Answer:
To calculate the percent composition, we need to know the masses of C, H, and O in a known mass of C9H8O4. It is convenient to consider 1 mol of C9H8O4 and use its molar mass (180.159 g/mole, determined from the chemical formula) to calculate the percentages of each of its elements:
%
C
9
mol C
×
molar mass C
molar mass
C
9
H
18
O
4
×
100
=
9
×
12.01
g/mol
180.159
g/mol
×
100
=
108.09
g/mol
180.159
g/mol
×
100
%
C
60.00
%
C
which of the following is a pure compound A. ethanol B. petrol C. steel D. tap water
Answer:
D. tap water
keep on learning!
Answer: ethanol
Explanation: as it is a pure compound and can sometimes be a mixture while all the rest are mixtures.
Number of energy levels containing electrons in iodine.
Answer:
First Energy Level: 2
Second Energy Level: 8
Third Energy Level: 18
Fourth Energy Level: 18
Element: Iodine
Group: 17
No. of electrons/shell: 2, 8, 18, 18, 7
One mole of gas at STP occupies a volume of
a 22.0L
b 20.0L
c 224
d 25.0 L
Answer: 22.4 L
Explanation:
the constant for one mol of gas at STP is always 22.4 L and this constant is used in equations when converting from L to mol or mol to L
hope this helps :)
what is the best way to memorize the periodic table
Answer:
- breaking it down into sections
-learn the element song
-use colors to learn the element groups
Explanation:
what also may help which is time-consuming is writing it out over and over if not I would prefer to learn the song it may seem childish a little but it will help in the long run.
Answer:
I personally have a method for learning stuff like this.
Try going one at a time, and ever once in awhile. Like memorize the first element, then the one next to it [in whichever order you please]
Ex: memorizing 1-10
1.. 1,2.. 1,2,3.. 1,2,3,4..
And then repeat that row until you can recite it almost without hesitation, then move onto another line.
This works for both placement memorization and element name.
someone helppp pleaseee
Answer:
Top LineNebula → Average Star → Red Giant → Planetary Nebula → White Dwarf
Bottom LineNebula → Massive Star → Red Supergiant → Supernova → Neutron Star or Black Hole (for the second box)
-TheUnknownScientist 72
Answer:
top- nebula average star, reg giant, planetary nebula, white dwarf
bottom- nebula, massive star, red supergiant, supernova, neutron star-black dwarf
A buffered solution has a pH of 7.5. What would happen to the pH if a small
amount of acid were added?
A. The pH would stay at about 7.5.
B. The pH would become less than 7.0.
C. The pH would increase to greater than 7.5.
D. The pH would decrease to 7.0.
For this buffered solution with a pH of 7.5, B. The pH would become less than 7.0.
What is pH?In Science, pH literally means the power of hydrogen ions and it can be defined as a measure of the molar concentration of hydrogen ions in a particular solution. Thus, it is typically used to specify the acidity, neutrality or basicity of any chemical solution.
On a pH scale, a solution with a pH of 7 is neutral while a solution with a pH below 7 is acidic and it's basic (alkaline) when its pH is above 7.
In this scenario, a buffered solution with a pH of 7.5 would become less than 7.0 when a small amount of acid is added to it.
Read more on power of hydrogen here: https://brainly.com/question/24242819
When you measure the temperature of hot soup you're measuring the
Answer:
Amount of Thermal Energy
Explanation:
One hundred points to whoever answers first and brainleist.
Is carbon ever lost in the cycle? Is it constantly conserved 100% of the time? What about mass and energy? Are mass and energy ever lost in a continuous cycle?
Answer:
Carbon is never really lost in the cycle. Carbon is constantly added and removed from the carbon cycle. Example..... Carbon dioxide is removed from the air by photosynthesis and dissolving in the ocean buttttt at the same time it is added to the atmosphere by respiration and combustion.
As for the mass and energy....the Law of Conservation of Matter states that matter cannot be created or destroyed.
Answer:
no its not ever lost
Explanation:
7. Justify why these ions do not exist under normal conditions.
(a) K2+
(b) 0-
K^+ can not exists because electrons are removed from an inner shell. The ion O^- can not exist because it will have an incomplete octet.
Stability of ionsIons are species that contain a positive or a negative charge. When we consider the electron configuration of ions, we can deduce the stability of the ion.
Let us consider the electron configuration of K^2+ which is 1s2 2s2 2p6 3s2 3p5 which means that the second electron is to be removed from an inner shell which implies greater energy expenditure hence it does not exist.
In the case of O^-, involves the formation of an ion with an incomplete octet which is not possible.
Learn more about ions: https://brainly.com/question/1782326
12 = 3X X =
7X = 57 X =
11X = 27.7 X =
Answer:
1. [tex]x=4[/tex]
2.[tex]x=\frac{57}{7}[/tex]
3.[tex]x=\frac{27.7}{11}[/tex]
Explanation:
Given the following questions:
[tex]12=3x[/tex]
[tex]7x=57[/tex]
[tex]11x=27.7[/tex]
In order to find the answers to these questions, we have to recognize that in order to isolate the variable we need to divide on both sides.
Question one:
[tex]12=3x[/tex]
[tex]\frac{3x}{3} =\div3[/tex]
[tex]12\div3=4[/tex]
[tex]x=4[/tex]
Question two:
[tex]7x=57[/tex]
[tex]\frac{7x}{7} =\div7[/tex]
[tex]57\div7=8.14285714=\frac{57}{7}[/tex]
[tex]x=\frac{57}{7}[/tex]
Question three:
[tex]11x=27.7[/tex]
[tex]\frac{11x}{11} \div11[/tex]
[tex]27.7\div11=2.51818182=\frac{27.7}{11}[/tex]
[tex]x=\frac{27.7}{11}[/tex]
Hope this helps.
Assume that there is a puddle that contains 12.0 kg of water and it froze outside since it is -1°C. The
custodian threw 6.00kg of salt (NaCl) onto the puddle and we assume that all the water melted and the
sodium chloride completely dissolved into the water. What temperature would it need to be to re-freeze
that solution?
The temperature that must be to freeze the solution would be -21.1 ° C.
How to calculate the freezing temperature of this solution?To calculate the freezing temperature we must take into account the following information.
Solution with a salt concentration of 10% is frozen at -6°CSolution with a salt concentration of 20% is frozen at -16°CSolution with a higher concentration is frozen at -21.1°CAccording to the above, it can be inferred that the puddle has a 50% concentration of salt because they had 12 kg of water and 6 kg of salt.
So the lowest freezing temperature would be 21.1°C because the puddle is 50% concentrated.
Note: This question is incomplete because there is some missing information. Here is the missing information:
A 10% salt solution freezes at about 20°F (-6°C), and a 20% solution freezes at 2°F (-16°C).The lowest freezing point obtainable for salt solutions is −21.1 °CLearn more about freezing in: https://brainly.com/question/14131507
Is this correct?? please help
Yes it is but I have to check so wait
A 6. 0 L container holds a sample of hydrogen gas at 150 kPa. The pressure increases to 2 atm and the temperature remains constant. What will the volume be? 0. 22 L 0. 44 L 2. 26 L 4. 50 L.
The volume of the container will be 0.45L.
What is Boyle's law?This law states that the product of volume and its pressure is constant for any gas.
Given, the Volume 1 of container 6.0L
V2 =?
Pressure 1 is 150 kPa
Increased pressure 2 is 2 atm
Temperature is constant.
By Boyle's law:
P1V1 = P2V2
[tex]150 \times 6 = 2\times V2 = 450[/tex]
Thus, V2 = 0.45 L.
Learn more about volume, here:
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Q1: What are some similarities in the way these insects produce sounds and the way instruments produce sounds?
Animals can produce sound by vibration of air in their vocal chords as in flutes and trumpets.
Animals can also produce sound by clicking body parts together as cymbals and tambourine.
What is sound?Sound is a form of energy that produces a vibration of air particles which can be heard by the ear.
Sound can either be produced by
wood,wind ,string,brass or percussion instruments.Animals such as dogs produce sound be making are to vibrate in their vocal chords as in wind instruments like trumpets and flutes.
Animals such as some birds can also produce sound by clicking body parts together just as in cymbals and tambourine.
Learn more about sound at: https://brainly.com/question/9349349
Why are the orbits of planets only nearly circular and not perfectly circular?
Answer:
As the planets mass distribution around the sun changes, the point which the planets orbit changes slightly, disrupting any circular orbits
Explanation:
Answer:
because postulates that the force of gravity weakens as the square of the distance between the two objects
Explanation:
pls mark as brailliest
35 points!!! please help me
Answer:
give answer of following questions and get 35 points.
Pure maple syrup has a high sugar content. Its composition is 70% sucrose (C12H2011). If you heat maple
syrup what will happen to its viscosity?
answer : It will decrease
Answer:
it will decrease
Explanation:
Answer:
A. it will decrease
Explanation:
trust
How many moles of atoms are in 454 g of lead?
Answer:
207.2
Explanation:
One mole of lead weighs 207.2 g. Thus, number of moles in 454 g of lead is determined by dividing the given mass by atomic mass that is ., 2.19 moles.
What is lead ?Lead is 82nd element in periodic table. It is in 14th group. Lead is classified among non-metals but it is a heavy metal in nature. Lead have many naturally stable isotopes of which two are radioactive.
A substance containing 6.02 × 10²³ atoms is called its one mole. This number is called Avogadro number. Hence, one mole of every elements contains Avogadro number of atoms. The mass of one mole of an element is called its atomic mass.
Atomic mass of lead (Pb) = 207. 2 g/mol
thus, number of moles in 454 g of Pb = given mass/atomic mass
no.of moles = 454 /207.2 = 2.19 moles.
Therefore, the number of moles of Pb in 454 g is 2.19.
Find more on lead:
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#SPJ2
Explain why hydrogen, not sodium, is formed at the cathode.
Answer:
because of its electro affinity
Explanation:
it is electro positive
Question 10(Multiple Choice Worth 5 points)
(04.05 LC)
During which of the following processes would carbon most likely be required?
O Breaking of rocks
O Generation of electricity
O Making of glucose
O Running of cars
I’m lost
Answer:
O Generation of electricity
Explanation:
because the others dont make sense to me and tbh carbon is used everyway and everywhere
16. For the reaction below, A) calculate the total bond energy, using the equation: Reactant energy - product energy = total energy.
Answer:
C=C divided by the co effiecient 11 would make the denominator of the photosynthesis equal 11 over 5 making this problem a polywhirl which wouldnt matter in the sense of the quake in energy change so thus making the answer 728 kJ/mol
Explanation: back in my day
Why should we turn of the main switch when there is a short circuit in your home
Explanation:
It is the safest way to shut down a circuit by switching off the main switch. If you haven't switched off the main switch and started directly working on it you are open to all kinds of harm one being electrocuted (since high current flows through the electric circuits due to the short circuit or overloading, the fuse wire heats and melts down) other methods of avoiding being electrocuted after turning the main switch off is by using insulating tools such as tools made of wood.
If 20 grams of NaF are used to make a 3.0 Liter solution. What is the concentration
(Molarity) of the solution?
7M
0.23 M
0.16 M
62 M
Answer: 0.16 M
Explanation:
molarity is a way to measure the concentration of solutions, the equation is the amount of solute in mol / liter of solution:
mol (solute) / L (solution)
the first thing you want to do is convert grams to moles:
20g NaF • 1 mol
———— = 0.47632464 mol
41.98817 g (molar mass of NaF)
then you just want to follow with the rest of the equation:
0.47632464 mol NaF / 3.0 L = 0.15877488 or 0.16 M (sigfigs)
hope this helps :)
How many protons, neutrons, and electrons does cobalt-60 have? Is this a "normal" isotope of cobalt and how do you know?
Which equation below is an example of a single-replacement reaction?
A.6CO2(g) + 6H2O(l) → C6H12O6(aq) + 6O2(g)
B.H2SO4(aq) + 2NaOH(aq) → Na2SO4(aq) + 2H2O(l)
C.Ca(OH)2(s) Δ→ CaO(s)+ H2O(l)
D.Zn(s) + 2HCl(aq)→ ZnCl2(aq) + H2(g)
The equation that depicts a single replacement reaction would be: Zn(s) + 2HCl(aq)→ ZnCl2(aq) + H2(g)
Single replacement reactionsThey are also known as single displacement reactions.
They are reactions in which one element takes the place of another in a compound. That is, one element replaces another in a compound.
Looking at all the reactions from A - D, one can see that the only reaction that exemplifies a single replacement reaction is D.
Here, Zn replaced H in HCl.
More on single replacement reactions can be found here: https://brainly.com/question/13328989
Someone help out plz?
1)
Create a new species of a plant and an animal that is well-suited
for living in the tundra ecosystem. Make a drawing of each, then
list and describe three characteristics that help each organism
thrive in its environment. Don't forget to name your plant and
animali
An organism that is well-suited for living in the tundra ecosystem should ideally be adapted to cold conditions. These organisms should take advantage of the growing season and survive in low humidity conditions.
What is a tundra ecosystem?Tundra is a special type of ecosystem characterized by low temperatures, a short growing season, and low humidity.
In consequence, any organism (either plant or animal) living in a tundra should exhibit adaptation to these climate conditions.
For example, plants in the tundra are able (i.e., they are adapted) to perform photosynthesis in extremely cold temperature conditions.
Learn more about the tundra here:
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What does this piece of evidence best support? the collision theory the Maxwell-Boltzmann distribution the effect of pressure on reaction rates the effect of temperature on reaction rates.
Particles are the smallest units of any state of matter that moves in a medium due to various factors. The particle movement best supports the collision theory.
What is collision theory?In a reactant, the particles move and collide with each other resulting in some amount of change and the collision between the atoms and the molecules are necessary for a chemical reaction to occur.
This theory of collision is used for the prediction of the rate of the reaction to occur and the chemical changes occurring in a gas or the reactant. This aids in understanding the rate of reaction occurring in a system.
The collision of the particles is proportional and related to the rate of the reaction. The amount of the concentration and their collision affects the rate at which the chemical change will occur.
Therefore, option A. the collision theory is supported here.
Learn more about collision theory here:
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What is the percentage of oxygen in carbon dioxide?.
Answer:
72.7%
Explanation:
The first thing you need to do here is to figure out the mass of oxygen in
1 mole of carbon dioxide. To do that, you must use the compound's molar mass.
Now, carbon dioxide has a molar mass of 44.01 g mol−1. This means that 1 mole of carbon dioxide has a mass of 44.01 g. Oxygen has a molar mass of 16.0 g mol−1, so 1 mole of oxygen atoms has a mass of 16.0 g.
This means that if you take 44.01 g of carbon dioxide, you know for a fact that it will contain: 32g oxygen.
This means that 100 g of carbon dioxide will contain:
100gCO2 × 32gO2 / 44.01gCO2 = 72.7 g Oxygen
Therefore, carbon dioxide has a percent composition of 72.7% oxygen, i.e. for every 100 gof carbon dioxide you get 72.7 g of oxygen.
Use the equation below to answer the following questions:
2 C4H10 + 13 O2 → 8 CO2 + 10 H2O
A) How many moles of O2, are needed to react with 25.9g of C4H10?
B) If 22.2 g of CO2 is produced, what mass of water is also produced?
C) How many moles of oxygen gas are needed to produce 0.30 moles of carbon dioxide?
Answer:
A (2.475 mol O2). B (11.35 g) C. (.4875 mol O2)
Explanation:
A.
convert 25.9 g C4H10 (68g/mol) to mol. --> .3808 mol
then use mole ratios from equation
.3808 mol C4H10 x (13 mol O2 / 2 mol C4H10). ---> 2.475 mol O2
B.
convert 22.2 g CO2 (44g/mol) to mol. ---> .5045 mol
.5045 mol CO2 x (10 mol H2O / 8 mol CO2) ----> .6306 mol H2O
convert .6306 mol to g ----> 11.35 g
C.
.3 mol CO2 x (13 mol O2 / 8 mol CO2) ---> .4875 mol O2