Would a salt-cured egg be a physical or chemical change?
For a science experiment, I placed an egg in water that had three tablespoons of salt for one week. After 4 days, the egg cracked. At the end of the week, I took it out and cracked the egg. The egg yolk was now solid. This is also called salt-cured eggs. However, I'm not sure whether this is a physical or chemical change.
Answer:
I believe it is a physical change
Explanation:
The telltale sign of a chemical change is the formation of a new substance. They also usually involve the production of energy (heat, light, sound etc.)
Aqueous solutions containing approximately 3 percent(w/w) H2O2 are sold in drug stores as a disinfectant. Determination of the actual concentration of H2O2 in a bottle of peroxide solution was done by diluting 1.50 mL to 100 mL with water, acidifying with dilute H2SO4 and titrating with a 0.01411 M KMnO4 solution. 32.17 mL of the permangate solution was needed to reach the end point of the titration. What is the actual molar concentration of the H2O2 solution]
Answer:
0.01804 M KMnO4 Solution.
Explanation:
3 Percent(w/w) H2O2 Are Sold In Drug Stores As A Disinfectant. ... H2O2 In A Bottle Of Peroxide Solution Was Done By Diluting 1.50 ML To 100 ML With Water, Acidifying With Dilute H2SO4 And Titrating With A 0.01804 M KMnO4 Solution.
According to the equation below, if 2.00 g of PCl5 react completely, how many grams of HCl will be produced?
PCl5+4H2O→H3PO4+5HCl
Answer:
1.75 g HCl
Explanation:
PCl₅ + 4H₂O → H₃PO₄ + 5HClFirst we convert 2.00 g of PCl₅ into moles, using its molar mass:
2.00 g ÷ 208.24 g/mol = 0.0096 mol PCl₅Then we convert PCl₅ moles into HCl moles, using the stoichiometric coefficients of the equation:
0.0096 mol PCl₅ * [tex]\frac{5molHCl}{1molPCl_5}[/tex] = 0.048 mol HClFinally we convert HCl moles into grams, using its molar mass:
0.048 mol HCl * 36.45 g/mol = 1.75 g HClOne method for preparing a nitrile is the dehydration of a primary amide.
a. True
b. False
An organic compound which has the empirical formula CHO has an approximate
molar mass of 145 g/mol. What is its probable molecular formula?
Answer:
Molecular formula => C₅H₅O₅
Explanation:
From the question given above, the following data were obtained:
Empirical formula = CHO
molar mass of compound = 145 g/mol
Molecular formula =?
The molecular formula of the compound can be obtained as follow:
Molecular formula = Empirical formula × n
Molecular formula = [CHO]ₙ
[CHO]ₙ = 145
[12 + 1 + 16]n = 145
29n = 145
Divide both side by 29
n = 145 / 29
n = 5
Molecular formula = [CHO]ₙ
Molecular formula = [CHO]₅
Molecular formula => C₅H₅O₅
what are the reasons that you cannot see many stars in the city nights?
Answer:
Because of the artificial lights influencing the dark night, turning it into a grey.
Write a structural formula for the principal organic product formed in the reaction of methyl bromide with each of the following compounds:
1. Sodium hydroxide
2. Potassium ethoxide
3. Sodium benzoate
4. Lithium azide
Answer:
1. CH3Br + NaOH --------> H3C---OH + Na---Br
Explanation:
Pls someone help me with this question pls
Answer:
D
Explanation:
A 72.0 g sample of an organic solid is dissolved in 180mL of water. The solid is extracted using one 60 mL extraction in the first extraction of an organic solvent which has a partition (distribution) coefficient with water of 10. The first extraction removed 55.4 g of solid from water. What are the numbers that need to go in box A and B to calculate the volume of solvent (y) that would be necessary to remove an additional 7.0g from the remaining sample dissolved in water. You DON'T have to complete the calculation to solve for y.
Answer:
[tex]V_{7.0}\approx 235ml[/tex]
Explanation:
From the question we are told that
mass of sample [tex]M=72.0 grams[/tex]
volume of water [tex]V=180 mL[/tex]
volume for extraction [tex]V'=60mL[/tex]
partition (distribution) coefficient water [tex]d=10[/tex]
initial extraction removal [tex]x=55.4g[/tex]
Generally the equation for the weight of sample [tex]x_n[/tex] is mathematically given by
[tex]x_n=x*(\frac{DV}{DV+V'})^n[/tex]
[tex]x_n=55.4(\frac{10*180}{10*180+60})^1[/tex]
[tex]x_n=53.613g[/tex]
Generally the weight extracted [tex]x_e[/tex] is therefore
[tex]w_e=x-x_n[/tex]
[tex]w_e=55.4-53613[/tex]
[tex]w_e=1.787[/tex]
[tex]w_e=1.787[/tex] is extracted with 60ml solvent .
Therefore volume of solvent (y) that would be necessary to remove an additional 7.0g
[tex]V_{7.0}=\frac{60}{1.767}*7[/tex]
[tex]V_{7.0}=235.030ml[/tex]
[tex]V_{7.0}\approx 235ml[/tex]
A flask contains a 1.00 mole of neon gas and 2.00 moles of argon gas. If the total pressure of the gases is 150.0 kPa, then what is the partial pressure of the argon gas in kPa?
Answer:
Partial pressure of Ar = 100.5 KPa
Explanation:
The following data were obtained from the question:
Number of mole of Ne = 1 mole
Number of mole of Ar = 2 moles
Total pressure = 150.0 KPa
Partial pressure of Ar =?
Next, we shall determine the mole fraction of Argon (Ar). This can be obtained as follow:
Number of mole of Ne = 1 mole
Number of mole of Ar = 2 moles
Total mole = 1 + 2 = 3 moles
Mole fraction of Ar = mole of Ar / total mole
Mole fraction of Ar = 2/3
Mole fraction of Ar = 0.67 mole
Finally, we shall determine the partial pressure of argon (Ar). This can be obtained as follow:
Mole fraction of Ar = 0.67 mole
Total pressure = 150.0 KPa
Partial pressure of Ar =?
Partial pressure = mole fraction of gas × total pressure
Partial pressure of Ar = 0.67 × 150
Partial pressure of Ar = 100.5 KPa
Which of these benefits the grassland by allowing light, warmth, moisture, and nutrients back into the soil?
fires
ponds
trees
rainfall
Answer:
Trees
Explanation:
I think sorry if I get it wrong
What keeps the Earth orbiting on its current path
in our solar system?
How much heat is transferred when 7.19 grams of H2 reacts with excess nitrogen, according to the following equation: N2(g) + 3 H2 (g) --> 2 NH3 (g) \DeltaΔH = +46.2 kJ
Answer:
[tex]Q=54.8kJ[/tex]
Explanation:
Hello there!
In this case, according to the given chemical reaction, it is possible for us to realize that the 46.2 kJ of energy are given per mole of reaction, which are related to 3 moles of hydrogen; Thus, we can calculate the energy per mole of hydrogen as shown below:
[tex]\Delta H=\frac{46.2kJ}{mol} *\frac{1mol}{3molH_2}\\\\ \Delta H=15.4\frac{kJ}{molH_2}[/tex]
Now, to calculate the total energy, we convert the grams to moles of hydrogen as shown below:
[tex]Q=7.19gH_2*\frac{1molH_2}{2.02gmolH_2}*15.4\frac{kJ}{molH_2} \\\\Q=54.8kJ[/tex]
Best regards!
What is orbit? A. An increase in centripetal motion and mass friction. B. Resistance of an object to avoid friction. C. Gravity causing a curved path as an object tries to go straight. D. How well an object floats.
Answer:
c
Explanation:
PART A: Which of the following statements best identifies a central idea of the article?
A. The media attention on Mars enthusiasts has caused space exploration to become one of the
most important issues facing Americans today.
B. While some private agencies are working on sending humans to Mars, many experts believe
that the barriers to such a voyage still remain high.
C. Despite the publicity surrounding private space missions, NASA remains optimistic that it
will be the first agency in the U.S. to send humans to Mars.
D. Private space agencies have no plans beyond landing on Mars, as opposed to the people of
NASA, who genuinely want to colonize Mars and explore space.
The central idea is despite publicity surrounding private space missions, NASA remains optimistic that it will be the first agency to send humans to Mars.
What is NASA?This is referred to as National Aeronautics and Space Administration and are involved in the science and technology related to space.
The article talks about publicity of private space missions and NASA being optimistic about being the first to achieve the feat of sending humans to Mars.
Read more about NASA here https://brainly.com/question/1350178
Rusting is a chemical reaction between Iron metal [Fe(s)] and oxygen gas [O2(g)] in a slightly acidic environment. Rusting is actually a multi-step reaction, however it has the net overall reaction of:
4Fe+3O2--->2FeO3
If 100.0 g of iron metal are converted into rust, how many moles of rust will have formed? (Assume unlimited oxygen gas.)
*Hint* You already converted 100.0 g of Fe into moles of Fe in a previous question, start there.
Answer:
0.895 mole of Fe₂O₃.
Explanation:
We'll begin by calculating the number of mole in 100 g of Fe. This can be obtained as follow:
Molar mass of Fe = 56 g/mol
Mass of Fe = 100 g
Number of mole of Fe =?
Mole = mass / molar mass
Number of mole of Fe = 100 / 56
Number of mole of Fe = 1.79 mole
Finally, we shall determine the number of mole of Fe₂O₃ produced by the reaction of 100 g (i.e 1.79 moles) of Fe. This can be obtained as follow:
4Fe + 3O₂ — > 2Fe₂O₃
From the balanced equation above,
4 moles of Fe reacted to produce 2 moles of Fe₂O₃.
Therefore, 1.79 moles of Fe will react to produce = (1.79 × 2)/4 = 0.895 mole of Fe₂O₃.
Thus, 0.895 mole of Fe₂O₃ was obtained from the reaction.
What is the value for AG at 5000 K if AH = -220 kJ/mol and S= -0.05 kJ/(mol-K)?
A. -195 kJ
B. -470. kJ
C. 30 kJ
D. 470 kJ
Answer:
C. 30 kJ
Explanation:
Hello there!
In this case, in agreement to the thermodynamic definition of the Gibbs free energy, in terms of enthalpy of entropy:
[tex]\Delta G= \Delta H-T\Delta S[/tex]
It is possible to calculate the required G by plugging in the given entropy and enthalpy as shown below:
[tex]\Delta G=-220kJ/mol-5000K*-0.05kJ/mol*K\\\\\Delta G=30kJ/mol[/tex]
Therefore, the answer is C. 30 kJ .
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Characterize the effect that changes will have on the vapor pressure (v.p.) and boiling point (b.p.) of a liquid by increasing the external pressure on the surface of a liquid at constant temperature. Group of answer choices v.p. does not change, b.p. decreases v.p. decreases, b.p. decreases v.p. does not change, b.p. increases v.p. decreases, b.p. does not change
Answer:
Vapor pressure does not changes , Boiling point of liquid increases.
Explanation:
The external pressure creates the water molecules to move rapidly. The boiling point of liquid will increase as a result of external pressure induced on the surface of the liquid. The temperature must be kept constant to bring the liquid to boil.
True or False?
Weak bases dissociate
completely into (OH)- and
metal cations.
Answer:
False
Explanation:
When weak bases dissociate, an equilibrium is established rather than dissociating 100%. So OH- and metal ions are partially ionized.
When would a topographic map be useful?
Answer:
Topographic maps are used by hikers and backpackers to plan routes, estimate travel times, find water, good campsites, and track their progress on hikes. They're designed to depict the three dimensional shape of the world (mountains, valleys, plains, etc.)
Explanation:
Which of the following combinations of quantum numbers is permissible?Question 23 options: n = 1, l = 2, ml = 0, ms = n = 4, l = 3, ml = 1, ms = n = 3, l = 3, ml = 1, ms = n = 2, l = 1, ml = –1, ms = 0 n = 4, l = 3, ml = 4, ms =
Answer: n= 4, , l= 3, [tex]m_l[/tex] = 1, permissible
Explanation:
Principle Quantum Numbers : It describes the size of the orbital and the energy level. It is represented by n. Where, n = 1,2,3,4....
Azimuthal Quantum Number : It describes the shape of the orbital. It is represented as 'l'. The value of l ranges from 0 to (n-1).For l = 0,1,2,3... the orbitals are s, p, d, f...
Magnetic Quantum Number : It describes the orientation of the orbitals. It is represented as [tex]m_l[/tex]. The value of this quantum number ranges from [tex](-l\text{ to }+l).[/tex]
Spin Quantum number : It describes the direction of electron spin. This is represented as [tex]m_s[/tex]. The value of this is [tex]+\frac{1}{2}[/tex] for upward spin and [tex]-\frac{1}{2}[/tex] for downward spin.
a) n=1 , l= 2, [tex]m_l[/tex] = 0, not permissible as l can not greater than n.
b) n= 4, , l= 3, [tex]m_l[/tex] = 1, permissible
c) n= 3, l= 3, [tex]m_l[/tex] = 1, not permissible as l can not equal than n.
d) n= 4 , l= 3, [tex]m_l[/tex] = 4, not permissible as [tex]m_l[/tex] can not greater than l.
All chemical reactions use reactants in a specific proportion or stoichiometry to regulate the amount of products produced. The __________ reactant is consumed completely during the reaction but some of the __________ reactant is left over.
a. limiting, excess
b. excess, limiting
c. proportional, ideal
d. chemical, stoichiometric
Answer: The answer is a. limiting, excess. I took the test.
Explanation:
What is one way humans can preserve biodiversity
Answer:
Reducing the amount of water you use, by having a 5-minute shower or not running the water when washing up the dishes, can help protect vital wetlands. Plant scientists are also working to help conserve by developing crop varieties that use less water.
Explanation:
Answer:
1. Most of the endangered organisms may represent a source of income.
2. The conservation or preservation may conflict with morals.
3. The role of the species or organisms might not be understood.
Explanation:
Biodiversity simply means the amount or number of living organisms that exist in the world.
The practice of protecting these existing living organisms for specific known purposes is regarded as the preservation or conservation of biodiversity.
This process or practice of preserving biodiversity is important to meet most of the human needs, such as generating income, source of food and fuel among others.
Why is SpaceX likely to succeed in a mission to Mars?
A. It only hires expert NASA employees as its employees.
B. It takes more risks than NASA, which cannot afford them.
C. It is run by Elon Musk, who is determined to get to Mars.
D. It has fewer restrictions than NASA does.
Answer:
C
Explanation:
It is run by Elon Musk, who is determined to get to Mars.
How many moles are there in 4.9x10^23 molecules of CO2?
F. 0.81 moles of CO2
G 8.14X10^45
H. 2.95X10^47
J. 2052.44
Answer:
0.81 molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\ [/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
[tex]n = \frac{4.9 \times {10}^{23} }{6.02 \times {10}^{23} } = \frac{4.9}{6.02} \\ = 0.813953...[/tex]
We have the final answer as
0.81 molesHope this helps you
Some students have said that a buffer is like a proton (H ) sponge. Evaluate this statement and explain both how a buffer is like a sponge and how it is not like a sponge. For your explanation, include chemical equations, data, and create and explain molecular-level drawings. (Question is taken from Orgill and Sutherland, 2008.) (Saloni)
Answer:
i) Buffer absorbs H^+ and OH^- ions preventing large changes in pH when small amounts of acid or base is added but when large amounts of acid or base is added there will be a change in pH
ii) absorption of liquid is related to a chemical reaction for a buffer system but it is not related a chemical reaction for a proton( H ) sponge.
Explanation:
i) Buffer like a proton ( H ) sponge
Buffer absorbs H^+ and OH^- ions preventing large changes in pH when small amounts of acid or base is added but when large amounts of acid or base is added there will be a change in pH
The pH of a Buffer follows the Henderson-Hasselbach model
pH = pKa + Log ([A-]/[HA])
when base is added
HA + OH^- -------> A- + H2O
when acid is added
A^- + H^+ ---------> HA
ii) Buffer not like a proton ( H ) sponge
absorption of liquid is related to a chemical reaction for a buffer system but it is not related a chemical reaction for a proton( H ) sponge.
Chemistry questions I NEED help with
Calculate the percent composition of C in carbon dioxide.
Answer:
27.27%
Explanation:
Options:
1. Unsaturated fat or saturated fat
2. Fatty acids, carbohydrates, sterols, or phospholipids
3. Fatty acids, carbohydrates, or triglycerides
Please helppp
Answer:
1. saturated
2. fatty acids
3. fatty acids
Explanation:
Answer:
option 2 is correct
Explanation:
define the term semiconductor and give an example of a metalloid
Answer:
A metalloid is a chemical element that exhibits some properties of metals and some of nonmetals.The closer you get to the zone, the more blurred the properties become. Metalloids tend to be semiconductors; silicon is the best known example of a semiconductor. Most microchips and microprocessors are made with silicon.
Explanation:
That is what i know on the answer
To solve this we must be knowing each and every concept related to metalloid. Therefore, in above given ways semiconductor can be defined.
What is metalloid?Metalloids are chemical elements with physical and chemical characteristics that fall between between metal and nonmetal.
A metalloid is indeed a chemical element with characteristics of both metals and nonmetals. The properties grow increasingly blurred as you move closer to the zone. The seven most well-known metalloids are boron, germanium, silicon, antimony, arsenic, tellurium, and polonium.
Metalloids are often semiconductors, with silicon being the most well-known example. Silicon is used to make the majority of microchips and microprocessors.
Therefore, in above given ways semiconductor can be defined.
To know more about metalloid, here:
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