Answer: number of atoms is 5.21 · 10^24
Explanation: Atomic mass of Be is 9.012 g/mol.
Number of moles n = m/M = 78.0 g / 9.012 g/mol =
Multiply this with Avogadro number Na = 6.022*10^23 1/mol
Some sugar is added to cold water in a beaker.
After some time, all the sugar dissolves and spreads throughout the water.
(a)(¡) Name the process that occurs which causes the sugar to spread throughout the water.
(ii) State two ways to make the sugar dissolve more quickly.
(b) Pure water can be obtained from the sugar solution using this apparatus.
Name the process used to obtain pure water from the sugar solution.
i) diffusion, concentration differences in gas and fluid disappears when particles of sugar are evenly spread in solution
ii) Heating the solution, mixing the solution
b) Distillation, solution is heated until water is vaporized and water vapour condenses in another part of apparatus.
Sugar is separated from water by evaporation of the sugar solution to dryness.
i) The process of that causes the sugar to spread throughout the water is called solvation. Solvation simply refers to the interaction of a solute and a solvent.
ii) To make the sugar to dissolve quicker;
The temperature of the solvent can be raisedThe system can be stirred periodicallyb)To obtain pure water from sugar, the sugar is evaporated to dryness. This is done by heating the sugar in a set up as shown in the image attached.
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in figure 21-4b in what direction is the force defeating the wire
Answer:
the one that has more power to it
How
many
molecules are in 8.55x10-15 moles of a substance
Answer:
Know this
1mole of a substance contains 6.022x10²³molecules
Now
8.55x10^-15moles x 6.022x10²³molecules/1mole
=5.15x10^9molecules.
If 13 grams of copper sulfate is reacted with zinc how much of each product is produced?
Answer:
No. Of Moles of zinc = m/Ar
= 13/ 65.38 = 0.198 moles
From balanced equation, Mole ration between CuSO4 and Zn is 1 : 1
So only 0.198 moles of CuSO4 reacts, it is in excess
Mass = no of Moles X Mr
Mass = 0.198 X 159.5 = 31.59 grams
Volume = mass m denisty
Volume j 31.59 / 3.6 = 8.78 ml
Explanation:
i think this wrong
Glycerol has a molar mass of 92.09g/mol. Its percent composition is: 39.12% C, 8.75% H,
and 51.12% O. What is the molecular formula for glycerol?
Answer:
Molecular formula => C₃H₈O₃
Explanation:
From the question given above, the following data were obtained:
Carbon (C) = 39.12%
Hydrogen (H) = 8.75%
Oxygen (O) = 51.12%
Molar mass of compound = 92.09 g/mol
Molecular formula =?
Next, we shall determine the empirical formula of the compound. This can be obtained as follow:
C = 39.12%
H = 8.75%
O = 51.12%
Divide by their molar mass
C = 39.12 / 12 = 3.26
H = 8.75 / 1 = 8.75
O = 51.12 / 16 = 3.195
Divide by the smallest
C = 3.26 / 3.195 = 1
H = 8.75 / 3.195 = 2.7
O = 3.195 / 3.195 = 1
Thus, the empirical formula is CH₂.₇O
Finally, we shall determine the molecular formula of the compound. This can be obtained as follow:
Empirical formula = CH₂.₇O
Molar mass of compound = 92.09 g/mol
Molecular formula =?
Molecular formula = Empirical formula × n
Molecular formula = [CH₂.₇O]ₙ
92.09 = [12 + (2.7×1) + 16] × n
92.09 = 30.7n
Divide both side by 30.7
n = 92.09 / 30.7
n = 3
Molecular formula = [CH₂.₇O]ₙ
Molecular formula = [CH₂.₇O]₃
Molecular formula = C₃H₈O₃
You are given 250 mL of a 12.0 M solution of KNO3. To obtain a 5.0 M, to what volume does the solution need to be diluted to?
600 ml
104.17 mL
0.24 mL
60 mL
Answer:
600 mL
Explanation:
molarity 1 * volume 1 = molarity 2 * volume 2. So this means 12 * 250 = 3000 and divide that by 5 to get 600 mL.
Balance the following Chemical Equation:
NaBr +CaCl2-> NaCl+ CaBr2
HELP ASAP!! 12pts!
What is the molarity of an aqueous solution containing 7.5 moles of
calcium chloride in 12.75 L of solution?
A. 0.59 M
B. 1.7M
C. 7.5M
D. 95.6 M
Answer:
The correct answer is 0.59M
Select the correct answer.
A sample taken from a layer of mica in a canyon has 2.10 grams of potassium-40. A test reveals it to be 2.6 billion years old. How much
potassium-40 was in the sample originally if the half-life of potassium-40 is 1.3 billion years?
OA.
4.20 g
© B.
8.40 g
OC.
12.6 g
O D. 16.8 g
O E. 25.2[H
Answer: B 8.40 g
Explanation:
How many moles of nitrogen are in 12 grams
Answer:
Explanation:
The chemical formula of nitrogen is N2
A mol of Nitrogen atoms = 14 grams
So N2 will have a molar mass of 14 * 2 = 28 grams
number of moles of N2 = given mass / molar mass
number of moles of N2 = 12 / 28
number of moles of N2 = 0.4286 mols
11
Cr2O3 + 2Al → 2Cr + Al2O3
Chromium is produced by reacting its oxide with aluminum. If 76 g of Cr2O, and 27 g of Al completely react to form 51 g of Al2O3. how many grams of Cr are formed?
Answer:
Deci trebuie sa te aplici cu 2 din3 pe suprafata pamanyului chinez
Explanation:
Deci 1287+2086+2762+7:5
What volume of water is needed to make 5.41 M solution with 47.71 moles of HCL?
Answer:
0.113 liters
Explanation:
5.41 M / 47.71 moles = 0.113 liters
4. A blue light is shined on objects X and Y. Object X appears to be blue, and object Y appears to
be black. Which of the following is correct?
A. Object X absorbs blue light, and object Y reflects blue light.
B. Object X reflects blue light, and object Y absorbs blue light.
C. Object X must be black, and object Y must be blue.
D. Object X must be blue, and object Y must be black.
A blue light is shined on objects X and Y. Object X appears to be blue, and object Y appears to be black when Object X reflects blue light, and object Y absorbs blue light. Hence option B is correct.
What is light ?Visible light spectrum is nothing but the range of wavelength of radiation from 4000 angstrom to 7000 angstrom(Violet to Red). light is a energy packet. Every Photon having different wavelength travels with same velocity c (velocity of light). When we focus numbers of colors from visible spectrum to a point, that point appears as a white light. hence white light is composed of numbers of Colors in it.
When we pass white light through a prism, as white light enters in the prism all the colors having different wavelength travels with different velocity in the prism due to that there is separation of colors from the white light. Therefore we get different colors of white light in the prism this phenomenon is know as dispersion of light.
Light can be reflected, absorbed, transmitted diffracted and scattered etc.
α + β + ν = 1 where α, β, ν are coefficient of absorption, reflection and transmission.
When any object appears to be black it means that radiation has been absorbed by that body, it has high absorption coefficient. and when a body appears to be colored, it means that object has reflected the particular color, it having high reflection coefficient.
Hence option B is correct.
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The total pressure of two unknown gases is 5 kPa. The partial pressure of one of the gases is 2.345 kPa, what is the partial pressure of the other gas?
Answer:
[tex]p_2=2.655kPa[/tex]
Explanation:
Hello there!
In this case, according to the Dalton's law, which states that the total pressure is equal the sum of the pressures of the gases in the mixture, we write the following for this system:
[tex]P_T=p_1+p_2[/tex]
Thus, we solve for the partial pressure of the gas #2 as shown below:
[tex]p_2=P_T-p_1\\\\p_2=5kPa-2.345kPa\\\\p_2=2.655kPa[/tex]
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In the Caribbean countries, general election is usually held every _ years
it is held every 4-5 years
What is formed when 2 non metals reacts?
A) covalent bond
B) ionic bond
C) molecular bond
Answer:
A) covalent bond
Explanation:
Covalent bonding generally happens between nonmetals.
1. Write the complementary DNA strand to the following AATTGCGC
What is the mass of disulfur pentoxide (S2O5)?
Answer: What is the mass of disulfur pentoxide (S2O5)?
Explanation:144.14g/mol
What causes the process of transmutation?
O A. A gamma ray is emitted from an atom's nucleus.
B. Mass is lost due to the formation of a nucleus.
C. Quarks in the nucleus shift between particles.
D. The number of protons in the nucleus changes.
Answer: D. The number of protons in the nucleus changes.
Explanation:
Transmutation occurs due to a change in the number of protons in the nucleus as this will cause the element to either become another isotope of the same element or an entirely new element altogether.
There are two types of transmutation; Natural and Artificial. Natural transmutation happens as unstable elements such as Uranium-238 try to find stability. They decay until they become a stable element. Artificial transmutation happens when atoms are collided with particles that cause them to change.
In which type of chemical reaction would two reactants join together and form one product
Answer:
Synthesis Reaction
Explanation:
A synthesis reaction occurs when two or more reactants combine to form a single product. In a decomposition reaction, one reactant breaks down into two or more products. This is the reverse of a synthesis reaction. Replacement reactions occur when elements switch places in compounds.
why dil. sulphuric acid cannot be used instead of dil.hcl in lab preparation of carbon dioxide gas?
Answer:
Because Sulphuric acid(H2SO4) is one of the substance which have a very high vigourous reaction if mix with chemicals thats why we take the same sulphuric acid but having lighter effects known to be as Dil.Sulphuric And so it is generally use for precaution while during experimentations Thats why we use it.
Hope it helps
Which best completes the analogy?
B Cells : Produce Antibodies :: T Cells : ___________________
A. Get rid of good cells that have been infected
B. Tell B cells to start making antibodies
C. Tell killer cells to attack
D. remember antigens that have attacked the body
Answer:
d
Explanation:
d
For many purposes, we can treat propane (C3H8) as an ideal gas at temperatures above its boiling point of -24C Suppose the temperature of a sample of propane gas is lowered from 14.0c to -1.0c and at the same time the pressure is changed.
If the initial pressure was0.75 kPa and the volume decreased by55.0% what is the final pressure? Round your answer to the correct number of significant digits.
it's 75 k bro thats the answer
What word describes different compounds which are found together but not combined chemically?
A compound contains two or more elements chemically joined together. A mixture contains two or more different substances that are not chemically joined together. The different substances in a mixture can be elements and/or compounds.
Blank O2 + blank Mg arrow blank MgO
Select the coefficients that balance the equation:
MgO *
A) 1,1,1
B) 1,2,2
C) 2,3,4
D) 1,4, 2
Answer:
its a
Explanation:
a
How many iron atoms are in Fe2O3?
Answer:
2 iron atoms in Fe2O3
How many particles in 352 moles of KLICO3?
O 106 particles
O 2.12 x 1026 particles
O 6.38 x 1025 particles
Answer:
there are 106 particles
what is a carnivore?
Answer:
I think its when someone eats only meat
Answer:
A meat eater. Or a animal that has a diet strictly set to other animals.
Explanation:
Hope this helps!
Give an example of a metal and a nonmetal you use in everyday life.
Answer:
A type of metal I use everyday in life in using the iron door knob on my doors.
A nonmetal I use everyday is chlorine for when I need to clean my pool.
Explanation:
Is this your intention?
Ricky and Shemane, who are stoked to be learning stoich, were working diligently on a chemistry assignment in class. Ricky realized that in most chemical reactions, there’s an excess of one reactant. How would Shemane correctly explain to Ricky why this occurs?
the reaction will continue until all of the limiting reactant is consumed.
reactions do not take place unless there are unequal amounts of reactants.
the reaction will continue until all of the excess reactant is consumed.
reactions occur too quickly if equal amounts of reactants are used.