Answer:
pH is a scale used to specify the acidity or basicity of an aqueous solution. Lower values correspond to solutions which are more acidic in nature, while higher values correspond to solutions which are more basic or alkaline.
Explanation:
Answer: “pH, quantitative measure of the acidity or basicity of aqueous or other liquid solutions. The term, widely used in chemistry, biology, and agronomy, translates the values of the concentration of the hydrogen ion—which ordinarily ranges between about 1 and 10−14 gram-equivalents per litre—into numbers between 0 and 14.” - my science teacher I don’t know where she gets her notes from
Explanation:
A compound ‘X’ is used for drinking, has pH =7.Its acidified solution undergoes decomposition in presence of electricity to produce gases ‘Y’ and ‘Z’ The volume of Y is double than Z. Y is highly combustible whereas Z is supporter of combustion. Identify X, Y & Z and write the chemical reactions involved.
Answer:
X = Water (H2O) ; Y = Hydrogen ; Z = Oxygen
Explanation:
2(H2O) -------> 2H2 + O2
A perfume bottle is dropped in the comer of a room. The odor of the perfume can be detected on the other side of the statement best describes this observation? Particles are moving from regions of high concentration to low concentration.Particles are moving from regions of low concentration to high concentration. Particles are moving through a small opening into a smaller volume. Particles are moving through a small opening into a larger volume.
Answer:
Particles are moving from regions of high concentration to low concentration.
hope this answer correct (^^)
Answer:
A. Particles are moving from regions of high concentration to low concentration.
Explanation:
took a test
A welding torch produces a flame by burning acetylene fuel in the presence of oxygen. This flame is used to melt a metal. Which energy transformation represents this process?
chemical energy into thermal energy
kinetic energy into potential energy
kinetic energy into electromagnetic energy
potential energy into chemical energy
Answer:
chemical energy into thermal energy
Explanation:
The reaction taking place is as follows
2C₂H₂ + 5O₂ = 4CO₂ + 2H₂O + Heat
In this reaction bonds present in acetylene is broken and new bond present in water and carbon dioxide are formed . In the whole process of bond breaking and bond formation , there is net loss of energy and that energy is released as heat energy .
Thus we can say that in the whole process , chemical energy is converted into heat energy .
Answer:
A: chemical energy into thermal energy.
Explanation:
Which substance is a mixture? Table salt, gasoline, aluminum, carbon dioxide?
Answer:
b.) gasoline
Explanation:
The rest mentioned are pure substances/compounds which is not a mixture.
A substance is said to be a mixture if they are not able to get dissolved completely in the solution. Gasoline is a mixture. Thus, option B is correct.
What are mixtures?Mixtures are the substances that are formed by mixing two or more compounds that have been not able to show any chemical bond and linkage. They are physical combinations rather than chemicals.
Gasoline is a homogeneous mixture that is formed by the combination of hydrocarbons and differs from other substances that are pure substances or compounds.
Table salt, aluminum, and carbon dioxide are pure substances that are formed of the same type of molecules or atoms. Table salt is made of Na and Cl atoms, aluminum is made of a single atom, and carbon dioxide of carbon and oxygen atom.
Therefore, gasoline is a mixture.
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(4 marks)
A farmer distributed his cabbages as follows: A certain hospital received a quarter of the
total number of bags. A nearby school received half of the remainder. A green grocer
received a third of what the school received. What remained were six bags more than
what the green grocer received. How many bags of cabbages did the farmer have?
(3
Answer:
Explanation:
Let the farmer had n no of bags of cabbage .
given to hospital = n / 4
given to school = 1/2 x 3n /4
= 3n / 8
given to grocer = 1 / 3 x (3n / 8 )
= n / 8
No of bags distributed
= n / 4 + 3n / 8 + n / 8
= 6n / 8
Remaining bag
= n - 6n / 8
= 2n / 8
According to question
2n / 8 = 6 + n / 8
n / 8 = 6
n = 48 .
2. Se combinan 40 g de SO2 y 25 g de O2 determine el porcentaje en masa del exceso con respecto a su masa inicial. P.A. (S = 32; O = 16) SO2 + O2 SO3
Answer:
60%
Explanation:
En la reacción:
2SO₂ + O₂ → 2SO₃
Donde 2 moles de SO₂ reaccionan por mol de O₂.
El peso atómico del SO₂ es:
1S = 32g/molₓ1 = 32g/mol
2O = 16g/molₓ2 = 32g/mol
SO₂ = 32g/mol + 32g/mol = 64g/mol
Y el peso atómico de O₂ es:
2O = 16g/molₓ2 = 32g/mol
Las moles de SO₂ y O₂ son:
SO₂: 40g ₓ (1mol / 64g) = 0.625 moles
O₂: 25g ₓ (1mol / 32g) = 0.7813 moles
Para una completa reacción de SO₂ se necesitan:
0.625 moles SO₂ ₓ (1mol O₂ / 2 mol SO₂) = 0.3125 moles de O₂
Así, las moles en exceso de O₂ son:
0.7813 moles - 0.3125 moles = 0.4688 moles O₂
En gramos:
0.4688 moles O₂ ₓ (32g / mol) = 15g O₂ están en exeso.
El porcentaje en exceso es:
15g / 25g ₓ 100 =
60%Please help, I don't under stand! Balance the following oxidation-reduction reaction and indicate which atoms have undergone oxidation and reduction. ____FeCl3 + ____H2S Imported Asset ____FeCl2 + ____S + ____HCl
Answer:
3 FeCl3 + H2S = 2 FeCl2 + S + 2 HCl
Explanation:
Fe goes form +3 to +2
S goes from -2 to 0
H and Cl are spectator ions
Fe3+ + 1e-= Fe2+
H2S = S + 2 H+ + 2e-
3 Fe3+ + H2S = 2 Fe2+ + S + 2 H+
3 FeCl3 + H2S = 2 FeCl2 + S + 2 HCl
Of the following, which can be used to identify an element present in a sample?
Answer:
idk but i tryed
Explanation:
The simplest way to use the periodic table to identify an element is by looking for the element’s name or elemental symbol. The periodic table can be used to identify an element by looking for the element’s atomic number. The atomic number of an element is the number of protons found within the atoms of that element.
Does anybody know how to do q4. Please show working out thanks.
Answer:
% purity of limestone = 96.53%
Explanation:
Question (4).
Weight of impure CaCO₃ = 25.9 g
Molecular weight of CaCO₃ = 40 + 12 + 3(16)
= 100 g per mole
We know at S.T.P. number of moles of CO₂ = 1 and volume = 22.4 liters
From the given reaction, 1 mole of CaCO₃ reacts with 1 mole or 22.4 liters of
CO₂.
∵ 22.4 liters of CO₂ was produced from CaCO3 = 100 g
∴ 1 liter of CO₂ will be produced by CaCO₃ = [tex]\frac{100}{22.4}[/tex]
∴ 5.6 liters of CO₂ will be produced by CaCO₃ = [tex]\frac{100\times 5.6}{22.4}[/tex]
= 25 g
Therefore, % purity of CaCO₃ = [tex]\frac{\text{Weight calculated}}{{\text{Weight given}}}\times 100[/tex]
= [tex]\frac{25}{25.9}\times 100[/tex]
= 96.53 %
What type of contamination do peroxides produce?
Answer:
The main hazard related to organic peroxides are their fire and explosion hazards. ... It is the double oxygen of the "peroxy" group that makes organic peroxides both useful and hazardous. The peroxy group is chemically unstable. It can easily decompose, giving off heat at a rate that increases as the temperature rises.
Explanation:
What is Rutherford atomic modle
Answer:
Rutherford's atomic model explained how the electrons surrounded the nucleus of protons and neutrons. His model showed how J. J. Thomson's Plum Pudding model was incorrect.
Answer:Rutherford model of an atom shows that an atom is mostly an empty space,with electrons orbiting a fixed positively charged nucleus in set.
Explanation:
How do I write these decimal numbers in expanded form? 0.913, 0.205, 0.047, 0.480
Thanks! :)
Explanation:
To write a decimal in expanded form, write the number as a sum of its place values.
0.913 = 0.9 + 0.01 + 0.003
0.205 = 0.2 + 0.005
0.047 = 0.04 + 0.007
0.480 = 0.4 + 0.08
2N2H4+ N2O4———3N2+4H2O SalmaKhan99 avatar How many grams of N2 gas will be formed by reacting 100g of N2H4 and 200g of N2 Kindly answer please
Answer:
131.26 g
Explanation:
From the balanced equation,
2 moles of N₂H₄reacts with 1 mole of N₂O₄ to give 3 moles of N₂
Now number of moles of N₂H₄ present in 100 g N₂H₄ is n = 100 g/molar mass N₂H₄.
Molar mass N₂H₄ = 2 × 14.01 g/mol + 1 × 4 g/mol = 28.02 g/mol + 4 g/mol = 32.02 g/mol
n₁ = 100/32.02 = 3.123 mol
Also
Now number of moles of N₂O₄ present in 200 g N₂O₄ is n = 200 g/molar mass N₂O₄.
Molar mass N₂O₄ = 2 × 14.01 g/mol + 16 × 4 g/mol = 28.02 g/mol + 64 g/mol = 92.02 g/mol
n₂ = 200/92.02 = 2.173 mol
Since the mole ratio of N₂H₄ to N₂O₄ is 2 : 1, We require 2 × 2.173 mol N₂H₄ to react with 2.173 mole N₂O₄
Number of moles of N₂H₄ required is 4.346. But the number of moles of N₂H₄ present is 3.123 so N₂H₄ is the limiting reagent.
So, from the equation, 2 moles of N₂H₄ produces 3 moles of N₂
Therefore number of mole N₂ = 3/2 moles of N₂H₄ = 3/2 × 3.123 mol = 4.6845 mol
From n = m/M where n = number of moles of nitrogen gas = 4.6845 mol and M = molar mass of nitrogen gas = 28.02 g/mol and m = mass of nitogen gas.
m = nM = 4.6845 mol × 28.02 g/mol = 131.26 g
So the mas of nitrogen gas produced is 131.26 g
What reaction is depicted by the given equation: Au3+ + 3e− Au
A. oxidation B. reduction C. combustion D. replacement E. neutralization
Answer:
The answer is option B.
Reduction
Hope this helps you
Answer:
plato answer b
Explanation:
Why is making proteins important
Silver is composed of a single type of atom and cannot be broken down into different substances. Silver is an example of a(n)
ОА.
element
ОВ.
compound
molecule
1. The atomic number of an element is 23 and its mass number is 56.
a. How many protons and electrons does an atom of this element have?
b. How many neutrons does this atom have?
Answer:
23 protons, 23 electrons, 33 neutrons
Explanation:
I don't know why my answer got deleted but no worries, I can answer again. The number of protons and electrons is equal to the atomic number which is 23 and the number of neutrons is 56 - 23 = 33 because atomic mass denotes the number of protons and neutrons.
(7) Give two examples of solid poeciption
(SOMEONE HELP!!! PLEASE) What are some similarities and differences between ionic and covalent bonds?
Answer:
Ionic and covalent bonds are different in many ways.
Explanation:
A covalent bond is where electrons are shared between several atoms and is apparent in H20 also known as water.
Ionic bonds occur when an atom "gives away" one of its electrons to another one, and due to this difference in charge, they are attracted to each other.
Here is a list of differences:
Ionic bonds are typically strongerCovalent bonds have atoms that are electrically neutral, while ionic bonds have electrically charged atomsCovalent bonds are far more common in nature than ionic bondsCovalent bonds from between two non metals, whereas ionic bonds are formed by a metal and a nonmetalIonic compounds are usually solid whereas Covalent compounds are usually liquid or gasCovalent bonds can form between two atoms of the same element, where this is not possible with ionic bonds.Here are some similarities:
Valence electrons are involved in both bonding processesThe result of both bonds is electrically neutral, even if each individual atom isn'tWhen atoms bond together, they release heat whether or not they are covalent or ionicBoth covalent and ionic bonds lead to stable compounds.Hope this helps!
Assuming constant pressure, rank these reactions from most energy released by the system to most energy absorbed by the system, based on the following descriptions:__________.
A: Surroundings get colder and the system decreases in volume.
B: Surroundings get hotter and the system expands in volume.
C: Surroundings get hotter and the system decreases in volume.
D: Surroundings get hotter and the system does not change in volume.
Answer:
C: The surroundings heat up and the system decreases in volume.
D: The surroundings heat up and the system does not change volume.
B: The surroundings heat up and the system expands in volume.
A: The surroundings get cold and the system decreases in volume.
Explanation:
The most exothermic reactions are those that release heat, that is to say, they give up the heat as it cools and the surroundings heat up.
As for endothermics, that is, those that absorb or capture the heat of the medium, they are variables that cool the environment that surrounds them and increase their internal temperature
Help. Why are state symbols used in chemical equations?
O A. They tell which reactions will happen and which won't.
B. They identify how much product will be made.
C. They identify what phase the substances are in.
O D. They tell how the atoms are arranged in the substances.
Answer:
The answer is option C.
They identify what phase the substances are in.
Hope this helps
A student lifts a box of books that weighs 350 N. The box is lifted 4.0 m. How much work does the student do on the box?
Explanation:
F=350N
d=4m
W=F*d
=350*4
=1400 NM
How much oxygen will contain the same number of atoms as the number of molecules in 73 g of HCI?
Answer:
64g of O2.
Explanation:
We'll begin by calculating the number of molecules in 73g if HCl.
This is illustrated below:
From Avogadro's hypothesis, we understood that 1 mole of any substance contains 6.02×10²³ molecules. This implies that 1 mole of HCl also contains 6.02×10²³ molecules
1 mole of HCl = 1 + 35.5 = 36.5g
Thus, if 36.5g of HCl contains 6.02×10²³ molecules, then 73g of HCl will contain = (73 x 6.02×10²³)/36.5 = 1.204×10²⁴ molecules.
Therefore, 73g of HCl will contains 1.204×10²⁴ molecules.
Now, we shall determine the mass of oxygen that will contain 1.204×10²⁴ molecules.
This can be obtained as follow:
1 mole of O2 = 16x2 = 32g
32g of O2 contains 6.02×10²³ molecules.
Therefore, Xg of O2 will contain 1.204×10²⁴ molecules i.e
Xg of O2 = (32 x 1.204×10²⁴)/6.02×10²³
Xg of O2 = 64g
Therefore, 64g of O2 will contain the same number of molecules (i.e 1.204×10²⁴ molecules) in 73g of HCl.
2.70g of Zn (s) reacts with 50.0 mL of 1.00 M HCl solution to produce hydrogen gas according to the reaction. (R = 0.08206 L·atm·K-1·mol-1) Zn(s) + 2HCl (aq) = ZnCl2 (aq) + H2(g) a) calculate mole of Zn used in this reaction b) calculate mole of HCl used in this reaction c) calculate which reactant is a limiting reactant d) calculate mole of hydrogen gas formed e) calculate volume of H2 gas at STP in Liters that will be produced during the reaction
Answer:
a. 0.0413 moles Zn
b. 0.0500 moles HCl
c. HCl is the limiting reactant
d. 0.0250 moles H₂
e. V = 0.56L
Explanation:
The reaction of Zn(s) with HCl is:
Zn(s) + 2HCl (aq) → ZnCl₂ (aq) + H₂(g)
Where 1 mole of Zn reacts with 2 moles of HCl.
a) To convert mass in grams to moles of a substance you need to use molar mass (Molar mass Zn: 65.38g/mol), thus:
2.70g Zn × (1mol / 65.38g) = 0.0413moles of Zn
b. Now, when you have a solution in molarity (Moles / L), you can know the moles of a volume of solution, thus:
Moles HCl:
50.0mL = 0.0500L × (1.00mol / L) = 0.0500 moles HCl
c. The limiting reactant is founded by using the chemical reaction as follows:
For a complete reaction of 0.0500 moles HCl you need:
0.0500 moles HCl × (1 mole Zn / 2 moles HCl) = 0.0250 moles Zn
As you have 0.0413 moles of Zn, and you need just 0.0250 moles for the complete reaction, Zn is the exces reactant and HCl is the limiting reactant
d.As HCl is limiting reactant and 2 moles of HCl react with 1 mole of H₂, moles of hydrogen formed are:
0.0500 moles HCl × (1 mole H₂ / 2 moles HCl) = 0.0250 moles H₂
e. Using PV = nRT, you can find volume of gas, thus:
PV = nRT
V = nRT / P
Where P is pressure 1atm at STP, n are moles, R is gas consant 0.08206Latm/molK and T is absolute temperature 273.15K at STP.
V = 0.0250molesₓ0.082atmL/molKₓ273.15K / 1atm
V = 0.56L
The pressure of a 1-L nitrogen gas sample at 25 ⁰C is 0.30 atm. The pressure of a 1-L oxygen gas sample at the same temperature is 0.25 atm. The oxygen gas sample is added to the nitrogen container. Argon gas is added to the mixture until the total pressure of the 1-L container reaches 1.00 atm, and the temperature is adjusted to 25 ⁰C. According to Dalton’s Law of Partial Pressures, the contribution of each gas to the total pressure of the gas mixture is: Nitrogen _____________ Oxygen _____________ Argon _____________
Answer:
Nitrogen = 0.3 atm
Oxygen = 0.25 atm
Argon = 0.45 atm
Explanation:
According to Dalton's law of partial pressure, the total pressure in the container is equal to sum of the partial pressures of the individual gases.
Given;
Total pressure of the gases, P_total = 1 atm
Pressure of nitrogen, P_nitrogen = 0.3 atm
Pressure of oxygen, P_oxygen = 0.25 atm
Pressure of argon, P_argon = ?
[tex]P_{total} = P_{nitrogen} + P_{oxygen} + P_{argon}\\\\1 \ atm= 0.3 \ atm + 0.25 \ atm + P_{argon}\\\\1 \ atm= 0.55 \ atm + P_{argon}\\\\ P_{argon} = 1 \ atm - 0.55 \ atm\\\\ P_{argon} = 0.45 \ atm[/tex]
Therefore, the contribution of each gas to the total pressure of the gas mixture is;
Nitrogen = 0.3 atm
Oxygen = 0.25 atm
Argon = 0.45 atm
Explain the methods of passive transport that move molecules across the plasma membrane of the cell.
What is the acceleration of the object’s motion? 0.5 m/s2 -0.5 m/s2 2 m/s2 -2 m/s2
Answer: -2m/s2
Explanation:
Using the following equation ; acceleration = Change in velocity / time
i.e a = v - u / t
where 'a' = acceleration
v = final velocity
u = initial velocity
t = time
Therefore; from the graph we have acceleration to be, 0 - 6m/s / 3s = -2m/s2
Which organism is a producer? A) Oak tree B) Mushroom C) Mountain Lion D) Butterfly
Answer:
A
Explanation:
Oak trees are producers because they make their own food through the process of photosynthesis.
Answer:
A. oak tree
Explanation:
A producer is an organism that produces or creates its own food through the process of photosynthesis. Certain organisms, like plants, algae and some bacteria undergo this process. Carbon dioxide, water, and light energy from the sun are turned into glucose and oxygen. The glucose becomes the food for the organism.
A mountain lion and a butterfly are both animals. A mushroom is a fungus. Therefore, the correct answer must be A. oak tree.
Examine the graph showing the half life of the radioactive isotope substance x. Based on this graph, what might be the best use of thos radioactive isotop?
Determining the age of the objects less than 50000 years old.
Long term radioactive dating such as in dating rocks
Short term radioactive imaging such as nuclear medicine.
Determining the age of objects over 1000000 years old
Answer:
Long term radioactive dating such as in dating rocks
Explanation:
If we examine the graph carefully, we will notice that the number of atoms falls to zero after about 40000 years. This is quite a long time! Many rock formations were formed thousands of years ago and their ages can only be measured by an isotope that has an equally long half life.
Hence for an isotope with such a long half-life, we can effectively measure the age of a rock formation that contains the particular isotope in question. Rocks are composed of diverse chemical isotopes which are normally used to determine the age of the rock formation. Since rocks were formed thousands of years ago, these isotopes must be capable of having a half-life of thousands of years also in order to be useful in measuring the age of rocks.
What characteristics determine how easily two substances change temperature? Check all that apply.
volume of the two substances in contact
amount of time the two substances are in contact
area in contact between the two substances
specific heat of the material that makes up the substances
Odensity of the two substances in contact
amount of time the two substances are in contact. area in contact between the two substances. specific heat of the material that makes up the substances. the density of the two substances in contact.
The characteristics determine how easily two substances change temperature is amount of time the two substances are in contact, area of contact between the two substances, specific heat of the material that makes up the substances and the density of the two substances in contact. Therefore, option B, C, D and E are correct.
When two substances have different temperatures come into contact?When two substances that have different surface temperatures come in contact, conduction happens. The substance with the higher temperature always transfers energy to the one with the lower temperature.
When two objects with different temperatures come in contact with one another, energy moves from the hotter (higher temperature) object to the cooler (lower temperature) object until both objects reach the same temperature.
The latitude of the location has an impact on the air temperature there. The location's elevation. separation from the ocean.
Thus, option B, C, D and E are correct.
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