Answer:
Dissolves a chemical sample well at high temperatures.
Does not dissolve a chemical sample well at low temperatures.
Explanation:
Recrystallization is a purification technique that involves mixing of an impure solid compound with a hot solvent leading to a saturated solution. As this solution cools, the compound to be purified becomes less soluble in the solvent, and pure crystals appear from the solution as the solution cools.
A good recrystallization solvent should
Not dissolve the compound that we want to purify at room temperature Dissolve the compound completely only at the solvent's boiling point Dissolve all the soluble impurities in the sample very well at room temperature.Have a fairly low boiling point such that its boiling point is lower than the melting point of the compound to be purified and evaporates easily when air-drying the sample.c5h12 compound name
3) Tears are produced by the lacrimal glands located:
A) above the lateral canthus of each eye
B) below the medial canthus of each eye
C) below the lateral canthus of each eye
D) above the medial canthus of each eye
E) behind the nasal bones
why does brain be liek fmrknve; n yyy eekf pls call for help
Answer:
man my brain like that to
Explanation:
Answer:
man my brain like that to
Explanation:
How can you use density to separate mixtures like sand and small plastic pellets?
Answer:
Slide a magnet through the mixture. When you take the magnet off, the iron filings are going to be attracted to the magnet and the sand will stay in the bowl
Explanation:
Answer:
Density can be used to separate the substances that make up a mixture, because each substance in a mixture has its own density. For example, if a mixture of sand and oil is placed in water, the sand will sink to the bottom of the container. The sand is more dense than the water.
Explanation:
Please mark me as brainy if this helps
please helpppppppppp
Answer:
Environmental factors such as diet, temperature, oxygen levels, humidity, light cycles
And the presence of mutagens can all impact which of an animal's genes are expressed, which ultimately affects the animal's phenotype.
Which chemical equation is balanced?
a. 2LiOH + CO2 → Li2CO3 + H2O
b. LiOH + CO2 → Li2CO3 + H2O
c. LiOH + 3CO2 → 2Li2CO3 + H2O
d. 4LiOH + CO2 → Li2CO3 + 2H20
The balance chemical equation is 2LiOH + CO2 → Li2CO3 + H2O. Therefore, option A is correct.
What is balance chemical equation ?A chemical equation is said to be balanced if the quantity of each type of atom in the reaction is the same on both the reactant and product sides. In a balanced chemical equation, the mass and the change are both equal.
The law of conservation of mass states that when a chemical reaction takes place, the mass of the reactants and products should be equal. As a result, during the chemical process, the number of atoms in each element remains constant. The chemical equation must be balanced as a result.
The chemical equation is said to be balanced if there are no inequalities. Every element in this illustration now has the same amount of atoms on the reactant and product sides.
Thus, option A is correct.
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CHEMISTRY HELP
Once the following equation is balanced, what is the correct coefficient for Z₂?
Answer:
The coefficient of Z₂ is 1.
Explanation:
From the question given above:
X + ZY —> XY + Z₂
Next, we shall balance the equation to obtain the coefficient of Z₂. This can be obtained as follow:
X + ZY —> XY + Z₂
There is 1 atom of Z on the left side and 2 atoms on the right side. It can be balance by putting 2 in front of ZY as shown below:
X + 2ZY —> XY + Z₂
There are 2 atoms of Y on the left side and 1 atom on the right side. It can be balance by putting 2 in front of XY as shown below:
X + 2ZY —> 2XY + Z₂
Now, we have 1 atom of X on the left side and 2 atoms on the right side. It can be balance by putting 2 in front of X as shown below:
2X + 2ZY —> 2XY + Z₂
Now the equation is balanced.
Thus, the coefficient of Z₂ is 1.
If 4.55 moles of hydrogen were reacted with excess nitrogenin the equations N2 + 3 H2 = 2 NH3 and 48.7 g of ammonia product was recovered what would be the percent yield of the reaction?
Answer:
Percent yield = 94.5%
Explanation:
Given data:
Number of moles of hydrogen = 4.55 mol
Mass of ammonia recovered = 48.7 g
Percent yield of ammonia = ?
Solution:
Chemical equation:
N₂+ 3H₂ → 2NH₃
Now we will compare the moles of ammonia and hydrogen.
H₂ : NH₃
3 : 2
4.55 : 2/3×4.55 = 3.03 mol
Theoretical yield of ammonia:
Mass = number of moles × molar mass
Mass = 3.03 mol × 17 g/mol
Mass = 51.51 g
Percent yield:
Percent yield = ( actual yield / theoretical yield ) × 100
Percent yield = (48.7 g/ 51.51 g) × 100
Percent yield = 0.945 × 100
Percent yield = 94.5%
What mass of solid aluminum hydroxide can be produced when 50.0mL of 0.200M aluminum nitrate is added to 200.0mL of 0.100M potassium hydroxide
Answer:
520 mg Al(OH)₃
Explanation:
The reaction that takes place is:
Al(NO₃)₂ + 3KOH → Al(OH)₃ + 3KNO₃Now we calculate how many moles of each reagent were added, using their concentrations and volumes:
Al(NO₃)₂ ⇒ 50.0 mL * 0.200 M = 10 mmol Al(NO₃)₂ KOH ⇒ 200.0 mL * 0.100 M = 20 mmol KOH10 mmol of Al(NO₃)₂ would react completely with (10*3) 30 mmol of KOH, there are not as many KOH mmol, so KOH is the limiting reactant.
We calculate how many moles of Al(OH)₃ are produced, using the limiting reactant:
20 mmol KOH * [tex]\frac{1mmolAl(OH)_3}{3mmolKOH}[/tex] = 6.67 mmol Al(OH)₃Finally we convert mmol of Al(OH)₃ to mg, using its molar mass:
6.67 mmol Al(OH)₃ * 78 mg/mmol = 520 mg Al(OH)₃How did Mendeleev arrange the known elements in his periodic table? O A. According to the number of protons O B. According to the number of electrons O C. According to atomic mass O D. According to atomic number
Mendeleev arranged the known elements in his periodic table according to atomic number (option D).
What is the periodic table?Periodic table is a tabular chart of the chemical elements according to their atomic numbers so that elements with similar properties are in the same group (column).
The chemical elements are organized by atomic number, from the element with the lowest atomic number, hydrogen, to the element with the highest atomic number, oganesson.
Dmitri Mendeleev is the Russian scientist that formulated the periodic table of chemical elements and arranged them in order of increasing atomic number.
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Answer: C.
Explanation:
according to atomic mass
Is burning physical or chemical change?
Answer:
a chemical change
Explanation:
lighting a match is a chemical change. chemical reactions cause chemical change. in a chemical reaction two or more substances, called the reactants, form different substances called products. hope this helped :)
Balance the following chemical equation: CH4+ Cl2 → CCl4+ HCI
Answer:
CH4 + 4Cl2 ===> CCl4 + 4HCl
Explanation:
I am pretty sure atleast?
What is one way in which sound and light are alike? PLEASE HELP IF YOU WANT BRAINLEIST AND TO HAVE YOUR COMMENT LIKED!!
A. They both travel easily through wood.
B. They are both types of energy.
C. both can travel through outer space.
D. They both make it easier for you to see what you are doing.
Answer:
They are both types of energy.
Explanation:
The last 2 are true for light, and the first one is true for sound.
Hope this is right, sorry if it is not.
please help and if u dont know that ok but pleas don't give me the wrong answer
Answer: The answer is 2 and 4
Answer: B
Explanation: Some types of waves are able to travel through space. Some can even travel through solids and liquids.
.. Identify how many atoms of each element are in the molecule: H2O2
Answer : There are 2 atoms of hydrogen element and 2 atoms of oxygen element are in [tex]H_2O_2[/tex] molecule.
Explanation:
Molecule : It is the smallest particle in the chemical compound or chemical element that has the same chemical properties of that compound or element.
Atom : It is the smallest unit of matter.
The given molecule is [tex]H_2O_2[/tex].
In the molecule of [tex]H_2O_2[/tex], there are two elements which are hydrogen and oxygen.
In the molecule of [tex]H_2O_2[/tex], there are 2 atoms of hydrogen element and there are 2 atoms of oxygen element.
Hence, there are 2 atoms of hydrogen element and 2 atoms of oxygen element are in [tex]H_2O_2[/tex] molecule.
Match the word with the definition. Write the correct letter in the space
provided. Reminder
that your answers should be blue.
A. Proton
B. Periodic Table
C. Atom
D. Chemical Symbol
E. Group
F. Atomic Number
G. Atomic Mass
H. Period
1. Electron
J. Neutron
K. Nucleus
1. Average mass of all the isotopes of that element
2. Series of elements arranged in rows on the periodic table
3 Smallest particle that still can be considered an element
4. Subatomic particle with no charge
5. An abbreviation of an element's name, usually one or two letters
6. Subatomic particles with a positive charge
7.
A small region in the center of an atom
8.
Arrangement of elements showing repeating pattern of their
properties
9. Series of elements arranged in columns on the periodic table
10.
Subatomic particles with a negative charge
11.
Number of protons in the nucleus of an atom
Answer:
this may be wrong and if it is im sorry
A=6
B=8
C=3
D=5
E=9
F=11
G=1
H=2
I=10
J=4
K=7
01:29:56
What must be true about two objects if heat is flowing between them?
The objects must be different temperatures.
The objects must be the same temperature.
The objects must both be over room temperature.
The objects must both be under room temperature.
Answer:
a
Explanation:
i just took the quiz
What is the definition of climate?
1) An area's long term weather pattern
2)When large air masses of different density, moisture, and temperature mee
3)The state of the atmosphere at a given place and time
4)Large volume of air that has similar characteristics of temperature and water
vapor content
Answer:
1) An area's long term weather pattern
Explanation:
Climate is defined as the weather pattern in an area for the long term. Climate means the usual condition of the humidity, temperature, wind, rainfall, and atmospheric pressure in the surface area of Earth for the long term. Usually the time period for a climate in a region is taken over 30-years.
Weather is the state of the atmosphere and climate the long-term weather pattern of the area. For example: degree to which it is hot or cold is weather and expect snow in the Northeast in every January is climate.
Hence, the correct answer is "1) An area's long term weather pattern".
GIVING OUT BRAINLIEST!!!!!!!!!
Which substance has the lowest specific heat?
O Beach sand
O
Beach water
O Ice
Pool water
How are food webs and food chains related? HELP IF YOU WANT BRAINLEIST!!
Food webs only contain consumers.
Food webs consist of only one food chain.
Food webs are made of many food chains.
Food webs only contain producers.
Answer: Food webs are made of many food chains is the answer.
Explanation:
Food web consists many food chains.
Give an example of chemical reaction that occurs in everyday life
Answer: metal and salt water
Explanation: salt starts to brake down metal and metal is everywhere in the ocean hope this helps
Answer:
baking a cake.
Explanation:
baking a cake is an example of a chemical reaction that happens daily because a new substance is forming when the cake is being baked. hope this helps! :)
A sample of hydrate sodium carbonate has a mass of 71.5 g. after heating, the anhydrous sodium carbonate has a mass of 26.5 grams. Calculate the % water.
Answer:
62.9%
Explanation:
Step 1: Given data
Mass of hydrate sodium carbonate (mNa₂CO₃.xH₂O): 71.5 gMass of anhydrous sodium carbonate (mNa₂CO₃): 26.5 gStep 2: Calculate the mass lost of water
We will use the following expression.
mH₂O = mNa₂CO₃.xH₂O - mNa₂CO₃
mH₂O = 71.5 g - 26.5 g = 45.0 g
Step 3: Calculate the percent of water in the hydrate sodium carbonate
We will use the following expression.
%H₂O = mH₂O / mNa₂CO₃.xH₂O × 100%
%H₂O = 45.0 g / 71.5 g × 100%
%H₂O = 62.9%
11-Which of the following would NOT be a Compound?
A?
B?
C?
D?
Answer:
A because it is not small enough
Explanation:
It's a of c Yea a or so pick that
why are concerns like safety and recycling important in astronomy
Answer:
Keep the world safe and clean
Explanation:
safety = keep people inline and help them from making bad decisions
clean = keep the world from being polluted or trashy
Astronomy deals with the study of celestial objects such as moon, stars, sun, planets, etc.
Safety is the art of being protected from danger
Recycling is the process of waste conversion. That is, useful materials are generated from wastes.
Astronomers, in their exploration of extraterrestrial bodies, need to ensure that proper measures are taken to ensure their safety in these locations. Unhealthy practices such as deforestation and indiscriminate waste disposal may cause environmental hazards such as global warming. This is a threat to the atmosphere.
Therefore, wastes have to be converted to reusable products to discourage indiscriminate disposals. Hence the importance of the terms "safety" and "recycling" in astronomy.
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Which term related to electromagnetism applies only to magnetic force
The IUPAC name of(CH3)2CHCH2CH=CH2
Answer:
4-Methyl-1-pentene
Explanation:
According to the International Union of Pure and Applied Chemistry (IUPAC), IUPAC nomenclature of organic chemistry is defined as the system of naming organic chemical compounds.
There are certain rules for naming organic chemical compounds as per IUPAC. The name of given (CH3)2CHCH2CH=CH2 will be based on the same rules.
At first find out the longest continuous chain and number the chain consecutively (preference given to double and single bonds), so numbering will start from right to left. the given chemical is 5 Carbon chain long.Then, identify the groups attached to this chain. Methyl is the only group attached to this chain at 4 Carbon.Assemble the name in alphabetical order using the full name using correct prefix and suffix.4-Methyl-1-pentene is the name of this chemical, as methyl is in 4th carbon position, Pent for 5 carbon chain and -ene (suffix) for one double bond).
Hence, the correct answer is "4-Methyl-1-pentene".
help please thank you
Which two statements are true about all generators?
They convert motion energy to electric energy.
They have a fixed pair of magnets and a rotating metal coil.
They’re powered by fossil fuels.
They convert electric energy to motion energy.
They use the relative motion of a magnet and a coil of wire.
Answer:
they have a fixed pair of magnets and a rolling coil they convert motion into electric energy they are powered by fosile fuels they use reletive motion of a magnet and coil of a wire
Explanation:
Answer:
They convert motion energy to electric energy.
They use the relative motion of a magnet and a coil of wire.
Explanation:
This is the correct answer.
What do tissues combine to form?
A. organisms
B. cells
C.organ systems
D. organs
When all the colors of the spectrum are combined, what will the human
eye see?
A black
B. blue
C. red
D. white
Answer: white?
Explanation:
When all the colors of the spectrum are combined and strike the human eye at the same time, the human eye will see white color. Therefore, option (D) is correct.
What is the electromagnetic spectrum?The electromagnetic spectrum can be described as the range of frequencies of electromagnetic radiation and its wavelengths and photon energies. The electromagnetic spectrum have range from below one hertz to above 10²⁵ hertz.
Electromagnetic radiation with a wavelength between 380 to 760 nm is detected by the human eye and recognized as visible light. Other wavelengths, especially near-infrared and ultraviolet are also sometimes referred to as light.
White light can be defined as a combination of lights of different wavelengths in the visible region of the spectrum. When white light is passed through a prism splits it up into the several colors of light observed in the visible spectrum.
Therefore, all the colors of the spectrum are combined, and the human eye will see white color.
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