Explanation:
this is the reason why aluminium's boiling point is higher than that of sodium. sodium forms Na+ ions, therefore 1 electron is lost from each sodium atom, whereas aluminium forms Al3+ ions, so 3 electrons are lost for each Aluminum atom. The number of delocalised electrons therefore increases from sodium to aluminium, and charge density of the ions increases as the ionic charge increases and size decreases.
chemistry class 9 chapter 1
Explanation:
i) Melting point = 15°C and Boiling point = 110°C
ii) The region C on graph there is only liquid state, the region A on graph there is only solid state.
iii) The straight line A1 - B1 shows that the melting point of solid wax and getting converted to liquid form.
iv) Latent heat of vaporization is a physical property of a substance.
It is defined as the heat required to change one mole of liquid at its boiling point under standard atmospheric pressure.
v) At 'B' the wax is at both solid and liquid state
1. A) Calculate DO of water at 25 0 C, P 0 = 1.01x10 5 Pa; given: water vapor pressure (25 0 C) is 3.2x10 3 Pa and Henry constant of oxygen in water is 1.3x10 -8 mol/l.Pa b) How's DO content changed as increase or decrease water temperature? Explain.
Answer:
cfvgbhnjmk,
Explanation:
what is displacement?
Answer:
the moving of something form it's places or position
Describe 5 importance matter to undergo changes
Answer:
melting, freezing, sublimation, deposition, condensation, and vaporization. These changes
Explanation:
hope it helps...i dont know if its right but i hope it helps
How to identify polar molecules
Answer:
Polar molecules occur when there is an electronegativity difference between the bonded atoms. Nonpolar molecules occur when electrons are shared equal between atoms of a diatomic molecule or when polar bonds in a larger molecule cancel each other out
Explanation:
The maximum number of electrons that can be present in an SHELL is
a) [tex]2 {n}^{2} [/tex]
b) [tex]2 {n}^{2} + 1[/tex]
c) 2n
d) none of these.
[tex]\huge\boxed{\fcolorbox{red}{blue}{ QUESTION }}[/tex]
The maximum number of electrons that can be present in an shell is
[tex] \orange{\underline{\huge{\bold{\textit{\green{\bf{OPTIONS}}}}}}} [/tex]
a) [tex]2 {n}^{2} [/tex]
b) [tex]2 {n}^{2} + 1[/tex]
c) 2n
d) none of these.
[tex] \huge\mathbb{\red A \pink{N}\purple{S} \blue{W} \orange{ER}}[/tex]
OPTION (a)
[tex]2 {n}^{2} [/tex]
[tex] \bold { \red{ \star{ \blue{EXAMPLES}}}}[/tex]
In First shell only 2 electron can be placed .
[tex]2 {n}^{2} \\ n = 1 \: (bez \: \: no \: \: shell \: = 1) \\ so \\ 2 { n}^{2} = 2 \times {1}^{2} = 2 \: electrons[/tex]
In second shell 8 electrons can be placed
[tex]2 {n}^{2} \\ n = 1(bez \: \: no\: \: shell \: = 2) \\ 2 {n}^{2} = 2 \times {2}^{2} = 2 \times 4 = 8 \: electrons[/tex]
Help ASAP only right answers only no spam don’t answer if you don’t know
Answer:
element.... ....
.....
effect of air and water on iron and zinc
Answer:
Rust
Explanation:
it does cool chemical things
`Answer is subscribe to XoX Snead on YT Explanation: b is the answer!!
Interms of air molecules, what gives a balloon its shape when air is blown into it
Answer: Because when you blow air /gas into a balloon you fill it with air particles ,so they more you blow u blow in more air particles so they tend to collide with each other ,so as they hit the walls of the balloons pressure is exerted ,so the pressure keeps the balloon inflated with its shape
Select all that apply Select the correct statements explaining how manometers measure the pressure of a gas in an experiment. Multiple select question.
In an open-end manometer, the gas pressure pushes on the Hg surface on one arm of the U tube and atmospheric pressure gas pushes on the other.
In an closed-end manometer, the gas pressure pushes on the Hg surface on one arm of the U tube and atmospheric pressure gas pushes on the other.
In an open-end manometer, the gas pressure is equal to the difference in column heights in the two arms of a U tube.
In an closed-end manometer, the gas pressure is equal to the difference in column heights in the two arms of a U tube.
The gas pressure is directly related to the height of a column of mercury it produces in a U tube.
Answer:
-In an closed-end manometer, the gas pressure is equal to the difference in column heights in the two arms of a U tube.
-In an open-end manometer, the gas pressure pushes on the Hg surface on one arm of the U tube and atmospheric pressure gas pushes on the other.
-The gas pressure is directly related to the height of a column of mercury it produces in a U tube.
Explanation:
Manometer is simply an instrument used for measuring the pressure that is acting on a column of liquid.
Now they could either be open ended or closed ended manometers.
However the difference between both of them is that;
Closed - end manometer are those used to measure absolute pressure while open end manometer is used to measure the gauge pressure.
From operation of a closed end manometer, the gas pressure is read from the difference in column heights of the two arms of the U tube being used. While in open end thermometer, the gas pressure will push the mercury surface on one arm of the U tube while the atmospheric pressure gas will push on the other arm.
Lastly, the height of a column of mercury in the U-tube is directly related to the gas pressure.
Thus, the correct options are A, D, E
Help please! Given that the enthalpy of reaction for a system at 298 K is –292 kJ/mol and the entropy for that system is 224 J/mol*K, what's the free energy for the system?
a) -87,793 kJ
b) -225 kJ
c) -66,751 kJ
d) 358 kJ
Answer:
C. -66, 751 kjExplanation:
hope it helps
Suppose that you chose sodium carbonate to precipitate the chromium ions from a solution of chromium (III) chloride. Write and balance the equation of this double-displacement reaction.
If the solution has a volume of 520 mL and the concentration of chromium (III) chloride is 0.224 M, how many grams of sodium carbonate should you add to the solution to precipitate out all the chromium ions?
Answer:
18.5g Na2CO3
Explanation:
Chromium (III) chloride, CrCl3, reacts with Na2CO3 as follows:
2CrCl3 + 3Na2CO3 → Cr2(CO3)3(s) + 6NaCl
Where 2 moles of CrCl3 react with 3 moles of Na2CO3 to produce 1 mole of Cr2(CO3)3 -The precipitate-
To solve this question we need to find the moles of CrCl3 added. With the chemical equation we can find the moles of Na2CO3 and its mass as follows:
Moles CrCl3:
520mL = 0.520L * (0.224mol/L) = 0.116 moles CrCl3
Moles Na2CO3:
0.116 moles CrCl3 * (3 mol Na2CO3 / 2mol CrCl3) = 0.175 moles Na2CO3
Mass Na2CO3 -Molar mass: 105.99g/mol-
0.175 moles Na2CO3 * (105.99g/mol) = 18.5g Na2CO3
Compare the energy requirements of a 50 year old woman and 50 year old man.
Explanation:
For both men and women, the basics of a balanced diet are the same. Men have higher caloric requirements than women since they have a bigger body (both in height and weight) and more muscular mass.
So, Men needs more energy.
50 year old woman require less energy than 50 year old man.
Energy transformation of a kettle?
Explanation:
Electrical energy into heat energy..hope it helps.stay safe healthy and happy...3. How many moles are present in 100 g of Ca(NO3)2?
PLEASEEE HELP ASAPP
0Answer: 0.6094
Explanation:
no of moles = mass / molar mass = 100/164.088= 0.6094 mole
Answer:
0.609 moles
Explanation:
mass in g ÷ atomic mass = moles
Ca(NO₃)₂ = 1 Ca 40.078 amu
2 N 28.0134 amu
+ 6 O 95.994 amu
____________________
164.0854 amu
100 g ÷ 164.0854 amu = 0.609 moles
three significant digits
Iron reacts with copper (I) sulfate to produce copper and iron (II) sulfate. If 4.32x10^25
particles of copper (I) sulfate react, how many moles of copper will be produced?
Fe + Cu2504 --> FeSO4 + 2Cu
Answer: 143.48 moles of copper will be produced.
Explanation:
We are given:
Number of particles of copper (I) sulfate = [tex]4.32\times 10^{25}[/tex]
According to the mole concept:
[tex]6.022\times 10^{23}[/tex] number of particles is contained in 1 mole of a compound
So, [tex]4.32\times 10^{25}[/tex] number of particles will be contained in = [tex]\frac{1}{6.022\times 10^{23}}\times 4.32\times 10^{25}=71.74mol[/tex] of copper (I) sulfate
The given chemical equation follows:
[tex]Fe+Cu_2SO_4\rightarrow FeSO_4+2Cu[/tex]
By the stoichiometry of the reaction:
If 1 mole of copper (I) sulfate produces 2 moles of Cu
So, 71.74 moles of copper (I) sulfate will produce = [tex]\frac{2}{1}\times 71.74=143.48mol[/tex] of Cu
Hence, 143.48 moles of copper will be produced.
a) the use of heat energy to react carbon dioxide with water to produce oxygen. b) a chemical reaction between carbohydrates and oxygen to produce carbon dioxide, water, and heat energy. c) a photochemical reaction involving carbon dioxide and water to produce carbohydrates and oxygen. d) a photochemical reaction involving carbon dioxide and oxygen to produce water and oxygen.
Answer: b) a chemical reaction between carbohydrates and oxygen to produce carbon dioxide, water, and heat energy
Explanation:
Based on the options, I assume that this is talking about the process of respiration. Respiration allows living things to produce energy by reacting carbohydrates with oxygen.
This results in the release of energy in the form of heat in a cell and also the formation of carbon dioxide and water. This type of respiration is known as Aerobic respiration.
Liquid octane (CH3(CH2)CH3) reacts with gaseous oxygen gas(O2) to produce gaseous carbon dioxide(CO2) and gaseous water (H2O). What is the theoretical yield of carbon dioxide formed from the reaction of 27.4g of octane and 77.8g of oxygen gas?
Answer:
The theoretical yield of carbon dioxide formed is 68.4 grams CO2
Explanation:
Step 1: Data given
Liquid octane = C8H18
gaseous oxygen gas = O2
gaseous carbon dioxide = CO2
gaseous water = H2O
Mass of octane = 27.4 grams
Molar mass of octane = 114.23 g/mol
Mass of oxygen = 77.8 grams
Molar mass of oxygen = 32.0 g/mol
Step 2: The reaction
2C8H18(l) + 25O2(g) → 16CO2(g) + 18H2O(g)
Step 3: Calculate number of moles
Moles = mass / molar mass
Moles of octane = 27.4 grams / 114.23 g/mol
Moles of octane = 0.240 moles
Moles of oxygen = 77.8 grams / 32.0 g/mol
Moles of oxygen = 2.43 moles
Step 4: Calculate the moles of the products
For 2 moles of octane we need 25 moles of O2 to produce 16 moles of CO2 and 18 moles H2O
O2 is the limiting reactant. It will completely react. (2.43 moles).
There will react 2.43/12.5 = 0.194 moles
There will remain 0.240 - 0.194 = 0.046 moles of octane.
There will be produced:
16/25 * 2.43 = 1.555 moles of CO2
18/25 * 2.43 = 1.750 moles of H2O
This is:
1.56 moles * 44.01 g/mol = 68.4 grams CO2
1.750 moles * 18.02 g/mol = 31.5 grams H2O
The theoretical yield of carbon dioxide formed is 68.4 grams CO2
A student is asked to seperate two liquids. Liquid A boils at 100°c and liquid B boils at 65°c. The student sets up a fractional distillation experiment, and after a few minutes a clear liquid is collected from the condenser. Explain which of the two liquids will be collected first. ( 2 marks).
Answer:
B
Explanation:
because B has a lower bp it needs less time and energy to turn into vapour and is collected into the condenser first
Boiling the solution causes the equilibrium in the following reaction to shift to the ________. HCO3- H3O --> H2CO3 H2O
Answer:
Right
Explanation:
The reaction of bicarbonate ion with acid is shown in the following equation;
HCO3- + H3O --> H2CO3 + H2O
This reaction is endothermic. This implies that energy must be absorbed from the surrounding as the reaction progresses.
Hence, when the solution is boiled, energy is supplied to the system in the form of heat and the forward reaction is favoured hence the equilibrium shifts to the right.
How is each nucleotide different from the others?
A. It has different bases.
B. It has different side chains.
C. It has different carboxyl groups.
D. It has different amine groups.
Answer:
a. po tamang sagot
Explanation:
pa pafoolow po pleasr
The DNA and RNA are polynucleotides which contain a chain of nucleotides monomers with different nitrogenous bases. Each nucleotide different from the others, as It has different bases. The correct option is A.
What is a nucleotide?A nucleotide is defined as a compound containing three component units, namely a pentose sugar (either ribose or 2-deoxyribose), a heterocyclic nitrogenous base (a substituted purine or a substituted pyrimidine) and a phosphate group.
The nucleotides are the phosphate esters of nucleosides. A nucleotide containing ribose as the sugar unit is termed as the ribonucleotide. While one containing 2-deoxyribose as the sugar unit is termed as the deoxyribonucleotide.
The nitrogenous bases in RNA are adenine, guanine, cytosine and uracil whereas in DNA the bases are adenine, guanine, cytosine and thymine. The purines are adenine and guanine whereas cytosine, thymine and uracil are pyrimidines.
Thus the correct option is A.
To know more about nucleotide, visit;
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draw the atomic model of sulphur with the details and electronic configuration
here's your answer hope this will help
Question 3 of 10 What does the first ionization energy represent? O A. The energy required to add an electron to a new energy level B. The energy to remove an energy level of electrons O C. The energy given off when an electron is gained D. The energy required to remove an electron from an atom SUBMIT
Answer:
D
Explanation:
The first ionization energy is the minimum energy required to remove the most loosely bound electron from an atom.
Good luck!
En un estudio de contaminantes, se cuantificó que el martes anterior se tenían 40 ppm de dióxido de carbono en el ambiente estudiado. Mientras que el jueves se reportó que se tenía 0.004% de esa misma sustancia. ¿Cómo se comparan estos valores?
A.
Las concentraciones no pueden compararse debido a que tienen diferentes unidades.
B.
Las concentraciones son iguales, por lo que se deben monitorear las causas en los dos días.
C.
El jueves hay mayor concentración de contaminante, por lo que se deben tomar medidas únicamente para ese día.
D.
El martes hay mayor concentración de contaminante, por lo que se deben tomar medidas únicamente para ese día.
The table shows the charge on three unknown subatomic particles.
X positive
Y no charge
Z negative
Which particle is most likely present in the space outside of the nucleus of the atom?
Answer:
Z negative
Explanation:
The negative charge shows that this is an electron. Electrons are present outside the nucleus of the atom and having negative charge. Usually represented by e-
Answer:
Only Z?
Explanation:
what are condition for formation of electrovalent bond
Answer:
The conditions for the formation of an electrovalent bond are as follows: The atom which changes into cation (+ ive ion) should possess 1,2 or 3 valency electrons. It will loose these electrons to form cation with +1,+2 or +3 charge
Methane is the main component of natural gas. Using the given reaction enthalpy, calculate the heat energy produced by the combustion of one kilogram of methane.
Answer: The heat energy produced is 53831.25KJ
Explanation:
METHANE is the main component of natural gas. It can undergo combustion reaction in air with a bright blue flame to produce carbondioxide and water. The heat of reaction (enthalpy) is negative because heat is absorbed during the chemical reaction. To calculate the heat energy produced by the combustion of one kilogram (1 kg) of methane the following steps are taken:
Molecular mass of methane =16 gm/mol.
So moles of 1 kg methane =
Given mass of methane ÷ molecular weight of methane
But the given mass = 1kg = 1000g
Therefore,
moles of 1000g methane = 1000÷16
= 62.5 moles
Hence, energy evolved = (moles of methane) × (heat of combustion)
Therefore,
heat energy produced= 62.5 × (-861.3kj)
= -53831.25kj
The heat energy produced by the combustion of one kilogram of methane is –53831.25 KJ
We'll begin by calculating the number of mole in 1 Kg of CH₄
Mass of CH₄ = 1 kg = 1000 g
Molar mass of CH₄ = 12 + (4×1) = 16 g/mol
Mole of CH₄ =?Mole = mass /molar mass
Mole of CH₄ = 1000 / 16
Mole = 62.5 moles Finally, we shall determine the heat energy produced from the reaction.CH₄ + 2O₂ —> CO₂ + 2H₂O ΔH = –861.3 KJ
From the balanced equation above,
1 mole of CH₄ reacted to produce –861.3 KJ.
Therefore,
62.5 moles of CH₄ will react to produce = 62.5 × –861.3 = –53831.25 KJ
Thus, –53831.25 KJ of heat energy is produced.
Complete Question is located in the attached photo
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how many moles are in 6.4grams of copper
Answer:
One mole of copper atoms has Avogadro number of copper atoms i.e. 6.022×10
23
atoms.
Given the mass of Copper is 6.4g
Number of Copper atoms in 6.4g =
molar mass
given mass
×Avogadro number
=
63.55
6.4
×6.022×10
23
copper atoms
=6.064×10
22
copper atoms
Explanation:
1. How many ATOMS of boron are present in 2.20 moles of boron trifluoride ? atoms of boron.
2. How many MOLES of fluorine are present in 5.35*1022 molecules of boron trifluoride ? moles of fluorine.
Answer:
1. How many ATOMS of boron are present in 2.20 moles of boron trifluoride? atoms of boron.
2. How many MOLES of fluorine are present in of boron trifluoride? moles of fluorine.
Explanation:
The molecular formula of boron trifluoride is [tex]BF_3[/tex].
So, one mole of boron trifluoride has one mole of boron atoms.
1. The number of boron atoms in 2.20 moles of boron trifluoride is 2.20 moles.
The number of atoms in 2.20 moles of boron is:
One mole of boron has ---- [tex]6.023x10^2^3[/tex] atoms.
Then, 2.20 moles of boron has
-[tex]=2.20 mol. x 6.023 x 10^2^3 atoms /1 mol\\=13.25x10^2^3 atoms[/tex]
2. Calculate the number of moles of BF3 in 5.35*1022 molecules.
[tex](5.35x10^2^2 molecules/6.023x10^2^3)x 1mol\\=0.0888mol[/tex]
One mole of boron trifluoride has three moles of fluorine atoms.
Hence, 0.0888moles of BF3 has 3x0.0888mol of fluorine atoms.
=0.266mol of fluorine atoms.
Where would (aq) (s) go in Cr(NO3)3+K3PO4
Answer:
Cr(NO3)3 (aq) +K3PO4 (s)
Explanation:
