Caffeine has the molecular formula, C8H10N4O2. What is the percent composition of caffeine?
Select one:
a) 33.33% C, 41.67% H, 16.67% N, and 8.33% O
b) 49.48% C, 5.19% H, 28.85% N, and 16.48% O
c) 25% C, 25% H, 25% N, 25% N, and 25% O
d) 27.92% C, 2.34% H, 32.56% N, and 37.19% O

Answer:

B. Unbalanced

Explanation:

I learned this in 8th grade.

:))) This is the right answer.

one mole of P weights about 31 grams

in one mole there are 6.022*10^23 atoms

we use the rule of threes

6.022*10^23atoms......weight..........31 grams

3.45*10^23 atoms.........weight...........x grams

x=(3.45*10^23*31)/6.022*10^23

x=106.95/6.022=17.76 grams

Answer:

Cl2, Chlorine molecule has a boiling point closest to that of argon.

This is because Chlorine is made up of discrete and simple molecules making up a simple molecular structure. The molecules associate through weak van der waal's forces of attraction hence low boiling point.

HCl has strong hydrogen bonds.

F2 is very small hence strong forces of attraction.

HF has strong hydrogen bonds

Answer:

2

Explanation:

Answer:

2H3[PO4] —> H4[P2O7] + H2O

Explanation:

2 M

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Unit 0

Aqueous Solutions

Step 1: Define

36.7 g CaF₂

300 mL H₂O

Step 2: Identify Conversions

Molar Mass of Ca - 40.08 g/mol

Molar Mass of F - 19.00 g/mol

Molar Mass of CaF₂ - 40.08 + 2(19.00) = 78.08 g/mol

1000 mL = 1 L

Step 3: Convert

Solute

Solution

Step 4: Find Molarity

Step 5: Check

Follow sig fig rules and round. We are given 1 sig fig as our lowest.

1.56677 M ≈ 2 M

The thermal energy (Q) needed : = 1882.8 J

Given

15g water from 25 °C to 50 °C

Required

The thermal energy (Q)

Solution

Heat can be calculated using the formula:  

Q = mc∆T  

Q = heat, J  

m = mass, g  

c = specific heat, joules / g ° C  

∆T = temperature difference, ° C / K  

Input the value :

Q = 15 g x 4.184 J/g°C x (50 °C- 20 °C)

Q = 1882.8 J

Mercury, Venus, Earth,Mars

Answer:

D: Mercury, Venus, Earth, Mars

Explanation:

Answer:

[tex]CH _{4}+ 2O _{2} → CO _{2} + 2H _{2}O[/tex]

for the balanced equation

[tex]from \: the \: equation \\ 1 \: mole \: of \: methane \: gives \: 1 \: mole \: of \: carbon \: dioxide \\ 7.4 \: moles \: of \: carbon \: dioxide \: will \: be \: given \: by \: (7.4 \times 1)moles \: of \: methane \\ = 7.4\: moles \: of \: methane \\ \\ since \: moles \: of \: oxygen \: double \: those \: of \: methane \\ moles \: of \: oxygen \: = 7.4\times 2 \\ = 14.8 \: moles \: of \: oxygen[/tex]

In case you don't know what Calcium Is:

a silver-white divalent metal, occurring combined in limestone, chalk, gypsum, etc., occurring also in vertebrates and other animals, as a component of bone, skeletal mass, shell, etc., and as a necessary element in nerve conduction, heartbeat, muscle contraction, and many other physiological functions.

Calcium can be found:

Calcium is a soft white chemical element found in bones and teeth

answer:

Using the definition..calcium may be used in the human body by nerve conduction, heartbeat, muscle contraction, and many other physiological functions.

·.•·°.hope this helped!!!·.•·°.

Answer:

The five basic types of chemical reactions are combination, decomposition, single-replacement, double-replacement, and combustion. Analyzing the reactants and products of a given reaction will allow you to place it into one of these categories. Some reactions will fit into more than one category.

Answer:

SEE BELOW HEHEHE YOURE WELCOME

Explanation:

Types of Chemical Reactions

The purpose of this experiment was to make observations of the reactants and products and then later use this information to write a balanced chemical equation. My question before this experiment was how will the reactants affect the products. The hypothesis I made before this experiment was that based off of the materials being used, a gas will form, and so will a solid. I still do not know what the variables are in this experiment such as the independent or dependent.

The materials used in this experiment were:

Bunsen Burner

Striker

Tongs

Test Tube

Test Tube Rack

Test Tube Holder

Spatula

Sand Paper

Transfer Pipette

Tweezers

Evaporating dish

The substances used in this experiment were:

Copper wire

Sodium carbonate

Copper sulfate

Potassium iodide

Lead nitrate

Zinc

In this experiment we started off by placing about 20 drops of copper sulfate solution into a test tube and then put zinc into the test tube and watched it as single replacement occurred and zinc sulfate was the product.Next we put 10 drops of potassium iodide into another test tube and 10 drops of lead nitrate into a separate test tube. Then we added the lead nitrate into the potassium iodide and watched as double replacement occurred as lead iodide formed and potassium nitrate formed as well. Next, I sanded down a piece of 3-inch copper wire until it was shiny and watched as combustion and synthesis occurred when we held the piece of copper over a bunsen burner. Copper oxide was found formed on the wire. The other reactant in this equation was oxygen gas. After this, we used a small spatula to place about half an inch of sodium carbonate in a clean test tube and then heated the tube over the flame and watched as decomposition took place and carbon dioxide was released. The reaction was a gas formation and 2 products were formed. This was the lab experiment.

Based on this experiment and my hypothesis made beforehand, my hypothesis was almost correct other than the fact that I did not think that color change would occur so I was surprised by that. But other than that, my data did support my hypothesis showing that a gas and a solid were formed in two different ways. One error I made was when I was recording the data in a data table, I did not notice a color change at first but I rewatched the experiment. One way that I could have improved this lab investigation was pay more attention to the precise details because those make a huge difference.

1. Heat needed = 293.25 J

2. Time to leave : 2 s

Given

1.5 g H2

Cp H2 = 14.27 g/J C

Δt= 13.7

Required

1. Heat needed

2. Fridge time

Solution

1. Heat can be formulated :

Q = m.c.Δt

Q = 1.5 x 14.27 x 13.7

Q = 293.25 J

2. Heat decreases = 150 J/s, so for 293.25 J :

[tex]\tt t=\dfrac{293.25~J}{150~J/s}=1.955~s\approx 2~s[/tex]

Answer: [tex]1.25dm^3[/tex] of unreacted oxygen is left.

Explanation:

To calculate the moles :

[tex]\text{Moles of solute}=\frac{\text{given volume}}{\text{Molar Volume}}[/tex]    

[tex]\text{Moles of} CO_2=\frac{3.60dm^3}{22.4dm^3}=0.161moles[/tex]

[tex]\text{Moles of} O_2=\frac{7.25dm^3}{22.4dm^3}=0.324moles[/tex]

[tex]C_3H_8(g)+5O_2(g)\rightarrow 3CO_2(g)+4H_2O(l)[/tex]  

According to stoichiometry :

3 moles of [tex]CO_2[/tex]  = 5 moles of [tex]O_2[/tex]  

Thus 0.161 moles of [tex]CO_2[/tex] =[tex]\frac{5}{3}\times 0.161=0.268moles[/tex]  of [tex]O_2[/tex]

moles of [tex]O_2[/tex]  left unreacted = (0.324-0.268) = 0.056

Volume of [tex]O_2[/tex] left unreacted = [tex]moles\times {\text {Molar volume}}=0.056mol\times 22.4dm^3/mol=1.25dm^3[/tex]

Thus [tex]1.25dm^3[/tex] of unreacted oxygen is left.

Answer:

heat and large amount of surface area

Explanation:

the heat and surface area allows the iron in the wool to combine with oxygen. by doing this it increases the mass of the steel wool

The mass of steel wool increases after burning because it reacts with oxygen in the air, leading to the formation of iron oxide.

After burning, steel wool's bulk grows due to the oxidation process. Iron oxide, also referred to as rust, is created when steel wool burns when it comes into contact with oxygen from the air.

The steel's iron reacts chemically with the oxygen to create iron oxide, which is heavier than the original iron. As a result of going through the oxidation process and becoming iron oxide, steel wool gains bulk.

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Answer:

None of the Above

Explanation:

The Athenosphere is able to flow but is also part of the UPPER LAYER meaning none of these choices are correct

Answer:

CH4 =Methane (one atom of carbon and four atoms of hydrogen). It is a group-14 hydride and the simplest alkane and is the main constituent of natural gas.

202= Oxygen.

CO2= Carbon dioxide (one Carbon atom and two oxygen atom)

2H20= 2H2O means two molecules of water(H2O)

CH and CO2= the main difference between CO2 and CO2e is that CO2 only accounts for carbon dioxide, while CO2e accounts for carbon dioxide

CO= Carbon monoxide (CO), a colorless, odorless, and tasteless gas. Carbonyl group, composed of a carbon atom double-bonded to an oxygen atom: C=O.

H2O = water ( one hydrogen atom and two oxygen atoms)

Answer:

1.p=mV................

Answer: [tex]2Ag^{+}(aq)+CO_3^{2-}(aq)\rightarrow Ag_2CO_3(s)[/tex]

Explanation:

Spectator ions are defined as the ions which does not get involved in a chemical equation or they are ions which are found on both the sides of the chemical reaction present in ionic form.

The given chemical equation is:

[tex]2AgF(aq)+Na_2CO_3(aq)\rightarrow Ag_2CO_3(s)+2NaF(aq)[/tex]

The complete ionic equation is;  

[tex]2Ag^{+}(aq)+2F^-(aq)+2Na^+(aq)+CO_3^{2-}(aq)\rightarrow Ag_2CO_3(s)+2Na^+(aq)+2F^-(aq)[/tex]

The ions which are present on both the sides of the equation are [tex]Na^+[/tex] and [tex]F^-[/tex] and are not involved in net ionic equation.

Hence, the net ionic equation is :

[tex]2Ag^{+}(aq)+CO_3^{2-}(aq)\rightarrow Ag_2CO_3(s)[/tex]

Answer:

C. ribosomes

Explanation:

Both prokaryotic and eukaryotic cells contain certain structures called ORGANELLES. They possess some in common and others are not found in one or the other. According to this question, a small, free-floating organelle made from nucleic acid and amino acid is found in both eukaryotes and prokaryotes. This organelle is RIBOSOMES.

Ribosomes are organelles responsible for the synthesis of protein in both eukaryotes and prokaryotes. They can be found free-floating or attached to endoplasmic reticulum. Ribosomes are predominantly made of RNA (nucleic acid) and proteins i.e. Ribosomal RNA (rRNA) and proteins is their structural constituent. Hence, the organelle in this question is RIBOSOME.

Explanation:

The molecules in the solute and solvent are only able to make dispersion forces with each other (as they aren't both polar). This only releases very little energy. Therefore overall, more energy is required than released and hence they won't mix.

34.5 grams

because the mass would multiply and do mass things

Answer: Mg and Ca

Explanation:

In the modern periodic table, Mg and Ca are the last pair of elects for which Newlands' Law of Octaves would hold true.

Law of Octaves is the generalization that was made by Newlands. It states that when chemical elements are arranged based on their increasing atomic weight, then the ones that have the same chemical and physical properties will occur after an interval of seven elements.

In such a case, every eighth element will have identical properties when the elements in the periodic table are arranged based on their atomic masses.

Based on the above information, Magnesium (Mg) has an atomic number of 12 while Calcium (Ca) has an atomic number of 20. Therefore, the elements follow the law of Octaves as they have a difference of 8 in their atomic numbers.

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Answer:The alpha particles that were fired at the gold foil were positively charged. ... These experiments led Rutherford to describe the atom as containing mostly empty space, with a very small, dense, positively charged nucleus at the center, which contained most of the mass of the atom, with the electrons orbiting the nucleus.

Explanation:Thomson's cathode ray experiment and Rutherford's gold foil experiment. ... that the atom is mostly empty space with a tiny, dense, positively-charged nucleus. ... mass of each particle was much, much smaller than that of any known atom. ... Why did Thomson conclude that electrons could be found in atoms of all elements?

Answer:

Ions are atoms that have either gain or lose electrons from the neutral atom.

A loss of electrons results in a positive ion, called a cation, a gain of electron results in a negative ion called an anion.

Ionic compounds are formed by the combination of a cation and anion, or metal + nonmetal.

When naming ionic compounds, name the cation first, and the anion second, changing the ending to ide.

Explanation:

Hope it helped!

Answer:

• [ lost ] or [ gained ]

• [ cation ], [ anion ]

• [ metal ] + [ non-metal ]

• [ cation ] and the [ anion ] to [ compound with suffix "ide" or "ode" ]

Answer:

cellular respiration takes place

Answer:

sunlight is absorbed to produce energy

Sorry if its worng

Answer:

B - migration of animals

Weathering of rocks will contribute most to the development of soil.

Weathering is the process in which rock particles are broken down into

smaller parts.

The smaller parts results in soil formation and is carried out through

physical and chemical factors.

The physical factors include:

The chemical factors include:

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Answer:

Each person has their own skill level. The smaller ramps are less risky and are for more beginner to amateur skaters. The larger ones are very risky but can be very nice if a person does tricks with it. They are geared for more experienced skaters. Different ramps allow for more people to hace fun skating without the risk of injury...

Answer:

B. fermentation

Explanation:

this process is called lactic fermentation where a molecule of gluclose(C6H12O6) is turned into two molecules of pyruvate(C3H4O3) and the pyruvate molecules are turned into lactic acid(C3H6O3) from this process two molecules of ATP are resulted

Answer:

Fermentation

Explanation: I took the test

Answer:

Your answer would be 2

Explanation:

The electron configuration for titanium is 1s22s22p63s23p63d24s2, according to the Jefferson Lab website. The element's 22 electrons are arranged in four energy levels surrounding the nucleus of the atom.

Electrons orbit the nucleus in energy levels, which are also called shells. These energy levels contain sub-shells, or orbitals, each of which holds a certain number of electrons. By looking at the electron configuration for titanium, it is possible to determine how its electrons are arranged.

There are two electrons in the s orbital of the first energy level. The second level contains eight electrons, with two in the s orbital and six in the p orbital. There are electrons in three orbitals of the third energy level. There are two in the s orbital, six in the p orbital and two in the d orbital. The fourth energy level has two electrons in its s orbital.

The study of chemicals and bonds is called chemistry.

The correct answer is 2.

The representation of electrons in the shell is called electronic configuration.  The electron configuration for titanium is [tex]1s^22s^22p^63s^23p^63d^24s^2[/tex],

Electrons orbit the nucleus in energy levels, which are also called shells.

These energy levels contain as follows:-

Each of which holds a certain number of electrons. By looking at the electron configuration for titanium, it is possible to determine how its electrons are arranged.  There are two electrons in the s orbital of the first energy level. The second level contains eight electrons, with two in the s orbital and six in the p orbital.

There are electrons in three orbitals of the third energy level. There are two in the s orbital, six in the p orbital, and two in the d orbital. The fourth energy level has two electrons in its s orbital.

Hence, the correct answer is A that is 2.

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