Answer:
344.1g
Explanation:
1
Which Element Am I (Core)
Names
1. I have 4 valence electrons and 2 energy levels. Which element am I?
2. Iam in group 16 with 2 energy levels. Which element am I?
3. I am in Period 2 and belong to the same group (family) as silicon. Which element am 1?
4. I have 7 valence electrons and 3 energy levels? Which elementar ?
5. I am in period 3 and I have 12 protons in my nucleus. Which element am 1?
Berr
Sul
ca
3
6
5
6. I am the only element with no neutrons in my nucleus. Which element am 17
6
7. I am the only metalloid with 3 energy levels. Which element am I?
8. I have 1 valence electron and 11 protons, which element am I?
9. Thave only one energy level that is full. Which element am I?
10.1 have 8 valence electrons and I have 4 energy levels. Which element am 1?
10
Answer:
1) Helium
2) Oxygen
3)Carbon
4) Chlorine
5) Magnesium
Explanation:
Helium has the electron arrangement 2, 2. There are two electrons in the first shell and two electrons in the second shell.
Oxygen is the first member of group 16, there are two energy levels in oxygen which are 2,6.
Carbon is in period 2 and is the first member of group 14 (the silicon family).
Chlorine has 7 valence electrons, the electrons are arranged as 2, 8, 7.
Magnesium has 12 protons and 12 electrons. It is the second member of period 3.
2. How many moles are there in 20 grams of Carbon?
Answer:
1.6666666666666 is the ans bcz in each mole there r 12 grams of carbon so the ans is goingtobe 20÷12
According to the mole concept, there are 1.66 moles in 20 grams of carbon.
What is a mole?
Mole is defined as the unit of amount of substance . It is the quantity measure of amount of substance of how many elementary particles are present in a given substance.
It is defined as exactly 6.022×10²³ elementary entities. The elementary entity can be a molecule, atom ion depending on the type of substance. Amount of elementary entities in a mole is called as Avogadro's number.
It is widely used in chemistry as a suitable way for expressing amounts of reactants and products.For the practical purposes, mass of one mole of compound in grams is approximately equal to mass of one molecule of compound measured in Daltons. Molar mass has units of gram per mole . In case of molecules, where molar mass in grams present in one mole of atoms is its atomic mass.
Number of moles is calculated as, mass/molar mass, thus on substitution , number of moles=20/12=1.66 moles.
Thus, there are 1.66 moles in 20 grams of carbon.
Learn more about moles,here:
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How to set up the rate expressions for the following mechanism?
A → B k1
B → A k2
B+C → D k3
If the concentration of B is small compared with the concentrations of A, C, and D, the steady-state approximation may be used to derive the rate law. Derive the rate law, and show that this reaction may follow the first-order equation at high pressures and the second-order equation at low pressures.
Answer:
Explanation:
From the given information:
A → B k₁
B → A k₂
B + C → D k₃
The rate law = [tex]\dfrac{d[D]}{dt}=k_3[B][C] --- (1)[/tex]
[tex]\dfrac{d[B]}{dt}=k[A] -k_2[B] -k_3[B][C][/tex]
Using steady-state approximation;
[tex]\dfrac{d[B]}{dt}=0[/tex]
[tex]k_1[A]-k_2[B]-k_3[B][C] = 0[/tex]
[tex][B] = \dfrac{k_1[A]}{k_2+k_3[C]}[/tex]
From equation (1), we have:
[tex]\mathbf{\dfrac{d[D]}{dt}= \dfrac{k_3k_1[A][C]}{k_2+k_3[C]}}[/tex]
when the pressure is high;
k₂ << k₃[C]
[tex]\dfrac{d[D]}{dt} = \dfrac{k_3k_1[A][C]}{k_3[C]}= k_1A \ \ \text{first order}[/tex]
k₂ >> k₃[C]
[tex]\dfrac{d[D]}{dt} = \dfrac{k_3k_1[A][C]}{k_2}= \dfrac{k_1k_3}{k_2}[A][C] \ \ \text{second order}[/tex]
Observe: Click Reset. Select the Gas collection setup. Chemists use this apparatus to collect any gases produced in the reaction. From the reaction flask, gases travel through a long tube and into a cylinder of water. As gases bubble into the cylinder, the water is displaced (removed) until the cylinder is filled with gas. Was any gas produced in the reaction? How do you know? I WILL GIVE POINTS AND BRAINLIEST IF YOU ANSWER CORRECTLY. THANK YOU :)
Answer:
Due to displacement of water.
Explanation:
If the water is displaced in the cylinder it means that the gas is produced in the reaction while on the other hand, if the water is not displaced in the cylinder so it means that the reaction does not produces any gas yet. So we can say that the displacement of waters indicates or shows us whether the gas is produced in the reaction or not.
tion 7
In the beginning of the reaction, A B+C, 2 moles of A are taken, out of which 0.5 moles
gets dissociated. What is the amount of dissociation of A?
(1) 0.5
(2) 1
(3) 0.25
(4) 4.2
what’s the answer please
Answer:
5 × 10⁻³ mol
Explanation:
Step 1: Given data
Volume of HCl solution (V): 25 cm³Molar concetration of the HCl solution (C): 0.2 mol/dm³Step 2: Convert "V" to dm³
We will use the conversion factor 1 dm³ = 1000 cm³.
25 cm³ × 1 dm³/1000 cm³ = 0.025 dm³
Step 3: Calculate the moles of HCl (n)
We will use the definition of molarity.
C = n/V
n = C × V
n = 0.2 mol/dm³ × 0.025 dm³ = 5 × 10⁻³ mol
What is the source of most of the salt in the oceans?
human activities adds salt into the ocean
O rivers and streams carry sediment containing salt to the ocean
O marine fish produce salt adding it into the ocean
wind blows the salt into the ocean
What mass of silver nitrate will be needed to react with 125 grams of magnesium chloride?
Answer: m = 4.2 gAgCl
Explanation:
Mass number 107 and 61 neutrons
What is the vapor pressure of a solution in which the mole fraction of the solute is 0.200 and the vapor pressure of the pure solvent is 100.0 torr? (Assume a single nonvolatile, nonelectrolyte solute).
a. 0 torr
b. 80.0 torr
c. 100.0 torr
d. 120.0 torr
e. 20.0 torr
Answer: The vapor pressure of a solution in which the mole fraction of the solute is 0.200 is 80.0 torr
Explanation:
As the relative lowering of vapor pressure is directly proportional to the amount of dissolved solute.
The formula for relative lowering of vapor pressure will be,
[tex]\frac{p^o-p_s}{p^o}=i\times x_2[/tex]
where,
[tex]p^0[/tex]= vapor pressure of pure solvent = 100.0 torr
[tex]p_s[/tex] = vapor pressure of solution = ?
i = Van'T Hoff factor = 1 for nonvolatile, nonelectrolyte solute
[tex]x_2[/tex] = mole fraction of solute = 0.200
[tex]\frac{100.0-p_s}{100.0}=1\times 0.200[/tex]
[tex]p_s=80.0torr[/tex]
The vapor pressure of a solution in which the mole fraction of the solute is 0.200 is 80.0 torr
2. Which of the following could the flame test be used for?
The definition of symbiotic is
O Having tiny tentacles
O consisting of two oxygen atoms
O having a hard external covering
O living in close association
Answer:
Living in close association
Explanation:
The theory of evolution states
Answer:
the theory of evolution states that all living things which exist today, and many more that are now extinct, evolved from simple life forms which first developed 3 billion years ago.
Explanation:
A gas has a pressure of 0.0370 atm at 50.0°C. What is the pressure at 0.00°C?
how does a buffer work?
A. it prevents added acids or bases from dissociating
B. it neutralizes acids or bases by precipitating a salt
C. it forms new conjugate pairs with the added ions
D. it bonds with the added H+ or OH- in solution
Answer:
It bonds with the added H+ or OH in solution.
Explanation:
What do chemists study?
A. The properties of matter and how matter changes
B. How matter and energy interact
C. Mathematical principles
D. Living things
SUBMIT
A. The properties of matter and how matter changes.
Answer: A. the properties of matter and how matter changes
Explanation:
just got it right
What is the electronegativity and bond polarity like in the "head" vs. the "tail" ends of soap?
Answer:
gay
Explanation:
very gay
an ionic bond consist of a gas and metal
Answer: yes
Explanation:
What are the main sources of outdoor air pollution and how do they cause smog?
Answer:
The common sources of outdoor air pollution are emissions caused by combustion processes from motor vehicles, solid fuel burning and industry. Other pollution sources include smoke from bushfires, windblown dust, and biogenic emissions from vegetation (pollen and mold spores).
smog is produced when sunlight reacts with nitrogen oxides in the atmosphere. Nitrogen oxides come from car exhaust, coal power plants, and factory emissions. When sunlight hits these chemicals, they form airborne particles and ground-level ozone—or smog.
plz need help right away !
Explanation:
1 mole = 6.02 x 10^23 atoms (Avogadro’s number)
Step 1) Determine how many grams of a substance are in the problem
Step 2) Find the amount of grams in 1 mole of the substance
3) Multiply step one by step two
3. Which state of matter has a defined shape?
HELP FAST
Answer:
Solid state of matter has a definite shapeThe answer to this is solids!
How many moles of Ca(OH)2 are needed to make 2.5 moles of CaCl2?
Explanation:
CaCl2 ⇄ Ca-²+2Cl-¹
1mole⇄1mole+2moles
So from above ..
1mole CaCl2 produce 1mole Ca-² & 2 moles of Cl-².
For 2.5 moles we multiply the above chemical eq. With 2.5
2.5CaCl2⇄2.5Ca-²+5Cl-¹
So from 2.5 moles of CaCl2 we get 2.5 mole calcium ion and 5 moles chloride ion…
At a certain temperature this reaction follows first-order kinetics with a rate constant of 2.01 s^−1
CICH2CH2Cl (g) → CH2CHCI (g) + HCl(g)
Suppose a vessel contains CICH2CH2Cl at a concentration of 1.34 M. Calculate how long it takes for the concentration CICH2CH2Cl to decrease to 20.0% of its initial value. You may assume no other reaction is important. Round your answer to 2 significant digits.
Answer:
0.80 seconds (2 significant figures)
Explanation:
The equation of the reaction is given as;
CICH2CH2Cl (g) --> CH2CHCI (g) + HCl(g)
Rate constant (k) = 2.01 s^-1
From the units of the rate constant, this is a first order reaction.
Initial Concentration = 1.34 M
t = ?
Final concentration = 20% of 1.34 = 0.268 M
The integrated rate law for a first order reaction is given as;
ln[A] = ln[A]o - kt
ln(0.268) = ln(1.34) - 2.01(t)
-2.01(t) = - 1.6094
t = 0.8007 ≈ 0.80 seconds (2 significant figures)
How will this system at equilibrium be affected by each of the conditions stated here? 2 Upper H Subscript 2 Baseline (g) + Upper O Subscript 2 Baseline (g) double-headed arrow 2 Upper H Subscript 2 Baseline Upper O (g) + heat. removal of H2O addition of O2 decrease in pressure increase in temperature
Answer:
removal of H2O
✔ System will shift toward the products.
addition of O2
✔ System will shift toward the products.
decrease in pressure
✔ System will shift toward the reactants.
increase in temperature
✔ System will shift toward the reactants.
Explanation:
The reaction Equation :
2H₂ (g) + O₂ (g) ↔ 2H₂O (g) + heat
Answer :
a) Removal of H₂O : The system will move towards the products of the reaction
b) addition of O₂ : The system will move towards the products of the reaction
c) decrease in pressure : The system will tend to move towards the reactants
d) Increase in temperature: The system will tend to move towards the reactants as well
Reason
In an equilibrium reaction changes to reactant components surroundings/conditions in which the reaction is been carried out can cause a significant change in the entire reaction process.
Hence; Removal of H₂O will cause the reaction system to move towards the products also the addition of O₂ will make the equation of the reaction system move towards the product
Decrease in pressure and Increase in temperature causes the equation to move towards the reactants of the reaction
Learn more about equilibrium reaction : https://brainly.com/question/16878977
How many molecules are there in 13.5g of lithium oxide?
please help!
Answer:
the answer is 29.8814
Explanation:
because this is the answer to your question
Which planet has these characteristics? - the only planet to have liquid water on its surface - almost three quarters of its surface is covered in water - has a nearly circular orbit
HELP ASAP!!! Plzzz
How many total atoms of oxygen are present in the molecules represented here?
Calculate [H+] and [OH-] as required for each of the following
solutions at 25 °C, and state whether the solution is neutral, acidic,
or basic.
a. 1.0x 10-5 MOH-
Q
b. 1.0x 10-7 MOH-
c. 10.0 MH+
Explanation:
The relationship between H+ and OH- at 25 °C is given as;
[H+} x [OH-] = 1.0 x 10-14 M
a. 1.0 x 10-5 M OH-
[OH-] = 1.0 x 10-5 M
[H+] = 1.0 x 10-14 M / [OH-] = 1.0 x 10-14 M / 1.0 x 10-5 M
[H+] = 1.0 x 10^(-14+5)
[H+] = 1.0 x 10^(-9)
pH = - log [H+]
pH = - log [10^(-9)]
pH = 9
This is a basic solution
b. 1.0 x 10-7 M OH-
[OH-] = 1.0 x 10-7 M
[H+] = 1.0 x 10-14 M / [OH-] = 1.0 x 10-14 M / 1.0 x 10-7 M
[H+] = 1.0 x 10^(-14+7)
[H+] = 1.0 x 10^(-7)
This is a neutral solution since [H+] and [OH-] are equal
c. 10.0 M H+
[H+] = 1.0 x 10 M
[OH-] = 1.0 x 10-14 M / [H+] = 1.0 x 10-14 M / 1.0 x 10 M
[OH-] = 1.0 x 10^(-14-1)
[OH-] = 1.0 x 10^(-15)
pH = - log [H+]
pH = - log [10^(1)]
pH = -1
This is an acidic solution since it has a pH of -1
what volume of copper metal is needed to react with 3.5 moles of silver nitrate
Answer:
3.40 g
Explanation: don't have one :P
4. Consider the following reaction:
A student performs a neutralization reaction at 298 K according to the following reaction:
NaHCO3 (8) + HCH,O2 (aq) → H20 (1) + CO2 (g) + NaC,H3O2 (aq)
The student adds 1.85 g of solid NaHCO3 into a flask containing 75.0 mL of 0.90 M HCH:02. The student
observes the formation of gas bubbles and also that the flask gets cooler to the touch as the reaction proceeds.
Considering all of the students observations that the student made, is the reaction thermodynamically favorable
at all temperatures, no temperatures, high temperatures or low temperatures. Justify (explain) your selection in
terms of AG
Answer:
High temperatures
Explanation:
NaHCO₃ (8) + HCH,O₂ (aq) → H₂O (l) + CO₂ (g) + NaC,H₃O₂ (aq)
As the flask gets cooler to the touch as the reaction proceeds, the reaction is endothermic. This means that ΔH is positive (ΔH>0).
As a gas is formed (bubbles are formed), ΔS is positive (ΔS>0).
In terms of ΔG:
ΔG = ΔH - TΔSIn order for the reaction to be thermodynamically favorable, ΔH has to be negative, thus:
The reaction is favorable if TΔS > ΔH.The greater the temperature, the easier it would be for TΔS to be greater than ΔH.
