Answer:
3.55 x 10^23 molecules F2
Explanation:
molecules = moles x avogadro number
1 mole of gas occupies 22.4 L
moles of F2 = 13.2/22.4= 0.589 moles
moles F2 = 0.589 x 6.022 x 10^23 = 3.55 x 10^23 molecules F2
Which of the following statements best describes the number of neutrons in an atom?
It is the same as the element's atomic number.
It is equal to the sum of atomic number and average atomic mass.
it is the same as the average atomic mass.
it is equal to the difference between atomic number and atomic mass number.
Answer:
its the last one
Explanation:
what is the constant Kc for Cd²+(aq)+4Br-(aq) CdBr4²-(aq)
Answer:
im only in 6th grade TwT
Explanation:
LOL
You want to decaffeinate your coffee by extracting the caffeine out with dichloromethane (they don't do it that way anymore, but they used to). It's too late to extract the caffeine from the coffee beans, because you've already brewed yourself a 200 mL cup of coffee. Your particular brand of coffee contains 100 mg of caffeine in that 200 mL cup. The partition coefficient of caffeine in dichloromethane/water is 9.0 (it is more soluble in the dichloromethane).
How much caffeine would still be in your 200 mL if you did:_____.
A. One extraction using 200 mL ofdichloromethane
B. Two extractions using 100 mL ofdichloromethan each.
Solution :
Partition coefficient Kd
[tex]$=\frac{\frac{\text{mass of caffeine in } CH_2Cl_2}{\text{volume of } CH_2Cl_2}}{\frac{\text{mass of caffeine in water}}{\text{volume of water}}}$[/tex]
= 9.0
A). 1 x 200 mL extraction :
Let m be the mass of caffeine in the water
Mass of caffeine in [tex]$CH_2Cl_2$[/tex] = 100 - m
[tex]$\frac{\frac{100-m}{200}}{\frac{m}{200}} = 9.0$[/tex]
[tex]$=\frac{100-m}{m} = 9.0$[/tex]
[tex]$= 10 m = 100$[/tex]
m = 10
Mass remaining in coffee = m = 10 mg
B). 2 x 100 mL extraction :
First extraction :
Let [tex]$m_1$[/tex] be the mass of caffeine in the water
Mass of caffeine in [tex]$CH_2Cl_2$[/tex] = [tex]$100-m_1$[/tex]
[tex]$\frac{\frac{100-m_1}{100}}{\frac{m_1}{200}} = 9.0$[/tex]
[tex]$=\frac{100-m_1}{m_1} = 4.5$[/tex]
[tex]$ 5.5 \ m_1 = 100$[/tex]
[tex]$m_1$[/tex] = 18.18
Mass remaining in coffee = [tex]$m_1$[/tex] = 18.18 mg
Second Extraction :
Let [tex]$m_2$[/tex] be the mass of caffeine in the water
Mass of caffeine in [tex]$CH_2Cl_2$[/tex] = [tex]$18.18-m_2$[/tex]
[tex]$\frac{\frac{18.18-m_2}{100}}{\frac{m_2}{200}} = 9.0$[/tex]
[tex]$=\frac{18.18-m_2}{m_2} = 4.5$[/tex]
[tex]$ 5.5 \ m_2 = 18.18$[/tex]
[tex]$m_2$[/tex] = 3.3
Mass remaining in coffee = [tex]$m_2$[/tex] = 3.3 mg
Select a reasonable explanation to account for the differences. There may be more than one possible reason that makes sense, just select one of them. It is possible not all of the water was evaporated from the sand, causing the recovered mass to be higher. It is possible not all of the water was evaporated from the sand, causing the recovered mass to be lower. While drying the NaCl, the liquid boiled and some splattered out of the evaporating dish, causing the recovered mass to be lower. While drying the NaCl, the liquid boiled and some splattered out of the evaporating dish, causing the recovered mass to be higher. There was no difference in recovered and original mass, so there is no difference to account for.
Answer:
It is possible not all of the water was evaporated from the sand, causing the recovered mass to be higher.
Explanation:
If not all the water is evaporated from the sand so the recovered mass to be higher than the sand from which more water is evaporated because evaporation of little amount of water causes less decrease in the recovered mass as compared to that sand from which more water is evaporated so more decrease occur in the recovered mass.
How many grams of sulfur is there in 10.8 grams of sodium sulfate?
please help
Answer:
2.44 g S
Explanation:
One mole of Na2SO4 contains 1 mol of S.
Step 1: Find out the moles of Na2SO4:
10.8 g Na2SO4/MM Na2SO4
Step2: Find out the moles of S:
moles S = moles Na2SO4
Step 3: Find out the mass of S.
mass S = moles S x MM S
Dimensional analysis:
? g S = 10.8 g Na2SO4 x (1mol Na2SO4/MM Na2SO4) x (1mol S/1mol Na2SO4) x (MM S/ 1 mol S) = (10.8/142.04)x32.1 = 2.44 g S
hi, if your looking for extra points (50+) and brainiest here is ur chance, answer this question correctly plz
Answer:
again, I'm going to say D lol.
HELP ME
Elements in a vertical column on the Periodic Table have similar properties and are all members of the same
of elements.
А
molecule
B
phase
С
atom
D
group
Answer:
D group
................
The volume of a gas is 18.6 L at 0.10 atm and 273 K. Calculate the pressure in
atms of the gas if its volume is changed to 1000 ml while the temperature remains
constant?
Answer:
1.86 atm
Explanation:
The following data were obtained from the question:
Initial volume (V₁) = 18.6 L
Initial pressure (P₁) = 0.10 atm
Final volume (V₂) = 1000 mL
Final pressure (P₂) =?
NOTE: The temperature is constant.
Next, we shall convert 1000 mL to L.
1000 mL = 1 L
Finally, we shall determine the final pressure of the gas as follow:
Initial volume (V₁) = 18.6 L
Initial pressure (P₁) = 0.10 atm
Final volume (V₂) = 1 L
Final pressure (P₂) =?
P₁V₁ = P₂V₂
18.6 × 0.10 = P₂ × 1
1.86 = P₂
P₂ = 1.86 atm
Thus, the final pressure of the gas is 1.86 atm
A 50.0-mL volume of 0.15 M HBr is titrated with 0.25 M KOH. Calculate the pH after the addition of 13.0 mL of KOH. Express your answer numerically.
Answer:
pH= 1.17
Explanation:
The neutralization reaction between HBr (acid) and KOH (base) is given by the following equation:
HBr(aq) + KOH(aq) → KBr(aq) + H₂O(l)
According to this equation, 1 mol of HBr reacts with 1 mol of KOH. Then, the moles can be expressed as the product between the molarity of the acid/base solution (M) and the volume in liters (V). So, we calculate the moles of acid and base:
Acid:
M(HBr) = 0.15 M = 0.15 mol/L
V(HBr) = 50.0 mL x 1 L/1000 mL = 0.05 L
moles of HBr = M(HBr) x V(HBr) = 0.15 mol/L x 0.05 L = 7.5 x 10⁻³ moles HBr
Base:
M(KOH) = 0.25 M = 0.25 mol/L
V(HBr) = 13.0 mL x 1 L/1000 mL = 0.013 L
moles of HBr = M(HBr) x V(HBr) = 0.25 mol/L x 0.013 L = 3.25 x 10⁻³ moles KOH
Now, we have: 7.5 x 10⁻³ moles HBr > 3.25 x 10⁻³ moles KOH
HBr is a strong acid and KOH is a strong base, so they are completely dissociated in water: the acid produces H⁺ ions and the base produces OH⁻ ions. So, the difference between the moles of HBr and the moles of KOH is equal to the moles of remaining H⁺ ions after neutralization:
moles of H⁺ = 7.5 x 10⁻³ moles HBr - 3.25 x 10⁻³ moles KOH = 4.25 x 10⁻³ moles H⁺
From the definition of pH:
pH = -log [H⁺]
The concentration of H⁺ ions is calculated from the moles of H⁺ divided into the total volume:
total volume = V(HBr) + V(KOH) = 0.05 L + 0.013 L = 0.063 L
[H⁺] = (moles of H⁺)/(total volume) = 4.25 x 10⁻³ moles/0.063 L = 0.067 M
Finally, we calculate the pH after neutralization:
pH = -log [H⁺] = -log (0.067) = 1.17
which statement explains this observation?
Answer:
should be D. Hope this helpsss!
which graph shows the volume amount of gas relationship expected for an ideal gas, known as Avogadro's law
Answer:
The answer is A
Explanation:
I got it right on the test
PLEASE PLEASE I do not understand may someone kindly help me pls
Answer:
It can be verified since the information came from a government article. Or you could trust the magzine/general article if its from a well known article. Explanation:
you get the point, you can add on to this. I can't make it the best since im not in your class learning. Good luck
Which of the following chemical substances has a triple
covalent bond?
A. carbon dioxide (CO2)
B. oxygen (0)
C. carbon monoxide (CO)
D. water (H,0)
Answer:
C. Carbon monoxide
Explanation:
Chemical substance which has a triple covalent bond is carbon monoxide.
What is a covalent bond?Covalent bond is defined as a type of bond which is formed by the mutual sharing of electrons to form electron pairs between the two atoms.These electron pairs are called as bonding pairs or shared pair of electrons.
Due to the sharing of valence electrons , the atoms are able to achieve a stable electronic configuration . Covalent bonding involves many types of interactions like σ bonding,π bonding ,metal-to-metal bonding ,etc.
Sigma bonds are the strongest covalent bonds while the pi bonds are weaker covalent bonds .Covalent bonds are affected by electronegativities of the atoms present in the molecules.Compounds having covalent bonds have lower melting points as compared to those with ionic bonds.
Learn more about covalent bonds,here:
https://brainly.com/question/19382448
#SPJ2
(12 points) please please help me thanks
Answer: i think its the thired one
Explanation:
Calcium carbonate decomposes to form calcium oxide and carbon dioxide, like this:
CaCO3(s)→CaO(s)+CO2(g)
At a certain temperature, a chemist finds that a 9.0L reaction vessel containing a mixture of calcium carbonate, calcium oxide, and carbon dioxide at equilibrium has the following composition:
Compound Amount
CaCO3 25.3 g
CaO 14.9 g
CO2 33.7 g
Calculate the value of the equilibrium constant Kc for this reaction. Round your answer to 2 significant digits.
Answer: The value of the equilibrium constant Kc for this reaction is 0.088
Explanation:
[tex]Molarity=\frac{x}{M\times V_s}[/tex]
where,
x = given mass
M = molar mass
[tex]V_s[/tex] = volume of solution in L
Equilibrium concentration of [tex]CaCO_3[/tex] = [tex]\frac{25.3}{100\times 9.0}=0.028M[/tex]
Equilibrium concentration of [tex]CaO[/tex] = [tex]\frac{14.9}{56\times 9.0}=0.029M[/tex]
Equilibrium concentration of [tex]CO_2[/tex] = [tex]\frac{33.7}{44\times 9.0}=0.085M[/tex]
The given balanced equilibrium reaction is,
[tex]CaCO_3(s)\rightleftharpoons CaO(s)+CO_2(g)[/tex]
The expression for equilibrium constant for this reaction will be,
[tex]K_c=\frac{[CaO]\times [CO_2]}{[CaCO_3]}[/tex]
Now put all the given values in this expression, we get :
[tex]K_c=\frac{0.029\times 0.085}{0.028}=0.088[/tex]
Hardness is the measure of a mineral's resistance to scratching.
True
False
Answer:
The answer to the question is true.
In the UNBALANCED chemical reaction for the combustion of acetylene (used in welding torches), determine at standard temperature and pressure, how many liters of
H2O gas are produced if 12 liters of Oxygen gas are completely consumed?
__C2H2 + __O2 —> __CO2 + __H2O
(Please help! Random answers for points will be reported)
Answer:
2 C2H2 + 5 O2 = 4 CO2 + 2 H2O
I've checked this multiple times this should be it
How many formula units make up 25.8g of magnesium chloride (MgCl2)? Express the number of formula units numerically.
Answer:
Explanation:
Kandndkjwnww
What is decarboxylation??
Gimme one reaction of it..
Answer:
Decarboxylation is a chemical reaction that removes a carboxyl group and releases carbon dioxide (CO2). Usually, decarboxylation refers to a reaction of carboxylic acids, removing a carbon atom from a carbon chain.
Explanation:
Please give me brainlist
*PLEASE HELP*
Write the word equation and the balanced symbol equation for the following reactions
1.Sulfuric acid reacting with sodium carbonate
2.Hydrochloric acid reacting with magnesium hydrogencarbonate
Answer:
1. H₂SO₄ + Na₂CO₃ ⇒ Na₂SO₄ + H₂O + CO₂
sulfuric acid + sodium carbonate ⇒ sodium sulfate + water + carbon dioxide
2. 2 HCl + Mg(HCO₃)₂ ⇒ MgCl₂ + 2 H₂O + 2 CO₂
hydrochloric acid + magnesium hydrogencarbonate ⇒ magnesium chloride + water + carbon dioxide
Explanation:
1. Sulfuric acid is H₂SO₄. Sodium carbonate is Na₂CO₃.
H₂SO₄ + Na₂CO₃ ⇒ Na₂SO₄ + H₂O + CO₂
sulfuric acid + sodium carbonate ⇒ sodium sulfate + water + carbon dioxide
2. Hydrochloric acid is HCl. Magnesium hydrogencarbonate is Mg(HCO₃)₂.
2 HCl + Mg(HCO₃)₂ ⇒ MgCl₂ + 2 H₂O + 2 CO₂
hydrochloric acid + magnesium hydrogencarbonate ⇒ magnesium chloride + water + carbon dioxide
Photosynthesis needs water and carbon dioxide to happen. These 2 ingredients are called _______.
250 ml juice has 22 g sugar how sugar is in 2000ml of juice
Answer:
176 grams of sugar
explanation is down
Explanation:
250 / 22 = 2000 / x250 ml to 22 grams = 2000 ml to x grams
cross multiply
(250)(x) = (2000)(22)
250x = 44,000
x = 44,000/250
x = 176 grams of sugar
Assume that the ratio of moles of Cl to moles of Cu are 2.39. If we can represent the formula by CuClx, what is the value for x? Round your answer to the nearest whole number. Do NOT include units. So, if you think the formula is CuCl6, you enter the number 6.
Answer:
x=2.
Explanation:
Hello there!
In this case, since we have a mole ratio of moles of Cl to moles of Cu as 2.39, it is possible to write the following:
[tex]\frac{2.39molCl}{1molCu}[/tex]
Thus, since the two possible copper chlorides are CuCl and CuCl₂, we can therefore infer that x=2 since it is close but not as close as it should to the whole number 2.
Best regards!
What is produced when concentrated aqueous sodium chloride is electrolysed?
A factory in your town uses cadmium as part of its manufacturing process. Due to recent economic conditions, cadmium is no longer available, and you must find a replacement. Suggest two elements that might be good replacements. Which of these would be your choice? Explain why.
Answer:
Zn
Explanation:
What are the reasons to determine the melting point of a sample in a melting point apparatus? Select one or more:
A. U Assessment of the sample's purity
B. Conversion of the solid sample to liquid
C. Identification of an unknown sample
D. Removal of impurities from the sample
To prepare a sample in a capillary tube for a melting point determination, gently tap the tube into the sample with the Choose... end of the tube down. Continue tapping until the sample Choose.. end of the tube down, tap the sample down slowly or Choose... to move the sample down Then, with the Choose... faster.
To prepare a sample in a capillary tube for a melting point determination, gently tap the tube into the sample with the a) open, b) closed end of the tube down. Continue tapping until the sample a) completely fills the tube b) is a couple millimeters high, c) has a single crystal in the tube. Then, with the a) closed, b) open end of the tube down, tap the sample down slowly or a) heat the tube up, b) drop the tube into a longer tube, c) shake the tube in the air to move the sample down faster.
Solution :
The reasons for the melting point determines :
the assignment of the sample's purityidentification of the unknown samplethe conversion of solid sample to the liquid completelyIn order to prepare the sample in the capillary tube for determining its melting point, we tap the tube gently into the sample with the open end of tube down. We then continue tapping the tube till the sample is couple of millimeters high.
Then the other close end of tube down, we tap the sample down again slowly or then dropping the tube into a longer tube so as to move down the sample faster.
Titanium(IV) chloride decomposes to form titanium and chlorine, like this:_____.
TiCl4(1)-→Ti(s) + 2 Cl 2(g)
At a certain temperature, a chemist finds that a reaction vessel containing a mixture of titanium(IV) chloride, titanium, and chlorine at equilibrium has the following composition:_____.
compound amount
TiCl4 4.18g
Ti 1.32g
Cl2 1.08g
Calculate the value of the equilibrium constant for this reaction. Round your answer to significant digits. Clears your work. Undoes your last action. Provides information about entering answers.
Answer:
K = 8.6x10⁻⁶
Explanation:
a chemist finds that a 5.2L reaction vessel...
To solve this question we need first to find the equation of the equilibrium constant using the chemical eqiation:
TiCl₄(l) ⇄ Ti(s) + 2Cl₂(g)
The equilibrium constant expression is:
K = [Cl₂]²
Because equilibrium constant is defined as the ratio berween concentrationa of products over reactant powered to its reaction coefficient. But pure liquids as TiCl₄(l) and pure solids as Ti(s) are not taken into account
Now, we need to find the molar concentration of Cl₂, [Cl₂]:
Moles Cl₂ -Molar mass: 70.9g/mol-:
1.08g * (1mol / 70.9g) = 0.0152 moles / 5.2L =
2.93x10⁻³M = [Cl₂]
K = (2.93x10⁻³)²
K = 8.6x10⁻⁶Calculate each of the following quantities:
a) Molarity of a solution prepared by diluting 27.0 cm3
of 0.150 M potassium chloride to
150.0 cm3
b) Molarity of a solution prepared by diluting 35.71 cm3
of 0. 0756 M ammonium
sulfate to 500 cm3
c) Final volume of a 0.05M solution prepared by diluting 10.0 cm3
of 0.155 M lithium
carbonate with water
Answer:
A. 0.027 M
B. 0.0054 M
C. 31 cm³
Explanation:
A. Determination of the final concentration (Molarity)
Initial Volume (V₁) = 27 cm³
Initial concentration (C₁) = 0.150 M
Final volume (V₂) = 150 cm³
Final congratulation (C₂) =?
C₁V₁ = C₂V₂
0.150 × 27 = C₂ × 150
4.05 = C₂ × 150
Divide both side by 150
C₂ = 4.05 / 150
C₂ = 0.027 M
Thus, the final concentration of the solution is 0.027 M
B. Determination of the final concentration (Molarity)
Initial Volume (V₁) = 35.71 cm³
Initial concentration (C₁) = 0.0756 M
Final volume (V₂) = 500 cm³
Final congratulation (C₂) =?
C₁V₁ = C₂V₂
0.0756 × 35.71 = C₂ × 500
Divide both side by 500
C₂ = (0.0756 × 35.71) / 500
C₂ = 0.0054 M
Thus, the final concentration of the solution is 0.0054 M
C. Determination of the final volume.
Initial Volume (V₁) = 10 cm³
Initial concentration (C₁) = 0.155 M
Final congratulation (C₂) = 0.05 M
Final volume (V₂) =?
C₁V₁ = C₂V₂
0.155 × 10 = 0.05 × V₂
1.55 = 0.05 × V₂
Divide both side by 0.05
V₂ = 1.55 / 0.05
V₂ = 31 cm³
Thus, the final volume of the solution is 31 cm³
Count how many jellybeans are in a jar if the jar has a mass of 30 grams, a
jelly bean has a mass of 2 grams, and the whole jar of jellybeans has a
mass of 230 grams.
Answer:
Ball 16 oz Pint Mason Jar outer dimensions are 5.2 height by 3.2 diameter – which could hold approximately 390 jelly beans. Ball 32 oz Quart Mason Jar outer dimensions are 6.9 height by 3.9 diameter – which could hold approximately 804 jelly beans.Oct 5, 2017
Explanation:
please mark me as brainliest
Answer:
100 jellybeans
Explanation:
Mass of Jar with jellybeans=230 grams
Mass of Jar=30 grams
Mass of 1 jellybean=2 grams
Mass of Jellybeans in jar
=Mass of Jar with jellybeans-Mass of Jar
=230 grams - 30 grams
=200 grams
2 grams=1 jellybean
1 gram=1/2 jellybean
200 grams=200*(1/2) jellybeans=100 jellybeans
What does this even mean? Help please and thank you!
Answer:
T₁ = P₁V₁T₂ / P₂V₂
Explanation:
The combine gas equation is given by:
P₁V₁ / T₁ = P₂V₂ / T₂
Where:
P₁ => is the initial pressure
V₁ => is the initial volume
T₁ => is the initial temperature
P₂ => is the final pressure
V₂ => is the final volume
T₂ => is the final temperature
Finally, we shall make T₁ the subject of the above expression. This can be obtained as follow:
P₁V₁ / T₁ = P₂V₂ / T₂
Cross multiply
T₁P₂V₂ = P₁V₁T₂
Divide both side by P₂V₂
T₁ = P₁V₁T₂ / P₂V₂
Thus, the formula for T₁ is:
T₁ = P₁V₁T₂ / P₂V₂