Answer:
Percentage purity of a substance can be calculated by dividing the mass of the pure chemical by the total mass of the sample, and then multiplying this number by 100.
Explanation:
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Determine the amount in grams of KCl that exists in 20.3 g of a solution that contains 1.14 % KCl by mass 1.14 g KCl
The mass of KCl that exists in 20.3 g of solution containing 1.14% by mass of KCl is 0.23 g
From the question given above, the following data were obtained:
Mass of solution = 20.3 g
Percentage of KCl = 1.14% = 1.14 / 100 = 0.0114
Mass of KCl =?[tex]Percentage = \frac{mass of solute}{mass of solution} * 100\\\\0.0114 = \frac{mass of KCl}{20.3} \\\\[/tex]
Cross multiply
Mass of KCl = 0.0114 × 20.3
Mass of KCl = 0.23 gTherefore, the mass of KCl in the solution is 0.23 g
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Stems are important plant structures because they _________.
A.
are the main sites of photosynthesis for plants
B.
are the only site of water and nutrient transport
C.
allow plants to absorb water and nutrients from the soil
D.
give the plant structure and support
Answer:
D
Explanation:
supports the plant,leaves and flowers
What’s the answer to this
Answer: 5
Explanation:
please brainliest me
I believe it is 3
Answer:
Explanation:
If a barometer were built using water (d=1.0 g/cm3) instead of mercury (d=13.6 g/cm3), would the column of water be higher than, lower than, or the same as the column of mercury at 1.00 atm? If the level is different, by what factor? Explain.
Mercury is a compound denser than water and when this happen, it stays lower.
So, in this case, water stays higher than mercury because its density is low.
The level is different by a factor of 13.6 times taller.
A sample of carbon dioxide gas has a pressure of 8.33 bar and a volume of 10.3 mL at a temperature of 29.1 °C. How many
molecules of carbon dioxide gas are in the sample?
molecules:
need help with this pleaseeeee
Answer:
1) 1, 1
3)1, 1
4) 1, 2
5) 2, 1
6) 1, 5
7) 2, 5
4. A student performs four trials of an investigation to determine the boiling point of water. How should the student handle the results?
A. The student should take the average of the minimum and maximum value of the results.
B. The student should use the value that is closest to 100ºC.
C. The student should use the maximum value of the results.
D. The student should take the average of the results from all four trials.
Answer:
i think its D
Explanation:
In order to get maximum accuracy, student should take average of results from all four trials.
What is accuracy?Accuracy in terms of chemistry can be defined as to how close a measurement is to the true value.There are three types of accuracy:
1) Point accuracy-It means accuracy is present at that point of scale only.It does not give any information about the accuracy of the instrument.
2)Percentage of true value--It is the accuracy which is determined by identifying accuracy of the instrument and comparing it with the measured true value.
3)Percentage of scale range- It is the accuracy which determines accuracy of the measurement.
Accuracy in case of instruments is neglected up to ±0.5 percent.Accuracy of measurements can be increased by taking multiple measurements and taking into account human errors.
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please answer, the question is attached below/above
Answer: No
Explanation: O is a recessive trait so at least there is a mutation, then no.
List key terms associated with the carbon cycle
The main parts of the carbon cycle are photosynthesis, respiration, diffusion, absorption, fossil fuel burning, and land use.
13500 mL convert to milliliters of mercury
Answer:approximately 5.627 × 1019 milliliters
Explanation:
Airflow through a long 0.2m square air conditioning duct maintained the outer duct surface temperature at 10degree.if the horizontal duct is uninsulated and exposed to air at 35degree in the crawl space beneath at home.
What is the heat gain per unit length of the duct.
Answer:
125°C/m
Explanation:
The difference in temperature will be:
35 - 10 = 25
The outer duct surface is heated 25°C by the air from 10°C to 35°C;
This heat gain is simply divided by 0.2m to get heat gain per unit length:
25/0.2 = 125
125°C/m
If you're American, this will be °F I believe, so the answer will be:
125°F/m
Which of these is the condensed structural formula for an alkane with four carbon
atoms?
O CH3CH2CH2CH3
H
HLH
1C
H
C2
LH
I
C
HTH Н
H
0-I
I
क
H
OCH3CHCHCH3
OC-C-C-C
Answer:
First option
Explanation:
The option that says CH3CH2CH2CH3 is the correct option (I hope that I am right because the order of the answers is not very clear :/)
Which best describes the energy change that takes place during deposition?
Heat energy released by the substance
Heat energy is maintained by the substance
Heat energy is slowly gained by the substance
Heat energy is quickly absorbed by the substance
Answer:
heat energy released by the substance
The energy change that takes place during deposition is that heat energy is released by the substance. This statement is true about deposition.
Deposition is a phase transition that occurs when a gas is converted directly to a solid without passing through the liquid state. During deposition, energy is released by the gas particles and absorbed by the surface, resulting in a decrease in the energy of the gas particles and an increase in the energy of the surface particles.As a result, the substance releases heat energy as it changes from a gas state to a solid state.
Therefore, the correct option is:Heat energy released by the substance.
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5. Which element would form
covalent bond with Oxygen (0)
Sodium (Na)
Calcium (Ca)
Aluminum (AI)
Selenium (Se)
Finding dead insects or mouse droppings in the kitchen indicates which of the following: Pest infestation Chemical contamination Food spoilage Cross contamination
Finding dead insects or mouse droppings in the kitchen is an indication of pest infestation.
Pests are living organisms that are capable of spreading diseases, causing economic damages, or generally constituting nuisance to the environment.
Pest infestation occurs when there is a high number of pests in the environment. When this occurs, their activities are felt in the environment in terms of causing a nuisance, and damaging properties or contaminating foods.
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How many atoms...
NAC2H3O2
Answer:
one Sodium (Na) atom, two oxygen (O) atoms, two carbon (C) atoms, and three hydrogens (H) atoms
Explanation:
Write a balanced chemical equation for the complete combustion of methanol, ethanol, propanol, butanol and paraffin wax(C25H52). This information will be needed for the experiment. Transfer the answer to the data sheets also. (10 pts)
Answer:
Explanation:
1. Methanol:
CH3OH + O2 ---> CO2 + 2H2O
2. Ethanol:
C2H5OH + 3O2 ----> 2CO2 + 3H2O
3. Propanol:
2C3H7OH + 9O2 ------> 6CO2 + 8H2O
4. Butanol
C4H9OH + 6O2 -------> 4CO2 + 5H2O
5. Paraffin Wax:
C25H52 + 38O2 ----> 25CO2 + 26H2O
Stems are important plant structures because they _________.
A.
are the main sites of photosynthesis for plants
B.
are the only site of water and nutrient transport
C.
allow plants to absorb water and nutrients from the soil
D.
give the plant structure and support
Answer:
D
Explanation:
Answer:
for plato users, the answer is: give the plant structure and support
Which of the following frequencies of light has the lowest energy?
Answer:
Radio waves have photons with the lowest energies. Microwaves have a little more energy than radio waves. Infrared has still more, followed by visible, ultraviolet, X-rays and gamma rays.help! giving brainliest.
Answer:
A
Explanation:
will group 2 elements gain electrons to bond with non-metals in group 16 in a 2:1 ratio
A student wants to show the transfer of heat energy without matter which investigation design would best help the student
A) an investigation of radiation through a current in a fluid
B) an investigation of radiation through electromagnetic waves
C) an investigation of conduction through collisions between particles in space
D) an investigation of conduction through the movement of particles through a solid
Answer:
C
Explanation:
According to the concept of thermal energy, transfer of heat energy can be depicted by investigation of conduction through collisions between particles in space.
What is thermal energy?Thermal energy is defined as a type of energy which is contained within a system which is responsible for temperature rise.Heat is a type of thermal energy.It is concerned with the first law of thermodynamics.
Thermal energy arises from friction and drag.It includes the internal energy or enthalpy of a body of matter and radiation.It is related to internal energy and heat .It arises when a substance whose molecules or atoms are vibrating faster.
These vibrating molecules and atoms collide and as a result of which heat is generated in a substance , more the collision of particles , higher is the thermal energy.
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the farm is a place where lot's of different__________and________live.goats have________that arch backward.the horns keep them___________.
horns insects animals protected
dog's are man's best friend.dogs eat ______to keep them energetic.dogs permanent__________are ________.a dogs teeth serve as _______and as tools for ________or________food
meat cutting powerful teeth weapon tearing
Answer:
plantsanimalshornsto protect it selfkaleliving with peoplescaring itspecialbite eatExplanation:
I know it's right, because this answer is from my self and I hope it's help to us. keep learning and God bless.
can someone tell me how to find moles in acid&base equations (simple explination pls)
Answer:
When the base neutralizes the acid, the number of moles of H+ = the number of moles of OH-. Therefore, the number of moles of H+ = 0.0125 moles. Every mole of HCl will produce one mole of H+; therefore, the number of moles of HCl = number of moles of H+. The concentration of the HCl is 0.25 M
Which of the following does NOT involve a physical change?
Answer:
Degradation of matter
Explanation:
Physical change is a temporary change.
Which of the following statements is true?
Select one:
a. All the answers are right
b. Aerobic and anaerobic bacteria don’t decompose organic matter
c. Aerobic bacteria produce bad smelling compounds
d. Anaerobic bacteria produce oxygen as one of their decomposition products
e. Anaerobic bacteria function in the absence of oxygen
What is the empirical formula of CoH1803? (4 points)
-O CH30
-C₂H50
-C₂H₂O
-O C₂H5O5
Answer:
-O CH30
Explanation:
My Head Is About To Explode
Seratonin is a neurotransmitter. The ratio of C atoms to N atoms is____
Answer:
5:1
Explanation:
The molecular formula of serotonin is C10H12N2O. Therefore, the ratio of C atoms to N atoms is 5:1, because you divide 10 and 2 by 2, and then you get 5:1.
A moon orbits in a roughly circular path around a planet with a mass of 8.6 x 1023 kg. The distance from the center of the moon to the center of the planet is 7.04 x 106 meters. Calculate the speed of the moon in m/s.
Explanation:
A moon orbits in a roughly circular path around a planet with a mass of 8.6 x 1023 kg. The distance from the center of the moon to the center of the planet is 7.04 x 106 meters. Calculate the speed of the moon in m/s.
Find the volume of 0.160 M sulfuric acid necessary to react completely with 75.0 g sodium hydroxide.
The volume of 0.160 M sulfuric acid necessary to react completely with 75.0 g sodium hydroxide is 0.15L
The reaction of sulphuric acid and sodium hydroxide is expressed as:
[tex]2NaOH + H_2SO_4 ==> Na_2SO_4 + 2H_2O[/tex]
Determine the moles of NaOH present
Molar mass of NaOH = 23 + 16 + 1 = 40g/mole
Given that mass of NaOH is 75.0g
Mole of NaOH = 75/40 = 1.875moles
Determine the number of moles [tex]H_2SO_4[/tex] needed to react with 1.875 moles NaOH
Moles of [tex]H_2SO_4[/tex] = [tex]\frac{1.875}{2} = 0.9375moles of H_2SO_4[/tex]
Recall that volume = Molar mass * number of moles
Volume of [tex]H_2SO_4[/tex] = 0.160 * 0.9375
Volume of [tex]H_2SO_4[/tex] = 0.15L
Hence the volume of 0.160 M sulfuric acid necessary to react completely with 75.0 g sodium hydroxide is 0.15L
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Ana was setting up a circuit to make a buzzer buzz. She didn’t have any wires, so she needed to find
something that had the same properties as wires. Which of the following would work for Ana’s circuit?
A. A steel knife
B. A wood chopstick
C. A plastic straw
D. A glass tube
Answer:
should be a or d, though im leaning towards d more. sadly can't narrow it down 100%. b nor c are correct since they are made out of wood and plastic which cannot allow electricity to pass by. copper and metal are effective conductors of electricity, which a steel knife and a glass tube is made out of.