Answer:
An endothermic reaction is when heat is needed by the reaction, so it draws heat from its surroundings, making them feel cold. Just like a ice pack.
how many atoms of gold are present in 0.6 gm of 18 caral gold? ( 24 caral gold in 100% pure) atomic weight of gold = 197?
Answer:
HERE'S YOUR ANSWERWe are given that the ring is made up of 20 carrat gold. 20 carrat gold means 20 parts of gold and 4 parts of other metal (usually copper or silver). Thus, the percentage of gold in 20 carrat gold will be
= (20 / 24) X 100
= 83.333 %
We can now calculate the mass of gold in the ring. We are given that the ring weighs 300 mg. So, the mass of gold in ring will be
= (83.333 / 100) X 300
= 250 mg
Thus, the mass of gold in 300 mg of the ring is 250 mg.
Now the molar mass of gold is 197 g. This means that there are 6.023 X 1023 atoms of gold in 197g of gold. Thus
197g of gold = 6.023 X 1023 atoms of gold
1g of gold = (6.023 X 1023 ) / 197 atoms of gold
250 mg or 0.25g of gold = (6.023 X 1023 X 0.25) / 197 atoms of gold
= 7.643 X 1020 atoms of gold
HOPE IT HELPS MAN ☺️Give the relation of energy (E) and frequency (v) as given by Planck. Calculate the frequency and energy of a photon of radiation having wavelength 3000°A.
Pls answer correctly,need it urgently...
Solution:-1
[tex]\\ \sf\longmapsto E=hv[/tex]
E denotes to Energy h denotes to planks constantv denotes to frequency.Solution:-2
Wavelength=3000Å[tex]\boxed{\sf \lambda=\dfrac{c}{v}}[/tex]
[tex]\\ \sf\longmapsto v=\dfrac{c}{\lambda}[/tex]
[tex]\\ \sf\longmapsto v=\dfrac{3\times 10^8m/s}{3000\times 10^{-10}m}[/tex]
[tex]\\ \sf\longmapsto v=0.001\times 10^{18}s^{-1}[/tex]
[tex]\\ \sf\longmapsto v=1.0\times 10^{15}s^{-1}[/tex]
Now
[tex]\\ \sf\longmapsto E=hv[/tex]
[tex]\\ \sf\longmapsto E=6.626\times 10^{-34}Js\times 1.0\times 10^{15}s^{-1}[/tex]
[tex]\\ \sf\longmapsto E=6.6\times 10^{-19}J[/tex]
describe the different system of measurement
Answer:
A system of measurement is a collection of units of measurement and rules relating them to each other. ... Systems of measurement in use include the International System of Units (SI), the modern form of the metric system, the British imperial system, and the United States customary system.
Explanation:
Hope it works!!!!
Answer:
Systems of measurement in use include the International System of Units (SI), the modern form of the metric system, the British imperial system, and the United States customary system.
what do y’all do when y’all brainly says “locked” and won’t show anymore answers !???
Answer:
Create a new account as the thing you're experiencing now is due to the fact that Brainly had blocked your account.
3g of clean mg ribbon and 8g of clean copper metal was burnt separately in equal volume of air and both mass reacted completely with air state and explain where they was greater change in mass??
Answer:
gshshs
Explanation:
bshsjskskehhshs
The copper metal is heated in the air. The magnesium ribbon emits a brilliant light and magnesium oxide, which is white. When oxygen is passed over copper (in the presence of heat), an oxidation reaction occurs, resulting in the formation of black copper oxide. The greater change in mass observed when they start to burned.
What is copper metal ?Copper is a mineral and an element that is essential to our daily lives. It is a significant industrial metal due to its high ductility, malleability, thermal and electrical conductivity, and corrosion resistance. It is a necessary nutrient in our diet.
Metals are a class of materials that have high electrical and thermal conductivity, as well as malleability, ductility, and high light reflection. Copper (Cu), aluminium (Al), and other metals are examples.
The combustion of magnesium ribbon is a combined reaction. This is due to the fact that magnesium reacts with oxygen to form the single product magnesium oxide. When magnesium ribbon is burned in air, it reacts with the oxygen in the air to form magnesium oxide.
Thus, 3g of clean mg ribbon and 8g of clean copper metal were burnt separately in equal volume of air and both mass reacted completely with air the greater change in mass observed when they start to burned.
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How can biodiesel be a solution to the problems of climate change?
Answer:
BIOHEAT is a biodiesel mix that can be utilized (without equipment changes) in most home heaters. BIOHEAT promptly diminishes various hurtful discharges from heater use (up to 80% contingent upon blend used) and the oil is made from nearby feedstocks like utilized cooking oil
Ribbon diagrams shows secondary structures and appear less detailed than other model types. In one to two sentences, give a reason the chemists would use ribbon diagrams. What type of information do they provide?
Answer:
They show helixes and proteins
Explanation:
Ribbon diagrams are the Richardson diagrams that represent the protein structures. Chemist prefers using Ribbon diagrams to show the various structure of the proteins.
What are ribbon diagrams?The Ribbon diagram is used to represent the structural organization of the protein in the polypeptide chains or individually. It shows the three-dimensional structure and organization of the protein framework.
The ribbon diagram for the secondary structure of the protein shows the intramolecular and intermolecular structure along with helixes and bonding. It shows the detailed structure of the protein organization including the helix and sheets.
Therefore, the ribbon diagram is used by chemists to determine the structure of the protein as they give the details about the helix and sheet.
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Which phrase correctly describes the molecular structure within a molecule?
Same molecular structure and same properties.
Molecular structure is three dimensional structure in which arrangement of atoms is placed.
The molecular structure of a compound determines the polarity and its reactivity.
The different states of matter solid, liquid and gas have different molecular structure and different properties from each other.
The molecular structure of a molecule will have same properties as of the entire molecule based on its state.
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Answer:
the location of atoms, groups, or ions relative to one another and the number, type, and location of covalent bonds
What is the answer to 9.7300x10^2+9.8700x 10^3 1.0843x 10^ in scientific notation
Explanation:
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How many moles of Cd and of N are contained in 132.4 g of Cd(N03)2-4H20? (b) How many molecules of water of hydration are in this same amount?
Answer: The given amount of [tex]Cd(NO_3)_2.4H_2O[/tex] contains 0.430 moles of Cd, 0.860 moles of N and [tex]2.59\times 10^{23}[/tex] molecules of water.
Explanation:
The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)
Given mass of [tex]Cd(NO_3)_2.4H_2O[/tex] = 132.4 g
Molar mass of [tex]Cd(NO_3)_2.4H_2O[/tex] = 308.5 g/mol
Plugging values in equation 1:
[tex]\text{Moles of }Cd(NO_3)_2.4H_2O=\frac{132.4g}{308.5g/mol}=0.430 mol[/tex]
1 mole of [tex]Cd(NO_3)_2.4H_2O[/tex] contains 1 mole of Cd, 2 moles of nitrogen atom (N), 10 moles of oxygen atom (O) and 8 moles of hydrogen atom (H).
So, 0.430 moles of [tex]Cd(NO_3)_2.4H_2O[/tex] will contain = [tex](1\times 0.430) = 0.430mol[/tex] of Cd and [tex](2\times 0.430)=0.86mol[/tex] of N
According to the mole concept:
1 mole of a compound contains [tex]6.022\times 10^{23}[/tex] number of molecules
So, 0.430 moles of [tex]Cd(NO_3)_2.4H_2O[/tex] will contain = [tex]\frac{6.022\times 10^{23}}{1mol}\times 0.430mol=2.59\times 10^{23}[/tex] number of water molecules.
Hence, the given amount of [tex]Cd(NO_3)_2.4H_2O[/tex] contains 0.430 moles of Cd, 0.860 moles of N and [tex]2.59\times 10^{23}[/tex] molecules of water.
what is the reactant(s) in the chemical equation below
3CO(g) + Fe2O3(s) 2Fe(s) + 3CO2(g)
Answer:
the reactants are carbon dioxide ,iron, oxygen
What is said to have happened to the electrons in an atom in its ground state absorbs a quantum of energy from light
Answer:
The electron from the ground state to occupy a next energy level. In this case,we say that the electron is excited
can you solve question 5 and 6 only
Answer:
oil floats on water because it is heavier than water
Salt is no longer visible after stirring as salt dissolves in water
by filtration
"Every action force creates a reaction force that is equal in strength and opposite in direction." This statement summarizes Newton's
Answer: Newton's Third Law of Motion.
Explanation:
Newton's Third Law of Motion simply states that every action force creates a reaction force and then, this reaction force will be equal in strength and opposite in direction.
The statement simply implies that in every interaction, there will be a pair of forces that is acting on the two interacting objects. An example of Newton's third law of motion can be seen when a person jumps, thenlegs of the person will apply a force to the ground which will then propel the person into the air.
giúp tớ với, mình học lớp 9 ạ
Answer: broooo what is this
Explanation:
number of moles from the formula is multiplied by the atomic mass of each _______, and then all those masses are added together.
A)
atom
B)
particle
C)
molecule
D)
electron
Answer:
D. electron
Explanation:
What will happen if we drink liquid nitrogen?
PLZ HELP ME A girl throws a ball and her dog chases it. What characteristic of living things is this dog demonstrating as it chases the ball?
A. Cells
B. Reproduction
C. Growth
D. Response
what is second explain it briefly
Explanation:
it is that when an object is moving 25 m per sec to calculate its time we can simply divide 1.5 by 25 and multiply by 1
The solubility of gases
when the temperature is
increased.
A. increases
B. decreases
C. does not change
Answer:
B. decreases
Explanation:
The solubility of gases in a liquid is inversely proportional to the temperature, it means that if you increase the temperature, the solubility decreases.
Two glasses labeled A and B had equal amounts of water. Ted heated the water in one of the glasses. He then put two drops of food coloring into each of the two glasses. The table shows the time taken by the food coloring in the two glasses to spread out.
Which of the following statements is correct?
A - The water in Glass B was heated; therefore, the particles in Glass B have greater kinetic energy and move faster.
B - The water in Glass A was heated; therefore, the particles in Glass A have greater kinetic energy and move faster.
C - The water in Glass B was heated; therefore, the particles in Glass B move slower.
D - The water in Glass A was heated; therefore, the particles in Glass A move slower.
Answer:
The answer is A: The water in Glass B was heated; therefore, the particles in Glass B have greater kinetic energy and move faster.
Explanation:
Think about it, if you boil water, whatever you put in the water is going to move around faster than if you put something in standing water.
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The water in Glass B was heated; therefore, the particles in Glass B have greater kinetic energy and move faster. The correct answer is A.
What is food coloring?Food coloring, or color additive, is any dye, pigment, or substance that imparts color when it is added to food or drink.
The food coloring we add to the water is pushed around by the water molecules. Since the molecules in warm water move around faster, the food coloring spreads out quicker in warm water than in cold water.
From the table, we can say that the water in glass B was heated by Ted and the molecules of food coloring spread out quickly in warm water and they have greater kinetic energy and move faster.
On the other hand, in glass A, the water is cold, so food coloring will not dissolve quickly.
Therefore, The water in Glass B was heated; therefore, the particles in Glass B have greater kinetic energy and move faster. The correct answer is A.
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Which of the following are held together by nonpolar covalent bonds?
The Periodic Table
A. Atoms of phosphorus (P) and chlorine (CI)
B. Atoms of chlorine (CI)
C. Atoms of chlorine (CI) and magnesium (Mg)
D. Atoms of magnesium (Mg)
Answer:
Answer: Atoms of chlorine (CI) and magnesium (Mg)
Answer: Atoms of chlorine (CI) and magnesium (Mg)is your answer
Xà phòng hoá hoàn toàn 22,2g hỗn hợp gồm 2 este HCOOC2h5 và ch3cooch3 bằng dung dịch naoh 1m ( đun nóng) thể tích dung dịch naoh tối thiểu cần dùng là
Answer:
I can't understand your language? can you write in English
I'm sorry
What is the AHsol for LiF → Lit + F-? The lattice energy is -1,036 kJ/
mol, the enthalpy of hydration for Lit is -499
kJ/mol, and the enthalpy of hydration for F-is-431 kJ/mol. Use A Hooi = -A Hat + AHhydr.
0-968 kJ/mol
-106 kJ/mol
106 kJ/mol
1,966 kJ/
mol
The heat of hydration is defined as the heat absorbed or evolved when one mole of a substance undergoes hydration. The heat of solution is the enthalpy change associated with he dissolution of a solute. The lattice energy is the heat. Lattice energy is the energy released when the components of the lattice are brought together from infinity.
Hence the heat of solution for LiF → Li^+ + F- is -1966 kJ/mol
Given that;
Heat of hydration = ΔH solution – ΔH lattice energy
Where,
ΔH solution = Heat of the solution
ΔH lattice energy = Lattice energy of the solution
The heat of solution or enthalpy of dissolution is defined as the enthalpy change associated with the dissolution of a solute in a solvent
From the formula above;
ΔH solution = Heat of hydration + ΔH lattice energy
Heat of hydration = [(-431) + (-499)] = -930 kJ/mol
ΔH solution = (-930) + (-1,036) = -1966 kJ/mol
Hence the heat of solution for LiF → Li^+ + F- is -1966 kJ/mol
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Predict the approximate Ksp of Cuz(AsO4)2 based on the measured potential of Cell 7. Use the equation given in the Background.
a. 1 x 10^-35
b. 4 x 10^14
c. 5 x 10^-17
d. 2 x 10^-21
Answer:
a. 1 x 10^-35
Explanation:
The correct compound given is: [tex]\mathsf{Cu_3(AsO_4)}_2[/tex]
To predict the approximate Ksp value of the given compound, we will need to express the oxidation-reduction half-reaction of the compound and its dissociation, then, we will use the Nernst equation to determine the approximate Ksp value.
To start with the reduction half-reaction:
[tex]\mathsf{Cu_3(AsO_4)_{2}(s) + 6e^- \to 2As O_{4}^{3-}_{(aq)}+3Cu(s) }[/tex]
The oxidation half-reaction is:
[tex]\mathsf{3Cu(s) \to 3CU^{2+}_{(aq)} + 6e^-}[/tex]
The overall cell reaction now is:
[tex]\mathsf{Cu_3(AsO_4)_{2}(s) \to 3Cu^+ (aq) + 2As O_{4}^{3-}_{(aq)} }[/tex]
From the reduction half-reduction, the number of moles of electrons (n) transferred is 6 moles.
By applying the Nernst equation:
[tex]\mathsf{E_{cell} = E^0_{cell} -\dfrac{0.0591V}{n}log [Cu^{2+}]^3[AsO_4^{3-}]^2 }[/tex]
At standard conditions;
The standard cell potential [tex]\mathsf{E^0_{cell} = -0.342 \ V}[/tex]
and [tex]\mathsf{E_{cell} = 0 \ V}[/tex] since it is at equilibrium.
∴
[tex]\mathsf{0 = -0.342 -\dfrac{0.0591V}{6}log [Cu^{2+}]^3[AsO_4^{3-}]^2 } \\ \\ \\ \mathsf{0.342 = -\dfrac{0.0591V}{6}log [Cu^{2+}]^3[AsO_4^{3-}]^2 }[/tex]
[tex]\mathsf{log [Cu^{2+}]^3[AsO_4^{3-}]^2 = \dfrac{-(0.342)*6}{0.0591 }}[/tex]
[tex]\mathsf{log [Cu^{2+}]^3[AsO_4^{3-}]^2 = -34.7}[/tex]
[tex]\mathsf{log [Cu^{2+}]^3[AsO_4^{3-}]^2 \simeq -35}[/tex]
[tex]\mathsf{[Cu^{2+}]^3[AsO_4^{3-}]^2 = 10^{-35}}[/tex]
[tex]\mathbf{K_{sp} = [Cu^{2+}]^3[AsO_4^{3-}]^2 = 1\times 10^{-35}}[/tex]
PLZ HELP ME Which of the following accurately descnbes the function of the nervous system? O
A To help parts of the body communicate
B. To prevent and fight disease C:
To allow the body to move O
D. To provide support for the body SUNT
Answer:
A
Explanation:
the nervous system helps parts of the body communicate.through nerves.
I hope this helps
hii pls help me to balance the equation and state the symbols thanksss
Answer:
I hope that the link above will be helpful
▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓
[tex]\boxed{\pmb{\green{\sf{2Mg +H_{2}SO_{4}\dashrightarrow H _{2}+Mg_{2}SO_{4}}}}}[/tex]
▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓
which is the answer?
Answer:
I could be wrong letter c
I need help on this question asap!
You are in a lab and you use 11.50 g of Na(s) to react with Cl(g). Below is the reaction that happens from this.
Na + Cl2 → NaCl
Your percent yield is 95%. From this info what is the actual yield?
Answer:
27.79 g to the nearest hundredth.
Explanation:
2Na + Cl2 ---> 2NaCl
Using the molar masses , the theoretical yield is:
46 g of Na yields 46 + 35.5*2 g NaCl
46 g ---> 117 g NaCl so
11.5 g ----> 117 * 11.5 / 46 g NaCl
But, as the yield is 90%
the actual yield is 0.95 * 117 * 11.5 / 46
= 27.79 g.
Prepare a project report on various samples of a) a mixture b) a compound c) an element (metal or nonmetal)
Answer:
Any substance that contains only one kind of an atom is known as an element. Because atoms cannot be created or destroyed in a chemical reaction, elements such as phosphorus (P4) or sulfur (S8) cannot be broken down into simpler substances by these reactions.
Example: Water decomposes into a mixture of hydrogen and oxygen when an electric current is passed through the liquid. Hydrogen and oxygen, on the other hand, cannot be decomposed into simpler substances. They are therefore the elementary, or simplest, chemical substances - elements.
Each element is represented by a unique symbol. The notation for each element can be found on the periodic table of elements.
The elements can be divided into three categories that have characteristic properties: metals, nonmetals, and semimetals. Most elements are metals, which are found on the left and toward the bottom of the periodic table. A handful of nonmetals are clustered in the upper right corner of the periodic table. The semimetals can be found along the dividing line between the metals and the nonmetals.
Explanation:
