Answer:
* The empirical formula of a compound shows the ratio of elements present in a compound
* The molecular formula of a compound shows how many atoms of each element are present in a molecule of a compound.
Example: the compound butene has a molecular formula of C4H8. The empirical formula
of butene is CH2 because there is a 1:2 ratio of carbon atoms to hydrogen atoms.
Quartz,SiO2,contains 46.7% silicon. What mass of silicon is present in 381 g of quartz?
Answer:
119 g.
Explanation:
An aqueous solution of sodium hydroxide is standardized by titration with a 0.104 M solution of hydrobromic acid. If 13.5 mL of base are required to neutralize 20.2 mL of the acid, what is the molarity of the sodium hydroxide solution?
Answer:
0.156 M
Explanation:
The neutralization reaction between hydrobromic acid (HBr) and sodium hydroxide (NaOH) is the following:
HBr(ac) + NaOH(aq) → NaBr(aq) + H₂O(l)
As we can see, 1 mol of HBr reacts with 1 mol NaOH. During a titration, at the equivalence point, the number of moles of NaOH added reacts completely with the number of moles of HBr:
moles of NaOH = moles of HBr
The moles of each reactant is calculated as the product of the molarity (M) and the volume (V):
M(NaOH) x V(NaOH) = M(HBr) x V(HBr)
We have the following data:
base: V(NaOH) = 13.5 mL
acid: M(HBr) = 0.104 M; V(HBr) = 20.2 mL
Thus, we calculate M(NaOH) from the equivalent point equation:
M(NaOH) = (M(HBr) x V(HBr))/(V(NaOH) = (0.104 M x 20.2 mL)/(13.5 mL) = 0.1556 M ≅ 0.156 M
What is the source of most of the salt in the oceans?
human activities adds salt into the ocean
O rivers and streams carry sediment containing salt to the ocean
O marine fish produce salt adding it into the ocean
wind blows the salt into the ocean
A low-pressure weather system comes into the city of Denver. The atmospheric pressure is 693 mmHg.693 mmHg. If 78.0%78.0% of dry air is nitrogen, what is the partial pressure of nitrogen in this low-pressure system?
Answer:
540.54 mmHg
Explanation:
We know that the partial pressure of a substance is defined as; Mole fraction * total pressure.
If the total amount of gases in the atmosphere is 100%, the mole fraction of nitrogen gas is now
78/100 = 0.78
Thus, partial pressure of nitrogen gas = 0.78 * 693 = 540.54 mmHg
Which planet has these characteristics? - the only planet to have liquid water on its surface - almost three quarters of its surface is covered in water - has a nearly circular orbit
Consider the elementary gas-phase reversible reaction A 3C Pure A enters at a temperature of 400 K and a pressure of 10 atm. At this temperature, KC 0.25(mol/dm3)2. Calculate the equilibrium conversion for each of the following situations: (a) The gas-phase reaction is carried out in a constant-volume batch reactor. (b) The gas-phase reaction is carried out in a constant-pressure batch reactor. (c) Can you explain the reason why there would be a difference in the two values of the equilibrium conversion
Answer:
a) Xac = 0.39
b) Xac = 0.58
c) There would be a difference in the two values of the equilibrium conversion because in constant pressure condition it would take longer time to reach the same conversion rate ( higher conversion equilibrium ) and this because the volume increase with the reaction at constant pressure
Explanation:
From elementary gas phase reaction
Cao = Po / RT
Po = 10
R = 82.06
T = 400 K
Cao = 3.05 * 10^-4 mol/cm^3 ≈ 0.305 mol/dm^3
Kc = 0.25 (mol/dm^3 )^2
Calculate the equilibrium conversion for each of the following situations
a) The gas-phase reaction is carried out in a constant-volume batch reactor
Xac = 0.39
b) The gas-phase reaction is carried out in a constant-pressure batch reactor
Xac = 0.58
c) There would be a difference in the two values of the equilibrium conversion because in constant pressure condition it would take longer time to reach the same conversion rate ( higher conversion equilibrium ) and this because the volume increase with the reaction at constant pressure
Attached below is a detailed solution as regards the question above
Which statement best describes how an electromagnetic motor works?
Electrons are moved through a magnet, creating a current. That current interacts with a circuit, moving the
conductor in the orientation of the field
Electrons are moved through a current, creating a circuit That circuit interacts with a magnet, moving the
conductor in the orientation of the field.
Electrons are moved through a circuit, creating a current That current interacts with a magnet, moving the
conductor in the orientation of the field
Electrons are moved through a magnet, creating a circuit That circuit interacts with a current, moving the
conductor in the orientation of the field
Answer:
Electrons are moved through a magnet, creating a current. That current interacts with a circuit, moving the conductor in the orientation of the field.
Explanation:
Electro magnetic fields are used to create electric current by the movement of electrons. When a coil of wire is wrapped around a magnet it pushes electrons and they flow through a magnet to create current. This current interacts with circuit to move conductor.
2. What three states of matter do we see every day?
HELP PLEASEE FAST OMG
Answer:
solid,liquids,gases & plasma
5. Write the two resonance hybrids for the carbocation that would be formed by protonation at C-1 of 2-methyl-1,3-pentadiene. Without doing a calculation, would you expect C-2 or C-4 (the two end carbons of the allylic cation) to have the most positive charge on it
Answer:
Follows are the solution to this question:
Explanation:
Please find the complete solution in the attached file.
Can you guys help me explain these? I will mark brainliest to whoever answers it right oh and this is due tommorow so im rushing!
Answer:
Conduction
Conduction moves heat through direct sub-atomic crash. A region of more prominent dynamic energy will move nuclear power to a region with lower active energy. Higher-speed particles will crash into more slow speed particles. The more slow speed particles will increment in motor energy subsequently. Conduction is the most widely recognized type of warmth move and happens through actual contact. Models is place your hand against a window or spot metal into an open fire.
The interaction of warmth conduction relies upon the accompanying components: temperature slope, cross-segment of the material, length of the movement was, and actual material properties. The temperature inclination is the actual amount that portrays the bearing and pace of warmth travel. Temperature stream will consistently happen from most sultry to coldest or, as expressed previously, higher to bring down active energy. Once there's warm harmony between the two temperature contrasts, the warm exchange stops.
Convection
At the point when a liquid, like air or a fluid, is warmed and afterward ventures from the source, it conveys the nuclear power along. This sort of warmth move is called convection. The liquid over a hot surface grows, turns out to be less thick, and rises.
Radiation
Thermal radiation generates from the emission of electromagnetic waves. These waves carry the energy away from the emitting object. Radiation occurs through a vacuum or any transparent medium (either solid or fluid). Thermal radiation is the direct result of random movements of atoms and molecules in matter. Movement of the charged protons and electrons results in the emission of electromagnetic radiation.
Number of atoms in 4.26 moles of (NH4)3PO4
Answer:
20 atoms
Explanation:
n=3
H =12
p=1
O=4
3+12+1+4=20
1. How many molecules are in 4.5 moles?
Answer:
depends on what molecule you are looking for
Explanation:
In one mole of stuff (atoms, molecules, eggses), there are NA individual items of that stuff. So, there are 4.5 × NA BCl3 molecules; i.e. 4.5 × 6.022×1023 ≅ 27×1023 individual molecules of BCl3
Heart attacks can cause sudden death.
True
False
Answer:
True
Explanation:
Which of these describes a Mole in Chemistry?
A. A counting term for substances
B. The Molar mass of substance in grams
C. 6.02 x 10^23
D. All of the above describe a mole
Answer: D. All of the above describe a mole
Explanation:
Mole is the unit for amount of substance. It is used for describing large number of particles.
According to avogadro's law, 1 mole of every substance weighs equal to molecular mass and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
For example: 1 mole of Na atom will weigh 23 grams and contains [tex]6.023\times 10^{23}[/tex] atoms.
Thus all the above describes a mole.
1
Which Element Am I (Core)
Names
1. I have 4 valence electrons and 2 energy levels. Which element am I?
2. Iam in group 16 with 2 energy levels. Which element am I?
3. I am in Period 2 and belong to the same group (family) as silicon. Which element am 1?
4. I have 7 valence electrons and 3 energy levels? Which elementar ?
5. I am in period 3 and I have 12 protons in my nucleus. Which element am 1?
Berr
Sul
ca
3
6
5
6. I am the only element with no neutrons in my nucleus. Which element am 17
6
7. I am the only metalloid with 3 energy levels. Which element am I?
8. I have 1 valence electron and 11 protons, which element am I?
9. Thave only one energy level that is full. Which element am I?
10.1 have 8 valence electrons and I have 4 energy levels. Which element am 1?
10
Answer:
1) Helium
2) Oxygen
3)Carbon
4) Chlorine
5) Magnesium
Explanation:
Helium has the electron arrangement 2, 2. There are two electrons in the first shell and two electrons in the second shell.
Oxygen is the first member of group 16, there are two energy levels in oxygen which are 2,6.
Carbon is in period 2 and is the first member of group 14 (the silicon family).
Chlorine has 7 valence electrons, the electrons are arranged as 2, 8, 7.
Magnesium has 12 protons and 12 electrons. It is the second member of period 3.
How can people conserve water at home?
Answer:
Turning off the water while brushing teeth, watching shower time.
Explanation:
Answer:
Take shorter showers.
Install water-saving shower heads or flow restrictors.
Turn off the water while brushing your teeth.
Turn off the water while shaving.
Explanation:
have a nice day
Perform the following
mathematical operation, and
report the answer to the
appropriate number of
significant figures.
653.12 + 12.10247 = [?
Answer:
665.22
Explanation:
you see wich numbers after the decimal points have the least numbers, the one with the least u have to round your answer to that
After performing the required mathematical operation (addition), the answer is equal to 665.22.
What are significant figures?In Mathematics, significant figures can be defined as the number of single digits or numerical values in the coefficient of a mathematical expression that are important and meaningful.
Since "653.12" has two (2) significant figures, we must ensure that 12.10247 also has two (2) significant figures as follows:
12.10247 to 2 S.F = 12.10.
Next, we would perform the required mathematical operation (addition):
653.12 + 12.10 = 665.22.
Read more on significant figures here: https://brainly.com/question/24491627
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What is the voltage in a circuit is the current is 3 amps and the resistance is 3 ohms
Answer:
9
Explanation:
V=I*R
3*3
Thats the answer
The dissociation constant of formic acid and acetic acid are 2.14×10^-4 and 1.81×10^-5 respectively. What is the relative strength of the acids
Answer: The formic acid is 3.5 times stronger than acetic acid.
Explanation:
The strength of an acid depends on its acid dissociation constant.
For a hypothetical monoprotic acid HA, the dissociation equilibrium is:
[tex]HA\rightleftharpoons H^++A^-[/tex]
[tex]K_a=\frac{[H^+][A^-]}{[HA]}[/tex]
More is the value of [tex]K_a[/tex] , greater is the dissociation and stronger is the acid.
[tex]\frac{Strength_{\text {formic acid}}}{Strength_{\text {acetic acid}}}=\sqrt{\frac{2.14\times 10^{-4}}{1.81\times 10^{-5}}}=3.5[/tex]
Thus formic acid is 3.5 times stronger than acetic acid.
how does a buffer work?
A. it prevents added acids or bases from dissociating
B. it neutralizes acids or bases by precipitating a salt
C. it forms new conjugate pairs with the added ions
D. it bonds with the added H+ or OH- in solution
Answer:
It bonds with the added H+ or OH in solution.
Explanation:
I’m stuck on this can I get a little help please
Answer:
table A
Explanation:
its table A because it requires less force push. the less force used the less friction there is.
the less friction there is the more smooth a surface is.
Cal is titrating 50.8 mL of 0.319 M HBr with 0.337 M Ba(OH)2. How many mL of Ba(OH)2 does Cal need to add to reach the equivalence point?
Answer:
[tex]V_{base}=24.04mL[/tex]
Explanation:
Hello!
In this case, according to the chemical reaction by which HBr reacts with Ba(OH)2:
[tex]2HBr+Ba(OH)_2\rightarrow BaBr_2+2H_2O[/tex]
We can see there is a 2:1 mole ratio between the acid and the base; thus, at the equivalent point we can write:
[tex]2M_{base}V_{base}=M_{acid}V_{acid}[/tex]
Therefore, for is to compute the volume of the used base, we proceed as shown below:
[tex]V_{base}=\frac{M_{acid}V_{acid}}{2M_{base}}[/tex]
And we plug in to obtain:
[tex]V_{base}=\frac{0.319M*50.8mL}{2*0.337M}\\\\V_{base}=24.04mL[/tex]
Best regards!
At a certain temperature this reaction follows first-order kinetics with a rate constant of 2.01 s^−1
CICH2CH2Cl (g) → CH2CHCI (g) + HCl(g)
Suppose a vessel contains CICH2CH2Cl at a concentration of 1.34 M. Calculate how long it takes for the concentration CICH2CH2Cl to decrease to 20.0% of its initial value. You may assume no other reaction is important. Round your answer to 2 significant digits.
Answer:
0.80 seconds (2 significant figures)
Explanation:
The equation of the reaction is given as;
CICH2CH2Cl (g) --> CH2CHCI (g) + HCl(g)
Rate constant (k) = 2.01 s^-1
From the units of the rate constant, this is a first order reaction.
Initial Concentration = 1.34 M
t = ?
Final concentration = 20% of 1.34 = 0.268 M
The integrated rate law for a first order reaction is given as;
ln[A] = ln[A]o - kt
ln(0.268) = ln(1.34) - 2.01(t)
-2.01(t) = - 1.6094
t = 0.8007 ≈ 0.80 seconds (2 significant figures)
which explains how coolers work?
Answer:
Forgive me if im wrong but i am pretty sure the answer is C
Explanation:
it initiates the healing process?
Answer:
platelets?
Explanation:
the question is vauge. but I hope you got it right!
Answer:
Cell division ?
Explanation:
What is limited reactant?
Answer:
The limiting reagent is the reactant that is used up completely. This stops the reaction and no further products are made. ... The limiting reagent can also be derived by comparing the amount of products that can be formed from each reactant.
Answer:
The limiting reagent is the reactant that is used up completely. This stops the reaction and no further products are made. ... The limiting reagent can also be derived by comparing the amount of products that can be formed from each reactant.
Explanation:
Disclaimer not my answer I looked it up
Why are cars manufactures exploring hydrogen fuel cell technology as a possiable replacement for gasoline burning engines
Mass number 107 and 61 neutrons
A) Suppose you separate a 3.02 g mixture of sand and salt. You recover 1.43 g of salt and 1.41 g of sand. What is the percent recovery of the mixture?
B) Suppose you separate a 3.02 g mixture of sand and salt. You recover 1.43 g of salt and 1.41 g of sand. What is the percent recovery of the mixture?
C) Calculate the percent by mass of a solution made from 15 g NaCl (the solute) and 69 g water.
D) What percent of 73.0 g is 26.1 g?
Answer:
A-B) 94 %.
C) 17.9 %.
D) 35.8 %.
Explanation:
Hello!
A-B) In this case, since the total mass of the mixture is 3.02 g and 1.43g+1.41g=2.84 g are recovered in total, we can compute the percent recovery as shown below:
[tex]\%rec=\frac{2.84g}{3.02g}*100\%\\\\\%rec=94\%[/tex]
C) Here, since the solution is made up of NaCl and water, we can say that the mass of the solution is 15g+69g=84g; thus, the percent by mass would be:
[tex]\%=\frac{15g}{84g}*100\%\\\\\%=17.9\%[/tex]
D) In this case, we simply divide 26.1 g by 73.0 g in order to obtain the percent:
[tex]\%=\frac{26.1g}{73.0g}*100\%\\\\\%=35.8\%[/tex]
Best regards!
The percentage in the cases are as follows;
A and B is; 94%C is; 17.9%D is; 35.8%Questions A and B are similar and can be solved as follows;
The total mass of the mixture is 3.02g.The recovered mass = 1.43g + 1.41g = 2.84g% recovery = (2.84/3.02) × 100%% recovery = 94%Question C can be solved as follows;
Total mass of solution = 15 + 69 = 84gMass of solute = 15g% by mass = (15/84) × 100%% by mass = 17.9%Question D can be solved as follows;
% = (26.1/73) × 100%% = 35.8%Read more:
https://brainly.com/question/24712879
Can you guys please help me I will mark brainliest to whoever answers this right.