Answer:
to collect pure hydrogen and avoid mixing with air
Trong các yếu tố sau đây: nồng độ, nhiệt độ, áp suất, diện tích tiếp xúc, chất xúc tác, có bao nhiêu yếu tố có thể ảnh hưởng tới tốc độ phản ứng?
Answer:
solubility of salt at 10 degree Celsius is 20 how does it what does it means what happens if the temperature of saturated solution is increased
Explanation:
solubility of salt at 10 degree Celsius is 20 how does it what does it means what happens if the temperature of saturated solution is increased
Which element will form In ion whose lonic radius is larger than its atomic radius?
(1) K
(2) F
(3) LI
(4) Mg
Answer:
Letter b so F
Explanation:
I hope this help
Explanation:
All five ions have an equal number of electrons and therefore share the same electron configuration. For example, a neutral calcium atom (Z=20) has 20 electrons; it loses two of them to form a Ca2+ cation, which would thus contain 20−2=18 electrons. Similarly, a phosphorus atom (Z=15) gains three electrons to form a P3− anion that contains 15+3=18 electrons.
Positively-charged protons in the nuclei attract the negatively-charged electron cloud. Each proton carries a +1 charge; the more protons an atom or ion contains the stronger the attraction it poses on its electron cloud. A nucleus of strong positive charge pulls its electron cloud towards itself tightly such that the latter would have a small radius.
The periodic table is arranged in the order of increasing proton number. Phosphorus comes the first among the five species and contains the least number of protons. Its ion would be the largest among the five. Calcium comes the last and forms the smallest ion.
Number of protons per nucleus P<S<Cl<K<CaStrength of Electrostatic attraction on the electron cloud P<S<Cl<K<CaIonic radius P3−>S2−>Cl−>K+>Ca2+
Chất tinh khiết là:
A. Có tính chất thay đổi
B. Có lẫn thêm vài chất khác
C. Gồm những phân tử đồng dạng
D. Không lẫn tạp chất
Answer:
The FitnessGram™ Pacer Test is a multistage aerobic capacity test that progressively gets more difficult as it continues. The 20 meter pacer test will begin in 30 seconds. Line up at the start. The running speed starts slowly, but gets faster each minute after you hear this signal. [beep] A single lap should be completed each time you hear this sound. [ding] Remember to run in a straight line, and run as long as possible. The second time you fail to complete a lap before the sound, your test is over.
fd
What is the mass percent of a sodium fluoride solution prepared by dissolving 0.64 moles of sodium fluoride into 63.5 grams of water?
The mass percent of a sodium fluoride solution prepared by dissolving 0.64 moles of sodium fluoride into 63.5 grams of water is 29.7%.
What is mass percent ?Mass percent is a means to describe a component in a specific combination or to convey a concentration. The mass percentage used to describe the solution composition indicates the mass of solute contained in a given mass of solution.
To determine the mass percent of an element in a compound, we divide the mass of the element in one mole of the compound by the compound's molar mass and multiply the result by 100.
Given:
Number of moles = 0.64 moles
Moles of sodium fluoride = Given mass/molar mass
0.64 moles = Mass / 42
Mass = 26.88gram
Mass % = Mass of solute/ mass of solution × 100
= 26.88/90.48 × 100
= 29.7 %
Thus, 29.7 % is the mass percent of a sodium fluoride solution prepared by dissolving 0.64 moles of sodium fluoride into 63.5 grams of water
To learn more about the mass percent, follow the link;
https://brainly.com/question/5394922
#SPJ6
which statement is generally true about CaCaI2 ?
Explanation:
"Its bonds are formed by large differences in electronegativity" is the statement among the choices given in the question that is generally true about CaCl2.
Which statement describes the periodic law?
Help please now!
Answer:
Answer is: elements in the same group have similar chemical properties. Periodic law is the arrangement of the elements in order of increasing atomic number.
what is true about solubility
Explanation:
Solubility is defined as a property of solutes by virtue of which they get dissolved in a favorable solvent. The solute can only be dissolved in any suitable solvent up to a limit at a given temperature. This is a characteristic of the the solute-solvent pairing.
Where does reduction occur in an electrochemical cell?
Answer:
The cathode is the electrode where reduction takes place.
so
reduction occur in Cathode in an electrochemical cell.
Answer: Cathode
Explanation:
.
What is the solubility of salt at 60°C if 2 gm of the salt is left behind when 7 gm of its saturated solution at that temperature dried?
a) 20
b) 40
c) 60
d) 80
40
Explanation:
because its Saturated
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?
PLZ HELP There are two main ways that organisms reproduce, or make more Individuals of their own kind. Which of the following is true of these two types of reproduction?
A. In one way, two parents are involved. In the other, there is only one parent
B. In reproduction that involves only one parent, the offspring are different from the parent. In reproduction that involves two parents, the offspring receive exact copies of the parents' DNA.
C. In both ways, offspring share characteristics with their parents but are not exactly the same. O
D. In both ways, all offspring are identical to each other but maji different from their parents.
Answer:
A
Explanation:
Two parents are involved in Sexual Reproduction but only one is involved in Asexual Reproduction.
25. Production is a. Transformation b. Reduction c Consumption d. Valuation
Answer:
a
Explanation:
I think a is the answer because when you produce something you transform it's raw materials to a finished good.
I hope this helps
3. Determine the pH value for calcium hydroxide, Ca(OH), with concentration of
0.05 mol dm3. [pH + pOH = 14).
Explanation:
Ca(OH) is a base
pOH = -Log[OH]
[OH] = 0.05
pOH = -Log(0.05)
pOH = 1.3
pH + pOH = 14
pH = 14 - pOH
pH = 14 - 2
pH = 12.7
17. The name of the reaction that produces esters is
A. addition.
B. anionic initiated polymerization.
C. radical initiated polymerization.
D. dehydration
Answer:
the name of reaction that produces esters is dehydration.
I need help getting this done
Answer:
I put the right structures in the pictures for you
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.
Unknown # 29
Flame Test Color: Green
Addition of HCl(aq): Bubbles
Addition of HCl(aq) and BaCl2(aq): NR (No Reaction)
Addition of HNO3(aq) and AgNO3(aq): White precipitate
What is the unknown ionic compound molecular formula?
Answer:
I think it's a sulphate ion, because when you add hydrochloric acid to it it produces bubbles and when you add barium chloride it then produces a white precipitate.its formula is SO4
I hope this helps
For the metal Mg 109.5g solution HCl 10%. a) Case of metal b) Its properties
Answer:
Explanation:
mg +2hcl=mgcl2 +h2
mhcl=10.95g
nhcl==0.3
nmg=1/2nhcl=0.15
mMg=3.6g
m mgcl2=14.25
cho hỗn hợp gồm alcl3 và fecl3 trình bày cách tách từng muối riêng ra khỏi hỗn hợp
Answer:
ném NaOH vào thì th AlCl3 tan hết còn lại kết tủa Fe(OH)3 lần.
Lọc kết tủa riêng phần dung dịch tan riêng
Rồi Cho HCl vô lại là xong
Explanation:
I have no idea how to do this and need help
Answer:
60.55%
Explanation:
nO3=155/48
nO2 used: 3/2nO3=4.84375
percent yield: 4.84375/8=60.55%
The addition of solute particles into a solution causes:
A. the solvent particles to be attracted to the solute particles and to have less kinetic energy.
B. the solute particles to bump the solvent particles out of the solution, making it easier to boil.
C. the solute particles to form seed crystals and make the solution freeze more easily.
D. the solvent particles to be spread further out and have more to move, increasing their kinetic energy.
Answer:
D. the solvent particles to be spread further out and have more to move, increasing their kinetic energy.
Explanation:
The addition of solute particles results in an increased boiling point. As the solutes increases so does the energy inside as the solutes add and occupies more space near the surface of the liquid.PLZ HELP ME WITH MY WORK
What is a compound?
A substance that is made from two different metals
B. A substance that cannot be broken into simpler substances
C. A substance that is made using a chemical reaction
D. A substance that can be separated by physical means
Answer:
C.
Explanation:
Answer A is incorrect because a compound doesn't have to be made with only metals.
Answer B is incorrect because that is actually the definition of a pure element.
Answer C is correct because to make a compound, there has to be a chemical reaction where bonds are formed and an entirely new substance is created.
Answer D is incorrect because compounds cannot be separated by physical means.
Hope this helps :D
A place where animals are protected in their natural habitat is called ------------------
answer is wildlife sanctuary
Answer:
a wildlife sanctuary
Explanation:
What volume of O2 is required to completely burn 15cm3 of pentane? Equation - C5H12 + O2 - CO2 + H2O.
Answer:
The volume of [tex]\rm O_2[/tex] required would be [tex]120\; \rm cm^{3}[/tex], assuming that both the pentane and the [tex]\rm O_2\![/tex] in this question are ideal gases and are under the same temperature and pressure.
Explanation:
Balance the equation for the reaction:
[tex]\rm ?\; C_{5}H_{12} + ?\; O_2 \to ?\; CO_{2} + ?\; H_{2}O[/tex].
Start by setting the coefficient of the molecule with the largest number of atoms to [tex]1[/tex].
In the combustion of alkanes (including pentane,) consider setting the coefficient of the alkane to [tex]1\![/tex].
[tex]\rm 1\; C_{5}H_{12} + ?\; O_2 \to ?\; CO_{2} + ?\; H_{2}O[/tex].
Number of carbon atoms among the reactants: [tex]5[/tex].
Number of hydrogen atoms among the products: [tex]12[/tex].
By the conservation of atoms, there would need to be the same number of carbon and hydrogen atoms (along with the oxygen atoms) among the products.
Hence, the coefficient of [tex]\rm CO_2[/tex] would be [tex]5[/tex] while the coefficient of [tex]\rm H_2O[/tex] would be [tex]12 / 2 = 6[/tex].
[tex]\rm 1\; C_{5}H_{12} + ?\; O_2 \to 5\; CO_{2} + 6\; H_{2}O[/tex].
There would be [tex]5 \times 2 + 6 \times 1 = 16[/tex] oxygen atoms among the products. Also by the conservation of atoms, there would be the same number of oxygen atoms among the reactants.
Hence, the coefficient of [tex]\rm O_2[/tex] would be [tex]16 / 2 = 8[/tex].
[tex]\rm 1\; C_{5}H_{12} + 8\; O_2 \to 5\; CO_{2} + 6\; H_{2}O[/tex].
The ratio between the coefficient of [tex]\rm O_2[/tex] and [tex]\rm C_{5}H_{12}[/tex] in the balanced equation is:
[tex]\displaystyle \frac{n({\rm O_2})}{n({\rm C_{5}H_{12}})} = \frac{8}{1} = 8[/tex].
In other words, it would take eight [tex]\rm O_2[/tex] molecules to react with one [tex]\rm C_{5}H_{12}[/tex] molecule.
Assume that both [tex]\rm O_2[/tex] and [tex]\rm C_{5}H_{12}[/tex] are ideal gases. Under the same temperature and pressure, the volume of the two gases would be proportional to the number of molecules in each gas:
[tex]\displaystyle \frac{V({\rm O_2})}{V({\rm C_{5}H_{12}})} = \frac{n({\rm O_2})}{n({\rm C_{5}H_{12}})} = \frac{8}{1} = 8[/tex].
In other words, it would take [tex]8\; \rm cm^{3}[/tex] of [tex]\rm O_2[/tex] to react with [tex]1\; \rm cm^{3}[/tex] of [tex]\rm C_{5}H_{12}[/tex] under these assumptions. It would then take [tex]8 \times 15\; \rm cm^{3} = 120\; \rm cm^{3}[/tex] of [tex]\rm O_2\![/tex] to react with [tex]15\; \rm cm^{3}\![/tex] of [tex]\rm C_{5}H_{12}\![/tex].
What is the name of this molecule?
H3C - C ≡ C - CH3
Answer: 1,2,3, or 4-butyne?
Explanation:
The given molecule is
H3C - C ≡ C - CH3
The numbering order is shown below:
H3C - C ≡ C - CH3
1 2 3 4
So, the alkyne group is in the second position.
The carbon chain has four carbons.
Hence, the IUPAC name of the given compound is:
2-butyne.
Is the following change an oxidation or reduction?
manganese (IV) oxide to manganese (III) oxide.
Answer:
12113
Explanation:
step by step:no
What is the standard reduction potential, E, for the half-reaction Al3+ (aq)
3e- -> Al(s)?
Answer:
E° = -1.66 V
Explanation:
The standard reduction potential is also known as the standard electrode potentials and it tries to find the probability that an element will be reduced or undergo reduction.
From activation series online showing the standard reduction potentials for half cells, the standard reduction potential of Al3+ (aq) + 3e- -> Al(s) is;
E° = -1.66 V
3. What would be the freezing point for a 5.7 molal aqueous sucrose (C12H22O) solution? The freezing
point depression constant for water = 1.86°C/m. Show your work.
Answer:
- 10.6° C
Explanation:
Given that,
In the aqueous sucrose solution,
Molality of the solution (m) = 5.7
Freezing point constant (K) = 1.86
To find,
The freezing point of the solution = ?
Method:
To find its freezing point, we will first find out if the solute demonstrates an electrolyte or not.
In case it is not, the van't Hoff factor i.e. ration of particles' concentration denoted by (i) would be taken as 1. So,
ΔT(change in temperature) = i * m * K (putting the given values)
= 1 * 5.7 * 1.86
= 10.6° C
Thus, the freezing point equals to 0 - 10.6° C = -10.6° C.
Each orbital can contain no more than 2 electrons. This is:
O A. Conservation of energy
OB. The Pauli exclusion principle
C. None of these
D. Hund's rule
Answer: B. The Pauli exclusion principle.
Explanation: Founders Educere answer ;)
what is the percentage composition of water in crystallization of oxalic acid
Answer:
5.17 percentage is water
Explanation:
answer from gauth math
