The amount of the nitrogen gas, N₂ molecules present is 2.68×10²² molecules
Avogadro's hypothesis1 mole of N₂ = 6.02×10²³ molecules
How to determine the mole of N₂We'll begin by calculating the number of mole of N₂. This can be obtained as follow:
Mass of N₂ = 1.25 gMolar mass of N₂ = 28.02 g/molMole of N₂ =?Mole = mass / molar mass
Mole of N₂ = 1.25 / 28.02
Mole of N₂ = 0.0446 mole
How to determine the molecules of N₂ presentFrom Avogadro's hypothesis,
1 mole of N₂ = 6.02×10²³ molecules
Therefore,
0.0446 mole N₂ = 0.0446 × 6.02×10²³
0.0446 mole N₂ = 2.68×10²² molecules
Thus, the molecules of N₂ present is 2.68×10²² molecules
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What is the correct iupac name of CH3-CH2-CH2CHO ?
the correct IUPAC name of the compound is 1-Butanal.
What are IUPAC names?It is a system of naming organic compounds based on the longest carbon-to-carbon single bonds. It does not matter whether these longest chains are continuous or in a ring.
Thus, when the compound with the chemical formula, CH3-CH2-CH2CHO is considered. The longest carbon-to-carbon chain is 4. The 1st carbon carries a functional group known as an aldehyde.
Aldehydes are equipped with the carbonyl group and have the general formula R−CH=O. They are also sometimes referred to as formyl.
Aldehydes are named after their parent alkane chains with a slight modification. The 'e' is replaced with 'al'
The aldehyde in this case has four carbons. This means that the parent alkane is Butane. Therefore, the name of the compound will be 1-Butanal.
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The equilibrium expression for the the reaction:
H2(g) + I2(g) <--> 2HI(g) would be:
Group of answer choices
A. K = 2[HI] / [H2][I2]
B. K = [H2][I2] / [HI]2
C. K = [H2][I2] / 2[HI]
D. K = [HI]2 / [H2][I2]
Answer:
D.) [tex]K = \frac{[HI]^{2} }{[H_{2} ] [I_{2} ] }[/tex]
Explanation:
The general equilibrium expression looks like this:
[tex]K = \frac{[C]^{c} [D]^{d} }{[A]^{a} [B]^{b} }[/tex]
In this expression,
-----> K = equilibrium constant
-----> uppercase letters = formulas
-----> lowercase letters = balanced equation coefficients
In this case, all of the reactants and products are gases, so they should all be included in the expression. The products are in the numerator and the reactants are in the denominator. This makes the correct expression:
[tex]K = \frac{[HI]^{c}}{[H_{2} ]^{a} [I_{2} ]^{b} }[/tex] <----- Insert formulas
[tex]K = \frac{[HI]^{2}}{[H_{2} ] [I_{2} ] }[/tex] <----- Insert coefficients
What is the name of the compound Fe3(PO4)2?
Group of answer choices
A. Iron (III) Phosphide
B. Iron (II) Phosphide
C. Iron (II) Phosphate
D. Iron (III) Phosphate
Answer:
Iron (II) Phosphate
Explanation:
The symbol of iron Fe and phosphate PO4 are reacted to form Iron Phosphate
The name of the compound Fe₃(PO₄)₂ is Iron(II) Phosphate. In this case, the iron ion is in the +2 oxidation state, and therefore, the compound is named "Iron(II) Phosphate." Hence option C is correct.
In this compound "Fe" represents the chemical symbol for iron. "3" following Fe indicates the presence of three iron atoms in the compound.
"(PO₄)" represents the phosphate ion, which consists of one phosphorus atom and four oxygen atoms. "2" following (PO₄) indicates the presence of two phosphate ions in the compound.
When naming this compound, we use Roman numerals in parentheses to indicate the oxidation state of the metal ion since iron can exist in different oxidation states.
Therefore, option C) Iron (II) Phosphate is correct.
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Burning 2.00 mol of hydrogen releases 483.6 kJ of energy. Determine how much energy, in kilojoules, must be supplied to convert 3.00 mol of water vapor into hydrogen gas and oxygen gas.
Express your answer with the appropriate units.
The amount of heat energy (in KJ) needed to convert 3 moles of water vapor into hydrogen gas and oxygen gas is 1450.8 KJ
Balanced equationWe'll begin by writing the balanced equation. This is illustrated below:
2H₂ + O₂ --> 2H₂O ΔH = 483.6 KJ
From the balanced equation above,
2 moles of water (H₂O) required 483.6 KJ to produce hydrogen gas and oxygen gas
How to determine the heat energy needed to convert 3 moles of water to hydrogen gas and oxygen gasThe heat energy needed to convert 3 moles of water can be obtained as illustrated below:
From the balanced equation above,
2 moles of water (H₂O) required 483.6 KJ to produce hydrogen gas and oxygen gas
Therefore,
3 moles of water (H₂O) will require = 3 × 483.6 = 1450.8 KJ to produce hydrogen gas and oxygen gas
Thus, we can conclude that the energy needed to convert 3 moles of water is 1450.8 KJ
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7. What is the molarity of the nitrate ion that is found in a solution made by dissolving 6.25g
of aluminum nitrate in a total volume of 325.0mL?
Answer:
0.271 M NO₃⁻
Explanation:
To find the molarity of the nitrate ion (NO₃⁻), you need to (1) convert grams to moles (via molar mass), then (2) convert moles Al(NO₃)₃ to moles NO₃⁻, then (3) convert mL to L, and then (4) calculate the molarity. When (Al(NO₃)₃) dissolves in water, it dissociates into 3 nitrate ions. The final answer should have 3 sig figs.
(Steps 1 + 2)
Molar Mass (Al(NO₃)₃): 26.982 g/mol + 3(14.007 g/mol) + 9(15.998 g/mol)
Molar Mass (Al(NO₃)₃): 212.985 g/mol
1 Al(NO₃)₃ = 1 Al³⁺ and 3 NO₃⁻
6.25 g Al(NO₃)₃ 1 mole 3 moles NO₃⁻
------------------------- x ----------------- x ----------------------- = 0.0880 moles NO₃⁻
212.985 g 1 mole Al(NO₃)₃
(Steps 3 + 4)
325.0 mL / 1,000 = 0.3250 L
Molarity = moles / volume
Molarity = 0.0880 moles / 0.3250 L
Molarity = 0.271 M
What does quantization refer to?
OA. Being able to move around freely
OB. Involving uncertainty in knowing a value
OC. Having a specific set of possible values
OD. Occupying a place in a continuous range
Answer:
Having a specific set of possible values
Find the amount of heat energy needed to convert 400 grams of ice at -38°C to steam at 160°C.
Group of answer choices
A. 246840 Joules
B. 159984 Joules
C. 331056 Joules
D. 1284440 Joules
The amount of heat energy needed to convert 400 g of ice at -38 °C to steam at 160 °C is 1.28×10⁶ J (Option D)
How to determine the heat required change the temperature from –38 °C to 0 °C Mass (M) = 400 g = 400 / 1000 = 0.4 KgInitial temperature (T₁) = –25 °C Final temperature (T₂) = 0 °Change in temperature (ΔT) = 0 – (–38) = 38 °C Specific heat capacity (C) = 2050 J/(kg·°C)Heat (Q₁) =?Q = MCΔT
Q₁ = 0.4 × 2050 × 38
Q₁ = 31160 J
How to determine the heat required to melt the ice at 0 °CMass (m) = 0.4 KgLatent heat of fusion (L) = 334 KJ/Kg = 334 × 1000 = 334000 J/KgHeat (Q₂) =?Q = mL
Q₂ = 0.4 × 334000
Q₂ = 133600 J
How to determine the heat required to change the temperature from 0 °C to 100 °C Mass (M) = 0.4 KgInitial temperature (T₁) = 0 °C Final temperature (T₂) = 100 °CChange in temperature (ΔT) = 100 – 0 = 100 °C Specific heat capacity (C) = 4180 J/(kg·°C)Heat (Q₃) =?Q = MCΔT
Q₃ = 0.4 × 4180 × 100
Q₃ = 167200 J
How to determine the heat required to vaporize the water at 100 °CMass (m) = 0.4 KgLatent heat of vaporisation (Hv) = 2260 KJ/Kg = 2260 × 1000 = 2260000 J/KgHeat (Q₄) =?Q = mHv
Q₄ = 0.4 × 2260000
Q₄ = 904000 J
How to determine the heat required to change the temperature from 100 °C to 160 °C Mass (M) = 0.4 KgInitial temperature (T₁) = 100 °C Final temperature (T₂) = 160 °CChange in temperature (ΔT) = 160 – 100 = 60 °C Specific heat capacity (C) = 1996 J/(kg·°C) Heat (Q₅) =?Q = MCΔT
Q₅ = 0.4 × 1996 × 60
Q₅ = 47904 J
How to determine the heat required to change the temperature from –38 °C to 160 °CHeat for –38 °C to 0°C (Q₁) = 31160 JHeat for melting (Q₂) = 133600 JHeat for 0 °C to 100 °C (Q₃) = 167200 JHeat for vaporization (Q₄) = 904000 JHeat for 100 °C to 160 °C (Q₅) = 47904 JHeat for –38 °C to 160 °C (Qₜ) =?Qₜ = Q₁ + Q₂ + Q₃ + Q₄ + Q₅
Qₜ = 31160 + 133600 + 167200 + 904000 + 47904
Qₜ = 1.28×10⁶ J
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An enzyme (MW 24 kDa, pI 5.5) is contaminated with two other proteins, one with a similar molecular mass and a pI of 7.0 while the other has a molecular mass of 100 kDa and a pI of 5.4. Suggest a procedure to purify the contaminated enzyme.
The procedure to purify/separate these enzymes might be associated with the ion exchange chromatography methodology.
What is ion exchange chromatography methodology?The ion exchange chromatography methodology is a technique to separate molecules such as proteins (in this case enzymes) based on their charge.
The ion exchange chromatography methodology is based on the use of different types of resins that allow the separation of molecules based on their charges and mass.
In conclusion, the procedure to purify/separate these enzymes might be associated with the ion exchange chromatography methodology.
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draw corresponding structure of 1-cyclophentylhexane.
Answer:
Hexane is a 6-carbon hydrocarbon.
Cyclopentyl is a 5-carbon, hydrocarbon ring.
The 1- indicates that the cyclopentyl is attached to the first carbon in hexane.
Two ways of drawing the structure of 1-cyclopentylhexane are below:
Machines have moving parts and electronics that can overheat in some situations. Engineers use metal heat sinks to help the heat escape from the machine. A heat sink is made of metal and usually has fins, which give the heat sink a large surface area. Why is it important for heat sinks to be made of metal and have a large surface area?
Answer:
to reduce friction and increase efficiency of the machime
Answer:
to reduce friction and increase efficiency of the machime
Explanation:
Predict and balance the following reaction:
Ag + Cu(NO3)2 →
Group of answer choices
A. Ag + Cu(NO3)2 → Ag + Cu(NO3)2
B. 2Ag + Cu(NO3)2 → Cu + 2AgNO3
C. The reaction does not occur.
D. Ag + Cu(NO3)2 → Cu + Ag(NO3)2
The prediction of the products and the balanced form of the above incomplete equation is as follows: Ag + Cu(NO3)2 → Cu + Ag(NO3)2 (option D).
How to balance a chemical reaction?According to this question, silver reacts with copper nitrate to form products that were not stated.
However, this reaction is an example of a displacement reaction, hence, silver will displace or replace copper in the compound to form copper and silver nitrate as products. The reaction is given as follows:
Ag + Cu(NO3)2 → Cu + Ag(NO3)2
This chemical reaction is said to be balanced because the number of moles of each atoms on both sides of the equation is the same.
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Round to 3 significant figures 78.6500
Answer:
78.7
Explanation:
The number has 4 significant figures: 7,8 6 and 5.
To round off to 3 significant figures, the target digit is the third significant figure in the number.The determining digit is the fourth significant figure in the number; it is 5 hence the target digit will go up by 1 and any digits to the right of it will be rounded down to 0.
Which of the following best describes how an ionic compound dissolves in water?
Group of answer choices
A. It separates into individual molecules and is a non-electrolyte.
B. It breaks into its individual ions and is an electrolyte.
C. It separates into individual molecules and is an electrolyte.
D. It breaks into its individual ions and is a non-electrolyte.
The statement that best describes how an ionic compound dissolves in water is as follows: it separates into individual molecules and is an electrolyte, which is option C.
What is an ionic compound?Ionic compound is any compound is a chemical compound composed of ions (charged atoms) held together by electrostatic forces termed ionic bonding.
Ionic compounds are electrolytes i.e. a substance when, in solution or when molten, ionizes and conducts electricity.
For example; sodium chloride (NaCl) is an ionic compound breaks down into sodium ions (Na+) and chloride ion (Cl-).
Therefore, the statement that best describes how an ionic compound dissolves in water is as follows: it separates into individual molecules and is an electrolyte.
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What is the number of moles of hydrochloric acid will there be in 10 mL of a given solution with a molarity of 0.5 mol/L?
Answer:
You are on the right track.
Explanation:
Indeed, your approach here will be to use the molar mass of aluminium hydroxide to convert the mass of the sample to moles and the mole ratio that exists between the two reactants to find the number of moles of hydrochloric acid consumed.
Al
(
OH
)
3
(
s
)
+
3
HCl
(
a
q
)
→
AlCl
3
(
a
q
)
+
3
H
2
O
(
l
)
The balanced chemical equation tells you that the reaction consumes
3
moles of hydrochloric acid and produces
3
moles of water for every
1
mole of aluminium hydroxide that takes part in the reaction.
So you can say that you have
0.75
g
⋅
the molar mass of Al
(
OH
)
3
1 mole Al
(
OH
)
3
78
g
⋅
the 1:3 mole ratio
3 moles HCl
1
mole Al
(
OH
)
3
=
0.029 moles HCl
−−−−−−−−−−−−−−
Since you know that the reaction produces the same number of moles of water as the number of moles of hydrochloric acid it consumes--the two chemical species have a
3
:
3
mole ratio in the balanced chemical equation--you can use the molar mass of water to say that the reaction will produce
0.029
moles H
2
O
⋅
18.015 g
1
mole H
2
O
=
0.52 g
−−−−−
The answers are rounded to two sig figs, the number of sig figs you have for the mass of aluminium hydroxide.
Explanation:
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Answer: 0.005 mol
Explanation:
Given information
Volume = 10 mL
Molarity = 0.5 mol / L
Given formula
Molarity = Mole / Volume
Convert volume unit to liters
1 L = 1000 mL
10 mL = 10 / 1000 = 0.01 L
Substitute values into the formula
Molarity = Mole / Volume
Mole = Molarity × Volume
Mole = (0.5) × (0.01)
Simplify by multiplication
[tex]\Large\boxed{Mole~=~0.005~mol}[/tex]
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Write a balanced equation for the following redox reaction using the oxidation number method:
Cl2 (g) + KI (aq) ---> I2 (s) + KCl (aq)
The balanced equation for the following redox reaction using the oxidation number method is as follows:
2K + 2I− + Cl 2 → I2 +2Cl− +2K+
What is a redox reaction?A redox reaction in chemistry is a chemical reaction in which some of the atoms have their oxidation number changed.
According to this question, the following balanced chemical equation is given:
Cl2 (g) + KI (aq) → I2 (s) + KCl (aq)
The oxidation number of the ions in a redox reaction changes, and in this case, the ionic reaction is as follows:
2K + 2I− + Cl 2 → I2 + 2Cl− +2K+
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Which metal will spontaneously react with Zn²⁺(aq), but will not
spontaneously react with Mg²⁺ (aq)?
Mn(s) metal will spontaneously react with Zn²⁺(aq), but will not
spontaneously react with Mg²⁺ (aq)
The Eo value of an electrochemical cell determines its spontaneity. Positive Eo electrochemical cells are spontaneous, and vice versa.
The relevant Eo of the half-cell in this instance are as follows for Mn(s) metal
Zn2+/Zn = -0.763v for Eo
2.37v for Eo Mg2+/Mg.
Mn2+/Mn = -1.18v for Eo.
Consequently, the equation for an Eo cell (with Zn as one of the half-cells) is: Eo Zn2+/Zn - Eo Mn2+/Mn = -0.763 - (-1.18) = 0.417v.
On the other hand, the equation for an Eo cell (with Mg as one of the half-cells) is: Eo Mg2+/Zn - Eo Mn2+/Mn = -2.37 - (-1.18) = -1.19v.
As a result, Mn(s) metal will spontaneously react with Zn2+(aq), but not with Mg2+ (aq)
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How much heat is needed to melt 10.0 grams of ice at -10°C until it is water at 10°C?
Group of answer choices
A. +83.6 J
B. +3963 J
C. -3963 J
D. -83.6 J
The heat needed to melt 10.0 grams of ice at -10°C until it is water at 10°C is 3,969.5 J. (approx= 3963J).
What is Sensible heat?Sensible heat is defined as the amount of heat that a body absorbs or releases without any changes in its physical state.
Q= c×m×∆T
What is Latent heat?Latent heat is defined as the energy required by a quantity of substance to change state.
When this change consists of changing from a solid to a liquid phase, it is called heat of fusion and when the change occurs from a liquid to a gaseous state, it is called heat of vaporization.
In this case, the heat Q that is necessary to provide for a mass m of a certain substance to change phase is equal to
Q= m×L
Where,
L is the latent heat
-10°C to 0 °CC= specific heat capacity of ice= 2.108 J/gK
M= 10 g
ΔT= T(final)– T(initial) = 0 °C – (-10 °C)= 10 °C= 10 K
Sensitive heat Q(1) = 2.108×10×10
= 210.8J
Heat needed to melt iceThe specific heat of melting of ice is 334 J/g, the heat needed to melt 10 grams of ice is
Q(2) = 10× 334
= 3340J
0°C to 10 °CC= specific heat capacity of liquid water is 4.187 J/gK
M= 10 g
ΔT= T(final) – T(initial) = 10 °C – 0 °C= 10 °C= 10 K because being a temperature difference, the difference is the same in °C and K.
Q(3) = 4.187×10×10
= 418.7 J.
Total heat required= Q1 + Q2 + Q3
Total heat required= 210.8 J + 3,340 J + 418.7 J
= 3969.5J
Thus, the heat needed to melt 10 gram of ice from temperature-10°C to 10°C is 3969.5. Therefore, option B is correct option.
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A 75.1 L sample of gas at 33.2 ºC and 365.7 mm Hg expands to 242.9 L at 6.5 ºC. What is the new gas pressure?
Answer:
103 mmHg
Explanation:
To find the new pressure, you need to use the Combined Gas Law:
P₁V₁ / T₁ = P₂V₂ / T₂
In this equation, "P₁", "V₁", and "T₁" represent the initial pressure, volume, and temperature. "P₂", "V₂", and "T₂" represent the final pressure, volume, and temperature. You can find the new pressure (P₂) after converting the temperatures from Celsius to Kelvin.
P₁ = 365.7 mmHg P₂ = ? mmHg
V₁ = 75.1 L V₂ = 242.9 L
T₁ = 33.2 °C + 273.15 = 306.35 K T₂ = 6.5 °C + 273.15 = 279.65 K
P₁V₁ / T₁ = P₂V₂ / T₂ <----- Combined Gas Law
(365.7 mmHg)(75.1 L) / 306.35 K = P₂(242.9 L) / 279.65 K <----- Insert values
89.649 = P₂(242.9 L) / 279.65 K <----- Simplify left side
25070.433 = P₂(242.9 L) <----- Multiply both sides by 279.65
103 = P₂ <----- Divide both sides by 242.9
using the ideal gas law, PV = nRT, in which R is 8.31 (L•kPa/mol-K), what would the temperature be if 0.75 moles of helium gas in a 2.0 L container have a pressure of 202.65 kPa
Answer:
65.0 K
Explanation:
To find the temperature, you need to use the Ideal Gas Law:
PV = nRT
In this equation,
-----> P = pressure (pKa)
-----> V = volume (L)
-----> n = moles
-----> R = Ideal Gas Constant (8.31 L*kPa/mol*K)
-----> T = temperature (K)
You can plug the given values into the equation and simplify to find the temperature.
P = 202.65 pKa R = 8.31 L*kPa/mol*K
V = 2.0 L T = ? K
n = 0.75 moles
PV = nRT
(202.65 pKa)(2.0 L) = (0.75 moles)(8.31 L*kPa/mol*K)T
405.3 = (6.2325)T
65.0 K = T
[05.01] How does the kinetic energy of a substance's particles in the solid phase compare to their kinetic energy in the liquid phase
Answer:
liquids have more kinetic energy than solids
Explanation:
water and ice are good examples
hotter the faster
kinetic can mean speed
solids held together by strong intermolecular forces of attraction
very little or no kinetic energy between the particles
solids are rigid and have definite shape and volume
liquid particles are held by weaker Vander Waal forces.
particles collide with each other and gain kinetic energy.
liquids have more kinetic energy than in the solid phase.
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If the temperature of a gas increased from 100 K to 200 K and the volume of a gas decreased from 20 L to 10 L, what is the new pressure if the original pressure was 100 kPa?
Group of answer choices
A. 100 kPa
B. 400 kPa
C. 200 kPa
D. 50 kPa
Answer:
B. 400 kPa
Explanation:
the pressure increases, when the temperature increases. and it increases, when the volume decreases.
both cases happen here, each with the factor 2.
so, the pressure increases by the factor 2×2 = 4.
4×100 = 400 kPa
Which of the following is not an organic compound?
OC6H14
O CO₂
OCH4
C12H22011
Answer:
Co2
Explanation
An organic compound includes Carbon and Hydrogen both bonded
Which type of scientist would most likely study how electricity could be
produced more efficiently?
OA. A physicist
OB. An Earth scientist
OC. A biologist
OD. A chemist
Answer:
A physicist
Explanation:
Physics is that aspect of science that deals with nature and matter in relation to energy. Electricity is a source for energy
3. Consider the following
energy levels of a hypothetical atom:
E4_-1.0 x 10-19.
-5.0 x 10-19 J
-10 x 10--193
E1
.-15 x 10-19
(a) What is the wavelength of the photon needed to excite an electron from E1 to E4? (b)
What is the energy (in joules) a photon must have in order to excite an
electron from
E2
to E3? (c) When an electron drops from E3 level to the E1, the atom is said tO undergo
emission. Calculate the wavelength of the photon emitted in this process.
a)λ = 1.43 x 10⁻⁷ m, b)λ =5 x 10⁻¹⁹ and, c)λ = 1.99 x 10⁻⁷ m.
What is an atom?A chemical element is uniquely defined by its atoms, which are tiny pieces of substance. A core nucleus, often surrounded by one or more electrons, makes up an atom. The charge of every electron is negative. The positively charged nucleus has one or more protons and neutrons, relatively heavy particles.An atom is referred to any elementary particle of matter with at least one proton. Examples of atoms are neon (N) and hydrogen (H) (Ne).Protons, which have a positive charge, and neutrons, which have no charge, make up its structure. All regular, naturally occurring atoms contain the long-lived particles protons, neutrons, and the electrons that orbit them.It is difficult to appreciate how little they are until you see how many atoms there are in your body. Around 7 octillion atoms make up one adult.a) The wavelength of the photon needed to excite an electron from E1 to E4:
ΔE = hc/λ
(-1 + 15) x 10⁻¹⁹ = 6.63 x 10⁻³⁴ x 3 x 10⁸ / λ
λ = 1.43 x 10⁻⁷ m
b) The energy (in joules) a photon must have in order to excite an electron from E2:
= (-5 + 10) x 10⁻¹⁹
λ = 5 x 10⁻¹⁹
c) An electron drops the E3 level to the E1 level, and the atom is said to undergo emission:
Change in energy = 10 x 10⁻¹⁹ J
10 x 10⁻¹⁹ = 6.63 x 10⁻³⁴ x 3 x 10⁸ / λ
λ = 1.99 x 10⁻⁷ m
The wavelength of the photon needed to excite an electron from E1 to E4 is 1.43 x 10⁻⁷ m.
The energy (in joules) a photon must have in order to excite an electron from E2 is 5 x 10⁻¹⁹.
An electron drops the E3 level to the E1 level, and the atom is said to undergo emission is 1.99 x 10⁻⁷ m.
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Perform the following operation and express the answer in scienfific notation 7.5x10 ^9 - 2.5 x 10^8
The answer is in scientific notation 34^67 42’063 1220.
The correct form for scientific notation is a x 10^b. where a is a number or decimal such that the absolute value of a is greater than or equal to 1 and less than 10, or 1 ≤ |a|. < 10. b is the power of 10 required to make the scientific notation mathematically equivalent to the original number.
To write this number in scientific notation, you must first shift the number of decimal places from the original number by 4 places between 4 and 2. We're subtracting from the exponent because we're shifting the decimal four places to the right.
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If the temperature of a gas is increased from 20°C to 35°C, what is the new pressure if the original pressure was 1.2 atm? Assume that volume is constant.
Group of answer choices
A. 0.6 atm
B. 1.3 atm
C. 1.0 atm
D. 2.6 atm
Answer:
B.) 1.3 atm
Explanation:
To find the new pressure, you need to use Gay-Lussac's Law:
P₁ / T₁ = P₂ / T₂
In this equation, "P₁" and "T₁" represent the initial pressure and temperature. "P₂" and "T₂" represent the final pressure and temperature. After converting the temperatures from Celsius to Kelvin, you can plug the given values into the equation and simplify to find P₂.
P₁ = 1.2 atm P₂ = ? atm
T₁ = 20 °C + 273 = 293 K T₂ = 35 °C + 273 = 308 K
P₁ / T₁ = P₂ / T₂ <----- Gay-Lussac's Law
(1.2 atm) / (293 K) = P₂ / (308 K) <----- Insert values
0.0041 = P₂ / (308 K) <----- Simplify left side
1.3 = P₂ <----- Multiply both sides by 308
Calculate the [H+] in a solution that has the following pH:
pH 8.57
pH 5.18
pH 1.30
Answer:
1.) [H⁺] = 2.69 x 10⁻⁹
2.) [H⁺] = 6.61 x 10⁻⁶
3.) [H⁺] = 5.01 x 10⁻²
Explanation:
The [H⁺] in a solution can be found using the following equation:
[H⁺] = 10^(-pH)
Therefore, you can plug the given pH into the equation and solve for the hydrogen ion concentration ([H⁺]).
1.) pH 8.57
[H⁺] = 10^(-pH)
[H⁺] = 10^(-8.57)
[H⁺] = 2.69 x 10⁻⁹
2.) pH 5.18
[H⁺] = 10^(-pH)
[H⁺] = 10^(-5.18)
[H⁺] = 6.61 x 10⁻⁶
3.) pH 1.30
[H⁺] = 10^(-pH)
[H⁺] = 10^(-1.30)
[H⁺] = 5.01 x 10⁻²
What is the specific heat of a substance if 1500 J are required to raise the temperature of a 300.0 g sample from 25°C to 40°C?
Group of answer choices
A. 33 J/g°C
B. 333 J/g°C
C. 4.18 J/g°C
D. .33 J/g°C
Answer:
D.) 0.33 J/g°C
Explanation:
To find the specific heat, you need to use the following equation:
Q = mcΔT
In this equation,
-----> Q = energy (J)
-----> m = mass (g)
-----> c = specific heat (J/g°C)
-----> ΔT = change in temperature (°C)
You can plug the given values into the equation and simplify to isolate "c".
Q = mcΔT <----- Equation
1500 J = (300.0 g)c(40 °C - 25°C) <----- Insert values
1500 J = (300.0 g)c(15) <----- Subtract
1500 J = (4500)c <----- Multiply 300.0 and 15
0.33 = c <----- Divide both sides by 4500
How many moles of HNO3 will be produced
from the reaction of 46.5 g of NO2 with excess
water in the following chemical reaction?
3 NO₂(g) + H₂O (1)→ 2 HNO3(g) + NO(g)
Answer:
0.674 moles HNO₃
Explanation:
To find the moles of HNO₃, you need to (1) convert grams NO₂ to moles NO₂ (via molar mass) and then (2) convert moles NO₂ to moles HNO₃ (via mole-to-mole ratio from equation coefficients). It is important to arrange the conversions in a way that allows for the cancellation of units. The final answer should have 3 sig figs to match the sig figs of the given value (46.5 g).
Molar Mass (NO₂): 14.007 g/mol + 2(15.998 g/mol)
Molar Mass (NO₂): 46.003 g/mol
3 NO₂(g) + H₂O (l) ------> 2 HNO₃(g) + NO(g)
46.5 g NO₂ 1 mole 2 moles HNO₃
------------------- x ------------------- x -------------------------- = 0.674 moles HNO₃
46.003 g 3 moles NO₂
Which of the following chemical equations depicts a balanced chemical reaction?
A. 2H₂ +202-> H₂O
B. 2H₂ +202-> 2H₂O
C. H₂ + O2-> H₂O
D. 2H₂ + O₂-> 2H₂O
Answer:
D.) 2 H₂ + O₂ -----> 2 H₂O
Explanation:
An equation is balanced when there is an equal amount of each element on both sides of the reaction. If these amounts are unequal, coefficients can be added to modify the amount of particular molecules.
A.) Not balanced
2 H₂ + 2 O₂ -----> H₂O
Reactants: 4 hydrogen, 4 oxygen
Products: 2 hydrogen, 1 oxygen
B.) Not balanced
2 H₂ + 2 O₂ -----> 2 H₂O
Reactants: 4 hydrogen, 4 oxygen
Products: 4 hydrogen, 2 oxygen
C.) Not balanced
H₂ + O₂ -----> H₂O
Reactants: 2 hydrogen, 2 oxygen
Products: 2 hydrogen, 1 oxygen
D.) Balanced
2 H₂ + O₂ -----> 2 H₂O
Reactants: 4 hydrogen, 2 oxygen
Products: 4 hydrogen, 2 oxygen