Answer:
Calcular la molaridad de una solución que se preparó disolviendo 14 g de KOH en suficiente
agua para obtener 250 mL de solución. (masa molar del KOH = 56 g/mol).
Resolución: de acuerdo a la definición de “molaridad” debemos calcular primero, el número de mol de soluto (KOH) que
se han disuelto en el volumen dado, es decir, “se transforma g de soluto a mol de soluto” por medio de la masa molar,
así:
56 g de KOH 14 g de KOH
----------------- = ------------------- X = 0,25 mol de KOH
1 mol X
Ahora, de acuerdo con la definición de molaridad, el número de mol debe estar contenido en 1000 mL (o 1 L) de
solución, que es el volumen estándar para esta unidad de concentración, lo que se determina con el siguiente planteamiento:
0,25 mol X
----------------------- = ------------------------- X = 1 mol de KOH
250 mL de solución 1000 mL de solución
Explanation:
the half-life of uranium-232 is 69 years. If the nuclear byproduct contains uranium-232, it is not considered safe for human contact until 99.2% of it has been decayed. How long will this take
It will take approximately 480 years for 99.2% of uranium-232 to decay.
The formula of radioactive half-life = [tex]\frac{N}{N₀} = (\frac{1}{2})^{n}[/tex]
Where N = amount of isotope remaining
N₀ = original amount of isotope
n = number of half-lives
From the given values:
N = 100 5 - 99.2%
N = 0.8 % = 0.008
N₀ = 100% = 1
Substituting to find n
0.008/1 = (1/2)ⁿ
㏒₁₎₂0.008 = n
n = ㏒0.008/㏒(1/2)
n = 6.96
Therefore, number of half-lives n = 6.96
One half-life = 69 years
6.96 half-lives = 6.96 * 69 = 480.24 years
Therefore, it will take approximately 480 years for 99.2% of uranium-232 to decay.
learn more at: https://brainly.com/question/17070257
Compared to an atom of C-12, an atom of C-14 has
A) fewer protons
C) more neutrons
B) fewer neutrons
D) more protons
Explanation:
Carbon-12 atoms have stable nuclei because of the 1:1 ratio of protons and neutrons.
Carbon-14 atoms have nuclei which are unstable. C-14 atoms will undergo alpha decay and produce atoms of N-14. Carbon-14 dating can be used to determine the age of artifacts which are not more than 50,000 years old.
At a constant temperature, a sample of gas occupies 1.5 L at a pressure of 2.8 ATM. What will be the pressure of this sample, in atmospheres, if the new volume is 0.92 L?
Using boyles law
[tex]\boxed{\sf v\propto \dfrac{1}{p}}[/tex]
[tex]\\ \sf\longmapsto P_1V_1=P_2V_2[/tex]
[tex]\\ \sf\longmapsto P_2=\dfrac{P_1V_1}{V_2}[/tex]
[tex]\\ \sf\longmapsto P_2=\dfrac{2.8\times 1.5}{0.92}[/tex]
[tex]\\ \sf\longmapsto P_2=\dfrac{4.2}{0.92}[/tex]
[tex]\\ \sf\longmapsto P_2=4.56atm[/tex]
[tex]\\ \sf\longmapsto P_2\approx 4.6atm[/tex]
Answer:
[tex]\boxed {\boxed {\sf 4.6 \ atm}}[/tex]
Explanation:
We are asked to find the new pressure given a change in volume. We will use Boyle's Law, which states the volume of a gas is inversely proportional to the pressure. The formula for this law is:
[tex]P_1V_1= P_2V_2[/tex]
Initially, the gas occupies 1.5 liters at a pressure of 2.8 atmospheres.
[tex]1.5 \ L * 2.8 \ atm = P_2V_2[/tex]
The volume is changed to 0.92 liters, but the pressure is unknown.
[tex]1.5 \ L * 2.8 \ atm = P_2* 0.92 \ L[/tex]
We are solving for the final pressure, so we must isolate the variable P₂. It is being multiplied by 0.92 liters. The inverse operation of multiplication is division, so we divide both sides by 0.92 L.
[tex]\frac {1.5 \ L * 2.8 \ atm}{0.92 \ L} = \frac{P_2* 0.92 \ L}{0.92 \ L}[/tex]
[tex]\frac {1.5 \ L * 2.8 \ atm}{0.92 \ L}= P_2[/tex]
The units of liters cancel each other out.
[tex]\frac {1.5 * 2.8 \ atm}{0.92 }=P_2[/tex]
[tex]\frac {4.2}{0.92} \ atm= P_2[/tex]
[tex]4.565217391 \ atm = P_2[/tex]
The original measurements of pressure and volume have 2 significant figures, so our answer must have the same. For the number we calculated, that is the tenths place. The 6 in the hundredth place tells us to round the 5 up to a 6.
[tex]4.6 \ atm \approx P_2[/tex]
The pressure is approximately 4.6 atmospheres.
If it takes 72 mL of 9 M KOH to neutralize 415 mL of sulfuric
acid (H2SO4) solution, what is the concentration of the H2SO4
solution?
M
The concentration of H₂SO₄ is 0.78 M
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
H₂SO₄ + 2KOH —> K₂SO₄ + 2H₂O
From the balanced equation above,
Mole ratio of the acid, H₂SO₄ (nₐ) = 1
Mole ratio of the base, KOH (n₆) = 2
Finally, we shall determine the concentration of H₂SO₄. This can be obtained as follow:
Volume of base, KOH (V₆) = 72 mL
Concentration of base, KOH (C₆) = 9 M
Volume acid, H₂SO₄ (Vₐ) = 415 mL
Mole ratio of the acid, H₂SO₄ (nₐ) = 1
Mole ratio of the base, KOH (n₆) = 2
Concentration of acid, H₂SO₄ (Cₐ) =?CₐVₐ / C₆V₆ = nₐ/n₆
Cₐ × 415 / 9 × 72 = 1/2
Cₐ × 415 / 648 = 1/2
Cross multiply
Cₐ × 415 × 2 = 648
Cₐ × 830 = 648
Divide both side by 830
Cₐ = 648 / 830
Cₐ = 0.78 MTherefore, the concentration of H₂SO₄ is 0.78 M
Learn more: https://brainly.com/question/4225093
The ion with a +3 charge 28 electrons and mass number of 71
Answer:
gallium
Explanation:
Ga +++ as it is the only ion with that features
Could someone help me with this too? Much appreciated! I am a bit stuck.
Answer:
CO
Explanation:
a leaking tap drops water at the rate of 3 drops every second.each drop is approximately 1 ml. how many liters of water will leak from the tap during a day?
a. 5 liters
b. 50 liters
c.500 liters
d.15 liters
A leaking tap that drops water at the rate of 3 drops every second, will leak 259.2 L in a day.
We know that a leaking tap drops water at the rate of 3 drops every second and that each drop is approximately 1 ml. The milliliters of water dropped every second are:
[tex]\frac{3drop}{1s} \times \frac{1mL}{1drop} = \frac{3mL}{1s}[/tex]
We want to know the number of seconds in 1 day. We will use the following conversion factors:
1 day = 24 h1 h = 60 min1 min = 60 s[tex]1day \times \frac{24h}{1day} \times \frac{60min}{1h} \times \frac{60s}{1min} = 86400 s[/tex]
3 mL of water are dropped every second. The mL of water dropped in 86400 s are:
[tex]86400 s \times \frac{3mL}{1s} = 259200 mL[/tex]
Finally, we will convert mL to L using the conversion factor 1 L = 1000 mL.
[tex]259200 mL \times \frac{1L}{1000 mL} = 259.2 L[/tex]
Approximately 259.2 L of water will be dropped in 1 day.
You can learn more about unit conversions here: https://brainly.com/question/19420601
what are the benefits of chemistry to the economy
Answer:
The role of Chemistry in the field of Economics is as a driving force in all industries, from basic materials for industrial machinery to industrial raw materials.
ANSWER THESE QUESTIONS PLEASE
No spam!! :/
Answer:
By definition, a pure substance or a homogeneous mixture consists of a single phase. A heterogeneous mixture consists of two or more phases. When oil and water are combined, they do not mix evenly, but instead form two separate layers.
Explanation:
Sorry only knew the answer to the first question
Answer:
To make a saturated solution, 36 gm of sodium chloride is dissolved in 100 gm of water at 293 K. Find its concentration at this temperature.
Mass per cent is a way of expressing a concentration or describing the component in a particular mixture. The solution composition can be expressed in mass percentage that depicts the mass of solute present in a given mass of solution.
The quantity of solute is expressed in mass or by moles. For a solution, the mass per cent is described as the grams of solute per grams of solution, multiplied by 100 to get the percentage.
Concentration
Mass of sodium chloride (Solute) = 36gm
Mass of water (solvent) = 100 gm
Mass of solution = 36+100
∴ Mass of solution = 136 gm
Concentration = (Mass of Solute / Mass of Solution) * 100
Concentration = (36/136) × 100
Concentration = 26.47%
Temperature
If temperature increases, solubility increases and if temperature decreases, solubility decreases.
It is possible to distinguish the particles of solute from those of solvent in a suspension, since particle size is bigger in suspensions, hence it is easier to distinguish the particles of solute.
Explanation:
Gimme the sandmeyer's reaction!!!
Explanation:
HERE IS YOUR ANSWER.....
Calculate the mass of naphthalene required to react stoichiometrically with the moles of 2-bromo-2-methylpropane that you have placed in the flask. Dispense that quantity of naphthalene into the weighing dish. There is some imprecision in delivering the powder onto the weigh boat, but a mass within 0.040 g of the calculated stoichiometric quantity will be sufficient for this experiment. Note that you can use a combination of the 1 g and the 0.1 g buttons to add the required mass. If you overshoot the goal, you can discard the weighing boat and get a new one. RECord the sample mass dispensed below. mass of naphthalene (g)
The reaction of 2-bromo-2-methylpropane and naphthalene is stoichiometrically in a mole ratio of 1:1.
Notice that in the question, the moles of 2-bromo-2-methylpropane placed in the flask wasn't mentioned. if I assume that it was 1.24 moles then;
1 mole of naphthalene reacts with 1 mole of 2-bromo-2-methylpropane
x moles of naphthalene reacts with 1.24 mole of 2-bromo-2-methylpropane
x = 1 * 1.24/1
= 1.24 moles of naphthalene
Molar mass of naphthalene = 128.2 g/mol
Mass of naphthalene = 128.2 g/mol * 1.24 moles of naphthalene
Mass of naphthalene =159 g
For more about how to solve stoichiometry problems:
https://brainly.com/question/1309057
how many atoms of hydrogen and oxygen are present in 5 gm of HNO3
ANSWER: note the amounts of atoms of all the component in HNO3, which are 1 atom of hydrogen, 1 atom of nitrogen and 3 atom of oxygen.
The reaction between NO2 and co to produce no and CO2 is thought to occur in two steps:
Step 1: NO2 + NO2 → + NO + NO3
Step 2: NO3 + CO → NO2 + CO2
The experimental rate law is rate = k[NO2]2.
Required:
a. Write the equation for the overall reaction. do not include phase abbreviations.
b. Identify the intermediate(s).
Answer:
Correct option is
A
Explanation:
The number of molecules of CO involves in the slowest step will be 0 because CO is not involve in the slowest step i.e. rate determing step.
How many grams of Br are in 445 g CaBr2 ?
Explanation:
The mass of bromine is 79.904, and since there are two of them in the Calcium Bromide molecule, we'll multiply it by 2 to get 159.808. Dividing that by the full mass of the molecule then multiply it by 100 will give you the answer.
PLEASE HELP!!
this is on USAtestprep
a)
b)
c)
d)
cuales son las caracteristicas de el livermorio
Answer:
Livermorium is a radioactive, artificially produced element about which little is known. It is expected to be a solid and classified as a metal. It is a member of the chalcogen group. Livermorium has four isotopes with known half-lives, all of which decay through alpha decay
Entropy, the degree of disorder is related to the number of configurations that a system can adopt. If the entropy of a system is 71.85 J/mole*K, the number of configurations possible for this system is:
(a) 7188
(b) 9967
(c) 5665
(d) 2183
Determine the number of hydrogen atoms connected to each carbon atom: The bond-line structure of a compound has a SMILES string of CC1CCN(CC1N(C)C2=NC=NC3=C2C=CN3)C(=O)CC#N. All the carbon atoms of the compound are highlighted and labeled a through p.
Answer:
dsgsdfd
Explanation:
a 82.6 L sample of gas exerts 350.8 mm hg pressure at 134.6 c°. what valine does the gas have at 736.4 mm hg and 42.8 c°
a. 30.5
b 4.13
c. 12.5
d. 134
need help ASAP
Answer:
nfururhrj waltz quiz amora7ersgdsYsdi6 whiz 53
96rduttie
Classify the following oxides as acidic, basic, amphoteric, or neutral:
(a) Select the acidic oxides:
A. CO₂
B. N₂O₅
C. Al₂O₃
D. NO
E. SO₃
(b) Select the basic oxides:
A. CaO
B. CO
C. SO₃
D. K₂O
E. BaO
(c ) Select the amphoteric oxides:
A. K₂O
B. Al₂O₃
C. CaO
D. CO₂
E. SnO₂
d) Select the neutral oxides:
A. CO
B. NO
C. SNO₂
D. N₂O₅
E. BaO
Answer:
(a).
» E. SO₃, sulphur trioxide.
(b).
» A. CaO, Calcium oxide.
» D. K₂O, potassium oxide.
» E. BaO, barium oxide.
(c).
» B. Al₂O₃, Aluminium oxide.
» E. SnO₂, tin (IV) oxide.
(d).
» A. CO, carbon monoxide.
» B. NO, nitrogen monoxide.
Explanation:
[tex]{ \underline{ \sf{ \blue{christ \:† \: alone }}}}[/tex]
What is the mass grams that are in 3.52 × 10²⁵ molecules of I₂
Answer:
As you know, one mole of any substance contains exactly
6.022
⋅
10
23
molecules of that substance - this is known as Avogadro's number.
Notice that you're dealing with more than
6.022
⋅
10
23
molecules of carbon dioxide, which means that you'll also be dealing with more than one mole of the compound.
More specifically, you'll have
1.5
⋅
10
26
molecules
⋅
1 mole CO
2
6.022
⋅
10
23
molecules
=
2.491
⋅
10
2
moles CO
2
Now, a substance's molar mass tells what the mass of one mole of that substance is. In carbon dioxide's case, its molar mass is equal to
44.01 g/mol
, which means that every mole of
CO
2
will have a mass of
44.01 g
.
In your case,
2.491
⋅
10
2
moles of
CO
2
would have a mass of
2.491
⋅
10
2
moles CO
2
⋅
44.01 g
1
mole CO
2
=
109.63 g
Rounded to two sig figs, the number of sig figs you have for the number of molecules of
CO
2
, the answer will be
m
C
O
2
=
110 g
Help ASAP 15 Points
A student is conducting their science experiment on the effect of caffeine on dogs. He has 3 groups of test subjects. The 1st group of dogs receives plain water. The 2nd group of dogs receives 10 mg of caffeine each, and the 3rd group receives 50 mg of caffeine each. He will measure their activity levels by recording how long each dog runs without stopping, after giving them the pills. What could be evaluated in this experiment to ensure reliability?
A. The different amounts of caffeine given could lead to different activity levels which would throw off the result of the experiment.
B. The group that receives water will be an outlier and throw off the best fit line.
C. The test subjects are dogs and not people, so their data is unreliable.
D. If the dogs are different breeds, their activity levels could be different because of their breed and not the caffeine. Reset Selection
Answer:
The independent variable of an experiment is the one that is intentionally changed or manipulated to see the results of changing said variable.
We are told that in each different group, the amount of caffeine that is given to the dog's changes - in the control group, they get no caffeine, in the 2nd group, they get 10 mg of caffeine each, and in the 3rd group, they get 50 mg of caffeine each.
Therefore, since the amount of caffeine that is given to the dogs is the only variable that is being manipulated, this is the independent variable.
Answer: The independent variable of an experiment is the one that is intentionally changed or manipulated to see the results of changing said variable.
The independent variable of an experiment is the one that is intentionally changed or manipulated to see the results of changing said variable.
We are told that in each different group, the amount of caffeine that is given to the dog's changes - in the control group, they get no caffeine, in the 2nd group, they get 10 mg of caffeine each, and in the 3rd group, they get 50 mg of caffeine each.
Therefore, since the amount of caffeine that is given to the dogs is the only variable that is being manipulated, this is the independent variable.
We are told that in each different group, the amount of caffeine that is given to the dog's changes - in the control group, they get no caffeine, in the 2nd group, they get 10 mg of caffeine each, and in the 3rd group, they get 50 mg of caffeine each.
Therefore, since the amount of caffeine that is given to the dogs is the only variable that is being manipulated, this is the independent variable.
Explanation:
PLEASE HELP! A machine uses filtration to separate a component from orange juice. Which component does the machine most likely separate from the mixture?
A - Pigment
B - Sugar
C - Pulp
D - Water
Answer: c
Explanation: Filtration is technically defined as the process of separating suspended solid matter from a liquid
Pulp is a lignocellulosic fibrous material prepared by chemically or mechanically separating cellulose fibers from wood, fiber crops .
Many commercial juices are filtered to remove fiber or pulp.
The correct answer is C, Pulp.
Orange is an example of a citrus fruit. Every citrus fruit has a pulp. The of pulp a citrus fruit is that stringy content in the endocarp of the fruit .
The pulp of a citrus fruit is where its juice is found.
When you want to prepare orange juice, you need to remove the pulp of the citrus fruit. This is done by filtering out the pulp from the juice.
Filtration is the process of removing larger particles. For a liquid juice, filtration is the process of removing solid particles from the orange juice.
https://brainly.com/question/11403039
What is the Equation of Reduction in Mg+F2 gives MgF2, I WILL MARK YOU AS BRAINLIST
Answer:
Mg+F2= Mgf2
Explanation:
F 2 is an oxidizing agent, Mg is a reducing agent. ; Pale-yellow to greenish gas with a pungent, irritating odor.
What happens during the fourth stage of technological design that is not necessary during the sixth or seventh stages of scientific investigation?
A design is remodeled after analysis and tested again.
An initial design is implemented and analyzed to gather data.
Conclusions are made and communicated to others.
Criteria are stated to help judge the success of the process.
Answer:
a design is remodeled after analysis and tested again
Explanation:
In the following reaction, what element is gaining mass?
Mg(s) + CuSO4(aq) -> MgSO4(aq) + Cu(s)
A. Mg
B. None of these
C. Cu
D. O
Mg gained mass because it went from being a single element (on the reactant side) to being a molecule (on the product side).
Mg element is gaining mass. Hence, option A is correct.
What is a chemical equation?A chemical reaction is a representation of symbols of the elements to indicate the number of substances and moles of reactant and product.
Mg gained mass because it went from being a single element (on the reactant side) to being a molecule (on the product side).
Hence, option A is correct.
Learn more about chemical equations here:
https://brainly.com/question/12363199
#SPJ5
How are all planets in the solar system similar?
A. They have a gas atmosphere.
B. They have a water atmosphere.
C. They have a gas-surface composition.
D. They have a rock surface composition.
THIS IS FOR SCIENCE!!!!!!
PLEASE HELP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Answer:
They have a rock surface composition.
Explanation:
I hope this will help you
Which of the following has the greatest effect on colligative properties?
A. Calcium chloride (CaCl2)
B. Sodium chloride (NaCl)
C. Aluminum Nitrate (Al(NO3)3)
D. Epsom salt (MgSO4)
Answer:
C. Aluminum Nitrate (Al(NO3)3)
Explanation:
This is because, when Aluminium nitrate dissolves in water, it dissociates to form four ions ( one aluminium ion and three nitrate ions ). Since colligative property depends on number of particles or ions present ( roult's law ), this will create much effect.
[tex]Al(NO _{3} )_{3(aq)} → Al {}^{3 + } _{(aq)} + 3NO {}^{ - } _{(aq)}[/tex]
Answer:
aluminum nitrate (Al(NO3)3)
it has the greatest effect on collimation properties .
Explanation:
(c) is correct option
How many shapes contains the same text: KTKEIHLPEQMKJAPDEK
In this figure, four shapes contains the same text as in the red oval. The text given in the red oval is KTKEIHLPEQMKJAPDEK.
What is shape?Shape is "the form of an object or its outline, outer boundary or outer surface".
What is text?Text is "a collection of words or letters that are understandable by the reader".
What is an oval?Oval is a rounded and slightly elongated outline or shape like that of an egg.
Hence, four shapes contains the same text as in the red oval.
To learn more about oval here
https://brainly.com/question/24323155
#SPJ2
A student records the time it takes for her pet rabbit to make it through a maze to a carrot. In one test, she has the
rabbit try to find the carrot at 8:00 AM after eating its first by meal of the day. In the other test, the rabbit tries to find the
carrot at 8:00 AM without having eaten its first meal of the day.
In this experiment, which variable is the outcome variable?
A. the time required to finish the maze
B. whether or not the rabbit finds the carrot
C. whether the rabbit is hungry or not
D. the time of day when the rabbit starts the maze mi
Answer:
The time required to finish the maze
The time required to finish the maze is the outcome variable of this experiment.
WHAT IS AN OUTCOME VARIABLE?
An outcome variable, also known as dependent variable or response variable, is the variable that the experimenter measures or records in the experiment. The outcome variable responds to changes made to the independent variable, hence, the outcome variable is dependent on the independent variable.In this question, a student conducts an experiment to determine the time it will take her pet rabbit to make it through a maze to a carrot.
She records the time it took the rabbit to finish the maze for each of the test. Hence, the outcome variable in this experiment is the time required for the rabbit to finish the maze.Learn more: https://brainly.com/question/19016612
