Answer:
D
Explanation:
A catalyst is a substance that increases the rate of a chemical reaction by lowering the activation energy without itself being consumed by the reaction.
Activation energy is the minimum amount of energy required for a chemical reaction to proceed in the forward direction.
A catalyst increases the reaction rate by providing an alternative pathway or mechanism for the reaction
How much heat is required to change 235 g of iodine at 25 degrees celsius into vapor at 198 degrees celsius? The melting point is 113.5 degrees celsius and the boiling point is 185.4 degrees celsius.
Answer:
koe Pgl smjega but kya karu mods ka acc mil nai raha and acc delete karna h
which would best be categorized as heat transfer by conduction?
a.) wearing a white shirt to stay cool on a summer day
b.) warming your body under the sun in summer
c.) feeling the heat from a lightbulb with your hand when touching the bulb
d.) feeling the heat from a light bulb while holding your hand from 6 inches away
Answer:
c.) feeling the heat from a lightbulb with your hand when touching the bulb
Explanation:
In heat transfer by conduction, feeling the heat from a lightbulb with your hand when touching the bulb will be categorised as the best condition.
Write a Claim based in this question: What happens in the atmosphere and how
is it related to the water cycle.
Answer:
The atmosphere is the superhighway in the sky that moves water everywhere over the Earth. Water at the Earth's surface evaporates into water vapor which rises up into the sky to become part of a cloud which will float off with the winds, eventually releasing water back to Earth as precipitation.
Explanation:
If you don't want to plagiarize change it up a bit.
Which objects are scratched?
Answer:
We would need a picture to help you out with this.
Explanation:
A student heated a mixture of iron filings and sulfur strongly. He saw a red glow spread through the mixture as the reaction continued. At the end of the experiment a black solid had been formed.
a) Explain what the red glow indicates.
b) Give the chemical name of the black solid.
c) Write a word equation that and a balanced chemical equation to represent the reaction which has taken place.
d) The black solid is a compound. Explain the difference between the mixture of sulfur and iron and the compound formed by the chemical reaction between them.
Please answer part a, b, c, and d.
If you don't know the answer to all parts but you know the answer to one part then please answer it will still help
Answer:
the answer is c or a am I right☺
Describe how you would crystalize potassium nitrate from it's aqueous solution
Answer:
Potassium nitrate crystals are among the safest and easiest crystals to grow. Potassium nitrate (KNO3) is also known as saltpeter. It’s used in processed meats, fertilizers, gunpowder, fireworks, and many science projects. Here’s how to make potassium nitrate crystals and a look at how to up your game to grow a big crystal.
Materials
It’s fine to do this project in your kitchen. All you need is:
Potassium nitrateWaterCooking pot or microwave-safe bowl
Explanation:
Thanks
what is meant by pure substance????
The line "Come, I will make the continent indissoluble" from "For You O Democracy" implies democracy will make the nation stronger than ever before. Given this, what is most likely the meaning of indissoluble?.
Answer:
Permanent
Explanation:
I took the text
An element has 3 electrons, 3 protons and 4 neutrons. What will be its atomic number and mass number? (
Answer:
its atomic number will be 3 and it's mass number will be 7. it is lithium
which side of the periodic table are the metals on
Answer:
left
Explanation:
Metals are to the left of the line (excluding hydrogen, which is a nonmetal), nonmetals are to the right of the line, and metalloids are to the immediate right of the line.
(Hope this helps can I pls have brainlist (crown)☺️)
how many moles are in 2.5g of n2
Answer:
0.089
Explanation:
n= m/M = 2.5/14 = 5/28 mol
ok done. thank to me :>
Will this reaction occur?
Ni (s) + H,O(1)
1
Yes
No
Which two statements are true for both compounds and mixtures?
A. They are made up of more than one type of atom.
B. Their particles all have the same chemical formula.
C. They can be separated into two or more elements.
D. Their particles are held together by chemical bonds.
Answer:
B and C
Explanation:
A. Their particles are held together by chemical bonds.
This option is incorrect for both compounds and mixtures. It is only true for Compounds.
B. They are made up of more than one type of atom.
This is correct. Both compounds and mixtures consists of different atoms of elements.
C. They can be separated into two or more elements.
This option is correct. Compounds are broken down into elements through chemical means.
D. Their particles all have the same chemical formula.
This is wrong. Mixtures do not have a chemical formula
b) Explain how a burette and a conical flask should be rinsed before a titration experiment?
[tex] \large \text{Answer} \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ [/tex]
If you rinse the burette with the solution to be used, then any tiny amounts of liquid remaining are the same as the solution used to fill the burette, so they will not change the concentration of the solution in any way. This is to prevent contamination.
~⭐Hope it helps you ⭐~
How can air pollution affect plants
A. Air pollution can block sun light from reaching plants
B. Air pollution can affect the water plants need.
C. Air pollution absorbs carbon dioxide.
D. Air pollution can change normal temperatures of a region.
Answer:
A
Explanation:
B) pollution doesn't affect water
C) Air pollution makes carbon dioxide
D) air pollution does not affect temperature
One of the following is not a property of metals
а
high malleability
ь
high compressibility
с
high melting point
d
high ductility
Answer:
option b
Explanation:
high compressibility is not a property of metal.
How do the isotopes hydrogen-2 and hydrogen-3 differ?
A. Hydrogen-2 has three protons.
B. Hydrogen-2 has no protons.
C. Hydrogen-3 has one more electron than hydrogen -2.
D. Hydrogen-3 has two neutrons.
PLS SOMEONE HELP
Answer:
C hydrogen 3 has 0one more electron than hydrogen 2
Explain how food is transformed to energy for our bodies.
Which two statements are true for both compounds and mixtures?
A. They are made up of more than one type of atom.
B. Their particles all have the same chemical formula.
O C. They can be separated into two or more elements.
D. Their particles are held together by chemical bonds.
Answer:
B and C is your best option
BRAINLIST ???
Which procedure would produce the best data for comparing the electrostatic forces between the molecules of different substances?
Heat each substance in liquid form for the same amount of time. Measure the temperature of each substance.
Heat each substance in liquid form to its boiling point. Measure the temperature of each substance.
Heat each substance in solid form to its melting point. Measure the quantity of each substance that has melted.
Heat each substance in solid form for the same amount of time. Measure the temperature of each substance.
The best data for comparing the electrostatic forces between the molecules of different substances can be obtained through this procedure: B. Heat each substance in liquid form to its boiling point. Measure the temperature of each substance.
An electrostatic force can be defined as a force of attraction or repulsion between two (2) stationary and electrically charged particles of a substance.
Basically, the force between two (2) charges is inversely proportional to the square of the distance between them and directly proportional to the magnitude of their charges.
In the molecule of a substance, an electrostatic force is mainly responsible for holding its atoms together while giving the molecule both structure and strength.
During an experiment that is aimed at obtaining the best data to compare the electrostatic forces between the molecules of different substances, the procedure that should be adopted include:
Each of the substance should be heated in liquid form to its boiling point.The boiling temperature of each substance should be measured and recorded.From the data, a comparison should be done to know which molecule contain atoms that are tightly held together.Read more: https://brainly.com/question/24031197
Answer:
B. Heat each substance in liquid form to its boiling point. Measure the temperature of each substance.
Explanation:
Just in case you couldn't find the answer. <3
What role do insects play in the fertilization process?[Bees]
AThey transport seeds from trees to the groundincorrect answer
BThey collect nectar from the interior parts of plantsincorrect answer
CThey deliver pollen from the stamens of plants to the ovaries of other plantsincorrect answer
DThey eat fruit, exposing the seeds so that they can sprout and grow
Answer:
C. They deliver pollen from the stamens of plants to the ovaries of other plants
Explanation:
hope this helps :)
1. Hydrogen and nitrogen combine to form ammonia. When nitrogen and hydrogen bond, nitrogen pulls the electrons from hydrogen toward itself. Which statement about the reactants is correct?
A) Hydrogen is oxidized, and nitrogen loses electrons.
B) Hydrogen is oxidized, and nitrogen is reduced.
C) Hydrogen gains electrons, and nitrogen is reduced.
D) Hydrogen is reduced, and nitrogen is oxidized.
2. Which phrase best defines a redox reaction?
A) A reaction in which the number of oxygen atoms is reduced.
B) A reaction in which elements are transferred between different atoms.
C) A reaction is which oxygen combines with different atoms.
D) a reaction in which elements are released from the system.
3.Which statement describes the process of oxidation?
A) Oxidation results in a loss of electrons, so the oxidation number increases.
B) Oxidation results in a gain of electrons, so the oxidation number increases.
C) Oxidation results in a gain of electrons, so the oxidation number decreases.
D) Oxidation results in a loss of electrons, so the oxidation number decreases.
4. Which chemical equation represents a redox reaction?
A) TiCl4(s) + 2H2O(g) → TiO2(s) +4HCl(g)
B) CaO(s) + SiO2(s) → CaSiO3(l)
C) CaCO3(s) → CaO(s) + CO2(g)
D)Fe2O3(s) + 2Al(s) → Al2O3(s) +2Fe(l)
5. Which elements are oxidized and reduced in the reaction below?
Br2 (l) + 2NaI(aq) → I2 (s) + 2NaBr(aq)
A) Bromine (Br) is oxidized, and iodine (I) is reduced.
B) Iodine (I) is oxidized, and bromine (Br) is reduced.
C) Sodium (Na) is oxidized, and bromine (Br) is reduced.
D) Bromine (Br) is oxidized, and sodium (Na) is reduced.
Answer:
1. Hydrogen is oxidized, and nitrogen is reduced.
2. a reaction in which electrons are transferred between different atoms
3. Oxidation results in a loss of electrons, so the oxidation number increases.
4. Fe2O3(s) + 2Al(s) → Al2O3(s) + 2Fe(l)
5. Iodine (I) is oxidized, and bromine (Br) is reduced.
Explanation:
Just took the test and made a 100
Answer:
OXIDATION UNIT TEST
1. Which statement best explains why magnesium and chlorine combine in a 1:2 ratio?
A. Magnesium has two valence electrons, and chlorine can accept one electron in its outer shell
2. Hydrogen and nitrogen combine to form ammonia. When nitrogen and hydrogen bond, nitrogen pulls the electrons from hydrogen toward itself. Which statement about the reactants is correct?
C. Hydrogen is oxidized, and nitrogen is reduced.
3. C3H8 + 5O2 → 3CO2 + 4H2O + energy
Which type of reaction is shown?
C. combustion
4. Which phrase best defines a redox reaction?
D. a reaction in which electrons are transferred between different atoms
5. Which statement describes the process of oxidation?
D. Oxidation results in a loss of electrons, so the oxidation number increases.
6. Which chemical equation represents a redox reaction?
D. Fe2O3(s) + 2Al(s) → Al2O3(s) + 2Fe(l)
7. Which statement correctly describes the oxidation number of the manganese atom (Mn) in MnI2 and MnO2?
A. Manganese has an oxidation number of +2 in MnI2 and +4 in MnO2.
8. Br2(l) + 2NaI(aq) → I2(s) + 2NaBr(aq)
Which elements are oxidized and reduced in the reaction?
D. Iodine (I) is oxidized, and bromine (Br) is reduced.
9. Which action occurs at an electrode of a galvanic cell?
D. electron transfer
10. Which statement best compares a battery and a galvanic cell?
A. A battery’s source of power is a galvanic cell in which a redox reaction produces electrical energy.
11. Zn + 2H+ → Zn2+ + H2
2Al + 3Cu2+ → 2Al3+ + 3Cu
Which elements are oxidized?
A. zinc (Zn) and aluminum (Al)
12. 2Cr(s) + 3Cu2+(aq) → 2Cr3+(aq) + 3Cu(s)
Which half reaction occurs at the cathode?
B. 3Cu2+(aq) + 6e– → 3Cu(s)
13. Written
14. Written
15. Written
I hope this helps!
Explanation:
I took the test shhh
why do we adjust coefficients when balancing chemical equations and not subscripts?
Answer:
By changing the coefficients you change the amount you have of certain compounds in the equation, whereas changing the subscript would change what compounds are actually in the equation because it would change the ratio of how many atoms of each element are in a compound.
For Example:
Outside of Balancing Equations, [tex]NO_{2}[/tex] (Nitrite) and [tex]NO_{3}[/tex] (Nitrate) are different because one forms a strong acid while the other forms a weak acid based on how many oxygen atoms are added to the compound. So in a chemical equation, if you change the subscripts, you change the entire compound so your reaction may be with a weak acid instead of a strong acid and give you a different product. Meanwhile, changing the coefficient changes the amount of the compound you have for the reaction in order to maintain the Conservation of Mass Law.
Find the pOH for the following:
A 1.34 x 10^-4 M solution of hydrochloric acid.
A) 10.13
B) 3.87
C) 4
D) 10
Answer:
A) 10.13 is the answer
Explanation:
Since HCl is a strong acid, its pH can be found by simply plugging it into the equation:
pH = -log[H+]
*H+ is just the concentration you were given*
Now that you have the pH, you just subtract it from 14 to find the pOH
I have attatched my work below. Hope this helps! :^)
To find the pOH of a solution, you can use the formula: pOH = -log10[OH-]
What is pOH?pOH is a measure of the concentration of hydroxide ions (OH-) in a solution. It is the negative logarithm (base 10) of the hydroxide ion concentration.
In this case, since we have hydrochloric acid (HCl), we need to consider the concentration of hydroxide ions (OH-) produced when HCl dissociates in water.
HCl is a strong acid and completely dissociates, meaning it produces an equal concentration of hydrogen ions (H+) and chloride ions (Cl-) in water. Since there are no hydroxide ions produced, the concentration of hydroxide ions is 0.
Therefore, the pOH of a hydrochloric acid solution is 0, and none of the options provided (A, B, C, D) is the correct answer.
Learn more about pOH at:
https://brainly.com/question/17144456
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In an ionic compound, the total positive charge of all the positive ions ____ the total negative charge of all the negative ions.
Answer:
I think it would be 0 since cations and anions must always combine in such a way so that their charges cancel.
What is true about the light shown above?
A. All of the light is refracted
B. All of the light is reflected
C. Some of the light is refracted, and some of the light is reflected
D. None of the light is refracted or reflected
Answer:
The answer is D. None of the light is refracted or reflected.
Explanation:
Just trust :)
HELP PLEASE GIVING OUT BRAINLIEST AND A LOT OF POINTS!!
for a molecule to exhibit hydrogen bonding the h must be covalently bonded to a?
Answer:
: fluorine, oxygen, or nitrogen.
Explanation:
Hydrogen bonding occurs only in molecules where hydrogen is covalently bonded to one of three elements: fluorine, oxygen, or nitrogen.
Hydrogen bonding occurs only in molecules where hydrogen is covalently bonded to one of three elements: fluorine, oxygen, or nitrogen. These three elements are so electronegative that they withdraw the majority of the electron density in the covalent bond with hydrogen, leaving the H atom very electron-deficient. The H atom nearly acts as a bare proton, leaving it very attracted to lone pair electrons on a nearby atom.
how does the solubility of oxygen in water affect the value of r you determined?
Answer:
R, the gas law constant, is a constant,
Solubility of gas is inversely proportional to temperature.
Solubility of gas ∝ 1/Temperature
That means as temperature increases the solubility gas goes on decreasing and vice versa.
But R is inversely proportional to temperature .
So Solubility ∝ R. (1/T ∝ R)
That means solubility of gas goes on increasing as R increases.
Step 2: Result
Result:
So from above conclusion the solubility of Oxygen in water increases that result into increasing R value.
Explanation:
please help I attached an image
Answer:
B
Explanation:
Nonmetals have nearly full valence shells and try very hard to get that last few electrons to complete their valence shell. This allows them to achieve noble gas stability. This is why they have high electronegativities and electron affinities.