Answer is: D. ΔH is negative for reaction A and ΔH is positive for reaction B.
There are two types of thermochemical reactions:
1) endothermic reaction (chemical reaction that absorbs more energy than it releases).
For example, ΔH(reaction) = 150 kJ/mol; this is endothermic reaction.
2) exothermic reaction (chemical reaction that releases more energy than it absorbs).
For example, ΔH(reaction) = -225 kJ/mol; this is exothermic reaction.
the change in enthalpy = the total bonding energy for the products of a reaction - the bonding energy of the reactants.
how many moles are in 7x10^56 formula units of CaCl2
Final answer:
To find the number of moles in 7x10⁵⁶ formula units of CaCl2, divide the given formula units by Avogadro's number.
Explanation:
To find the number of moles in 7x10⁵⁶ formula units of CaCl2, we need to know the molar mass of CaCl2. The molar mass of CaCl2 is 110.98 g/mol. To convert formula units to moles, we can use Avogadro's number, which is 6.022 × 10²³ particles/mol. So, we can calculate the number of moles as follows:
7x10⁵⁶ formula units * (1 mol / 6.022 × 10^23 formula units) = 1.16x10³³ moles
one wavelength used by telstar 401 satellite is 7.807 cm. what is the frequency of this light in MHz?
Given:
Wavelength used by the satellite (λ) = 7.807 cm
To determine:
The frequency (ν) in MHz
Explanation:
Frequency is related to the wavelength by the following equation:
ν = c/λ
where c = speed of light = 3*10¹⁰ cm/s
ν = 3*10¹⁰ cm.s⁻¹/7.807 cm = 3843 *10⁶ s⁻¹
Now, the SI of frequency is Hertz (Hz) where:
1 Hz = 1 s⁻¹
Therefore, ν = 3843 * 10⁶ Hz
Since 1 Megahertz (MHz) = 10⁶ Hz,
ν = 3843 MHz
Ans: The frequency of light is 3843 MHz
what form of the ideal gas law would you use to calculate
the volume of a gas
[tex]V=\frac{nRT}{P} [/tex]
Ideal gas equation:-
[tex]PV=nRT[/tex]
Here, [tex]P[/tex] is the pressure, V is the volume, R is the gas constant, n is the number of moles, T is temperature.
So, from the above equation, the ideal gas law would you use to calculate the volume of a gas is as follows:-
[tex]V=\frac{nRT}{P} [/tex]
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which is another name for a homogenous mixture?
A. compound
B. Element
C. Solution
D. Substance
C: Solution is another name for Homogenous mixture
Visible light, X Rays infrared radiation and radio waves all have the same
The answer is speed of light. All kinds of light waves travel at 3.00 m/s.
Visible light, X Rays, infrared radiation, and radio waves are all forms of electromagnetic radiation. They vary in terms of their wavelength and frequency. Despite these differences, they share the same basic characteristic: the ability to travel in wave form.
Explanation:Visible light, X Rays, infrared radiation, and radio waves are all types of electromagnetic radiation. They may vary in wavelength and energy, but they share the same basic nature: they are all forms of energy that travel in waves and do not need a medium to propagate.
For instance, the key difference between these types of electromagnetic radiation is their wavelengths and frequency: radio waves have long wavelengths and low frequencies, while X-rays have short wavelengths and high frequencies. Visible light exists somewhere in the middle of this spectrum, with wavelengths longer than X-rays but shorter than radio waves.
Infrared radiation, on the other hand, has photons with energies slightly less than red light, has wavelengths on the order of a micron (um), and sits right next to visible light on the radiation spectrum.
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Beta decay can be described by the emission of an _______
That would be the emission of an electron.
Beta decay can be described by the emission of an electron.
Beta decay happens when an atom has too many protons or too many neutrons in its core. This causes the atom to be unstable and release an electron in the process.
If an ice cube is added to a warm drink, what changes about the thermal energy of the molecules in the ice cube and drink ?
The thermal energy heats up the energy in the ice cube causing it to melt and cool off the drink slightly.
Determine the rate law, including the values of the orders and rate law constant, for the following reaction using the experimental data provided. (4 points)
A + B yieldsproducts
Trial
[A]
[B]
Rate
1 0.10 M 0.20 M 1.2 × 10-2 M/min
2 0.10 M 0.40 M 4.8 × 10-2 M/min
3 0.20 M 0.40 M 9.6 × 10-2 M/min
Answer: Rate law=[tex]k[A]^1[B]^2[/tex], order with respect to A is 1, order with respect to B is 2 and total order is 3. Rate law constant is [tex]3L^2mol^{-2}s^{-1}[/tex]
Explanation: Rate law says that rate of a reaction is directly proportional to the concentration of the reactants each raised to a stoichiometric coefficient determined experimentally called as order.
[tex]Rate=k[A]^x[B]^y[/tex]
k= rate constant
x = order with respect to A
y = order with respect to A
n = x+y = Total order
a) From trial 1: [tex]1.2\times 10^{-2}=k[0.10]^x[0.20]^y[/tex] (1)
From trial 2: [tex]4.8\times 10^{-2}=k[0.10]^x[0.40]^y[/tex] (2)
Dividing 2 by 1 :[tex]\frac{4.8\times 10^{-2}}{1.2\times 10^{-2}}=\frac{k[0.10]^x[0.40]^y}{k[0.10]^x[0.20]^y}[/tex]
[tex]4=2^y,2^2=2^y[/tex] therefore y=2.
b) From trial 2: [tex]4.8\times 10^{-2}=k[0.10]^x[0.40]^y[/tex] (3)
From trial 3: [tex]9.6\times 10^{-2}=k[0.20]^x[0.40]^y[/tex] (4)
Dividing 4 by 3:[tex]\frac{9.6\times 10^{-2}}{4.8\times 10^{-2}}=\frac{k[0.20]^x[0.40]^y}{k[0.10]^x[0.40]^y}[/tex]
[tex]2=2^x,2=2^1[/tex], x=1
Thus rate law is [tex]Rate=k[A]^1[B]^2[/tex]
Thus order with respect to A is 1 , order with respect to B is 2 and total order is 1+2=3.
c) For calculating k:
Using trial 1: [tex]1.2\times 10^{-2}=k[0.10]^1[0.20]^2[/tex]
[tex]k=3 L^2mol^{-2}s^{-1}[/tex].
Which of these forces is acting on a baseball sitting on level ground? A. applied force B. frictional force C. gravitational force
C. gravitational force
C.) Gravitational Force
Help Please!!
1.
(02.03 LC)
Geologic time is a way to _______. (3 points)
measure the size of Earth over time
measure the sequence of events on Earth over time
determine natural processes
determine common ancestry in fossils
2.
(02.03 LC)
Scientists can use rock layers to determine which of the following? (3 points)
The mass of Earth
The size of Earth
The age of Earth
The amount of land on Earth
3.
(02.03 LC)
What does the theory of evolution tell us about living things? (3 points)
The environment can make them change rapidly over a short period of time.
They create fossils when they die.
Their environment makes them change slowly over time.
They can give us clues about extinct species.
The first answer would be:
Measure the sequence of events on earth over time.
I believe the second answer would be:
The age of earth. ( I say this because geological time is used to describe timing and the relationship of events in earths history)
I’m not sure about number 3 but I hope this was somewhat useful!!
Which atom has five electrons in its outer level and 10 electrons in the inner energy levels
The atom with five outermost electrons, and ten inner electrons has been Phosphorus.
The energy levels in the atom have been the representation of the electron address. The electrons have been present in the energy level have been jumped from the lower level to the higher level.
Electrons in Energy LevelThe atom with five electrons in the outermost shell has belonged to group 15 of the periodic table. The inner number of electrons in the atom has been 10.
The total number of electrons are 15 in the atom. The element with 15 electrons has been Phosphorus.
Thus, the atom with five outermost electrons, and ten inner electrons has been Phosphorus.
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Which statement describes the flow of electricity if a small motor is connected to the gap in the wire and the circuit is closed?
what are the statements that you are able to choose from or do you just have to know?
Rank the following quantities from smallest to largest: 5,200, dozen, pair,gross,ream.
5,200
dozen = 12
pair = 2
gross = 144
ream = 500
Pair, dozen, gross, ream, 5,200
why do food scientists need to understand chemistry
Food scientists need to understand chemistry for various reasons, including understanding the composition of food, ensuring food safety and quality, and studying the nutritional value of food.
Explanation:Food scientists need to understand chemistry for several reasons. First, chemistry is necessary to understand the composition of food and how different chemicals interact with each other during processing, cooking, and preservation. Second, knowledge of chemistry helps food scientists ensure the safety and quality of food by understanding the potential chemical hazards and the best ways to prevent them. Third, chemistry is essential for studying the nutritional value of food and how the body metabolizes different nutrients.
an element has an isotope with a mass of 203.973 amu and and abundance of 1.40%. another isotope has a mass of 205.9745 amu with an abundance of 24.10%. a third isotope weighs 206.9745 amu and is 22.10%, and the fourth isotope weighs 207.9766 amu and an abundance of 57.40. calculate the average atomic mass and identify the unknown element.
Answer is: the average atomic mass 217.606 amu.
Ar₁= 203.973 amu; the average atomic mass of isotope.
Ar₂ = 205.9745 amu.
Ar₃ = 206.9745 amu.
Ar₄ = 207.9766 amu.
ω₁ = 1.40% = 0.014; mass percentage of isotope.
ω₂ = 24.10% = 0.241.
ω₃ = 22.10% = 0.221.
ω₄ = 57.40% = 0.574.
Ar = Ar₁ · ω₁+ Ar₂ · ω₂ + Ar₃ · ω₃ + Ar₄ · ω₄.
Ar = 203.973 amu · 0.014 + 205.9745 amu · 0.241 + 206.9745 amu · 0.221 + 207.9766 amu · 0.574.
Ar = 2.855 amu + 49.632 amu + 45.741 amu + 119.378 amu.
Ar = 217.606 amu.
But abundance of isotopes is greater than 100%.
It should be lead, with the fourth isotope weighs 207.9766 amu and an abundance of 52.40.
which equation represents alpha decay
An architect wants to design a solar house in the northern hemisphere. For maximum, which side of the house should have the most windows?
Hello!! My answer would be that they should add the solar panels that faces the south. Since the sun rises in the east and sets in the west, the south portion would get both sunlight from the east and west sides. I hope this helps!!
In the northern hemisphere in order to get maximum solar gain, the solar house should face south side as the sun's heat energy falls maximum there.
Worth *20 points* Helpppp
Was the graph that you constructed for acceleration linear in nature (a line)? Why or why didn’t it take this shape?
How does the scientific method help scientists?
The scientific method is a sequential process that uses predictions from hypotheses to derive observations and conclusions. It helps scientists to collect empirical evidence to prove the theory.
What is the scientific method?The scientific method has been defined as an empirical approach to using acquired knowledge to draw observations and conclusions from the hypothesis. It helps scientists to answer questions by performing research and experiment.
It allows the establishment of a hypothesis that can be proved true or false by conducting experiments and making observations based on analysis.
The observation allows the findings to be concluded. The data can be interrupted by scientists to conclude their research study with credibility.
Therefore, scientific methods are useful for scientists.
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What is the covalent compond using prefixes for P4S5
Tetraphosphorus pentasulfide
The covalent compound with the molecular formula P4S5 is named tetraphosphorus pentasulfide, using the numerical prefixes 'tetra-' for four atoms of phosphorus and 'penta-' for five atoms of sulfur.
The covalent compound P4S5 can be named using the appropriate numerical prefixes according to the rules for naming binary covalent compounds. In this case, the prefix for four is 'tetra' and the prefix for five is 'penta'. Therefore, the name would be tetraphosphorus pentasulfide.
To name the compound, first, identify the elements present: phosphorus (P) and sulfur (S). Then, apply the prefixes that correspond to the number of atoms of each element in the molecule: tetra- for four phosphorus atoms and penta- for five sulfur atoms. Combine these with the root name of the elements, and add the suffix '-ide' to the second element.
Which is the best example of a country that is dependent on other countries
The best example of a country that is dependent on other countries is a country that has very little or less fertile soil to make its resources.
Vietnam, a peripheral nation, greatly depends on core nations for industrialization, jobs, and aid. The 19th-century U.S. also showed dependency by borrowing heavily from abroad for economic development. This is a reflection of how nations are interconnected in the global marketplace.
Explanation:A prime example of a country that heavily depends on other countries is Vietnam. It is considered a peripheral nation, which means it has little industrialization and relies on more industrialized nations, called core nations, for jobs and aid. Their industries are often owned or leased by companies from these core nations, which causes a shift in power and resource distribution.
Another example can be seen in the United States during the 19th century. The country borrowed heavily from abroad, showing its dependency on external aid for its economic prosperity. This is basically a result of the interdependence of economies in our global marketplace.
Everyday items like food, clothes, and electronic gadgets are often products of international trade, giving rise to the intertwined economic systems of nations. For instance, the car you drive may be from Japan, while the fuel comes from the Middle East. Countries, therefore, rely heavily on one another to meet their needs and continue business operations.
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what are the five rules for significant figures? Give some examples
"There are three rules on determining how many significant figures are in a number: Non-zero digits are always significant. Any zeros between two significant digits are significant. A final zero or trailing zeros in the decimal portion ONLY are significant."
Final answer:
In chemistry, significant figures are used to indicate the precision or certainty of a measurement. There are five rules for determining the number of significant figures in a measurement.
Explanation:
In chemistry, significant figures are used to indicate the precision or certainty of a measurement. There are five rules for determining the number of significant figures in a measurement:
All non-zero digits are significant.
Zeroes between non-zero digits are significant.
Leading zeroes (zeros to the left of the first non-zero digit) are not significant.
Trailing zeroes (zeros to the right of the last non-zero digit), if there is a decimal point, are significant.
Trailing zeroes (zeros to the right of the last non-zero digit), if there is no decimal point, may or may not be significant.
Examples:
a. 5.87 has three significant figures (rule 1)
b. 0.031 has two significant figures (rule 1 and rule 4)
Given that ∆G for the reaction below is -957.9kj, what is ∆Gf of
H2O?
4NH3(g)+4NO(g)+6H2O(g)
∆Gf, NH3=-16.66kj/mol
∆Gf, NO=86.71kj/mol
∆Grxn = sum of ∆Gf (products) - sum of ∆Gf(reactants)
The reaction is
4NH3(g)+ 5O2 ---> 4NO(g)+6H2O(g)
∆Grxn = [ 4 X ∆Gf(NO) + 6 X ∆Gf(H2O)] - [ 4∆Gf(NH3) + 5 ∆Gf(O2)]
∆Grxn = [4 X (86.7) + 6 ∆Gf(H2O)] -[ 4 (-16.66) + 5(0)]
∆Grxn = [346.8 + 6∆Gf(H2O)] - [-16.66 + 0]
∆Grxn = -957.9 = [346.8 + 6∆Gf(H2O)] - [-66.64 + 0]
-957.9 = [346.8 + 6∆Gf(H2O)] - [-66.64 + 0]
∆Gf(H2O) = -90.74
This is based on information provided by you.
However the answer should be nearly -241.8
Answer:
- 228.6 kJ/mol.
Explanation:
I got bandz
Based on the knowledge about genetic links between organisms, which category of classification was added to Linnaean Taxonomy?
Class
Domain
Kingdom
Phylum
Bacteria, archaea, eukarya This is all I know. Hope it helps.
In 1735 Carlous Linneaus a Botanist said that there needs to be a way to classify organisms and living things. He decided that he'll sort organisms into seven major taxa, or groupings. He called the highest taxa kingdom and the lowest taxa species. This is known as the first idea in the process of Linnaean Taxonomy.
Then in 1990 Carl Wossen a microbiologist and biophysicist added to this idea saying that he Linnaean taxonomy works well, but it could be better. Thta there could be a better way into classifying and grouping kingdoms. He then created 3 domains: Bacteria, Archaea, and Eukarya, aka, regular bacteria, extreme bacteria, and everything else.
This furthermore is the method we use in classifying living things.
The answer is: B, Domain.
A beaker contains a solution of calcium hydroxide (Ca(OH)2) in water. A student places a straw in the beaker and then breathes into the solution through the straw. As the student breathes into the solution, a white precipitate forms. What is the most likely composition of the precipitate? H2O CaCO3 CH3OH
CaCo3 was the correct answer.
The most likely composition of the precipitate is CaCo3
What's known as the answer?A homogenous combination of two or greater materials in relative amounts that can be varied continuously up to what is referred to as the limit of solubility. The term solution is commonly applied to the liquid country of matter, but solutions of gases and solids are feasible.
What's the answer to calcium hydroxide and water referred?Limewater is the commonplace call for a saturated aqueous answer of calcium hydroxide. Calcium hydroxide, Ca(OH)2, is moderately soluble at room temperature in water (1.5 g/L at 25 °C).
What's a solution of calcium hydroxide and water?Calcium hydroxide, additionally known as slaked lime, Ca(OH)2, is obtained by the movement of water on calcium oxide. when combined with water, a small proportion of it dissolves, forming an answer known as limewater, the relaxation final as a suspension referred to as milk of lime.
When Ca OH 2 is dissolved in water what are the goods?A saturated solution of Ca(OH)2 can be prepared with the aid of the response of calcium metal with water. Calcium is oxidized through water, yielding calcium hydroxide and hydrogen fuel.
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How much heat is needed to raise the temperature of 9g of water by 20oC?
180 Joules; The specific heat for water (amount required to raise 1 gram 1 oC) is ,4.184. So just multiply that with the mass of the substance (in grams)
9x20=180
Which type of compound is typically soluble in water?
carbonate hydroxide sulfate phosphate
sulfate because sulfate
Answer:
hydroxide
Explanation:
Hydroxides are highly soluble in water for example KOH. Carbonates, sulfates and phosphates are insoluble or sparing soluble in water. Sulfates of calcium, barium, strontium and lead are insoluble. The other remaining sulfates are soluble. Only phosphates and carbonates of ammonium, sodium and potassium are soluble. The other remaining phosphates are insoluble.
Balance the chemical equation. (Blank) N2O3 → (Blank) N2 + (Black) O2
The balanced equation is as below
2 N₂O₃ → 2N₂ + 3O₂
Explanation
According to the law of mass conservation the number of atoms in reactants side must be equal the to the number of atoms in products side.
Therefore the balanced reaction above is balanced since the number of atoms in reactants side are equal to number of atoms in products side.
For there 4 atoms of N in reactants side and 4 in products side.
The balanced equation is 2 N₂O₃ → 2N₂ + 3O₂
What is the net ionic
charge for an oxygen ion
Answer:
2-
Step-by-step explanation:
An O atom is neutral because it has the same number of protons as electrons.
O is in Group 16, so it adds two electrons to get a complete octet.
Since it has two extra electrons, the charge on an oxygen ion is 2-.
which compounds will most likely dissociate when dissolved in water? select all that apply
A) barium hydroxide
B) ethanol
C) glucose
D) silver nitrate
E) dichloromethane
F) postassium chloride
The following compounds are soluble in water and will dissociate when dissolved in water.
A) barium hydroxide
B) ethanol
C) glucose
D) silver nitrate
E) dichloromethane
F) postassium chloride
The other compounds ethanol and glucose are also soluble in water but do not dissociate when dissolved in water.
A lot of compound do dissociate when dissolved in water. The following compounds are soluble in water and will dissociate when dissolved in water. They are;
Barium hydroxide Silver nitrate Potassium chloride
A lot of compounds do dissociate when dissolved in water. The Substances that dissolve in water is said to produce ions called electrolytes.
Electrolytes can chemically react with water to produce ions or they may be ionic compounds that dissociate to yield cations and anions, when they have been dissolved.
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