Answer:
lenses is used to refract light inward or outward
there are two type of lenses. Concave and convex lense
Convex lense converge ray of light
Concave lense diverge ray of light
useful application =:
=> camera
=> flashlight
=> lasers
=> Binoculars and Telescope
hope it helps
Answer:
Explanation:
Lenses are made of glass or other transparent materials for light. They are optically dense so light slows down on entering it. It is called refraction which bends the light on entering and leaving the lenses.
Refraction by lenses can be used for all kinds of optical applications, e.g. camera, telescope, magnifying glasses, solar heating.
what element in magma is most abundant
Answer:
Oxygen and Silicon
Explanation:
Oxygen and Silicon are the most abundant elements in magma, SiO₂
-TheUnknownScientist
HC2HO3(aq)+H2O(l)⇄H3O+(aq)+C2HO3−(aq)
pKa=3.18
at 25°C
The equilibrium for the acid ionization of HC2HO3 is represented by the equation above. If 10.0mL of 0.20MHC2HO3 reacts with 5.0mL of 0.10MNaOH, which of the following could be used to calculate the correct pH of the resulting solution?
A) pH=pKa+log(0.100.20)
B) pH=pKa+log(0.0050×0.100.0100×0.20)
C) pH=pKa+log[((0.0050×0.10)0.0150)/((0.0100×0.20)−(0.0050×0.10)0.0150)]
D) pH=pKa+log[((0.0050×0.10)+(0.0100×0.20)0.0150)/((0.0100×0.20)−(0.0050×0.10)0.0150)]
Answer:
C) pH=pKa+log[((0.0050×0.10)0.0150)/((0.0100×0.20)−(0.0050×0.10)0.0150)]
Explanation:
To find the pH of a buffer (The mixture of the weak acid and its conjugate base) we have to use Henderson-Hasselbalch equation:
pH = pKa + log [Base] / [Acid]
Where pKa is the pka of the buffer and [] is molar concentration of the species of the buffer
The [Base] is equal to the concentration of NaOH added:
0.10M * (0.005L / 0.015L)
And the concentration of the acid [Acid] is the initial concentration of the acid - the concentration of the NaOH added:
0.0100L * (0.20M)/0.0150L - 0.10M * (0.005L / 0.015L)
That means the pH of the buffer is:
C) pH=pKa+log[((0.0050×0.10)0.0150)/((0.0100×0.20)−(0.0050×0.10)0.0150)]
Answer:
C) pH=pKa+log[((0.0050×0.10)0.0150)/((0.0100×0.20)−(0.0050×0.10)0.0150)]
Explanation:
The equilibrium for the acid ionization of HC2HO3 is represented by the equation above. If 10.0mL of 0.20MHC2HO3 reacts with 5.0mL of 0.10MNaOH, which of the following could be used to calculate the correct pH of the resulting solution. pH=pKa+log[((0.0050×0.10)0.0150)/((0.0100×0.20)−(0.0050×0.10)0.0150)]
PLEASE HURRY!!!
It took Mrs. Murphy 5.5 hours traveling at a rate of 113 km/hr to finally reach her parents house.
How far did she travel?
Write the balanced equation for the equilibrium reaction for the dissociation ofsilver chloride in water, and write the K expression for this reaction. Then create an ICE chart. Since we know the equilibrium concentration of the silver ion, we can solve for Ksp.Does it agree with the literature value
Answer:
See explanation
Explanation:
Hello there!
In this case, since the the concentrations are not given, and not even the Ksp, we can solve this problem by setting up the chemical equation, the equilibrium constant expression and the ICE table only:
[tex]AgCl(s)\rightleftharpoons Ag^+(aq)+Cl^-(aq)[/tex]
Next, the equilibrium expression according to the produced aqueous species as the solid silver chloride is not involved in there:
[tex]Ksp=[Ag^+][Cl^-][/tex]
And therefore, the ICE table, in which x stands for the molar solubility of the silver chloride:
[tex]\ \ \ \ \ \ \ \ \ \ \ \ \ \ AgCl(s)\rightleftharpoons Ag^+(aq)+Cl^-(aq)[/tex]
I - 0 0
C - +x +x
E - x x
Which leads to the following modified equilibrium expression:
[tex]Ksp=x^2[/tex]
Unfortunately, values were not given, and they cannot be arbitrarily assigned or assumed.
Regards!
Consider the following data on some weak acids and weak bases
acid
Ka
name formula
acetic acid
HCH3CO2
1.8 x10−5
hydrocyanic acid
HCN
4.9 x 10−10
base
Kb
name formula
pyridine
C5H5N
1.7 x 10−9
ammonia
NH3
1.8 x 10−5
Use this data to rank the following solutions in order of increasing pH. In other words, select a '1' next to the solution that will have the lowest pH, a '2' next to the solution that will have the next lowest pH, and so on.
a. 0.1M NaCH3CO2
b. 0.1M NH4Br
c. 0.1M NaBr
d. 0.1M KCN
Answer:
b < c < a < d
Explanation:
The weak acid with the lowest pKa will be the most acidic. In the other way, the conjugate base which the acid is weak will be strong.
The weak base with the lowest pKb will be the most basic. And the conjugate base of the weak base will be a strong acid.
Ka Acetic acid = 1.8x10-5
Ka HCN = 1.9x10-10
Kb pyridine = 1.7x10-9
Kb NH3 = 1.8x10-5
NH4Br is the conjugate base of a weak base. That means is a strong acid.
NH4Br has the lowest pH
NaBr is the conjugate base of a strong acid, HBr. That means NaBr is neutral
The most basic between the conjugate base of the acetic acid, NaCH3CO2 and KCN is KCN because the acetic acid is the stronger acid regard to HCN.
The rank is:
NH4Br < NaBr < NaCH3CO2 < KCN
b < c < a < dun MODELO ATÓMICO es:
a. Una esfera con partículas positivas y negativas
b. La estructura mínima de la materia.
c. Una serie de descubrimientos.
d. La representación de un átomo donde se explica su comportamiento y características.
Answer:
Creo que es D pero no tan segura
Explanation:
7.In the oxidation of ethane: 2 C2H6 + 7 02 + 4CO2 + 6H2O how many
liters of O2 are required to react with 90 grams of ethane?
Answer:
If reaction is taking place at room temperature and pressure(rtp)
= 360 litres of O₂ at rtp
If reaction is taking place at standard temperature and pressure(stp):
= 336 litres of O₂ at stp
Explanation:
2C₂H₆ + 70₂ → 4CO₂ + 6H₂O
1 mole of C₂H₆ = (12 × 2) + (1 × 6) = 24 + 6 = 30g
2 moles of C₂H₆ = 30 × 2 = 60g
From the equation:
1 mole of 0₂ reacts with 2 moles of C₂H₆
1 mole of 0₂ reacts with 60g of C₂H₆
? moles of 0₂ react with 90g of C₂H₆
[tex]\frac{90}{60}[/tex]= 1.5 moles of O₂
Considering condition of reaction taking place whether room temperature and pressure(rtp) or standard temperature and pressure(stp)
If room temperature and pressure(rtp):
1 mole of 0₂ occupies 24 liters/24000 cm³/ 24 dm³ of O₂
1.5 moles of O₂ occupies (24 × 1.5) litres of O₂
= 360 litres of O₂ at rtp
If standard temperature and pressure(stp):
1 mole of 0₂ occupies 22.4 liters/22400 cm³/ 22.4 dm³ of O₂
1.5 moles of O₂ occupies (22,4 × 1.5) litres of O₂
= 336 litres of O₂ at stp
Write a balanced equation for the double-replacement precipitation reaction described, using the smallest possible integer coefficients. A precipitate forms when aqueous solutions of nickel(II) nitrate and sodium carbonate are combined. Do not include states such as (s) or (aq). It is not necessary for you to indicate which of the products is the precipitate.
Answer:
Ni(NO₃)₂ + Na₂CO₃ ⇒ NiCO₃ + 2 NaNO₃
Explanation:
Let's consider the unbalanced equation for the reaction that occurs when aqueous solutions of nickel(II) nitrate and sodium carbonate are combined. This is a double-replacement precipitation reaction.
Ni(NO₃)₂ + Na₂CO₃ ⇒ NiCO₃ + NaNO₃
We will balance the equation using the trial and error method.
First, we will balance Na atoms by multiplying NaNO₃ by 2.
Ni(NO₃)₂ + Na₂CO₃ ⇒ NiCO₃ + 2 NaNO₃
As we can see, the equation is balanced.
Which of the following contains the highest number of electrons?
OA) hydroxide ion
OB) oxonium ion
C) ammonium ion
OD) oxide ion
O E) all of them contains the same number of electrons
When H2(g) reacts with F2(g) to form HF(g) , 542 kJ of energy are evolved for each mole of H2(g) that reacts. Write a balanced thermochemical equation for the reaction with an energy term in kJ as part of the equation.
Answer:
H₂(g) + F₂(g) ⇒ 2 HF(g) ΔH°rxn = -542 kJ
Explanation:
Let's consider the unbalanced equation that occcurs when H₂(g) reacts with F₂(g) to form HF(g).
H₂(g) + F₂(g) ⇒ HF(g)
In order to get the balanced equation, we will multiply HF(g) by 2.
H₂(g) + F₂(g) ⇒ 2 HF(g)
To convert a balanced equation into a thermochemical equation, we need to add the standard enthaply of the reaction, considering that 542 kJ of energy are evolved for each mole of H₂(g) and there is 1 mole of H₂(g) in the balanced equation. By convention, when energy is released, it takes a negative sign. The thermochemical equation is:
H₂(g) + F₂(g) ⇒ 2 HF(g) ΔH°rxn = -542 kJ
Determine the number of electrons in an Cl ion with a charge of -3
Answer:
There are 20 electrons.
Explanation:
Chlorine has 17 electrons in its atom to begin with (you can tell from the proton number in the periodic table).
A charge of -3 means that the chlorine atom gained 3 electrons, and now needs to lose 3 electrons to return to its atom configuration.
Potassium nitrate, KNO3 , has a molar mass of 101.1 g/mol. In a constant-pressure calorimeter, 13.3 g of KNO3 is dissolved in 213 g of water at 23.00 °C . KNO3(s)−→−−H2OK+(aq)+NO−3(aq) The temperature of the resulting solution decreases to 19.60 °X . Assume that the resulting solution has the same specific heat as water, 4.184 J/(g·°C) , and that there is negligible heat loss to the surroundings. How much heat was released by the solution
Answer:
[tex]Q_{sln}=-3219.25 J[/tex]
Explanation:
Hello there!
In this case, for this calorimetry problem, it is possible for us to infer that the heat of the reaction of dissolution of KNO3 is absorbed by the solution composed by the former and water so that we can write:
[tex]Q_{rxn}=-Q_{sln}[/tex]
Thus, given the mass, specific heat and temperature of the solution, we plug in the data to obtain the heat absorbed, by the reaction:
[tex]Q_{rxn}=-m_{sln}C_{sln}\Delta T _{sln}\\\\Q_{rxn}=-(13.3+213)g(4.184\frac{J}{yg\°C} )(19.60-23.00)\°C\\\\Q_{rxn}=3219.25J[/tex]
Also, we can say the the heat released by the solution was -3219.25 J.
Best regards!
Which of the two Lewis/electron dot structure representations, which is
the correct one for oxygen gas? PICTURE BELOW
Answer:
A
Explanation:
You are performing an acid-base neutralization reaction in the laboratory to determine the concentration of an unknown base. You are supposed to titrate it with a monoprotic acid, but your lab partner accidentally fills your buret with sulfuric acid, a diprotic acid, with the same concentration as the acid called for in the experiment. How will the volume of diprotic acid compare to the volume of monoprotic acid you would have used
Answer:
Volume is reduced to half
Explanation:
Acid base titration are commonly used reactions in a lab, and are ofter used to get pH or different kind of solutions.
The neutralization of an acid base reaction is reached, when the solution (having added an indicator previously) changes its original color. chemically speaking, this occurs when the number of moles of the acid and the base are balanced and equal. In other words the following:
n₁ = n₂ (1)
This expression can also be expressed in function of concentration and volume:
M₁V₁ = M₂V₂ (2)
From here, solving for V₁:
V₁ = M₂V₂ / M₁
Now, this expression is true only when we have the same kind of substance that can lose or gain the same number of hydrogens.
Lets suppose that we have as base NaOH (Monoprotic base) and HCl (monoprotic acid), the titration reaction would be:
NaOH + HCl --------> NaCl + H₂O
As both of the species are monoprotic, the number of moles are the same when they reach the equilibrium, so, expression (2) can be used, and calculate volume or concentrations.
However, in this case, a partner made a mistake and use a diprotic acid, in this case, H₂SO₄, In this case, things chance because H₂SO₄ is diprotic, meaning that we need to dissociate two hydrogens in equilibrium, therefore, expression (2) would be something like this.
Acid: 1; Base: 2
H₂SO₄ + 2NaOH ------> Na₂SO₄ + H₂O
nH₂SO₄ = n₁ = 1
nNaOH = n₂ = 2
n₁/n₂ = 1/2
2n₁ = n₂ (3)
Writting this, in function of concentration and volume, it would be:
2M₁V₁ = M₂V₂ (4)
From here, if we solve for the volume of the acid (V₁):
V₁ = M₂V₂ / 2M₁
Therefore, according to this expression, we can see that the volume required of the acid would be half the volume required of the monoprotic acid. For example, if we need 50 mL of Chloridic acid to reach the equivalence point with NaOH, then, with H₂SO₄ it will only need 25 mL. This, of course, assuming that concentrations are the same, and volume of the base used, the same.
Hope this helps
2 Which of the gases in air are elements? Explain how you can tell.
Answer:
I'll explain.
Explanation:
The molecules of two different elements, nitrogen and oxygen, make up about 99 percent of the air. The rest includes small amounts of argon and carbon dioxide. Oxygen is the life-giving element in the air. You can tell because they're on the periodic table which is a table for elements.
Explanation:
nitrogen and oxygen are the gases in the air which are elements you can simply say it by looking the periodic table
Generally the ionization potential in a period increases, but there are some exceptions. The one which is not an exception is
1) Be & B 2) N & O 3) Mg & Al 4) Na & Mg
Answer:
Generally, the first ionisation energy increases along a period. But there are some exceptions one which is not an exception
Are sperm and egg cells exact copies of the plant cell
Answer:
No
Explanation:
thats scientifically impossible
The Swedish chemist Karl Wilhellm was the first to produce chlorine in the lab
2NaCl + 2H2SO4 + MnO2 -----> Na2SO4 + MnSO4 + H2O + Cl2
If Dr. Wilhellm started with 50.0 g of each reactant, which reactant is the limiting reactant?
Answer:
Explanation:
Remark
Interesting que8stion. You have to figure out how many mols are present in each reactant. Since all periodic tables are different, I'm going to use rounded numbers. If it is too close, I will go further.
NaCl
Na = 23
Cl = 35.5
1 mol = 58.5 grams
given = 50.0 grams
Mols for the reaction = 50/58.5 = 0.855
H2SO4
H2 = 2*1 2
S = 1 * 32 32
O4 = 4*16 64
1 mol = 98 grams
mols present = 50/98 = 0.510
MnO2
Mn = 1 * 55 = 55
O2 = 2*16 = 32
1 mol = 87 grams
mols available = 50/87 = 0.5747
Discussion
Na Cl and H2SO4 both require 2 moles for every mol of Cl2 produces.
H2SO4 has 0.51 mols available for a reaction
NaCl has 0.855 moles available for a reaction
MnO2 has 0.575 moles available for a reaction.
Given those numbers 0.510 mols of H2SO4 will only produce 0.255 mols of chlorine and the rest will be reduced in a similar manner. H2SO4 is the limiting reagent (reactant).
In other words only 0.510 moles of NaCl will be used and 0.855 - 0.510 moles will be left over on the reactants side.
only 0.575 moles of MnO2 will be used and 0.065 moles will be left over.
The oddity in the result shows up because the balance numbers in the equation give a ratio of 2 to 1 for H2SO4 and NaCl The 2 belongs to the reactants and the 1 for the chlorine.
4NH3 + 502 - 6H20 + 4NO
How many grams of O2 are required to produce 0.3 mol of H20?
4NH3 + 5O2 --> 6H2O + 4NO
How mant grams of NO are produced from 1.55 mol of NH3?
4NH3 + 5O2 --> 6H2O + 4NO
How many grams of NO is produced if 12g of 02 is combined with ammonia?
Explanation:
4NH3 + 502 - 6H20 + 4NO
How many grams of O2 are required to produce 0.3 mol of H20?
4NH3 + 5O2 --> 6H2O + 4NO
How mant grams of NO are produced from 1.55 mol of NH3?
4NH3 + 5O2 --> 6H2O + 4NO
How many grams of NO is produced if 12g of 02 is combined with ammonia?
What is the correct definition of temperature
Answer:
i'm pretty sure its the last answer and if not its the 2nd one
Select the TRUE statements below regarding the coordination compound prepared in lab. Group of answer choices The coordination compound contained a complex ion that was covalently bonded to sulfate. The ligand must have at least one unshared pair of valence electrons in order to covalently bond with transition metal in the coordination compound. Ethanol was used during crystallization of the coordination compound because the compound is soluble in ethanol. The ammonia is covalently bonded to the transition metal. The colors of many coordination compounds are the result of light absorption by the d electrons on the transition metal.
Answer: Hello the compound is missing but I was able to get the Full question and missing compound . ( compound = copper sulfate )
answer : statement ; 2 , 3 and 5
Explanation:
The true statements regarding the coordination compound ( copper sulfate ) are :
The ligand must have at least one unshared pair of valence electrons in order to covalently bond with transition metal in the coordination compound ( statement 2 )Ethanol was used during crystallization of the coordination compound because the compound is soluble in ethanol ( statement 3 ) The colors of many coordination compounds are the result of light absorption by the d electrons on the transition metal ( statement 5 )During the coordination of compounds dative bonds exits between the transition metals and the Ligands molecules
Which of the following regions has an economy based on processing food and consumer goods?
A. Western Europe
B. Eastern Europe
C. northern Europe
D. southern Europe
No links plz
Answer:
B. Eastern Europe
Explanation:
The economy of Eastern Europe depends on producing foods. For example, Poland and Belarus are two countries in Eastern Europe, and they both produce chocolates. Producing foods isn't the only detrimental part of the region's economic data. The other half depends on consumer goods. For example, Estonia and Latvia are good countries in packaging food. The answer to the question is B.
WILL GIVE BRAINLIEST!!!
Answer:
The answer is B
Explanation:
The answer is B because representative particles can only be atoms.
give same examples of ways that people destroy the plant animals relationship?
What unit should you think of when using coefficients?
Answer:
Far as I know coefficients are unitless. sorry if this don't help ;)
To achieve the highest return during recrystallization of a given solid, one must: Group of answer choices Add the minimum amount of boiling solvent necessary to dissolve the solid to be crystallized. Add an excess amount of cold solvent necessary to dissolve the solid to be crystallized. Add the minimum amount of cold solvent necessary to dissolve the solid to be crystallized. Add an excess amount of boiling solvent necessary to dissolve the solid to be crystallized.
Answer:
Option A
Explanation:
Addition of too much of solvent will make the solution dilute due to which the crystals will not form. Hence option D is incorrect
On the other hand adding a minimum amount of boiling solvent will give a saturated solution for recrystallization. Hence, option A is incorrect
Addition of cold solvent will lower the rate of formation of crystals. Hence, both option B and C are incorrect
please help i don’t know this:(
Answer:
29.5 days
Explanation:
orginally 27.3 days but 29.5 days is also correct
how a scientist might use a graph of the
relationship between population growth and time to identify
a trend
A mixture of He, Ar, and Xe has a total pressure of 2.40 atm. The partial pressure of He is 0.300 atm, and the partial pressure of Ar is 0.250 atm. What is the partial pressure of Xe?
Express your answer to three significant figures and include the appropriate units.
The partial pressure of Xe in the mixture is 1.850 atm. (partial pressure of Xe = Total pressure - Partial pressure of He - Partial pressure of Ar = 1.850 atm).
To find the partial pressure of Xe, we need to subtract the partial pressures of He and Ar from the total pressure.
Total pressure = partial pressure of He + partial pressure of Ar + partial pressure of Xe
Given:
Total pressure = 2.40 atm
Partial pressure of He = 0.300 atm
Partial pressure of Ar = 0.250 atm
Let's solve for the partial pressure of Xe:
Partial pressure of Xe = Total pressure - Partial pressure of He - Partial pressure of Ar
Partial pressure of Xe = 2.40 atm - 0.300 atm - 0.250 atm
Partial pressure of Xe = 1.850 atm
Therefore, the partial pressure of Xe in the mixture is 1.850 atm.
To learn more about partial pressure of Xe here
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what is the difference between transmutation and natural radioactivity
