Answer:
D.Something that can be observed or measured without changing the identity of the substance.
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 ☺️What is known about a reaction with a negative enthalpy?
A. The reaction is endothermic,
B. The reaction is spontaneous,
C. The reaction is exothermic,
D. The reverse reaction is favored,
Considering the definition of enthalpy of reaction, the correct answer is option C. a reaction with a negative enthalpy indicates that the reaction is exothermic.
Definition of enthalpy of reactionThe enthalpy of a chemical reaction as the heat absorbed or released when chemicals are transformed into a chemical reaction and it occurs at constant pressure.
The enthalpy is an extensive property, that is, it depends on the amount of matter present.
Finally, it must be taken into account that:
A reaction is called exothermic if its enthalpy of reaction is negative (that is, if the system gives up heat).A reaction is called endothermic if its enthalpy of reaction is positive (that is, if the system absorbs heat).SummaryIn summary, a reaction with a negative enthalpy indicates that the reaction is exothermic.
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Name any two mixture that can be separated by this distillation
Answer:
Simple distillation is used to separate salt from seawater, to separate sugar from water.
Explanation:
please help me with this question.
ps: kindly include a drawing.
Answer:
gallium has orthorhombic and forms ionic bonds with metals
Explanation:
Which of the following describes a biotic factor of an ecosystem interacting with an abiotic factor in the ecosystem?
O A child lying on the grass
O A duck diving into a lake
O A raindrop falling onto the ground
O A puddle evaporating due to the heat
Answer:
a duck diving into a lake
Explanation:
Biotic factors are living or once living organisms in the ecosystem. These are obtained from the biosphere and are capable of reproduction.
Abiotic factors are non-living physical or chemical elements in the ecosystem. Examples include: water, air, soil, sunlight, and minerals.
describe an activity to separate the mixture of sand and water
Answer:
Sedimentation and decantation
Explanation:
Sedimentation and decantation: Mixture is kept undisturbed for some time. After some time, sand being heavier and insoluble in water, settles down at the bottom of container. Now, water is poured into another container to separate it from sand.
Answer:
evaporation or destillation
Explanation:
When sand is added to water it either hangs in the water or forms a layer at the bottom of the container. Sand therefore does not dissolve in water and is insoluble. It is easy to separate sand and water by filtering the mixture. Salt can be separated from a solution through evaporation.
Is backbonding is possible in BF4- ? If no then why?
Answer:
No, because Flourine can only form 1 bond, thus backbonding is not obtainable
500kg, 42m, 675g, and 10m/s are all examples of what typed of data?b
500kg, 42m, 675g, and 10m/s are all examples of a: continuous data.
A numerical data can be defined as a data set that is expressed in numbers only or a data set consisting of numbers rather than words. A numerical data is also known as a quantitative data.
Generally, numerical data are classified into two (2) main categories and these are;
Discrete data: a discrete data is a data set in which the number of possible values are either finite or countable. Some examples are; the value of a fair die, number of pen in a box, number of eggs in a crate, etc.Continuous data: a continuous data is a data set that has infinitely many possible values and as such those values cannot be counted, which simply means they are uncountable. Any data (quantity) such as mass, height, volume, weight, density, velocity, length, pressure, temperature, speed, distance, time are generally classified as continuous data.In conclusion, mass (500 kg), height (42m), mass (675g), and speed (10m/s) are all examples of a: continuous data.
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how many moles of sodium are produced in 46g of substance?
Answer:
Only 2moles are produced from it
What name is given to a non-metal when it forms an ion, and what type of charge does it have?
Answer:
Anions name is given to a non-metal when it forms an ion, and it has negative charge.
Answer:
Non metals form negative ions and negatively charged ions are called anions.
Hope I'm correct!!
26. Which of the following Is a reason that Venus is not ideal for supporting life?
• It lacks an atmosphere allowing for frequent meteorite collisions.
It
has a thick atmosphere which causes extremely high temperatures.
It has the perfect amount of atmosphere, but not enough hydrogen.
It
has a thin atmosphere which prevents llquid water from
existing on the planet surface.
Answer:
It has a thick atmosphere which causes extremely high temperatures.
Explanation:
please answer
√In the morning, when the sun rises in the east, your shadow will be seen on the
•East
•West
•North
•South
√From which part of plant cotton and jute obtained
Answer:
hi
Explanation:
1 east
2 the flower bud for cotton and for jute the leaves
plz mark me as a BRAINLIST
Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide: CaO (s) + H2O (l) → Ca(OH)2 (s) In a particular experiment, a 2.00-g sample of CaO is reacted with excess water and 2.14 g of Ca(OH)2 is recovered. What is the percent yield in this experiment? a. 107 b. 1.07 c. 2.88 d. 81.1 e. 93.3
Answer:
The option closest to the percentage yield is option;
d. 81.1
Explanation:
The given chemical equation of the reaction is presented as follows;
CaO (s) + H₂O (l) → Ca(OH)₂
The mass of CaO in the experiment, m = 2.00 g
The volume of water with which the CaO was reacted = Excess volume of water
Number of moles = Mass/(Molar mass)
The mass of Ca(OH)₂ recovered, actual yield = 2.14 g
The molar mass of CaO = 56.0774 g/mol
The number of moles of CaO in the reaction, n₁ = 2.00 g/(56.0774 g/mol ≈ 0.036 moles
The molar mass of Ca(OH)₂ = 74.093 g/mol
The number of moles of Ca(OH)₂ in the reaction, n₂ = 2.14 g/(74.093 g/mol) ≈ 0.029 moles
From the given chemical reaction, one mole of CaO reacts with one mole of H₂O to produce one mole of Ca(OH)₂
Therefore, 0.036 moles of CaO will produce 0.036 moles of Ca(OH)₂
Mass = Number of moles × Molar mass
The mass of 0.036 moles of Ca(OH)₂ ≈ 0.036 moles × 74.093 g/mol = 2.667348 grams
∴ The theoretical yield of Ca(OH)₂ = 2.667348 grams
[tex]Percentage \ yield = \dfrac{Actual \ yield}{Theoretical \ yield} \times 100 \%[/tex]
The percentage yield = (2.14 g)/(2.667348 grams) × 100 = 80.23%
Therefore, the option which is closest is option d. 81.1.
Which of the following increases as you move up a column of the periodic table?
Number of electrons
Atomic radius
Atomic Number
Electronegativity
Answer:
electronegativity increases
Scientific notation ? Please help
(5.55 x 10^15) x (8.88 x 10^18)
Explanation:
I first take back the numbers to their original forms that is to say (5.55×10^15) = 5550000000000000 and (8.88×10^18) = 8880000000000000000 therefore the difference of the two will be 887445 which is notated to (8.87445×10^5)
Answer: (8.87445×10^5)
Another name of shorthand configuration is
A. Nobel gas configuration
B. Aubfau configuration
C. Unabbreviated configuration
D. None of these
Answer:
A. Noble gas configuration
What can form as a result of a chemical reaction?
Answer:
O. compounds
Explanation:
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a sample of element X contains 90% X-35 atoms,8.0%X-37 atoms, and 2.0% X-38 atoms. The average atomic mass will be closest to which value?
Answer:
35.2.
Explanation
R.A.M= Mass of isotopes divide by 100 percent
1 atm is equal to
O 1 mmHg
• 14.7 mmHg
• 76 mmHg
© 760 mmHg
Answer:
C 760 mm of hg
because this is the atmospheric pressure at sea level
what are the products of the neutralization reaction between HCl and Ca(OH)2
A. CaCl2 and H2O
B. Cl2 CaO, and H2
C.CaCl and H3O+
D.CaH and HClO
what charge does an atom that has gained electrons have?
Answer:
I think it's positive charge
10. What do you understand by a balanced chemical equation? Explain with the an example.
the smell spreads immediately after you burn agarbatti in this example what is your condition about intermolecular force
Answer:
The aroma of agarbatti spreads quickly once you burn it because the particles in the agarbatti move endlessly in all directions. Both, the air and aroma, have large intermolecular forces which is why the molecules of air scatter immediately once agarbatti is burned.
in h-atom if x is radius of first bohrs orbit de broglie wavelength of an atom in 3rd orbit is a.3πx b.6πx c.9x/2 d.x/2
please I need complete explanation fast
Answer:
can you type question properly.
I'm having trouble understanding what "the difference in energy between the products and reactants from the surroundings" means. Can you help explain what this means? please
Answer:
The energy change in a chemical reaction is due to the difference in the amounts of stored chemical energy between the products and the reactants. This stored chemical energy, or heat content, of the system is known as its enthalpy.
Explanation:
Due to the absorption of energy when chemical bonds are broken, and the release of energy when chemical bonds are formed, chemical reactions almost always involve a change in energy between products and reactants. By the Law of Conservation of Energy, however, we know that the total energy of a system must remain unchanged, and that oftentimes a chemical reaction will absorb or release energy in the form of heat, light, or both.
why is m3 is derived unit?
Answer and Explanation:
There are 7 base units, m is one of them. Any unit made up of a combination of them is a derived unit. Also, any unit that is defined to be equivalent to a combination of base units is a derived unit.
A mixture of liquids having almost the same boiling point cannot be separated by simple distillation?Why?
Answer:
Distillation:
Distillation is the process in which two or more liquids are separated on the basis of their boiling points.
Process:
Liquid mixture is heated. The liquid which is of low boiling point evaporates first and is condensed separately. This is followed by the liquid having more boiling point than the previous one and so on.
Reason:
A mixture of liquids having almost same boiling points cannot be separated. This is because both the liquids will evaporate at almost the same time when heated and thus, we will obtain the same liquid mixture again. No separation will occur.
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Hope this helped!
~AH1807Peace!What eventually happens to all radioactive isotopes?
A. They become stable after one half-life.
B. They emit particles, electromagnetic radiation, or both.
C. They absorb energy when they decay.
D. They are pulled apart by strong nuclear forces.
Answer:
B. they emit particles electromagnetic radiation or both
Radioactive isotopes emit particles, electromagnetic radiation, or both. The correct option is B.
Radioactive decay occurs in all radioactive isotopes and involves the release of particles, electromagnetic radiation, or both.
Radioactive decay occurs owing to the instability of the isotope's atomic nucleus.
The nucleus releases surplus energy in the form of particles (such as alpha particles or beta particles) or electromagnetic radiation (such as gamma rays) in order to achieve a more stable state.
This random process continues until the radioactive isotope is converted into a stable isotope.
Thus, correct option is B.
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What type of reaction is shown below:
Ethanoic acid + propanol -> propyl ethanoate + water
A. Polymerization
B. Addition (water)
C. Elimination
D. Esterification
Answer:
c
Explanation:
because mix with propanol
Which of the following has maximum number of atoms?
(a) 18 g of H2O
(b) 18 g of O2
(c) 18 g of CO2
(d) 18 g of CO4
Answer:
(a) 18 g of H2O
Explanation:
The molecule with great number of moles will have great number of atoms.
By observation, since all compounds have same mass, water has the least molcular mass
[tex]H_{2} O = \: 18 \: g[/tex]
Answer:
18g of H2O
Explanation:
the molecule with great number of moles will have great number of atoms .
(a) option is correct
