5. What is a hypothesis and how is it used?
Answer: a supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation.
A hypothesis is used in an experiment to define the relationship between two variables. The purpose of a hypothesis is to find the answer to a question. A formalized hypothesis will force us to think about what results we should look for in an experiment. The first variable is called the independent variable
i hopes this helps :)
Calculate the entropy change when 4.31 g of H2 reacts with O2 according to the reaction
2 H2(g) + O2(g) → 2 H2O(l)
at 298 K and 1 atm pressure. The standard molar enthalpy of formation of H2O(l) at 298 K is −285.8 kJ/mol. The corresponding free energy of formation is −237.2 kJ/mol.
Answer in units of J/K.
Answer:
Explanation:
ΔG = Δ H - T ΔS
Given , ΔG = -237.2 kJ / mol
Δ H = - 285.8 kJ / mol
T = 298
Putting the values in the equation
-237.2 = - 285.8 - 298 x ΔS
ΔS = .163 kJ / mole K
moles of water formed = 4.31 / 2 = 2.155
entropy change required = 2.155 x .163 kJ / K
= 351.26 J / K .
Explain the term rate of a chemical reaction.
Answer:
The rate of a reaction is a measure of how quickly a reactant is used up, or a product is formed.
Explanation:
Calculate number of moles in 42g of silicon.
Answer:
[tex]\frac{3}{2}[/tex]
Explanation:
No of moles : [tex]\frac{given mass}{atomic mass}[/tex]
so the given mass is 42 gm and atomic mass of silicon is 24 when u solve it u get 3/2
Which is a dominant trait that Mendel observed in pea plant
A. Bumpy pods
B. Short height
C. Yellow seeds
D. White flowers
it is not A
Answer:
C, yellow seeds
Explanation:
In Mandel's studies, he proved that yellow seeds were to be dominant and green seeds were to be recessive.
Answer:
c. yellow seeds
Explanation:
i toke the test
Which noble gases is closest to magnesium? On the periodic table? What must happen if a magnesium atom for it to have an electron arrangement similar to that of a noble gas?
Answer:
Neon and loose electrons
Explanation:
Magnesium has an electron configuration of 2e 8e 2e, and Neon is 2e,8e. For Mg to have a similar electron arrangement it must loose its two valence electrons and make it an ion.
Answer:
Noble neon gas is the closest.
Explanation:
noble Neon gas
The Magnesium would have to lose two electrons
in a hydraulic lift system, the output force is greater than the input force because
Answer:
In a hydraulic lift system, the output force is greater than the input force because the pressure acting on the output piston is greater than the pressure acting on the input piston.
Explanation:
how would you differentiate between acid and bases if the list of their chemical formula is given to you
How has cooperation played a role in life's major evolutionary transitions?
Answer:
The cooperation of a species is shown throughout history. Including in our history. Where it be physical evolution or technological. We have helped each other with building, advice, locations, Reproduction, etc.
The hottest place in California is Death Valley with a record temperature of 130 ⁰F. Calculate the temperature in ⁰C and K.
Answer:
54.(4)° C (the 4 in the parentheses means the 4 goes forever), 327.594°K
Explanation:
When you convert 130°F to °C, you will get 54.(4)°C, and the 4 in the parentheses goes forever, and 130°F to °K is 327.594°K, hope it helps!
Rain is falling at 2.00 inches per hour. How many inches have fallen in 6000.0 seconds?
40POINTS AND BRAINLIEST Discuss the orders in which electrons are filled in the s and d subshells of the first three elements in group11
Step 1: add electrons to fill the 1s subshell (maximum of 2 electrons), when this is full, go to step 2. Step 2: add electrons to fill the 2s subshell (maximum of 2 electrons), when this is full, go to step 3. Step 3: add electrons to fill the 2p subshell (maximum of 6 electrons), when this is full, go to step 4. Step 4: add electrons to fill the 3s subshell (maximum of 2 electrons), when this is full, go to step 5. Step 5: add electrons to fill the 3p subshell (maximum of 6 electrons), when this is full, go to step 6. Step 6: add electrons to the 4s subshell (maximum of 2 electrons), when this is full, go to step 7. Step 7: add electrons to the 3d subshell (maximum of 10 electrons), when this is full, go to step 8. Step 8: add electrons to the 4p subshell (maximum of 6 electrons), when this is full, go to step 9. etc
So for Cu would be: 1s^22s^22p^63s^23p^63d^9
Ag would be: 1s^22s^22p^63s^23p^63d^104s^24p^64d^105s^1
Au would be: 1s^22s^22p^63s^23p^63d^104s^24p^64d^105s^25p^64f^145d^106s^1
how many molecules are in CO²
Answer:
53.11× 10²³ molecules
Explanation:
Given data:
Number of molecules of CO₂ = ?
Mass of CO₂ = 388.1 g
Solution:
Formula:
Number of moles = mass/ molar mass
Molar mass of CO₂ = 12× 1 + 16×2
Molar mass of CO₂ = 44 g/mol
Now we will put the values in formula.
Number of moles = 388.1 g/ 44 g/mol
Number of moles = 8.82 moles
Now we will calculate the number of molecules by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ molecules
8.82 mol × 6.022 × 10²³ molecules / 1 mol
53.11× 10²³ molecules
Brainliest plz?
Answer:
Now times by Abogadros constant: 1* 6.022*10^23=6.022*10^23 molecules of CO2 are present.
Explanation:
We know the molar mass of CO2(g) is 44.01⋅g⋅mol−1 . And so Avogadro's number of carbon dioxide molecules have this mass... And we take the product of the quotient... Molecules of carbon dioxide=5.00⋅mol×6.022×1023⋅mol−1≅30×1023⋅carbon dioxide molecules.
Where in equation for photosynthesis does carbon dioxide belong
Answer:
The equation for photosynthesis is 6 CO2 + 6 H2O + light --> C6H12O6 + 6 O2, so carbon dioxide will be found in the reactant part of the equation.
A horse traveled a distance of 20 miles in 2
hours. What was the horse's speed?
Answer:
The horses speed was 10 miles per hour.
Explanation:
20/2=10
Hope this helps!
You come across a mysterious substance that has a mass of 1.8225 x 10 to the power of 2g
and a volume of 0.025 L (1L = 1000 mL). Using the density formula what is the density
Answer:
192
Explanation:
Bc its 182
Which changes involve forming or breaking chemical bonds?
A.burning and digesting
B.boiling and melting
C.burning and melting
D.rusting and cutting
Answer:
d
Explanation:
i took the test
The unknown element (Johnsonium, Jo) contains three naturally occurring isotopes. The relative abundances and atomic mass are:
Moorium-36: abundance = 1.32%, mass = 35.978amu
Moorium-38: abundance = 3.25%, mass = 37.963amu
Moorium-40: abundance = 95.43%, mass = 39.962amu
What is the average atomic mass of "Moorium?"
Answer:
Average atomic mass of moorium is 39.844 amu.
Explanation:
Given data:
Atomic mass of moorium-36 = 35.978 amu
Relative abundance of moorium-36 = 1.32%
Atomic mass of moorium-38 = 37.963 amu
Relative abundance of moorium-38 = 3.25%
Atomic mass of moorium-40 = 39.962 amu
Relative abundance of moorium-38 = 95.43%
Solution:
Average atomic mass moorium = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass)+ (abundance of 3rd isotope × its atomic mass) / 100
Average atomic mass of moorium = (1.32×35.978)+(3.25×37.963)+(95.43×39.962) /100
Average atomic mass of moorium = 47.491 + 123.380 +3813.574 / 100
Average atomic mass of moorium = 3984.445 / 100
Average atomic mass of moorium = 39.844 amu
a sample of alcohol has a density 0.82 g/ml.what is the mass of 5500 mL of the alcohol
Answer:
The answer is 4510 gExplanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volumeFrom the question
density = 0.82 g/mL
volume = 5500 mL
We have
mass = 0.82 × 5500
We have the final answer as
4510 gHope this helps you
Helium gas (He) is an element and not a compound. Why is this true?
Explain the term catalyst and how it affects the rate of a chemical reaction.
Answer:
Catalyst. A catalyst speeds up a chemical reaction, without being consumed by the reaction. It increases the reaction rate by lowering the activation energy for a reaction. Energy diagrams are useful to illustrate the effect of a catalyst on reaction rates.
Explanation:
What type of reaction is the equation 2NaCl → 2Na +Cl2?
Answer:
Synthesis reaction
Explanation:
This is a synthesis reaction. When you combine sodium metal (Na) with chlorine gas (Cl), you form sodium chloride or kosher salt (NaCl).
Hope this explanation helps!
Which term describes this molecular shape?
A. Tetrahedral
B. Bent
C. Trigonal planar
D. Linear
Answer:
A
Explanation:
Tetrahedral
The term that describes the molecular structure is Tetrahedral. The correct option is A.
What is molecular structure?The molecular structure is the structure of the molecular compounds. It tells the presence of ions and bonds in a compound. It is the arrangement of atoms, groups, or ions in a molecule, as well as the quantity and distribution of chemical bonds.
The use and importance of molecular structure are comprehending Nature's complex design principles and blueprints depend on understanding molecular structure.
Perhaps we can start to imitate her lovely items more cheaply and with less negative environmental effects if we can comprehend her plans and fundamental materials. The given compound is tetrahedral.
Thus, the correct option is A. Tetrahedral.
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Formula for all possible isomers of hexane
Answer:
1) n-Hexane. 2) 2-Methyl pentane(IUPAC name) or Isohexane(common name). 3) 2,2-Dimethylbutane(IUPAC name) or Neohexane(common name). 4) 3-Methylpentane
Explanation:
Annalise observes a streak of light in the sky and says she is seeing a shooting star. What is she most likely observing?
a falling star
an asteroid
a meteor
a dwarf planet
Answer: A Meteor
Explanation:
A streak of light in the sky and says she is seeing a shooting star. She's most likely observing is a meteor. Therefore, option C is correct.
What is a meteor ?A meteor is an object from space or a meteoroid that touches down on Earth. The air on the space rock creates drag that causes it to become incredibly heated as it falls toward Earth.
When the earth travels through cometary debris during its orbit around the Sun, meteor showers will result. Although the Earth's orbit around the Sun is nearly round, the majority of comets have very elliptical orbits.
A meteoroid becomes a meteor, or a streak of light in the sky, if it gets close enough to Earth and enters its atmosphere. These light striations are sometimes referred to as "shooting stars" due to their appearance. However, stars are not what meteors are.
Thus, option C is correct.
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NEED HELP FAST!!!!
Points A and B are locations on the banks of a river. What are the dominant processes occurring at locations A and B? *
A. deposition at location A; erosion at location B
B. erosion at location A; deposition at location B
C. deposition at both locations A and B
D. Erosion at both locations A and B
Answer:
C
Explanation:
What happens to particles in a sample of liquid when the liquid is heated and cooled?
During a change in state, energy is transferred in the form of
heat
light
moisture
motion
Answer:
heat I think.....
Hope it will help you......During a change in state, energy is transferred in the form of heat.
Hence, Option (A) is correct.
What is States of matter ?
When energy is added or removed to matter in the form of heat, it changes state to form a state of matter.
A state of matter is defined as one of the ways in which matter can interact with itself to form a homogeneous phase.
Therefore , During a change in state, energy is transferred in the form
of heat. Hence, Option (A) is correct.
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Please help I’ll give brainiest!
Answer:
Im sorry if u get it worng but is it the 3rd one?
Explanation:
HELPPPP I WILL GIVE YOU BRAIN THINGG WHATEVER ITS CALLED
We have learned that there are five steps to reading a new piece of music. Can you name all five steps?
Notes, Pitches, Articulation, Phrasing, and Musical Extras.