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:
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!
Which type of solution below has a cloudy appearance? (Choose all that apply)
a. Colloids
b. Suspensions
c. Solutions
d. Alloys
The type of solutions which are appearing cloudy are called colloids. Therefore, option a is correct.
What are colloids ?Colloids are mixtures in which particles of one substance are evenly dispersed throughout another substance, creating a stable mixture. The particles in a colloid are larger than those found in a solution, but smaller than those found in a suspension.
Colloids can be found in various states of matter, including solid, liquid, and gas, and they can be formed from a wide range of substances, such as polymers, metals, and biological molecules.
One important characteristic of colloids is their ability to scatter light. This phenomenon, known as the Tyndall effect, occurs when light passes through a colloid and is reflected by the particles, causing the mixture to appear cloudy or hazy.
Colloids also exhibit unique properties related to their size and shape, such as viscosity, surface tension, and Brownian motion. They appear cloudy in nature.
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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
How many mL of 14.5M lithium carbonate solution must be used to deliver 4.20 g of lithium ion
Answer:
10.3 g Li) / (6.9410 g Li/mol) x (1 mol Li3PO4 / 3 mol Li) / (0.750 mol/L Li3PO4) = 0.6595 L = 660. mL
Explanation:
Which of the following is true regarding the difference between velocity and speed? *
Velocity can be negative whereas speed can only be positive.
Velocity includes a direction whereas speed is a numerical value only.
Velocity relies on displacement whereas speed relies on distance.
All of the above.
Answer:
All of the aboveSpeed is the time rate at which an object is moving along a path, while velocity is the rate and direction of an object's movement. Put another way, speed is a scalar value, while velocity is a vector.
Explanation:
Hope it is helpful.....
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.
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List a couple general characteristics of primary consumers and list a few examples.
How many mL of 14.5M lithium carbonate solution must be used to deliver 4.20 g of lithium ion
Answer:
. 750 M
Explanation:
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
2KMnO4 + 16HCl -> 5Cl2 + 2KCl + 2MnCl2 + 8H2O If 6.0 moles of KCl are produced, how many moles of HCl were reacted?
Answer:
Explanation:
You just use the balance mole numbers from the equation.
moles HCl needed/16 from the balanced equation ==> 6KCl/2 from equation
x / 16 = 6/2 Multiply both sides by 16
x = 16 * 6 / 2
x = 48
You need 48 mols of HCl
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…
2. Which of the following could the flame test be used for?
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.
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
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
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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]
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
If 25.00 mL of 6.00 M HCl is transferred by pipet into a volumetric flask and diluted to 5.00 L, what is the molarity of the diluted HCl?
Answer:
0.03 M
Explanation:
The computation of the molarity of the diluted HCI is given below:
As we know that
(M1) × (V1) = (M2) × (V2)
Now
(M2) = {(M1) × (V1)} ÷ (V2)
or
Molarity of the diluted HCl,(M2) is
= {6 × 25} ÷ 5000
= 0.03 M
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.
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
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
What is the mole percent of ethanol (C2H5OH), which consists of 71.0 g of ethanol for every 18.6 g of water present?A. 87.7%.B. 22.1%.C. 26.5%.D. 73.5%.E. 71.0%.
Answer:
Mole percent of Ethanol = 0.5986 * 100 = 59.86%
Explanation:
Mole percent is the percentage of the total moles that is of a particular component.
We have to covert the ethanol and water to moles. This is given by the equation;
Number of moles = Mass / Molar mass
Ethanol;
Number of moles = 71 / 46.07 = 1.5411 mol
Water;
Number of moles = 18.6 / 18 = 1.033 mol
Total mol = 1.5411 mol + 1.033 mol = 2.5741 mol
Mole percent of Ethanol = Number of moles /(Ethanol) / Total moles * 100
Mole percent of Ethanol = 1.5411 mol / 2.5741 mol * 100
Mole percent of Ethanol = 0.5986 * 100 = 59.86%
Some instruments differentiate individual quanta of electromagnetic radiation based on their energies. assume such an instrument has been adjusted to detect quanta that have 3.50× 10–16 j of energy. what is the wavelength of the detected radiation? give your answer in nanometers.
Answer:
5.68×10¯¹⁰ m
Explanation:
From the question given above, the following data were obtained:
Energy (E) = 3.50×10¯¹⁶ J
Wavelength (λ) =?
Energy (E) and wavelength (λ) are related according to the following formula:
E = hv/λ
Where
E => is the energy
h => is the Planck's constant
v => is the velocity of electromagnetic radiation
λ => is the wavelength of the radiation.
With the above formula, we can obtain the wavelength of the radiation as follow:
Energy (E) = 3.50×10¯¹⁶ J
Planck's constant (h) = 6.63×10¯³⁴ Js
Velocity (v) = 3×10⁸ m/s
Wavelength (λ) =?
E = hv/λ
3.50×10¯¹⁶ = 6.63×10¯³⁴ × 3×10⁸ / λ
3.50×10¯¹⁶ = 1.989×10¯²⁵/ λ
Cross multiply
3.50×10¯¹⁶ × λ = 1.989×10¯²⁵
Divide both side by 3.50×10¯¹⁶
λ = 1.989×10¯²⁵ / 3.50×10¯¹⁶
λ = 5.68×10¯¹⁰ m
Thus, the wavelength of the radiation is
5.68×10¯¹⁰ m
If you have 0.36mol C that reacts with excess CuO, how many atoms do you have of Cu?
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.
What is the electronegativity and bond polarity like in the "head" vs. the "tail" ends of soap?
Answer:
gay
Explanation:
very gay
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
A gas has a pressure of 0.0370 atm at 50.0°C. What is the pressure at 0.00°C?
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:
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