Answer:
B.
Explanation:
The amount of space between the particles in a medium reduces as its density rises, which causes light to bend. 2. This impact is highest for light that is close to the medium's surface and weakest for light that is far away from the medium's surface.
What does a negative AH for a molecule mean?
A. Energy was released when the molecule was formed from its
elements.
B. Energy was added when the molecule was formed from its
elements.
C. Energy was added when the molecule changed phases.
D. Energy was released when the molecule went through a phase
change.
A negative enthalpy (ΔH)for a molecule means energy was released when the molecule went through a phase change.
What is change in enthalpy (ΔH)?The enthalpy change of a reaction is the amount of heat absorbed or released as the reaction takes place.
Also, the amount of energy required to change the phase of a material is known as the enthalpy,
A negative enthalpy entails the amount of energy released during an exothermic reaction.
Thus, a negative enthalpy (ΔH)for a molecule means energy was released when the molecule went through a phase change.
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A lead ball is added to a graduated cylinder containing 50.6 ml of water, causing the level of the water to increase to 93.0 mL. What is the volume in milliliters of the lead ball, Vieras? Viead =
42.4 ml is the volume in milliliters of the lead ball if a lead ball is added to a graduated cylinder containing 50.6 ml of water.
What is a graduated cylinder?A tall narrow container with a volume scale is used especially for measuring liquids.
The graduated cylinder contains water
mL is a volume unit.
Water volume = 50.6 ml
The lead ball caused an increase in volume from 50.6 ml to 93.0 mL.
The new volume is the lead ball volume plus the original water volume :
Final volume = Vlead ball+ Water original volume
[tex]93.0 mL= V_(lead ball) +50.6 ml[/tex]
[tex]V_(lead ball) = 93.0 mL - 50.6 ml[/tex]
[tex]V_(lead ball) = 42.4 ml[/tex]
Hence, 42.4 ml is the volume in milliliters of the lead ball.
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Could really use a few pointers on this question!
From the calculations, we can see that the theoretical yiled of NO2 is 100L of NO2
What is the theoretical yield?The theoretical yield is that calculated from the stoichiometry of the reaction.
We can see that 1 mole of O2 produced 2 moles of NO2. Thus;
2.23 moles of O2 will produce 4.46 moles of NO2
Since 1 mole of NO2 occupies 22.4 L
4.46 moles of NO2 occupies 100L of NO2
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the density (g/ml) of 6 pennies with a mass of 18.53 grams and a volume of 2.0 ml
Answer: 9.27 g/mL
Explanation:
[tex]d=\frac{m}{v}=\frac{18.53}{2.0}=\boxed{9.27 \text{ g/mL}}[/tex]
What is the product of the unbalanced equation below?
H₂(g) + Cl₂(g) →
The Periodic Table
OA. H₂(g) + Cl₂(g)
OB. H₂Cl₂(9)
O C. HC1₂(g)
OD. HCI(g)
D
Explanation:
B/c both the hydrogen and chlorine have the same valance number so if a metal or non metal have the same valance number you should cancel out the numbers and you will have to put only the non metal or metals.
Helium occupies 293 mL at 788 Torr and 25C. If the sample is condensed into a 0.115 liter flask, what will the new pressure be, assuming constant temperature?
Answer:
=2007.69 Torr
Explanation:
The new pressure of helium gas assuming constant temperature is equal to 2007.69
Torr.
Given the following data:
Initial volume = 293 mL
Final volume = 0.115 L
Initial pressure = 788 Torr
Temperature = 25°C.
Conversion:
Initial volume = 293 mL to L = 293/1000=0.293L
To determine the new pressure assuming constant temperature, we would apply Boyle's law:
Mathematically, Boyle's law is given by the formula;
PV=K
P1V1=P2V2
Where;
P1 is the original (initial) pressure.
P2 is the final pressure.
V1 is the original (initial) volume.
V2 is the final volume.
Substituting the given parameters into the formula, we have;
788×0.293 = P2 × 0.115
230.884 = 0.115P2
P2 = 230.884/0.115
P2 =2007.69
The enzyme provided is a stock solution which should be diluted 50-fold with 0.001M HCl immediately before use.
Enzyme :1mg/ml chymotrypsin A in 0.001M HCl
How do I work out this calculation, if I want the 5ml of the diluted enzyme?
In order to prepare a 50-fold diluted enzyme, 0.1 mL of the stock solution of the enzyme is taken and made up to 5.0 mL with 0.001M HCl.
What is dilution?Dilution is a process whereby a solution of lower concentration is prepared from one of a higher concentration.
Dilution is done by using the dilution formula below:
C1V1 = C2V2C1; Initial concentration of enzyme = 1 mg/mL
C2; Final concentration of enzyme = 1/50 mg/ml = 0.02 mg/ml
V1; Initial volume of enzyme = y
V2; Final volume = 5.0 ml
V1 = C2V2/C1
V1 = 0.02 * 5/1 = 0.1 mL
Therefore, in order to prepare a 50-fold diluted enzyme, 0.1 mL of the stock solution of the enzyme is taken and made up to 5.0 mL with 0.001M HCl.
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Chemical equation of isopropyl alcohol and ethanoic acid
Answer:
chemical formula of isopropyl alcohol can also be written as: C3H7OH, CH3CHOHCH3 or (CH3)2CHOH.
chemical formula of ethanoic acid is CH₃COOH.
How many grams of KNO3 are required to prepare 0.250 L of 0.70 M solution?
Answer:
about 3
Explanation:
just did this for the points just being honiest
What is the conjugate base of CH3COOH in the reaction below?
CH₂COOH(aq) + H₂O(/) — H₂O¹(aq) + CH₂COO¯(aq)
O A. H₂0
OB. CH3COO
О с. он-
OD. H30+
Answer: B. [tex]\text{CH}_{3}\text{COO}^{+}[/tex]
Explanation:
To find the conjugate base, you add a hydrogen ion and add 1 to the overall charge.
CH[tex]_3[/tex]COO⁻ is the conjugate base of CH[tex]_3[/tex]COOH in the given reaction. Therefore, the correct option is option B.
What is conjugate base?Conjugate acids and bases are ideas included in the Bronsted-Lowry acid-base theory. An acid losses a hydrogen ion as it splits into its electrons in water. The conjugate base of the acid is the species that results.
A conjugate base comprises the base participant, X-, of two compounds that convert into one another by acquiring or losing a proton, according to a more comprehensive definition. In a chemical process, the conjugate base has the capacity to either gain and absorb a proton. The proton and hydrogen is given away in the process by the conjugate acid. CH[tex]_3[/tex]COO⁻ is the conjugate base of CH[tex]_3[/tex]COOH in the given reaction.
Therefore, the correct option is option B.
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URGENT!!! Based on the following reaction, how much water is produced when oxygen react with 1 mole of C₂H8?
C₂H8 (g) + 40₂ (g) →2CO2 (g) + 4H₂O(g)
Answer:
4 moles
Explanation:
For every mole of deuteriomethane consumed, 4 moles of water are produced.
So, the answer is 4 moles
select the correct answer from each drop down menu how do you the freezing point and boiling point of a solution compare with those of us pure solvent? The freezing point of the solution is ___ and the boiling point is _____ than that of its pure solvent.
Explanation:
select the correct answer from each drp down
PLEASE HELP!
The vapor pressure of benzene at 25 °C is 95.1 mm Hg and of toluene 28.4 mm Hg. The mass fractions of benzene and toluene in a solution are 0.5.
a) Calculate the partial pressure of benzene and toluene above the solution.
b) Calculate the total vapor pressure above the solution.
c) Calculate the vapor composition above the solution.
Benzene be B
Toluene be T
We have made then one lettered to make things easier
[tex]\sf P^0_B=95.1mmHg,P^0_T=28.4mmHg[/tex][tex]\sf x_B=x_T=0.5[/tex][tex]\\ \rm\Rrightarrow \dfrac{P^0_B-P_B}{P^0_B}=x_B[/tex]
[tex]\\ \rm\Rrightarrow 95.1-P_B=95.(0.5)[/tex]
[tex]\\ \rm\Rrightarrow 95.1-P_B=47.55[/tex]
[tex]\\ \rm\Rrightarrow P_B=47.55mmHg[/tex]
And
[tex]\\ \rm\Rrightarrow \dfrac{P^0_T-P_T}{P^0_T}=x_T[/tex]
[tex]\\ \rm\Rrightarrow 28.4-P_T=28.4(0.5)[/tex]
[tex]\\ \rm\Rrightarrow P_T=14.2mmHg[/tex]
Total vapour pressure
28.4+95.1123.6mmHgwhen energy is transferred does it increase or decrease
Answer:
About energy transfers:
Explanation:
When there is an energy transfer energy is neither created, nor destroyed. This means when that when one energy store decreases, one or more others must increase.
What is the equilibrium constant of a reaction?
A. It is the concentrations of products multiplied by the
concentrations of reactants.
о
B. It is the number of moles of reactants subtracted from the number
of moles of products.
C. It is the ratio of the concentrations of products to the
concentrations of reactants.
D. It is the ratio of the number of moles of products to the number of
moles of reactants.
Answer:
C. It is the ratio of the concentrations of products to the
concentrations of reactants.
Explanation:
Which two nuclides are isotopes of the same element
Answer:
1940K and 1939K Isotopes are two forms of the same element that have different numbers of neutrons in the nucleus. This means same symbol, and same atomic number (subscript), but different mass number (superscript).
The "iodine clock reaction" is a popular chemical demonstration. As part of that demonstration, the I−3 ion is generated in the reaction
S2O2−8(aq)+3I−(aq)⟶2SO2−4(aq)+I−3(aq)
In one trial, the unique rate of reaction was 6.93 μmol⋅L−1⋅s−1. What was the rate of reaction of iodide ions?
1. Initial Rate = _______ μmol⋅L−1⋅s−1 ??????
What was the rate of formation of sulfate ions?
2. Rate of formation = _______ μmol⋅L−1⋅s−1 ??????
In one trial, the unique rate of reaction was 6.93 μmol⋅L−1⋅s−1, the initial rate is 17.4 μmol⋅[tex]l^-^1[/tex]⋅[tex]s^-^1[/tex] and rate of formation of sulfate ions was 11.6 μmol⋅[tex]l^-^1[/tex]⋅[tex]s^-^1[/tex]
What is the rate of recation?Reaction rate, in chemistry, is the speed at which a chemical reaction proceeds.
[tex](S_2O_8)^-^2 (aq) + 3 I^-(aq)[/tex] → [tex]2 S0_4^-^2 (aq) + 3I^- (aq)[/tex]
Rate of the reaction = -Δ [[tex]S_20_8^-^2[/tex]] /Δ t = -1/3 Δ [[tex]I^-[/tex]] /Δ t
5.8 μmol⋅[tex]l^-^1[/tex]⋅[tex]s^-^1[/tex] = -1/3 Δ [[tex]I^-[/tex]] /Δ t
-Δ [[tex]I^-[/tex]] /Δ t =17.4 μmol⋅[tex]l^-^1[/tex]⋅[tex]s^-^1[/tex]
So the rate of reaction of iodide ion =17.4 μmol⋅[tex]l^-^1[/tex]⋅[tex]s^-^1[/tex]
+1/2Δ [[tex]S0_4^-^2[/tex]] /Δ t = rate of reaction
+1/2Δ [[tex]S0_4^-^2[/tex]] /Δ t = 5.8 μmol⋅[tex]l^-^1[/tex]⋅[tex]s^-^1[/tex]
+ Δ [[tex]S0_4^-^2[/tex]] /Δ t = 5.8 X 2 = 11.6 μmol⋅[tex]l^-^1[/tex]⋅[tex]s^-^1[/tex]
Rate of formation of sulfate ions=11.6 μmol⋅[tex]l^-^1[/tex]⋅[tex]s^-^1[/tex]
Hence, the initial rate is 17.4 μmol⋅[tex]l^-^1[/tex]⋅[tex]s^-^1[/tex] and rate of formation of sulfate ions was 11.6 μmol⋅[tex]l^-^1[/tex]⋅[tex]s^-^1[/tex]
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How many moles of a gas can be contained in a 1600-cm° flask at 25°C and 75 kPa?
Volume=1600cm³=1.6dm³=1.6L
Temperature=25°C=273+25=298K
Pressure=75000Pa
Now
Apply ideal gas equation
PV=nRTn=PV/RTn=75000(1.6)/8.314(298)n=48.43molThe number of moles needed is
n=48.43mol.
Calculations
Given the values of the volume and temperature, we would convert them to the required units.
Volume=1600cm³=1.6dm³=1.6L
Temperature=25°C=273+25=298K
Pressure=75000Pa
We would use the ideal gas equation
PV=nRT
n=PV/RT
n=75000(1.6)/8.314(298)
n=48.43mol
What most likely happens when water vapor cools?
It changes into gas.
It changes into liquid.
Its temperature increases.
Its temperature remains constant.
Answer:
hello :)
Explanation:
Water vapor in the air reaches its dew point as it cools in the air around the can, forming liquid drops of water. Condensation is the process where water vapor becomes liquid.
The radius of a single atom of a generic element X is 169 picometers (pm) and a crystal of X has a unit cell that is body-centered cubic. Calculate the volume of the unit cell.
The volume of the unit cell is 2.67 x 10⁻²⁸ m³.
What is the volume of a unit cell of a body-centered cubic crystal?In a body-centered cubic unit cell, the volume occupied by the particles of the substance is about 68% of the total unit cell.
Assuming that a single atomic a sphere, the volume is:
Volume(atom) = 4/3 x π x r³
Volume(atom) = 4/3 x π x (169 x 10⁻¹²)³
Volume(atom) = 2.02 x 10⁻²⁹ m³
There are a total of 9 atoms in a body-centered unit cell, so the total volume occupied by atoms is:
2.02 x 10⁻²⁹ x 9
= 1.82 x 10⁻²⁸ m³
Volume of cell = (1.15 x 10⁻²⁸ ) / 0.68
Volume of cell = 2.67 x 10⁻²⁸ m³
Therefore, the volume of the unit cell is 2.67 x 10⁻²⁸ m³.
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20.0 g of bromic acid, HBrO3, is reacted with excess HBr.
HBrO3 (aq) + 5 HBr (aq) → 3 H2O (l) + 3 Br2 (aq)
What is the theoretical yield of Br2 for this reaction? Round your answer to the nearest gram.
After Rounding off The percentage yield is 64%
What is Percentage Yield ?It is the ratio of actual yield to theoretical yield multiplied by 100% .
It is given in the question
20.0 g of bromic acid, HBrO3, is reacted with excess HBr.
The reaction is
HBrO₃ (aq) + 5 HBr (aq) → 3 H₂O (l) + 3 Br₂ (aq)
Actual yield = 47.3 grams
Molecular weight of Bromic Acid is 128.91 gram
Moles of Bromic Acid = 20/128.91 = 0.155 mole
Mole fraction ratio of Bromic Acid to Bromine is 1 :3
Therefore for 0.155 mole of Bromic Acid 3 * 0.155 = 0.465 mole of Bromine is produced.
1 mole of Bromine = 159.8 grams of Bromine
0.465 of Bromine = 74.31 grams of Bromine
Percentage Yield = (47.3/74.31)*100 = 63.65 %
After Rounding off The percentage yield is 64% .
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Answer:
74g
Explanation:
The other person had said that the Percentage Yield = (47.3/74.31)*100 = 63.65 %
So, since to find the percent yield you have to divide the actual yield by the theoretical yield, I would assume the theoretical yield is 74.31g (74g if you round to the nearest gram)
Calculate AH for the reaction:
2N2 (g) + 6H20 (g) → 302 (g) + 4NH3(g)
Answer:
Explanation:
4NH₃ (g) + 3O₂ (g) ⇒ 2N₂ (g) + 6H₂ O(1)
Δ[tex]H_r={\sum}{ \Delta }H_f(\text{product})-{\sum}{ \Delta }H_f(\text{reactant})[/tex]
ΔH r =(2ΔH f(N 2 )+6ΔH f (H 2 O(l)))−(4ΔH f (NH 3 (g))+3ΔH f (O 2 (g)))
ΔH rex =[2×0+6×(−286)]−[4×(−46)+3×0]=−1716+186
ΔH rex =−1532kJ/mol
Thermodynamics is a branch of physical chemistry that studies heat and its effects and interactions. Governed by the four main laws, thermodynamics plays a huge role in physics and chemistry, and is also responsible for the law of conservation of energy, a fundamental rule in science.
ASAP 100 POINTS Which molecules carries instructions for inherited traits
A.DNA
B CARbohydrate
C.Protein
D.Lipid
Answer:
A.DNA
Explanation:
Ahaa Its gona be right
Answer:
D.N.A.
Explanation:
Hi student! Let me help you out on this question.
D.N.A. is the molecule which carries instructions for inherited traits.
[tex]\therefore,Option\quad A \quad is \quad correct[/tex]
Hope that this helped! have a good day ahead.
2. Calculate the mass, in grams, for 3.47 moles of each of the following:
a. lead(II) acetate
b. sodium chloride
Explanation:
1 moles Lead(II) Acetate to grams = 325.28804 grams
3.47 moles Lead(II) Acetate to grams = 325.28804 ×3.47 grams=1128.749 grams
1 moles sodium chloride to grams=58.5 grams
3.47 moles sodium chloride to grams=58.5×3.47 grams
=202.995 grams
Consider the following reversible reaction:
2 CO(g) + O₂(g) 2CO₂(g). Describe a way to increase the CO concentration at equilibrium. Explain your reasoning.
The given equilibrium reaction indicates the reaction between carbon monoxide and the oxygen and forms carbon dioxide. In this reaction, by increasing the concentration of the carbon monoxide, the equilibrium shifts towards the right. Since, the reactant concentration increases, the equilibrium stress decreases the concentration of the reactants and therefore, the equilibrium shift towards the right side of the equation.
reaction indicates that carbon monoxide reacts with oxygen and forms carbon dioxide gas.
By increasing the concentration of carbon monoxide image, the equilibrium in the reaction shifts towards the right.
The effect of change of pressure, concentration and temperature on the state of equilibrium can be predicted with the help of a principle known as Le Chatelier's principle. Here by increasing the concentration of CO₂, the amount of CO formation can increase.
What is Le Chatelier's principle?If a system in equilibrium is subjected to a change in concentration, pressure or temperature, the equilibrium shifts in the direction that tends to reduce or to counteract the effect of change. When the concentration of any substance in equilibrium is increased, the equilibrium shifts in the direction which decreases the concentration of that substance.
On other hand, increasing the concentration of any of the products results in shifting the equilibrium in the backward reaction forming more products. So here increasing the amount of CO₂, shifts equilibrium in the backward direction and forms more amount of CO.
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Convert 26.02 x 1023 molecules of C2H8 to grams. Round your answer to the hundredths place.
No of molecules=26.02×10²³molecules
No of moles
26.02×10²³/6.023×10²³4.3molMolar mass
C2H82(12)+8(1)24+832g/molMass
Moles×Molar mass32(4.3)137.6g[tex]\\ \tt{:}\longrightarrow No\:of\:moles=\dfrac{Molecules}{Avagadro\:no}[/tex]
[tex]\\ \tt{:}\longrightarrow No\:of\:moles=\dfrac{26.02\times 10^{23}}{6.023\times 10^{23}}[/tex]
[tex]\\ \tt{:}\longrightarrow No\:of\:moles=4.32mol[/tex]
Molar mass of Ethane=32g/molWe need the mass
[tex]\\ \tt{:}\longrightarrow No\:of\:moles\times molar\:mass[/tex]
[tex]\\ \tt{:}\longrightarrow 32(4.32)[/tex]
[tex]\\ \tt{:}\longrightarrow 138.24g[/tex]
a 40 g sample of water absorbs 500 calories of energy, how much did the water temp changed?
2.99 °C is the change in temperature if a 40 g sample of water absorbs 500 calories of energy.
What is specific heat capacity?The specific heat capacity is defined as the quantity of heat (J) absorbed per unit mass (kg) of the material when its temperature increases 1 K (or 1 °C), and its units are J/(kg K) or J/(kg °C).
Given data:
m = 40 g
Q = 500 J
Specific heat capacity of water = 4.18 J/g°C
Change in Temperature =?
The formula for Heat Energy is given by:
Q = mcp∆T
where: Q - Heat Energy
m - mass
cp - specific heat
∆T = change in temperature, [tex]T_2 - T_1[/tex]
Solution:
Substituting the value of m, specific heat capacity of water and Q in the formula,
500 J = (40 g)(4.18 J/g°C)(∆T)
∆T = 2.99 °C
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A gas cylinder contains 5.0 kg of propane. How many propane molecules are in the cylinder? The Avogadro constant, L = 6.022 x 1023 mol^-1
A 6.8 × 10^22
B 7.2 x 10^22
C 6.8 × 10^25
D 7.2 x 10^25
[1 mark]
Answer:
Here's your answer.
M(C3H8) = 44 g/mol
n(C3H8) = 5000 (g)/44 (g/mol) = 113,6 mol
[tex] N = n \times N_{a} = 113,6 \times 6,02 \times {10}^{23} \\ \\ = 684,1 \times 10 ^{23} \sf{molecules} [/tex]
Hope it helps you from my sideCalculate 5.1234 + 0.033÷ 1.650 and report to the correct number of significant figures.
5.1434 contains 5 significant figures and 4 decimals.
What is a significant figure?All zeros that occur between any two non-zero digits are significant. For example, 108.0097 contains seven significant digits.
Calculation:
5.1234 + 0.033÷ 1.650 = 5.1434
5.1434 contains 5 significant figures and 4 decimals. 5.1434 rounded to 4 sig figs is 5.143, to 3 sig figs is 5.14, and to 2 sig figs is 5.1.
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A sample of gas is collected in a flask with a volume of 267 mL at a pressure of 771 mmHg and a temperature of 21C. If the mass of the gas is 1.05 g, what is the molar mass of the gas?
Answer:
M=93.5g/mol
Explanation:
I did this in class and it was a review. :)