What is the standard enthalpy of a reaction for which the equilibrium constant is (a) doubled, (b) halved when the temperature is increased by 15 K at 310 K
Answer:
a) 48KJ
b) -48KJ
Explanation:
Given that;
ln(K2/K1) = ΔH°/R(1/T2 - 1/T1)
K2= equilibrium constant at T2
K1 = equilibrum constant at T1
R = gas constant
T1 = initial temperature
T2 = final temperature
When we double the equilibrium constant K1; K2 = 2K1
T1 = 310 K
T2 = 310 + 15 = 325 K
ln(2K1/K1) =- ΔH°/R(1/T2 - 1/T1)
ln2 = -ΔH°/8.314(1/325 - 1/310)
0.693 = -ΔH°/8.314(3.08 * 10^-3 - 3.2 * 10^-3)
0.693 = -ΔH°/8.314 (-0.00012)
0.693 = 0.00012ΔH°/8.314
0.693 * 8.314 = 0.00012ΔH°
ΔH° = 0.693 * 8.314/0.00012
ΔH° = 48KJ
b) K2 =K1/2
ln(K1/2/K1) =- ΔH°/R(1/T2 - 1/T1)
ln (1/2) = -ΔH°/8.314 (1/325 - 1/310)
-0.693 = -ΔH°/8.314 (-0.00012)
-0.693 = 0.00012ΔH°/8.314
-0.693 * 8.314 = 0.00012ΔH°
ΔH°= -0.693 * 8.314/0.00012
ΔH°= -48KJ
Which of the following issues do you think is most important when addressing food problems on a global scale?
Political instability in third-world countries
The need for exotic spices to make foods taste better
Removing chemicals from pesticides that could be harmful to the environment
Rising global temperatures that intensify droughts
Producing foods that use less land and feed more people
Ensuring humane and healthy treatment of farm animals
Answer:
Removing chemicals from pesticides that could be harmful to the environment
Explanation:
This is a main food issue that is not only state-wide but global
1st option doesn't say anything about food issues which makes it unnecessary to address
2nd option is a suggestion and not necessary
4th option is again not exactly towards food issues so no need to address for this question
5th option isn't a issue as much as just something we could do for convenience and stability
6th option should already be in act and is unlawful to do which leads me to the correct option
3rd option is correct because it is still okay globally to put chemicals into our food to keep it looking better for longer amounts of time. Yet it is dangerous to us living beings and the environment.
So therefore 3rd option is correct
(have a great day!)
Plastic is used to cover the copper wire in the power codes of appliances because plastic differs from copper in _________
Answer:
in copper from different plastics because appliances of codes to power day in wire copper the cover to use to plastic
A bicyclist travels the first 800 m of a trip with a speed of 10 m/s, the next 500 m with an
average speed of 5 m/s and the final 1200 m at a speed of 13 m/s. Find the average speed of
the bicyclist for this trip.
Answer:9.18 m/s
Explanation:
The average speed for the entire trip is found ......total distance/total time. Remember r*t=d, so divide both sides by t and get r = d/t.
So the cyclist went 800+500+1200 m = 2500 m for total distance.
10t =800 leads to t=80 sec
5t=500 leads to t=100 sec
13t = 1200 leads to t = 92.3 sec
total time is 272.3 sec
Average speed for the entire trip is 2500 / 272.3 = 9.18 m/s
4Al(s) + 302(g) -> 2Al2O3(s)
How many oxygen atoms are in the product when 4 atoms of solid
aluminum react with 3 molecules of oxygen gas?
Answer:
6 oxygen atoms
Explanation:
when 4 atoms of solid aluminium react with 3 molecules of oxygen gas, 6 oxygen atoms will be in the product
How does Avogadro's number relate to a mole?
A. Avogadro's number is used to measure mass, and a mole is used
to count particles.
B. A mole is a larger amount than Avogadro's number.
C. Avogadro's number represents the number of particles in one
mole.
O
D. Avogadro's number applies to any item, but a mole can only be
used to count atoms.
Answer:
C.) Avogadro's number represents the number of particles in one
mole.
Explanation:
Considering the definition of Avogadro's number, the correct answer is option C. Avogadro's number represents the number of particles in one mole.
Avogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023×10²³ particles per mole.
Avogadro's number represents a quantity without an associated physical dimension, so it is considered a pure number that allows describing a physical characteristic without an explicit dimension or unit of expression.
Avogadro's number applies to any substance.
Finally, the correct answer is option C. Avogadro's number represents the number of particles in one mole.
Learn more about Avogadro's Number:
brainly.com/question/11907018?referrer=searchResults brainly.com/question/1445383?referrer=searchResults brainly.com/question/1528951?referrer=searchResultsIs CO a acidic
or basic
oxide and why
Answer:
Carbon monoxide is generally treated as though it was a neutral oxide, however truth be told it is extremely, somewhat acidic. It doesn't respond with water, yet it will respond with hot concentrated sodium hydroxide answer for give an answer of sodium methanoate.
Explanation:
Can someone please walk me through this?-- 25 pts!
Calculate the change of enthalpy for the reaction CH4 (g) + NH3 (g) --> HCN (g) +3H2 (g) from the following reactions:
Reaction 1: N2 (g) + 3H2 (g) --> 2NH3 (g); Change in enthalpy(∆ H): -91.8 kJ/mol
Reaction 2: C (s, graphite) + 2H2 (g) --> CH4 (g); Change in enthalpy(∆ H): -74.9 kJ/mol
Reaction 3: H2 (g) + 2C (s, graphite) + N2 (g) --> 2HCN (g); Change in enthalpy(∆ H): +270.3 kJ/mol
I have to include the following:
>The numerical answer with correct units.
>State which reactions, if any, you had to "Flip". ("Flipping" refers to modifying one of the reactions above to make a chemical be present on the other side-- like flipping an N2 that is on the reaction side. If it needs to be on the product side, you flip the reaction. Hope that makes sense.)
>State which reactions you had to multiply, if any, to get the correct amount of the compound. Also, include how much you multiplied the reaction by.
NH3(g) + CH4(g) ⇒ HCN + 3H2 ∆ H:255.95
Further explanationGiven
Reaction and the enthalpy
Required
The change of enthalpy
Solution
Reaction 1
N2 (g) + 3H2 (g) --> 2NH3 ∆ H: -91.8 kJ/mol⇒reverse
2NH3 ⇒ N2 (g) + 3H2 (g) ∆ H: +91.8 kJ/mol
Reaction 2
C (s, graphite) + 2H2 (g)⇒ CH4 (g) ∆H: -74.9 kJ/mol ⇒reverse
CH4 (g) ⇒ C (s, graphite) + 2H2 (g) ∆H: +74.9 kJ/mol ⇒ x2
2CH4 (g) ⇒ 2C (s, graphite) + 4H2 (g) ∆H: +149.8 kJ/mo
Reaction 3
H2 (g) + 2C (s, graphite) + N2 (g) ⇒ 2HCN (g);∆ H: +270.3 kJ/mol
Add up all the reactions and remove the same compound from different sides :
2NH3 ⇒ N2 (g) + 3H2 (g) ∆ H: +91.8 kJ/mol
2CH4 (g) ⇒ 2C (s, graphite) + 4H2 (g) ∆H: +149.8 kJ/mol
H2 (g) + 2C (s, graphite) + N2 (g) ⇒ 2HCN (g) ∆ H: +270.3 kJ/mol
-----------------------------------------------------------------------------------------
2NH3(g) + 2CH4(g) ⇒ 2HCN + 6H2 ∆ H: 511.9 ⇒ :2
NH3(g) + CH4(g) ⇒ HCN + 3H2 ∆ H:255.95
What information does the potential energy diagram reveal about a reaction?
Answer: The energy changes that occur during a chemical reaction can be shown in a diagram called a potential energy diagram, or sometimes called a reaction progress curve. A potential energy diagram shows the change in potential energy of a system as reactants are converted into products.
Explanation:
Answer:
It shows whether the reaction is exothermic or endothermic.
Explanation:
A sample of water is heated from 10 °C to 50 °C using 286 J of energy. What is the mass of water that was heated? help
Answer:
Mass of water == 1.71 g
Explanation:
Given data:
Initial temperature of water = 10°C
Final temperature of water = 50°C
Energy absorbed = 286 J
Mass of water = ?
Solution:
Specific heat capacity:
It is the amount of heat required to raise the temperature of one gram of substance by one degree.
Specific heat capacity of water is 4.18 J/g.°C
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 50°C - 10°C
ΔT = 40°C
by putting values,
286 J = m × 4.18 J/g.°C × 40°C
286 J = m × 167.2 J/g
m = 286 J / 167.2 J/g
m = 1.71 g
Which type of matter would transmit sound
waves fastest?
A. air at 5°C
B. air at 20°C
C. ice at 0°C
.D. seawater at 20°C
C.ice at 0 degree
Explanation:
because sound transmit faster in solid medium as there molecules are cosely packed
Answer:
The Answer to this question is given below in this explanation section.
Explanation:
"C" option is correct
"ice at 0°C"
sound waves can only travel through a solid,liquid or gas medium.They travel fastest in solids,then liquid and slowest in gases.
Three phases of matter(gas,liquid and solid) sound wave travel in the slowest through gases fastest through solids.Sound wave need to travel through a medium such as solid liquid and gases.The sound wave move through each of these medium by vibrating the molecule in the matter.The molecule in solid are packed very tightly.Liquid as not packed are tightly.And gases are very loosely packed.This enables sound to travel much faster through a solid than gas.Sound travel about four time faster and further in water than it does in air.Sound waves travel about thirteen times faster in wood than air.They also travel faster on hotter days as the molecule bump into each other more often then when it is cold.Sound travels more quickly through solid then through liquids and gases because the molecules of a solid are closer together and,therefore can transmit the vibration faster.sound travels most slowly through gases because the molecule of a gas are farthest apart.
A compound with the empirical formula CH2 was found to have a molar mass of approximately 84g. What is the molecular formula of the compound?
Answer:
C6H12
Explanation:
Molar mass of C =12.0 H=1.0
12x + 2(1x) = 84
x = 6
so it should be C6H12
The molecular formula of the compound will be C₇H₁₄.
What is the empirical formula?The empirical formula of the compound gives the simplest ratio of the number of different elements present in a compound. The molecular formula of the compound provides the actual number of each element present in a compound. This formula is generally used and can be determined as a multiple of the empirical formula of a compound.
The empirical formula offers the ratio of the number of each atom in a given compound. The composition of a compound is directly determined by its empirical formula.
Given, the empirical formula of the compound is CH₂.
The empirical formula mass of the compound = 12 + 2 = 14 g
The molar mass of the compound = 84 g
The multiple will be = 84/12 = 7
The molecular formula of the compound = (CH₂)₇ = C₇H₁₄
Therefore, the molecular formula of the compound is C₇H₁₄.
Learn more about the empirical formula, here:
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In a chemical reaction which cannot occur:
Select one:
a. new elements are formed
b. heat is released
c. light is produced
d. a temperature change
Explanation:
Light can't get produced whilst a chemical reaction.
1) Why are most fossils found in sedimentary rocks? *
10 points
A. Sedimentary rocks are not very old.
B. Organisms live only in areas with sedimentary rock
C. Organisms can be preserved in sedimentary rock
D. Sedimentary rocks are found only if the surface of the ground.
Answer:
i think it might be c
Explanation:
i'm not positive though
Answer:
C
Explanation:
Sedimentary rocks can contain fossils because, unlike most igneous and metamorphic rocks, they form at temperatures and pressures that do not destroy fossil remains.
H2O2 → H2O + O2 as a balanced equation
Answer:
2H2O2 → O2 + 2H2O
Explanation:
2H2O2
H : 2x2= 4
O : 2x2=4
O2 + 2H2O
H : 2x2=4
O : 2+2=4
First, be sure to count all of H and O atoms on each side of the chemical equation. Once you know how many of each type of atom you have you can only change the coefficients (the numbers in front of atoms or compounds) in order to balance the equation.
How many moles are in 1.806 x 1024 molecules of bromine?
2.999 mol Br
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Using Dimensional AnalysisAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Explanation:Step 1: Define
1.806 × 10²⁴ molecules Br
Step 2: Identify Conversions
Avogadro's Number
Step 3: Convert
[tex]\displaystyle 1.806 \cdot 10^{24} \ molecules \ Br(\frac{1 \ mol \ Br}{6.022 \cdot 10^{23} \ molecules \ Br} )[/tex] = 2.999 mol Br
Step 4: Check
We are given 4 sig figs. Follow sig fig rules and round.
Our final answer is already in 4 sig figs, so there is no need to round.
Answer:
[tex]\boxed {\boxed {\sf About \ 2.999 \ moles \ of \ bromine}}[/tex]
Explanation:
To convert from moles to molecules, we must use Avogadro's Number.
[tex]6.022*10^{23}[/tex]
This tells us the number of particles (atoms, molecules, ions, etc) in 1 mole. In this problem, the particles are molecules of bromine in 1 mole of bromine.
[tex]6.022*10^{23} \ molecules \ Br / 1 \ mol \ Br[/tex]
1. Convert from moles to molecules
Use Avogadro's number as a fraction or ratio.
[tex]\frac{6.022 *10^{23} \ molecules \ Br}{1 \ mol \ Br}[/tex]
Multiply this fraction by the given number of bromine molecules.
[tex]1.806 *10^{24} molecules \ Br *\frac{6.022 *10^{23} \ molecules \ Br}{1 \ mol \ Br}[/tex]
Flip the fraction so the molecules of bromine can cancel out.
[tex]1.806 *10^{24} \ molecules \ Br* \frac{1 \ mol \ Br}{6.022 *10^{23} \ molecules \ Br}[/tex]
[tex]1.806 *10^{24} * \frac{1 \ mol \ Br}{6.022 *10^{23}}[/tex]
Multiply and condense the expression into 1 fraction.
[tex]\frac{1.806 *10^{24} \ mol \ Br}{6.022 *10^{23} }[/tex]
Divide.
[tex]2.999003653 \ mol \ Br[/tex]
2. Round
The original measurement, 1.806*10^24 has 4 significant figures (1, 8, 0, and 6). We must round our answer to 4 sig figs. For the answer we found, that is the thousandth place.
[tex]2.999003653 \ mol \ Br[/tex]
The 0 in the ten-thousandth place tels us to leave the 9 in the thousandth place.
[tex]\approx 2.999 \ mol \ Br[/tex]
There are about 2.999 moles of bromine in 2.806 *10^23 molecules.
You have 1.2 moles of NH 4 NO 3 in a 6 M solution. How many liters is that?
A) 0.5 L
B) 0.72 M
C) 0.72 L
D) 2 L
Answer:
Volume = 0.2 L
Explanation:
Given data:
Number of moles of NH₄NO₃ = 1.2 mol
Molarity of solution = 6 M
Volume of solution = ?
Solution:
Formula:
Molarity = number of moles / volume of solution
by putting values,
6 M = 1.2 mol / Volume
Volume = 1.2 mol / 6 mol/L
Volume = 0.2 L
What is the total pressure in units of kPa in a 7.85 L container that contains 4.45 moles of N2 and 2.45 moles of O2 at a temperature of 307 K?
Answer:
32.42
Explanation:
fda
S + 6 HNO3 --> H2SO4 + 6 NO2 + 2 H2O
How many moles of HNO3 must react to form 14.5 moles of H2O?
Answer:
43.5 moles of HNO₃.
Explanation:
The balanced equation for the reaction is given below:
S + 6HNO₃ —> H₂SO₄ + 6NO₂ + 2H₂O
From the balanced equation above,
6 moles of HNO₃ reacted to produce 2 moles of H₂O.
Finally, we shall determine the number of mole of HNO₃ required to produce 14.5 moles of H₂O.
This can be obtained as illustrated below:
From the balanced equation above,
6 moles of HNO₃ reacted to produce 2 moles of H₂O.
Therefore, Xmol of HNO₃ will react to produce 14.5 moles of H₂O i.e
Xmol of HNO₃ = (6 × 14.5)/2
Xmol of HNO₃ = 43.5 moles
Therefore, 43.5 moles of HNO₃ is required to produce 14.5 moles of H₂O.
Look at the food web below.
grass
wheat
grasshopper
mouse
toad
snake
hawk
Which organisms would be at the bottom of the energy pyramid for this
ecosystem?
Explanation:
At the bottom of the energy pyramid, there would be the producers.
In here the producers are grass and wheat. (D)
what kind (ionic or covalent) bond is FeCl2 + Na2CO3? (iron (II) chloride + sodium carbonate).
Answer:
corbonate
Explanation:
i think so. not sure
what happens after we die? spirtually and physically
Help me asap it’s for my chem
Squeeze out juice from an unripe orange. Put tiny piece of Zinc or Aluminum foil into the juice. Leave the mixture for a few minutes. State and explain your observation.
Answer:
A colorless odorless gas evolves
Explanation:
Orange juice is highly acidic. Unripe orange juice is even more acidic! As a result of this, unripe orange juice irritate the digestive tract.
We know that metals that are high up in the activity series evolves hydrogen gas when in contact with acids.
Hence, given the low pH of unripe orange juice, zinc or aluminium will evolve colorless odorless hydrogen gas after some minutes.
To separate a mixture of large gravel and sand, the most effective method would be
Answer:
Sieve
Explanation:
A sieve or screen would be the best tool to use when separating a mixture of sand and gravel.
Answer:
the third option on edge:)
Explanation:
Refer to the electron distribution to answer 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s¹. What would be the period or series number of the atom?
A.6
B.5
C.4
D.3
I need the answer now plss help
C.5
Given:
Electron distribution: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s¹.
A number of electrons present in valence shell of penultimate Shell represents the group of elements.
For s block elements: No. of group=number of valence shell electron.
p block elements: no. of group= 2 + 10 + number of valence electrons.
d block elements: no. of group= number(n-1)d electrons + number of electrons in nth shell.
Here, the differential electron is in p orbital hence, it belongs to p block
No. of group= 2+ 10 + 3=15 i.e. 15th group or VA group.
Therefore, the correct option is B.
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Which physical property is found in alkali metals that isn't found in alkaline earth metals?
Question 6 options:
Alkali metals have two electrons in their outer orbital.
Alkali metals bond directly with carbon to form carbides.
Alkali metals are soft and have low melting points.
Alkali metals are diamagnetic.
Answer:
Alkali metals are soft and have low melting points.
SHOW WORK
A person weighs 150 lbs, what is that weight in kg?
A family consumes 2.5 gallons of milk per week. How many liters of milk do they need to buy for one month? (Assume there are exactly 4 weeks in 1 month) SHOW WORK
Answer:
37.85 liters
Explanation:
they need 10 gallons for a month (2.5*4)
after that, convert gallons to liters (conversion to liters= 3.785)
10*3.7585= 37.85
What is true about elements that are in the same column group or family
The given question is incomplete. The complete question is:
Which is true of Elements on a periodic table in the same group (family)?
A; Elements in the same family have similar chemical properties because they have the same number of electron shells.
B; Elements in the same family have similar chemical properties because they have the same number of valence electrons.
C; Elements in the same family have few similar properties as they have different numbers of electron shells.
D; Elements in the same family are always the same type of Elements and have the same number of protons.
Answer: B; Elements in the same family have similar chemical properties because they have the same number of valence electrons.
Explanation:
Elements are distributed in groups and periods in a periodic table.
Elements that belong to same groups will show similar chemical properties because they have same number of valence electrons. The chemical reactivity of elements is governed by the valence electrons present in the element.
Example: Flourine, chlorine and bromine are elements which belong to Group 17. They have 9, 17 and 35 electrons respectively and contain 7 valence electrons each and need one electron to complete their octet.