Answer:
C₁₅N₃H₁₅
Explanation:
Follow the sequence ...
%/100wt => grams/100wt => moles => mole ratio => reduce mole ratio (divide by smaller mole value) => empirical ratio.
Note: If the above calculation comes out with a fraction (for most textbook problems) do the following:
--.25 => multiply empirical ratio by 4
--.50 => multiply empirical ratio by 2
--.75 => multiply empirical ratio by 4
Or, if initial data is given in grams, convert to %/100wt. (example at end of problem)
This Problem:
%/100wt. grams moles =mass/formula wt.
%C = 75.95% => 75.95g => 75.95g/12.0107g·mol⁻¹ = 6.325 mole OS
%N = 17.72% => 17.72g => 17.72g/14.0067g·mol⁻¹ = 1.2651 mole N
%H = 6.33% => 6.33g => 6.33g/1.00794g·mol⁻¹ = 6.28 mol H
(∑ = 100% | assume 100g cpd => ( grams => 100g compound would contain 75.95g C, 17.72g N & 6.33g H )
=> mole ratio => C : N : H => 6.3235 : 1.2651 : 6.28
=> reduce mole ratio ( divide by smaller mole value ) ...
=> 6.3235/1.2651 : 1.2651/1.2651 : 6.28/1.2651 => empirical ratio is => 5:1:5
empirical formula => C₅NH₅
empirical formula wt. = 5C + 1N + 5H = 5(12) + 1(14) + 5(1) = 79
=> molecular ratio (n) => molecular wt (given) = N · empirical formula wt
=> N = molecular wt / empirical wt = 240/79 = 3
∴ Molecular Formula is => C₅NH₅ X 3 => C₁₅N₃H₁₅
________________________________________
EXAMPLE: Empirical Formula Problem with initial data in grams:
Assume an oxide of Osmium (compd wt) = 2.89 grams contains 2.16 gram Osmium, what is the empirical formula?
Use given mass values to calculate %/100wt then use the sequence
% => grams => moles => reduce => emp. ratio => emp. formula
%Os = 2.16g/2.89g x 100% = 74.74%
%Oxy = [(2.89g -2.16g)/2.89] x 100% = 25.26% or use 100% - 74.74% = 25.26%
% => g => moles => reduce => emp formula
%Os = 74.74% => 74.74g => 74.74g/190.23g·mol⁻¹ = 0.3929 mol Os
%Oxy = 25.26% => 25.26g => 25.26g/16g·mol⁻¹ = 1.5788 mole Oxy
Reduce mole ratio (divide by smaller mole value) => empirical ratioo
=> Os:Oxy => 0.3929/0.3929 : 1.5788/0.3929 = 1 : 4
=> Empirical Formula => OsO₄
In fossil comparisons, it helps to know about similar:
living things
questions
incomplete remains
Answer:
Fossils tell us when organisms lived, as well as provide evidence for the Fossils are the preserved remains or traces of animals, plants, and other organisms from the past. Fossils, by comparing the anatomies of both modern and extinct species, allows scientists to study the skin, hair, and organs of ancient creatures.
Explanation:
write the chemical equation of the reaction with a change in colour
Answer:
(i) Change in colour (ii) Change in temperature (iii) Formation of precipitate
Explanation:
(i) Change in colour: Reaction between lead nitrate solution and potassium iodide solution. Pb(NO3)2(aq)+2KI → PbI2(s)+2KNO3(aq) In this reaction, colour changes from colourless to yellow. (ii)Change in temperature: Action of dilute sulphuric acid on zinc. Zn(s) + H2SO4(aq) → ZnSO4(aq) + H2 In this reaction, heat is evolved (iii) Formation of precipitate: Action of barium chloride on sodium sulphate. BaCl2(aq) +Na2SO4(aq) → BaSO4(s) +2NaCl(aq) BaSO4(s)
A fat is composed, in part, of long chains of carbon and hydrogen. This fat as a molecular
mass of 847 grams/mole and an empirical formula of C9H170. Determine the molecular
formula.
Answer:
[tex]C_{54}H_{102}O_6[/tex]
Explanation:
Hello!
In this case, since the molar mass of the empirical formula is:
[tex]MM_{empircal}=9*12.01+17*1.01+16.00=141.26g/mol[/tex]
Thus, the ratio of the molecular to the empirical formula is:
[tex]\frac{847g/mol}{141.26g/mol} =6.0[/tex]
Thus, the molecular formula is six times the empirical formula:
[tex]C_{54}H_{102}O_6[/tex]
Best regards!
6. Elements in column (group) 18 (8A) are called the________ and the outermost electrons are found in
the p sublevel. Color these elements a different color and reference this group on the legend.
Answer:
Noble gases
Explanation:
Noble gases have filled electron shells (group 18=8 electrons) and are all odorless, colorless, monatomic gases with very low chemical reactivity.
Which molecular compound is composed of the greatest number of atoms?
A. Carbon Dioxide
B. Dinitrogen Monoxide
C. Potassium Phosphide
D. Sodium Chloride
Answer:
Answer:
Potassium Nitride is composed of the greatest number of atoms.
Explanation:
find the number of atoms present in each compound we will write down their molecular formulas and then we will add up the number of atoms present in them.
A: Dinitrogen Monoxide:
Chemical formula of Dinitrogen Monoxide is N₂O. Therefore, it contains two atoms of Nitrogen and one atom of oxygen Hence, in total it contains 3 atoms.
B: Sodium Chloride:
Chemical formula of Sodium Chloride is NaCl. Therefore, it contains one atom of Sodium and one atom of Chlorine Hence, in total it contains 2 atoms.
C: Potassium Nitride:
Chemical formula of Dinitrogen Monoxide is K₃N. Therefore, it contains three atoms of Potassium and one atom of Nitrogen Hence, in total it contains 4 atoms.
D: Carbon Dioxide:
Chemical formula of Carbon Dioxide is CO₂. Therefore, it contains one atom of Carbon and two atoms of Oxygen Hence, in total it contains 3 atoms.
Explanation:
Connor turns on a hair dryer to style his hair in the morning. Which choice identifies all of the energy transformations in the system?
electrical -- heat sound, and motion
electrical -- sound and motion
heat-electrical and sound
heat and sound -motion
Answer:
It is electrical → heat, sound, and motion
because a hair dryer makes heat to dry your hair and sound is the blowing and motion is how it goes
Explanation:
Answer:
A
Explanation:
electrical -- heat sound, and motion
What is geberal formula for alkane?
Answer:
CnH2n+2
Explanation:
Alkane have double and two atoms of hydrogen than carbon atoms
Like C4H10
n = 4
CnH2n+2
C4H2×4+2
C4H10
read carefully and do this questions all part all questions if someone do this questions I will make you brainly and give you thanks.
Answer:
2a. Calcium chloride
2b.hydrochloride acid
2c. water molecules
2d.hydrochloric acid
2e.carbon dioxide
Explanation:
CaCO3+2HCl＝CaCl2+CO2+H2O
When Earth’s Plates shift the result is a(n)______.
Answer:
An earthquake could occur.
Answer:
The correct answer is (lava)
Explanation:
Youre welcome
When the plates move they collide or spread apart allowing the very hot molten material called lava to escape from the mantle. When collisions occur they produce mountains, deep underwater valleys called trenches, and volcanoes.
What does it mean for heat to be transferred by thermal conduction?
Answer:
thermal energy
Explanation:
Thermal conduction is the diffusion of thermal energy (heat) within one material or between materials in contact. The higher temperature object has molecules with more kinetic energy; collisions between molecules distributions this kinetic energy until an object has the same thermal energy throughout.
Answer:
energy is transferred when one molecule collides with another.
Explanation:
aP33x
GIVING BRAINLIEST AND 20 POINTS
Which number represents precipitation on the hydrologic cycle diagram?
1
2
3
4
Answer:
Number three, because precipitation is rain, which comes from cumulonimbus clouds. Precipitation happens when clouds have accumulated enough evaporated water for the cloud to get heavy and need to get rid of some of the water, which it does through condensing the water and then delivering it as rain.
Hope this helps! Have a wonderful day! (Please give me brainliest and thank you!)
:)
Explain three types eye protection and their appropriate uses
Answer:
safety glasses, safety goggles, face shield, they protect your eyes from harmful liquids, bright lights
A) Calculate the vapor pressure of a 7% by mass benzaoic acid in ethanol solution at 30°C. The vapor pressure of pure ethanol at this temperature is 13.40 kPa. ( assume a 100 g of solution)
B) Calculate the boiling point of the solution above
Answer:
the answer is C
Explanation:
an alloy is a metal that has?
An alloy always has two or more elements/metals in it. An alloy always has at least metal in it.
Steels have iron and carbon in it. Bronze is copper and tin, or aluminum, or manganese, or zinc. German silver isn't silver at all and contains copper, zinc, and nickel.
Hope this helps!
4)
On a hot day, your friend brings you some iced tea to cool off. Only, its unsweetened. You add sugar, but it just does not dissolve
fast enough. Which procedure would speed up the dissolving process?
A)
Add the sugar in the dark.
B)
Add larger crystals of sugar, or sugar cubes.
C)
Take the tea up to the top of a close mountain.
D)
• Take out the ice and stir it up outside where it is warmer.
Answer: D)
• Take out the ice and stir it up outside where it is warmer.
Explanation:
Answer:
thank you! I made it to an 100% on USA test prep...
the answer is: Take out the ice and stir it up outside where it is warmer.
Explanation:
I have a lot of rain last night when I go to bed. Stay safe!
What size volumetric flask would you use to create a 0.50 M
solution using 10.00 g of CaBr2
Answer:
Explanation:
First convert the grams of Calcium Bromide to moles by using the atomic weight. Then use the formula for molarity, which is moles per liter.
CaBr2 = 199.9 g/mol
10/199.9 = 0.05 moles of CaBr2
[tex]0.5M=\frac{0.05mol}{x}[/tex]
x = 0.1L or 100mL
As illustrated, the below manometer consists of a gas vessel and an open-ended U-tube containing a nonvolatile liquid with a density of 0.993 g/mL. The difference in heights of the liquid in the two sides of the manometer is 32.3mm when the atmospheric pressure is 765 mm Hg. Given that the density of mercury is 13.6 g/mL, the pressure of the enclosed gas is ________ atm. Group of answer choices
Answer:
1.01atm is the pressure of the gas
Explanation:
The difference in heights in the two sides is because of the difference in pressure of the enclosed gas and the atmospheric pressure. This difference is in mm of the nonvolatile liquid. The difference in mm Hg is:
32.3mm * (0.993g/mL / 13.6g/mL) = 2.36mmHg
As atmospheric pressure is 765mm Hg and assuming the gas has more pressure than the atmospheric pressure (There is no illustration), the pressure of the gas is:
765mm Hg + 2.36mm Hg = 767.36 mmHg
In atm:
767.36 mmHg * (1atm / 760 mmHg) =
1.01atm is the pressure of the gas
Given:
Density of mercury = 13.6 g/mLDensity of nonvolatile liquid = 0.993 g/mLDifference in height = 32.3mmAtmospheric pressure = 765 mm HgNow,
The density of Hg will be:
= [tex]\frac{13.6}{0.791}[/tex]
= [tex]17.2 \ mm[/tex]
then,
= [tex]32.3\times (\frac{1 \ mm \ Hg}{17.2} )[/tex]
= [tex]18.73 \ mm \ Hg[/tex]
hence,
The pressure will be:
= [tex]765-18.73[/tex]
= [tex]746.27 \ mm \ Hg[/tex]
= [tex]0.993 \ atm[/tex]
Thus the above answer is right.
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In order to dissolve a chemical sample in a recrystallization solvent, add the room-temperature solvent ___________ in an Erlenmeyer flask on a hot plate. Turn on the heat, starting at __________________. Using a _______, add additional solvent from a second container on the heat source. Swirl the sample flask after each addition, and try to add _______________ in order to dissolve the solid.
Answer:
just until it covers the sample
a low setting and increasing gradually
pipet
as little solvent as possible
Explanation:
In order to dissolve a chemical sample in a recrystallization solvent, add the room-temperature solvent just until it covers the sample in an Erlenmeyer flask on a hot plate. Turn on the heat, starting at a low setting and increasing gradually. Using a pipet, add additional solvent from a second container on the heat source. Swirl the sample flask after each addition, and try to add as little solvent as possible in order to dissolve the solid.
PLS HELP ME WITH MY ASSIGNMENT WILL MARK BRAINLIEST!
Answer:
D. anions ; +1
Explanation:
Alkali metals tend to lose one electron and form ions with a single positive charge. 'alkali metals typically lose 1 eclectron to form anions with a charge of +1".
Estimate how much heat in joules is released when 25.0 g of water (C = 4.184 J/g°C) is cooled from 80.0°C to 30.0°C?
Answer:
5230 J
Explanation:
m = 25 g = 0,025 kg
c = 4,184 J /(g * °C) = 4184 J /(kg * °C)
[tex]t_{1}[/tex] = 80 °C
[tex]t_{2}[/tex] = 30 °C
The formula is Q = c *m * ([tex]t_{2} - t_{1}[/tex])
Calculating:
Q = 4184 * 0,025 * (30 - 80) = 5230 J
Note that we get a negative heat (-5230 J). It just means that it is released.
The amount of heat will be 5230 j.
What is heat?
Heat is a type of energy that is transferred between both the system and its surroundings as a result of temperature variations.
Calculation of heat.
Given data:
Mass = 25.0 g = 0.025 kg
C = 4.184 J/g°C
[tex]T_{1}[/tex] = 80.0°C
[tex]T_{2}[/tex] = 30.0°C
Q= ?
By using the formula of heat.
Q = MC ([tex]T_{2} - T_{1}[/tex])
Put the value of given data in heat equation.
Q(heat) = 0.025 × 4.184 ( 30 - 80)
Q(heat) = 5230 J.
Therefore, the amount of heat will be 5230 J.
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The ground -state electron configuration contains 6p unpaired electrons .
The electronic configuration is the depiction of the electron present in the atomic shells. The ground-state electron configuration containing three unpaired 6p electrons is bismuth.
What is electronic configuration?The electronic configuration is said to be the representation of the distribution of the electrons in the orbitals or the sub-shell of the atom. It shows the arrangement from the lower to higher energy levels.
The element which contained an unpaired 6p electron is bismuth (Bi). It has an atomic number, 83, and an electron configuration: [Xe] 4f¹⁴5d¹⁰6s²6p³. The p orbital can accommodate six electrons and hence the three electrons are unpaired.
Therefore, in the electronic configuration with unpaired 3p orbitals, the element will be bismuth.
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Your question is incomplete, but most probably your full question was, The ground-state electron configuration contains three unpaired 6p electrons, what is the element symbol?
For each of the following compounds, decide whether the compound's solubility in aqueous solution changes with pH.
a. Ca(OH)2
b. CuBr
c. Ca3(PO4)2
Answer:
a. pH raises
b. pH neutral
c. pH raises
Explanation:
First of all we need to dissociate these compounds.
Ca(OH)₂ → Ca²⁺ + 2OH⁻
This is the calcium hydroxide, a strong base.
In this case, we are giving OH⁻ to medium, so the pH will be increased.
OH⁻ + H⁺ ⇄ H₂O
Hydroxides will neutralize the protons in order to make water, but if we have many OH, we talk about a basic solution where pH is lower than 7.
b. CuBr → Cu⁺ + Br⁻
This is similar to NaCl, a ionic salt which is neutral.
The ions from this salt, do not make hydrolisis, that's why pH does not change.
c. Ca₃(PO₄)₂ → 3Ca²⁺ + 2PO₄⁻³
Calcium cathion comes from a strong base. It means, that the ion can not make hydrolisis because it is the conjugate weak acid.
Phosphate anion comes from a weak acid, it can gives OH⁻ to medium so pH will increase; the PO₄⁻³ anion is the conjugate strong base of the phosphoric acid, that's why it can react:
PO₄⁻³ + H₂O ⇄ H₂PO⁻² + OH⁻
When running an experiment, it is essential to record data and observations within your lab notebook. The data and observations are then discussed and analyzed, results and discussion. However, as you write a conclusion, some data are more important to include than others. Which of the following data would you include if you had to write a conclusion in for outcome of this week's LLE experiment?
a. MP range of product
b. mass of product
c. mass of flask and cork support
d. instrument used to evaporate the solvent
e. volume of crude reaction mixture used
f. % recovery
g. volume of acid and base used
h. theoretical MP
i. mass of flask, cork support, and product
Answer:
% recovery
MP range of product
mass of product
Explanation:
Liquid–liquid extraction (LLE) is a process of transferring one (or more) solute(s) which are present in a feed solution to another immiscible liquid (solvent). The other solvent that becomes enriched in the target solute(s) is called extract. The original feed solution that is depleted in solute(s) is subsequently referred to as the raffinate.
This method is used to purify compounds and separate mixtures of compounds. This is very important when we want to isolate a product from a reaction mixture.
The percent recovery is the amount of solute that is transferred to the extract. This is the most important data to be recorded in an LLE experiment.
The melting point range necessarily helps us to identify the product and the mass of solid tells us the quantity of the solid obtained after extraction.
An attractive force between all objects that have mass is knows as ____________. The more mass, the more of this type of force. The more distance between objects, the less of this type of force.
A. Friction
B. Normal force
C. Air resistance
D. Gravity
Answer:
C . Air resistance
Explanation:
Answer:
Gravity (D)
Explantion:
The more mass the more gravitational force
the more distance the less gravitational force
Of the predators in the image, which one is most likely a keystone species?
O pine marten
O mountain lion
O eagle
O wolf
Answer:
mountian lion
Explanation:
Ve. In what layer do weather balloons fly?
Earth layers
Answer:
stratosphere
Explanation:
The empirical formula of a sample of gold bromide was found by adding aluminum metal to an aqueous solution of gold bromide, displacing gold metal.
a. True
b. False
Answer:
a. True
Explanation:
The formula for determining the gold bromide formula, aqueous solution is added. When the solution is introduced with aluminum metal, the gold bromide reacts and displaces the gold metal. This is an electrolysis technique which is used for metals.
You are boiling water to cook some noodles. You notice bubbles forming on the bottom of the pot. Your brother thinks it is a chemical change. Is he correct?
Yes. The bubbles contain hydrogen and oxygen that separated from the water.
Yes. The bubbles are now filled with air.
No. The water changes into carbon dioxide.
No. It is a physical change when water is heated and is converted into water vapor.
Answer:
i think its Yes. The bubbles contain hydrogen and oxygen that separated from the water but i could be wrong so i would just wait to see if anybody else says anything
Explanation:
The three temperate marine climates are?
Marine west coast, humid subtropical, and Mediterranean.
Can you locate any mountains in the tropical zones?
Answer:
At even lower levels mountain lands grade into other types of landform and vegetation—e.g., tropical or temperate forest, savanna, scrubland, desert, or tundra. The largest and highest area of mountain lands occurs in the Himalaya -Tibet region; the longest nearly continuous mountain range is that along the west coast of the Americas from Alaska in the north to Chile in the south.
eh-
Explanation: