous intensity - candela (cd)
Mass - kilogram (kg)
Explanation:
Answer:
The seven SI base units, which are comprised of:
* Length - meter (m)
* Time - second (s)
* Amount of substance - mole (mole)
* Electric current - ampere (A)
* Temperature - kelvin (K)
* Luminous intensity - candela (cd)
* Mass - kilogram (kg)
Explanation:
Hope this helps :)
Plz, give me brainliest if u can... if I'm right, idrc if u do or not, just askin.
who said
"there are electrons dispersed evenly within a large area of positive material"
A. Rutherford
B. Schrodinger
C. Bohr
D. Thomas
Awnser: The awnser would be (D) Thomas
Explanation:
Use Quizlet
How can the knowledge of a material’s chemical makeup or use be utilized?
A. To classify minerals
B. To identify minerals
C. To determine the color of the minerals
D. To determine how to break down minerals
To identify minerals
Each material chemical makeup are a variety of chemical compounds which has each own category. They have different functional groups which helps people identify which material they look for. For instance, hydroxyl group has chemical makeup of alcohol
To identify minerals
Explanation:
Each material chemical makeup are a variety of chemical compounds which has each own category. They have different functional groups which helps people identify which material they look for. For instance, hydroxyl group has chemical makeup of alcohol
What is a product made from nonrenewable resources?
a shirt made from natural plant fibers
a bookshelf made from wood
a nail made from the metal iron
a paintbrush made from horse hair
Answer:
C. a nail made from the metal iron
Explanation:
I did the test.
The product made from non-renewable resources is nail made from the metal iron.
What are nonrenewable resources?Non renewable resources are materials that do not replenish themselves but they are easily exhausted or diminished after a period of time.
Therefore, The product made from non-renewanleable resources is nail made from the metal iron.
Learn more about nonrenewable resources below.
https://brainly.com/question/14432353
#SPJ2
How is color a physical change
Answer:Physical changes involve states of matter and energy. No new substance is created during a physical change, although the matter takes a different form. The size, shape, and color of matter may change. Physical changes occur when substances are mixed but don't chemically react.
Explanation:
chemistry question worth 40 points!!
Which of the following is an example of a buoyant force acting on a piece of
bread?
O A. The piece of bread floats on the surface of a lake.
B. The piece of bread travels in uniform circular motion.
C. The piece of bread remains still despite an applied force.
D. The piece of bread travels with straight-line horizontal
acceleration.
An example of the buoyant force on a piece of bread is the piece of bread floats on the surface of body water such as a lake.
What is the buoyant force?This is a force experienced by objects when they are in a body of water. This force implies objects have an upward force, which in many cases causes them to float.
What are some examples of this force?Any object that is submerged in water but floats or shows to have an upward force is an example of this force. Based on this, the option that clearly shows the buoyant force is a bread floating on a lake.
Learn more about buoyant force in: https://brainly.com/question/21990136
Answer:
A
Explanation:
this happens in massive star which convert hydrogen into helium?
Answer:
nucleosynthesis. A star's mass determines what other type of nucleosynthesis occurs in its core (or during explosive changes in its life cycle).
Use the periodic table to determine the electron configuration for aluminum (Al) and arsenic (As) in noble-gas notation.
Al:
[Ar]3s23p1
[He]2s22p63s23p1
[Ne]3s23p1
[Ne]3s23p2
Answer:
C
Explanation:
[Ne]3s23p1
Answer:
C
Explanation:
24 of 30
19
20
21
22
23
24
25
26
27
28
Which feature can distinguish between an elemental molecule and a compound molecule?
whether the molecule is formed from at least two atoms
O whether the molecule is formed by the sharing of electrons
O whether the molecule is a gas or a liquid
O whether the molecule is made from different types of atoms
Answer:
whether the molecule is formed from at least two atoms
Explanation:
A feature that distinguishes an elemental molecule and a compound molecule is whether the molecules are formed from at least two atoms.
An elemental molecule is a molecule that contains two or more of the same kind of elements.
A compound molecule contains two or more different kinds of molecules.
An example of elemental molecule is oxygen gas, O₂. An example of a compound molecule is water H₂O.A molecule is a unit of a compound that can represent such a compound.
Therefore, what distinguishes an elemental molecule from a compound molecule is whether a molecule forms from at least two atoms.
Aspirin synthesis involves the addition of an acetyl group to salicylic acid in a condensation reaction with an alcohol. The acetyl group could be added with a carboxylic acid but the preferred procedure is to use the acid anhydride. Why is preferable to use an acid anhydride for ester formation with an alcohol rather than a carboxylic acid? Select one: Carboxylic acids react with water in an undesired side reaction. Acid anhydrides are generally easier and safer to handle than carboxylic acids. Carboxylic acids change the pH of the solution too much for the reaction to proceed. Acid anhydrides are less stable than esters so the equilibrium favors the ester product.
Answer:
The correct appropriate will be Option 1 (Acid anhydrides are less stable than esters so the equilibrium favors the ester product.)
Explanation:
Acid anhydride, instead of just a carboxyl group, is typically favored for esterification. The predominant theory would be that Anhydride acid is somewhat more volatile than acid. This is favored equilibrium changes more toward the right of the whole ester structure. Extremely responsive than carboxylic acid become acid anhydride as well as acyl chloride. Thus, for esterification, individuals were most favored.The other options offered are not relevant to something like the scenario presented. So, the solution here is just the right one.
Please help i don’t understand
What type of energy is elastic energy?
A. Kinetic energy
B. Chemical energy
C. Nuclear energy
D. Potential energy
ASAP
Answer:
D. potential energy
Explanation:
What is the difference between a mixture and a compound ??
Answer:
Explanation:
Compound are substances which can be formed by chemically combining two or more elements. Mixtures are substances that are formed by physically mixing two or more substances.
A reaction where heat is added is a(n)
endothermic reaction
heterogeneous reaction
reversible reaction
in endothermic reaction heat is added
What is the enthalpy of reaction for the decomposition of calcium carbonate?
CaCO3(s) Right arrow. CaO(s) + CO2(g)
Answer:
Explanation:
You will need to look up the Standard Heats of Formation* for each substance and apply Hess's Law Equation.
ΔH⁰(rxn) = ∑ΔH⁰(Products) - ∑ΔH⁰(Reactants)
*Std Heats of Formation can be found in the appendix of most college chem texts.
For this problem:
Given CaCO₃(s) => CaO(s) + CO₂(g)
∑ΔH⁰: -635.1 Kj/mole -393.5Kj/mole -1206.9
ΔH⁰(rxn) = [(-393.5 Kj/mole) + (-393.5Kj/mole)] - (-1206.9Kj/mole)
= (-635.1 -393.5 + 1206.9) Kj/mole
= +178.3 Kj/mole
Answer:
656.3 kJ
This reaction is endothermic
Explanation:
edge 2020
If 298 mL of 0.575 M CuCl2 is diluted into 750 mL, what is the concentration of new solution?
Answer:
The answer is 0.228 MExplanation:
To find the concentration of new solution we use the formula
[tex]C_1V_1 = C_2V_2[/tex]
where
C1 is the concentration of the stock solution
V1 is the volume is the volume of the stock solution
C_2 is the concentration of the diluted solution
V2 is the volume of the diluted solution
Since we are finding the the concentration of new solution
[tex]C_2 = \frac{C_1V_1}{V_2} \\[/tex]
From the question
C1 = 0.575 M
V1 = 298 mL
V2 = 750 mL
We have
[tex]C_2 = \frac{0.575 \times 298}{750} \\ = 0.228466666...[/tex]
We have the final answer as
0.228 MHope this helps you
As the vibration of molecules increases, the _____ of the substance increases.
temperature
internal energy
kinetic energy
all of the above
Answer:
Answer option D- all of the above
A chemist carefully measures the amount of heat needed to raise the temperature of a 341.0 mg
sample of a pure substance from 8.4 ℃
to 21.5 ℃. The experiment shows that 4.03 J of heat are needed.
- What can the chemist report for the specific heat capacity of the substance?
Answer:
The specific heat of substance is 0.90 j/g.°C.
Explanation:
Given data:
Mass of sample = 341.0 mg (341.0/1000 = 0.341 g)
Initial temperature = 8.4 °C
Final temperature = 21.5 °C
Heat needed = 4.03 J
Specific heat capacity of substance = ?
Solution:
Specific heat capacity:
It is the amount of heat required to raise the temperature of one gram of substance by one degree.
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = T2 - T1
ΔT = 21.5 °C - 8.4 °C
ΔT = 13.1 °C
4.03 J = 0.341 g × c ×13.1 °C
4.03 J = 4.4671 g.°C × c
c = 4.03 J /4.4671 g.°C
c= 0.90 j/g.°C
The specific heat of substance is 0.90 j/g.°C.
Select the correct answer. What happens if you double the number of batteries used in a circuit? (Assume all of the batteries are the same.) ОА. . The current doubles only. O B. B. The voltage doubles only. O C. The current decreases. OD. The voltage decreases. O E. The voltage and current doubles.
Answer:
THE ANSWER IS "O E. The voltage and current doubles."
I IT HELPS YOU....
Answer:
They are both doubled, answer E
Explanation:
16.4 A cylinder of water contains oxygen in solution. The cross- sectional area of the cylinder is 2 cm2 and the length of the cylin- der is 5 cm. At one end of the cylinder the concentration of oxygern is maintained at 0.2 mol m-3, this concentration falls linearly to 0.05 mol m-3 at the other end of the cylinder. The diffusion con- stant of oxygen in water is 8 × 10-10 m2 s-1. How many moles of oxygen pass down this cylinder every second? What mass of oxy- gen passes down the cylinder each second?
Answer:
A) oxygen moles/sec = 48 * 10 ^-14 mol/sec
B) mass of oxygen = 1536*10^-14 grams
Explanation:
cross sectional area of cylinder = 2cm^2 = 2 * 10^-4 m^2
length of cylinder = 5 cm = 0.05 m
concentration at one end = 0.2 mol m^-3
concentration falls linearly at other end = 0.05 mol m^-3
Diffusion constant of oxygen = 8 * 10^-10 m^2 s^-1
A ) Number of moles of oxygen passing every second
N = A * D * [tex]\frac{dc}{dt}[/tex] ------- ( 1 )
A = area , D = diffusion constant, [tex]\frac{dc}{dt}[/tex] = rate of change of diffusion
dc /dt = ( 0.2 - 0.05 ) / 0.05 = 3 mol m^-4
back to the equation
N = ( 2 * 10^-4 ) * ( 8 * 10^-10 ) * ( 3 ) = 48 * 10 ^-14 mol/sec
B) Mass of oxygen passing down the cylinder each second
This can be obtained by converting : 48 * 10^-14 moles to grams
1 mole of oxygen = 32 grams of oxygen
therefore : 48 * 10^-14 moles of oxygen = ( 32 * (48*10^-14) = 1536*10^-14 grams
40. Which of these is an example of an
anhydrous compound?
A) H2O
C) CuSO4.5H2O
B) CaSO4
D) CaSO4 · 2H2O
Explanation:
CuSO4.5H2O and CaSO4.2H2O
Answer:
CaSO4 is an example of anhydrous compound
Reason:
Calcium Sulphate (CaSO4) does not contain water in its crystal structure, unlike other minerals.
