Cho các dung dịch: Glucozơ, glixerol, fomanđehit, etanol. Có thể dùng thuốc thử nào sau đây để phân biệt được cả 4 dung dịch trên?
A. Cu(OH)2; B. Dung dịch AgNO3 trong NH3;
C. Na kim loại; D. Nước brom.
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Answer:
chắc là câu B í
Explanation:
5+64
this is TOTALLY SOOOO hard so help me
^thats what she said
Answer:
69
Explanation:
I thought that I answer is correct
Answer:
The answer is 69
Explanation:
Because if you add one its 66, and so on, hope this helps! but if you add five it will be 69, if you need help with easy equations let me know
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
which chloride is a coloured solid rtp
Answer:
sodium chloride
hope that helped :)
Answer:
Chlorine is a greenish yellow gas at room temperature and atmospheric pressure. ... yielding chlorine water, and from this solution a solid hydrate of ideal ...
list three factors that affect the rate of a chemical reaction
Answer: 1) temperature, 2) add a catalyst, and 3) concentrations
Explanation: A rise in temperature adds kinetic energy to the reactants, leading to more frequent, and energetic collisions, which will often accelerate the reaqction. A catalyst is an agent that helps the reaction move forward more quickly by offering a substrate that aids in orienting the reactants for more efficient reaction. A higher concentration increases the chances of collisons that result in products.
What is the name for the compound li2so4
Answer:
Explanation:
Lithium Sulphate
Answer:
Lithium sulfate is a white inorganic salt with the formula Li2SO4. It is the lithium salt of sulfuric acid.
What does the prefix trans-indicate?
A. There are at least two double bonds in the molecule.
B. The carbons on either side of the double bond are pointed in
opposite directions.
C. The molecule is an alkane with no double bonds.
O D. The carbons on either side of the double bond are pointed in the
same direction
Answer:
B. The carbons on either side of the double bond are Pointed in opposite directions
What is the chemical formula for carbon tetrafluoride?
The Periodic Table
1
mono-
2
di-
3
4
tetra-
5
penta-
hexa-
6
7
hepta-
8
Oct-
9
nano-
10
deca-
The number of joules required to heat one gram of a substance one degree Celsius is _____.
endothermic
temperature
exothermic
specific heat capacity
Which sentence describes existing cells?
All cells, once formed, continue to live forever.
All cells come from previously existing cells.
All the cells that are on Earth have always been here.
All cells develop from the remains of other cells.
Which of the following is a scientific question you could ask about the game
of basketball?
A. Do you enjoy basketball more than volleyball?
B. Which team is this year's best?
C. Which player should be traded to another team?
D. Do teams that practice more win more games?
SUBMIT
The scientific question related to the game of basketball is option D: "Do teams that practice more win more games?"
This question is scientific because it explores a cause-and-effect relationship between practice and game outcomes. It can be investigated through empirical observation and data analysis.
To answer this question, researchers could collect data on the practice hours of different basketball teams and compare them to their corresponding game performance. Statistical analysis could be used to determine if there is a correlation between practice time and winning percentage or other performance metrics.
By examining a large sample of teams over an extended period, researchers could draw conclusions about the impact of practice on game outcomes. This scientific inquiry would contribute to the understanding of the factors that influence team success in basketball and could potentially inform training strategies and coaching techniques.
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Which of the following molecules contains six bonding electrons?
A C2H4
B CO2
C H2S
D NCl3
Answer:
c2h4 (etthane........
bexcuse it has 6 bond of hydrogen
C₂H₄ molecules contains six bonding electrons. Therefore, option A is correct.
What do you mean by the term bonding ?Chemical bonding is the process through which two or more atoms, molecules, or ions establish a chemical link to create a chemical compound. The atoms in the resultant molecule are held together by these chemical bonds.
Chemical bonds have three basic characteristics that must be taken into account: their strength, length, and polarity. The distribution of electrical charge among the atoms connected by a bond determines its polarity.
C₂H₄ molecules has six bonding electrons. This molecule is called as Ethylene. When bonding is done between two atoms, each atom shares a pair of electrons with each other.
Hence, for every one bond, two electrons are shared between two atoms
Thus, option A is correct.
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name some examples of chemical solutions and maybe give a clear explanation as to what chemical solutions are
Answer:
Some examples of solutions are salt water, rubbing alcohol, and sugar dissolved in water. ... In our example of salt water, the solute is the salt. Solvent: this is the substance that makes up the majority of the solution. This is the part where the solute is dissolved.
Explanation:
I hope they should be right answer
9. During an experiment the students prepared three mixtures A)Starch in water B) Sodium chloride solution C) Tincture of Iodine. i) Students observed a visible beam of light through mixture A. Why? ii) Tincture of lodTe did not show Tyndall effect. Explain reason. ill) How can you relate particle size to Tyndall effect?
Answer:
See explanation
Explanation:
Tyndall effect refers to the scattering of light in a solution. Tyndall effect occurs when the size of particles in the solution exceeds 1 nm in diameter. Such solutions are actually called false solutions.
In tincture of iodine, the size of particles in solution is less than 1 nm in diameter hence the solution does not exhibit Tyndall effect. Hence, tincture of iodine is a true solution.
Therefore, if the size of particles in solution exceeded 1nm in diameter, Tyndall effect is observed.
PLS HELP!! WILL MARK BRAINLIEST! 99 POINTS!
You're going to first balance the chemical equation.
After that, convert the grams of Na into moles of Na, and then multiply that with the ratio of moles of NaCl to Na, and then convert the mol of NaCl into grams in order to obtain the theoretical yield, since we are given that Na is the limiting reactant.
After that, plug the values into the yield formula, doing some basic algebra, and you should get your result.
You're going to first balance the chemical equation.
After that, convert the grams of Na into moles of Na, and then multiply that with the ratio of moles of NaCl to Na, and then convert the mol of NaCl into grams in order to obtain the theoretical yield, since we are given that Na is the limiting reactant.
After that, plug the values into the yield formula, doing some basic algebra, and you should get your result.
Which equation describes a physical change? i. H2O(s) ⟶ H2O(l) ii. Na+(aq)+Cl−(aq) +Ag+(aq)+NO3−(aq) ⟶ AgCl(s)+Na+(aq)+NO3−(aq) iii. CH3OH(g)+O2(g) ⟶ CO2(g)+H2O(g) iv. 2H2O(l) ⟶ 2H2(g)+O2(g) v. H+(aq)+OH−(aq)⟶ H2O(l)
Answer:
The answer is "Option i"
Explanation:
In this question, only option (i) is correct, and others were wrong which can be defined as follows:
In option (ii):
[tex]Na^+\ (aq)+Cl^- \ (aq) +Ag^+ \ (aq)+NO_3^- \ (aq) \to AgCl\ (s)+Na^+ \ (aq)+NO_3^-\ (aq) \\\\[/tex]
It is the complete ionic equation.
In option (iii):
[tex]CH_3OH\ (g)+O_2\ (g) \to CO_2\ (g)+H_2O\ (g)[/tex]
It is the combustion reaction but a not balanced equation.
In option (iv):
[tex]2H_2O\ (l) \to 2H_2\ (g)+O_2\ (g)[/tex]
It is the decomposition equation.
In option (v):
[tex]H^+\ (aq) +OH^-\ (aq)\to H_2O\ (l)[/tex]
It is the complete ionic equation.
How many moles of oxygen are required to react completely with 5 mol C8H18?
Answer:
62.5 moles of O₂.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
2C₈H₁₈ + 25O₂ —> 16CO₂ + 18H₂O
From the balanced equation above,
2 moles of C₈H₁₈ reacted with 25 moles of O₂.
Finally, we shall determine the number of mole of O₂ needed to react with 5 moles of C₈H₁₈. This can be obtained as shown below:
From the balanced equation above,
2 moles of C₈H₁₈ reacted with 25 moles of O₂.
Therefore, 5 moles of C₈H₁₈ will react with = (5 × 25) / 2 = 62.5 moles of O₂.
Thus, 62.5 moles of O₂ is needed for the reaction.
A pupil has drawn the electronic structure of fluorine and the diagram is shown below. However,
mistakes have been made. State three mistakes that have been made.
The first shell can only hold 2 electrons, but the pupil placed in 8 electrons.
The second shell can hold up to 8 electrons, but the pupil only placed in 2 electrons.
Flourine only has 9 total electrons, yet there are 10 electrons in the diagram.
Answer:
Explanation:
In the Fluorine atom there are 2 electrons in the innermost shell and 7 i the outer shell.
what is a cubic unit cell ?
cubic unit cell is the smallest repeated unit which have all angles equal to 90 and all have edge lengths equal
It is the type of the Unit cell which is having all angles equal to 90 and all sides equal to each other
it's is a unit cell with cubic structure
What is an atomic mass unti
Explanation:
a unit of mass used to express atomic and molecular weights, equal to one twelfth of the mass of an atom of carbon-12.
Answer:
Atomic Mass Unit is also called Dalton. It is used to express atomic and molecular weight. It is defined as 1/12 of the mass of an unbound neutral atom of carbon.
what is the name of this organic molecule
Answer:
C2H4 Ethylene
Explanation:
Hope it helps! :)
Using your answers from part C, complete the chemical formula of each compound. If the number of ions is 1, leave that
number out of the formula.
Drag each number to the correct location. Numbers may be used more than once
Answer:
1;1, 2;1, 3;1, 1;2, 1;1, 3;2, 1;3, 2;3, 1;1.
I hope this will help.
Answer:
This is what the answer looks like
Explanation:
If 16.4 grams of calcium nitrate is heated as shown in the reaction:
2Ca(NO3)2 -> 2CaO + 4NO2 + O2.
Calculate the volume of nitrogen dioxide produced at STP.
Answer:
7.2
Explanation:
you first have to find the number of moles of nitrogen dioxide by using the number of moles for calcium nitrate and the mole to mole ratios
number of moles of calcium nitrate=mass/mm
=16.4/102
=0.16g/mol
then you use the mole to mole ratios
2 : 4
0.16: x
2x/2=0.64/2
x=0.32g/moles of nitrogen dioxide
then you use the formula for the volume
v=22.4n
=22.4×0.32
=7.2
I hope this helps
PLS GUYS ITS FOR 10TH GRADE CHEM
Answer:
1. 2.63x10^6
2. 39.2
Both answers have been rounded
One the first chemistry test. 12 students got As, 18 students got Bs, and 20 students got Cs.
a. What is the percentage of students received Bs.
b. What is the percentage of students who received Cs?
Express your answer to the ones place.
Answer:
A. 36 percent recieved Bs
B. 40 percent of students received Cs
Explanation:
Amount of students: 12+18+20=50
Students with Bs: (18÷50) x 100 = 36%
Students with C's: (20÷50) x100 = 40%
On the first chemistry test 12 students got A, 18 students got B, and 20 student got C. Thus the percentage of students received B is 0.36 and percentage of students received c is 0.40
What is the percentage of students received B and C?In mathematics, a number or ratio expressed as a fraction of 100. It is often denoted using the percent sign %. A percentage is a dimension less unit and it has no unit.
In above question 12 student got A, 18 student got B, and 20 student got C.
So total number of student = 12 + 18 + 20 = 50.
Then the percentage of students received B is as follows:-
Percentage of students who got B = (student who got B/Total number of student) X 100.
=(18/50) X 100
= 36%
Now percentage of students who got C = (No of students who got C/Total students)X100
=(20/50) X 100
=40%.
Therefore,On the first chemistry test 12 students got A, 18 students got B, and 20 student got C. Thus the percentage of students received B is 0.36 and percentage of students received c is 0.40 percentage of students who got B is 36% and percentage of students who got C is 40%
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in order to decrease the freezing point of 500. g of water to 1.00° c how many grams of ethylene glycol (C2H602)must be added (KF=1.86°C kg solvent)
Answer:
if wrong sorry ok????
how is electrovalent bond formed ? Describe with an example .
Answer:
For example, the bond between the sodium and chlorine atoms in sodium chloride (NaCl) is formed by the transfer of an electron from sodium to chlorine, creating Na + and Cl – ions. ... The electrostatic attraction between these ions provides the bonding in NaCl.
Define force and speed
Force = The external energy that changes or tends to change the state of any body or object is called force.
Speed = The rate of distance is called speed.
Answer:
Force is a push or pull which changes or tend to change the position of a body.
The rate of change its position with time or magnitude is called speed.
A sample of gas has a volume of 20 cm³.The pressure is changed to 90 kPa at constant temperature,while the volume increases to 75 cm³.What was the original pressure of the gas?
Answer:
337.5kPa ~ 338kPa
Explanation:
Using the ideal gas law PV=nRT we have the following definitions from the problem:
V(initial) = 20cm³
P(initial) = ?kPa
V(final) = 75cm³
P(final) = 90kPa
Since we know that the number of moles of the sample did not change, nor did the temperature, nor does the ideal gas constant (R) we can rewrite this equation to state:
P(initial)V(initial) = nRT =P(final)V(final) ~ P(initial)V(initial) = P(final)V(final)
Rearranging this equation as we are solving for the initial pressure we find that:
P(initial) = (P(final)V(final))/V(initial)
P(initial) = ((90kPa)(75cm³))/20cm³
P(initial) = 337.5kPa ~ 338kPA
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