The international system of units is known as SI and is a metric system. Mostly used as a system of measurement. It is used in science, technology, and nearly in every part of the country. The system includes coherent units known as derived units.
A mole is not a base unit or any property of the units. It can be used for physical and chemical comparison and hence the mole of substance can be performed with the number of particles of the substance.Hence the option B is correct.
Learn more about the frequently used in chemical calculations.
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Một hỗn hợp X gồm CH3OH; C2H5OH; phenol có khối lượng 28,9 gam phản ứng vừa hết với 100ml dung dịch NaOH 2M. Phần trăm theo khối lượng phenol là ? Biết C = 12; O = 16; H = 1; Na = 23. *
Answer:
nNaOH = 0,2 mol
Trong hỗn hợp các chất đề bài cho chỉ có phenol tác dụng với NaOH
C6H5OH + NaOH → C6H5ONa + H2O
0,2 ← 0,2 (mol)
⟹ mphenol = 0,2.94 = 18,8 gam
⟹
%mC6H5OH=18,8/28,9 x100%= 65,05%
Explanation:
What is occurring during boiling?
A. Solvent particles increase in kinetic energy until they knock solute particles out of the solution and into the air.
B. Solute particles increase in kinetic energy until they knock solvent particles out of the solution and into the air.
C. Vapor pressure is greater than atmospheric pressure and water molecules escape from the solution into the air.
D. Atmospheric pressure is greater than vapor pressure, and water molecules escape from the solution into the air.
Reset Selection
Answer:
D: Atmospheric pressure is greater than vapor pressure,and water molecules escape from the solution into the air.
Atmospheric pressure is greater than vapor pressure, and water molecules escape from the solution into the air, which occurs during boiling. The correct option is D.
What is boiling?Boiling is a process when more heat is given to any liquid, it starts to boil. When the temperature is increased, boiling happens, but only in liquid. The molecules of liquid start to turn into vapor and start to escape into the atmosphere.
It is also called the vaporization of the liquid. The boiling points of different liquids are different, and they start to boil at their own temperature.
Thus, the correct option is D. Water molecules escape from the solution into the air when atmospheric pressure exceeds vapor pressure.
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A student conducts an experiment to determine how the temperature of water affects the time for sugar to dissolve. In each trial, the student uses a different amount of water and a different temperature of water. What is wrong with this experimental design? A.The student changed more than one independent variable. B.The student did not change enough independent variables. C.The student needs to perform more trials. D.The student does not have a dependent variable.
What is wrong with the experimental design is that the student changed more than one independent variable.
WHAT AN EXPERIMENT SHOULD CONTAIN?
An experiment is a procedural method of solving a scientific problem or answering a scientific question. An ideal experiment should contain two variables namely: independent variable and dependent variable. Dependent variable: This is the variable that the experimenter measures in the experiment. The dependent variable responds to changes made to the independent variable. Independent variable: This is the variable that is manipulated in an experiment in order to bring about a response.In the experiment conducted by the student in this question in order to determine how the temperature of water affects the time for sugar to dissolve. The independent variable is the DIFFERENT TEMPERATURE OF WATER while the dependent variable is the TIME TAKEN FOR SUGAR TO DISSOLVE.
N.B: An experiment should have only one independent variable and all other variables should be kept constant. This is to have a reliable result.
However, this student used two independent variables (temperature and amount of water) for the experiment, which is wrong for the experimental design.Therefore, the fact that the student changed more than one independent variable is wrong for the experimental design.
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Answer:
The student changed too many variables.
Explanation:
in k-12 took the quiz
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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****URGENT****
I need help!!!
the answers are there, i need someone to explain please!
Explanation:
your answer was correct
In ionic bonding Question 41 options: the electrons are shared between the atoms. the process of forming an ionic bond is highly endothermic overall. the bonding that occurs is usually between two nonmetal atoms. a noble gas configuration is formed for each element or ion. At least two of the above statements are correct.
Answer: In ionic bonding (a noble gas configuration is formed for each element or ion).
Explanation:
IONIC bonding, which is also called electrovalent bonding involves the complete transfer of electrons from one atom to another in order to attain a noble gas electron configuration.
The noble gases or group 0 elements have a completely filled outermost shell of eight electrons. This makes them generally very stable, that is, unreactive. There is a natural drive for other atoms to attain the electron configuration of group 0 (inert gases) elements. This usually results in atoms entering into chemical combinations by losing, gaining or sharing electrons.
Ionia compound such as sodium chloride
--> have high melting points because alot of heat energy is required to break the attractive forces between the ions;
--> are hard and brittle;
--> are soluble in water;
--> conduct electricity when in solution or molten form because the ions are able to move about, that is, they are electrolytes
Write down the constituent elements present in the following compounds.
a. Sodium Sulphate
b. Baking Soda
c. Limestone
d. Bleaching powder
e. Ammonia
f. Caustic Soda
g. Glucose
h. Ammonium Carbonate
I. Acetic acid
j. sulphuric acid
Answer:
in sodium sulphate there is sodium an sulphur
Bài 19 với ạ, ai giúp em với ❤️❤️❤️❤️❤️
Answer:
we're are u from
Explanation:
also the writing from that paper look really cool
what does porous mean
Answer:
porous = allowing liquid or air to pass through slowly
I hope it's helpful
Answer:
It is a rock or or other materials, having minutes interstices through which liquid or air may pass.
6c.Calculate the maximum volume, in dm3, of chlorine gas at Stp that can be obtained from 23.4 tonnes of molten sodium chloride. 1 tonne= 10^6 Mr of NaCl=58.5 molar volume of chlorine at stp= 24dm3 Give your answer in standard format.
Answer:
4.48×10⁶ dm³
Explanation:
We'll begin by converting 23.4 tonnes to grams (g). This can be obtained as follow:
1 tonne = 10⁶ g
Therefore,
23.4 tonnes = 23.4 × 10⁶
23.4 tonnes = 2.34×10⁷ g
Thus, 23.4 tonnes is equivalent to 2.34×10⁷ g
Next, we shall determine the number of mole in 2.34×10⁷ g of NaCl. This can be obtained as follow:
Mass NaCl = 2.34×10⁷ g
Molar mass of NaCl = 58.5 g/mol
Mole of NaCl =?
Mole = mass / molar mass
Mole of NaCl = 2.34×10⁷ / 58.5
Mole of NaCl = 4×10⁵ moles
Next, we shall determine the number of mole of chlorine, Cl₂ produced from the reaction. This can be obtained as follow:
2NaCl —> 2Na + Cl₂
From the balanced equation above,
2 moles of NaCl reacted to produce 1 mole of Cl₂.
Therefore, 4×10⁵ moles of NaCl will react to produce = (4×10⁵ × 1)/2 = 2×10⁵ moles of Cl₂.
Thus, 2×10⁵ moles of Cl₂ were obtained from the reaction.
Finally, we shall determine the volume of Cl₂ produced. This can be obtained as follow:
1 mole of Cl₂ at stp = 22.4 dm³
Therefore,
2×10⁵ moles of Cl₂ at stp = 2×10⁵ 22.4
2×10⁵ moles of Cl₂ at stp = 4.48×10⁶ dm³
Thus, the volume of chlorine obtained from the reaction is 4.48×10⁶ dm³
Which of the following olosaic structures represents a poskwe 9 protons, 10 mentions and 10 elections 12 protons, 1814 neutrons and 12 elections 12 protons, 12 neutrons and 10 elections
Answer:
migraine
Explanation:
d
True or False: All material has the same density.
Answer:
Different materials have different densities. So it is False
Answer:
The answer is False
Unknown # 21
Flame Test Color: Lilac
Addition of HCl(aq)= NR (No Reaction)
Addition of HCl(aq) and BaCl2(aq)= White precipitate
Addition of HNO3(aq) and AgNO3(aq)= NR (No Reaction)
What is the unknown ionic compund molecular formula?
Which of the following is an example of combustion?
O A. potassium chlorate -> potassium chloride + oxygen
B. aluminum + cobalt chloride -> aluminum chloride + cobalt
O c. hexane + oxygen carbon dioxide + water
OD. sodium cyanide + hydrochloric acid -> sodium sulfate + hydrogen cyanide
what is cytoplasm ? what does it contain?
Answer:
Cytoplasm is a thick solution that fills each cell and is enclosed by the cell membrane. It is mainly composed of water, salts, and proteins. All of the organelles in eukaryotic cells, such as the nucleus, endoplasmic reticulum, and mitochondria, are located in the cytoplasm.
Answer:
Explanation:
Cytoplasm is a thick solution that fills each cell and is enclosed by the cell membrane. It is mainly composed of water, salts, and proteins. All of the organelles in eukaryotic cells, such as the nucleus, endoplasmic reticulum, and mitochondria, are located in the cytoplasm. ...
Can you tell me name of chemicals in sea Please?
this is my attachment answer hope it's helpful to you
what is electronic configuration?
Answer:
In atomic physics and quantum chemistry, the electron configuration is the distribution of electrons of an atom or molecule in atomic or molecular orbitals.
A place where animals are protected in their natural habitat is called ------------------
answer is wildlife sanctuary
Answer:
a wildlife sanctuary
Explanation:
What is an atomic mass unit? Write down the electric charge of proton neutrons and electric.
Answer:
protons has a positive charge.
Neutrons does not have a charge (neutron = neutral)
Electrons has a negative charge
What is te SI unit of time?
Answer:
second (S) is the SI unit of time.
Answer:
second
Explanation:
the gap between any two intervals is called time
time can be measured in hour,minute,second
but second is the SI unit of time
How many joules of energy are required to melt 125 g of water?
Answer for this question is 45,000
Energy is referred to by scientists as the capacity for work. People have figured out how to transform energy from one form to another and then use it to accomplish tasks, making modern civilization possible.
Explain about the energy?Energy is the ability to do tasks. It can exist in various forms, including potential, kinetic, thermal, electrical, chemical, and nuclear.
Energy can take on a variety of shapes. Examples of these include: electrical energy, sound energy, chemical energy, nuclear or atomic energy, light energy, heat energy, mechanical energy, gravitational energy, and so on. Each form has the ability to shift or transform into the others.
The sun is one of the most significant energy sources. Most of the energy on earth comes from the sun, which is where it all began. We get
Answer for this question is 45,000
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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!if 1.35 g of aluminum occupies 0.500 cm^3. what is the density of aluminum
Answer:
2.7
Explanation:
Density= mass/volume
= 1.35/0.500
= 2.7
cual es la importancia de los solidos en la vida ?
Answer:
La comida es un sólido y no podemos vivir sin comida. Algunos sólidos son buenos conductores de calor y electricidad; otros son aislantes. Los sólidos se utilizan todos los días en la vida.
Is the following change an oxidation or reduction?
manganese (IV) oxide to manganese (III) oxide.
Answer:
12113
Explanation:
step by step:no
What is required for dynamic equilibrium?
A. A closed system.
B. The forward and backward reactions occur under the same conditions.
C. A reversible reaction.
D. All of these
Answer:
A. all of them
Explanation: Edtell
Which of the following would not be considered matter?
clouds
trees
rain
air
light
Answer:
light
Explanation:
Have a nice day
Answer:
light
Explanation:
Can someone help me please
Which statement describes the law of conservation of energy?
All systems will exchange matter and energy with their surroundings.
All systems can exchange energy, but not matter, with their surroundings.
Energy cannot be created nor destroyed, but it changes from one form to another.
Energy is destroyed in most chemical reactions when new products are formed.
Answer:
All systems will exchange matter and energy with their surroundings.
Explanation:
Answer:c
Explanation:
Are you ready kids?
Aye, aye Captain.
I can't hear you!
AYE, AYE CAPTAIN!
Oooooooooh.
Who lives in a pineapple under the sea?
Spongebob squarepants!
Absorbent and yellow and porous is he?
Spongebob squarepants!
If nautical nonsense be something you wish!
Spongebob squarepants!
Then drop on the deck and flop like a fish!
Spongebob squarepants!
Ready?
Spongebob squarepants.
Spongebob squarepants.
Spongebob squarepants.
Spongebob squarepants.
Spongebob-squarepants.
Which atom's ionization energy is greater than that of phosphorus (P)?
A. Ba
B. K
C. As
D. CI
Answer:
Chlorine
Explanation:
the ionization increases as you get closer to the top right. since chlorine (Cl) is the only one of the answer choices that is closer to the top right corner compared to phosphorous (P), that is the answer.
Answer:
cl
Explanation:
because ionization energy decrease from left to right
