Which of the following have been determined as the oldest living tree types on Earth? Select all that apply.
Bristlecone pine
Mesquite
Sequoia
Ponderosa pine
Answer:Sequoia,Bristle pine
Explanation:
An "empty" container is not really empty if it contains air. How many moles of nitrogen are in an "empty" two-liter cola bottle at atmospheric pressure and room temperature (25∘C)? Assume ideal behavior.
Answer:
number of moles = 0.08175 moles
Explanation:
To solve this question, we will use the ideal gas law:
PV = nRT
where:
P is the pressure = 1 atm
V is the volume of the gas = 2 liters
n is the number of moles we want to find
R is the general gas constant = 0.0821 L-atm/mol-K
T is the temperature = 25°C = 25 + 273 = 298°K
Now, substitute with the givens in the equation to get n as follows:
PV = nRT
1 * 2 = n * 0.0821* 298
n = [tex] \frac{1*2}{0.0821 * 298} = 0.08175 [/tex] moles
Hope this helps :)
[tex]\boxed{{\text{0}}{\text{.06 mol}}}[/tex] of nitrogen are contained in a 2 L cola bottle at atmospheric pressure and room temperature.
Further Explanation:
An ideal gas contains a large number of randomly moving particles that are supposed to have perfectly elastic collisions among themselves. It is just a theoretical concept, and practically no such gas exists. But gases tend to behave almost ideally at a higher temperature and lower pressure.
Ideal gas law is considered as the equation of state for any hypothetical gas. The expression for the ideal gas equation is as follows:
[tex]{\text{PV}} = {\text{nRT}}[/tex] ......(1)
Here, P is the pressure of nitrogen.
V is the volume of nitrogen.
T is the absolute temperature of nitrogen.
n is the number of moles of nitrogen.
R is the universal gas constant.
Rearrange equation (1) to calculate the number of moles of nitrogen.
[tex]{\text{n}} = \frac{{{\text{PV}}}}{{{\text{RT}}}}[/tex] ......(2)
Firstly, the temperature is to be converted into K. The conversion factor for this is,
[tex]{\text{0 }}^\circ {\text{C}} = {\text{273 K}}[/tex]
So the temperature of nitrogen is calculated as follows:
[tex]\begin{aligned}{\text{Temperature}}\left( {\text{K}}\right)&=\left( {25 + 273} \right)\;{\text{K}}\\&=298\;{\text{K}}\\\end{aligned}[/tex]
The pressure of nitrogen is 1 atm.
The volume of nitrogen is 2 L.
The temperature of nitrogen is 298 K.
Universal gas constant is 0.0821 L atm/K mol.
Substitute these values in equation (2).
[tex]\begin{aligned}{\text{n}}&=\frac{{\left({{\text{1 atm}}}\right)\left({{\text{2 L}}}\right)}}{{\left({{\text{0}}{\text{.0821 L atm/K mol}}}\right)\left({{\text{298 K}}} \right)}}\\&={\text{0}}{\text{.0817 mol}}\\&\approx {\text{0}}{\text{.08 mol}}\\\end{aligned}[/tex]
As we know, air contains 78 % of nitrogen. So the moles of nitrogen are calculated as follows:
[tex]\begin{aligned}{\text{Number of moles of }}{{\text{N}}_2} &=\left({{\text{0}}{\text{.08 mol}}}\right)\left({\frac{{{\text{78}}\;{\text{\% }}}}{{{\text{100}}\,{\text{\% }}}}}\right)\\&={\text{0}}{\text{.0624 mol}}\\&\approx {\mathbf{0}}{\mathbf{.06 mol}}\\\end{aligned}[/tex]
Learn more:
1. Which statement is true for Boyle’s law: https://brainly.com/question/1158880
2. Calculation of volume of gas: https://brainly.com/question/3636135
Answer details:
Grade: Senior School
Subject: Chemistry
Chapter: Ideal gas equation
Keywords: ideal gas, pressure, volume, absolute temperature, equation of state, hypothetical, universal gas constant, moles of gas, initial, final, moles of nitrogen, 0.08 mol, 0.06 mol, 298 K, 273 K, P, V, n, R, T, room temperature, atmospheric pressure.
Match the following type of reactions to the correct equation.
Pb(NO3)2 + 2HCl --> PbCl2 + 2HNO3
2C2H6 + 7O2 --> 4CO2 + 6H2O
Ca + 2HCl --> CaCl2 + H2
H2O + CO2 --> H2CO3
CaCO3 --> CaO + CO2
-------------------------------
These are the choices for each they can be used once
Decompitiontion
Single Replacement
Synthesis
Combustion
Double Replacement
--------------------------------
If an organism has more specialized cells, its cells _________. are all the same have their own function do not have any function can survive on their own
Answer:
have their own function
Explanation:
Specialized cells are cells that have a specific function in the body of a multicellular living being. These cells can function to form tissues, organs, muscles, bones and other body structures. An example that can be used to explain the concept of specialized cells is stem cells. These cells are undifferentiated cells, but they have a great capacity for specialization. Once stem cells specialize, they can form new tissues and other body structures.
Isabel wants to determine the mass of a metal block. What is the SI unit for mass
What was observed during Rutherford's experiment?
A: Most of the particles went through the foil, but some were deflected.
B:Most of the particles were deflected, but some went through the foil.
C:None of the particles went through the foil.
D: All of the particles went through the foil.
Which statement about van der Waals forces is true?
Answer:
A. When the forces are weaker, a substance will have higher volatility.
Explanation:
edge 2020
Which of the following correctly completes the following equation:
Nitrogenous base + sugar + phosphate group = ?
Nucleotide
Amino Acid
Enzyme
Antibody
A. Nucleotide is the correct answer
Illustrate the Lewis dot structure for AlH4^-
Lewis dot structures, also known as electron dot structures, are schematics that show the interatomic chemical bonds in a molecule. Additionally, they show how many lone pairs there are overall in each of the atoms that make up the molecule.
The electrical structures of the elements, especially the electron pairings, are reflected in the Lewis dot structures. Lewis structures can be viewed as "electron bookkeeping" and are a helpful approach to condensing some bonding-related information. Each dot in a Lewis dot structure corresponds to 1 electron.
The electrons that do not belong to the outermost shell are omitted while designing Lewis dot structures and only the valence electrons are taken into account.
Here the Lewis structure of AlH₄⁻ is:
To know more about Lewis dot structure, visit;
https://brainly.com/question/29153090
#SPJ6
What are the functions of protein in organisms?
What is the mass of 8.90 moles of magnesium chloride, MgCl2?
Express your answer numerically in grams.
What are some visible signs of an acid-base reaction?
describe how the 3 different types of seismic waves move and affect the movement of the material they pass over or through!!!!!!!!1
PLEASE HELP HURRY!!!!!!!!!!!
TRUE or FALSE. The particles of a gas are packed closely together and don't have as much movement as the particles of a solid or liquid.
The statement is false as gas particles are separated by large distances, move randomly, have no definite shape or volume, and can expand to fill their container.
Explanation:The statement is FALSE. In the gas state, the particles are not packed closely together; rather, they are separated by large distances compared to their sizes. Gas particles have enough energy to overcome intermolecular interactions, allowing them to move about randomly and occupy all the accessible volume within a container. These particles are in constant motion, colliding elastically with each other and the walls of the container, and this motion becomes more rapid as the temperature increases. Gases have no definite shape or volume, and thus expand to fill the container they are in, contrasting the behavior of solids and liquids, where particles are more closely packed together.
which of the following was originally a tenet of Dalton's atomic theory, but had to be revised about a century ago
a. Atoms are tiny indivisible particles
b.Atom of different element can combine with one another in simple whole number ratios
c.compounds are made by combining atoms
d. Atoms of the same element are identical
If your in Connections Academy these would be the atoms and elements unit test:
1) c.
2) a.
3) b.
4) d.
5) a.
6) c.
7) a.
8) b.
9) b.
10) d.
11) d.
12) c.
13) c.
14) c.
15) a.
16) d.
17) c.
18) c.
19) c.
20) d.
21) c.
22) d.
23) 6 protons, 6 electrons and 7 neutrons
The rest your on your own. Hope this helps ;)
The postulate of the theory that has been a tenet and revised has been the consideration of the atom to the invisible particle. Thus, option A is correct.
Dalton's atomic theory has been the accepted theory and has been used for the determination of the structure of the atom. According to Dalton's theory, the atoms have consisted of the positively charged nucleus with the negative charge electrons revolving around it.
Dalton's theory conclude the atom to be a tiny particle, that can neither be created nor destroyed. The same element has been consisted of the same atoms.
The postulate of the theory that has been a tenet and revised has been the consideration of the atom to the invisible particle. Thus, option A is correct.
For more information about Dalton's atomic theory, refer to the link:
https://brainly.com/question/13157325
4. Which of the following statements is true?
Chemical reaction rates vary with the conditions of the reaction, but nuclear decay rates do not.
Nuclear decay rates vary with the conditions of the reaction, but chemical reaction rates do not.
Both chemical reaction rates and nuclear decay rates vary with the conditions of the reaction.
Neither chemical reaction rates nor nuclear decay rates vary with the conditions of the reaction.
6. Transmutation involves
nuclear change.
chemical change.
both a nuclear change and a chemical change.
neither a nuclear change nor
4) The answer is: Chemical reaction rates vary with the conditions of the reaction, but nuclear decay rates do not.
Differences between nuclear and chemical reactions:
1) The electrons of an atom participates in a chemical reaction and protons in nuclear reaction.
2) Chemical reactions involve the rearrangement of electrons, because there is transfer, loss, gain and sharing of electrons in chemical reactions.
3) Nuclear reactions can produce new elements, because number of protons and neutrons is changed, chemical reactions donot produce new element.
4) Chemical reactions require heat or an input of energy to occur, this is activation energy.
5) Isotopes of the same element behave differently in a nuclear reaction, because isotopes have different number of neutrons, so products of a nuclear reaction is different.
6) The answer is: nuclear change.
Transmutation is a process that involves a change in the nucleus of an atom. It can be natural or artificial.
For example: 14/7 N + 4/2 He --> 17/8 O + 1/1 H.
This example is the first artificial nuclear transmutation described by Rutherford in 1919.
Artificial transmutation can be expressed by nuclear reaction:
Target Nuclide + Bombardment Particle → New Nuclide + Ejected Particle.
Baking soda and vinegar can be used to model a volcanic eruption in a science demonstration because they bubble violently when mixed. What can be concluded about mixing vinegar and baking soda? Baking soda and vinegar make a uniform mixture. Vinegar and baking soda react to form a new gaseous substance. Vinegar boils when it comes in contact with baking soda. Baking soda has a lower density than vinegar.
Answer: Option (b) is the correct answer.
Explanation:
A chemical reaction is defined as one which tends to bring change in composition of reactants leading to the formation of new substances or products.
So, when baking soda and vinegar come in contact with each other then they chemically combine to each other. This is because a gas is formed upon their reaction which shows it is a chemical reaction.
Thus, we can conclude that vinegar and baking soda react to form a new gaseous substance.
Which of the following are correct statements?Check all that apply. A.Potassium (K) and magnesium (Mg) are not in the same periodic table period. B.Potassium (K) and magnesium (Mg) are both nonmetals. C.Carbon (C) and oxygen (O) are in the same periodic table group. D.Potassium (K) and magnesium (Mg) are not in the same periodic table group. E.Carbon (C) is a metal and oxygen (O) is a nonmetal. F.Carbon (C) and oxygen (O) are both metalloids
Distillation is used to separate _____.
heterogeneous mixtures
suspensions
colloids
solutions
The answer is solution cap a.. n....s
Which instrument is most often used to measure acid volume before a titration begins?
a burette
a beaker
a volumetric pipette
an Erlenmeyer flask
A volumetric pipette
Answer : The correct option is, a volumetric pipette
Explanation :
Volumetric pipettes : It is a type of instrument that are used in volumetric analysis. It is used for the exact smaller volume of a sample solution or a reagent.
In the volumetric pipette, the upper part of the pipette has a ring like mark that marks its calibrated volume.
Burette : It is used in the titration for the known concentration of the solution.
Beaker : It is not used in the titration because it is not accurate for the measurement.
Erlenmeyer flask : It is a conical flask which is also used in the titration.
Hence, a volumetric pipette instrument is most often used to measure acid volume before a titration begins.
List at least two chemical reactions that resulted in a white precipitate. For these reactions, list the possible chemical name of the precipitate. What do these reactions (and the others with white precipitates) have in common?
If y'all could help, that'd be gr8
Two examples of precipitation reactions that form white precipitates are the combination of calcium chloride with silver nitrate to form silver chloride, and the reaction of lead (II) nitrate with potassium iodide to form lead iodide (though not white).
In the context of precipitation reactions, two examples that result in a white precipitate are:
Lead (II) nitrate solution reacts with a potassium iodide solution forming a yellow precipitate of lead iodide (although the precipitate is not white, it helps illustrate the concept of precipitation reactions).
When a solution of calcium chloride is mixed with a silver nitrate solution, a white precipitate of silver chloride is formed. The potential reaction would be:
CaCl2(aq) + 2AgNO3(aq) → 2AgCl(s) + Ca(NO3)2(aq)
These reactions involve combining two soluble ionic compounds that yield an insoluble compound, forming a precipitate that is visible at the bottom of the reaction vessel. A commonality among precipitation reactions is that they involve solubility rules to predict which combination of ions will produce an insoluble salt in the double-displacement reactions.
Magnesium has three isotopes. Magnesium-24 has a percent abundance of 78.99% Magnesium- 26 has a percent abundance of 11.01% What is the percent abundance of mangesium- 25?
Which of the following statements correctly describes the relationship between volume (V) and number of moles (n) illustrated in the following plot for a gas constant temperature and pressure.
The correct statement is that best describes the relationship between volume of gas and mole is [tex]\boxed{{\text{The volume of gas is directly proportional to amount (moles)of gas }}}[/tex].
Further explanation:
Ideal gas:
An ideal gas contains a large number of randomly moving particles that are supposed to have perfectly elastic collisions among themselves. It is just a theoretical concept, and practically no such gas exists. But gases tend to behave almost ideally at a higher temperature and lower pressure.
The expression for the ideal gas equation of gas is as follows:
[tex]{\text{PV}}={\text{nRT}}[/tex] ...... (1)
Here,
P is the pressure of the gas.
V is the volume of gas.
n denotes the number of moles of gas.
R is the gas constant.
T is the temperature of gas.
Rearrange equation (1) for V and we get,
[tex]{\text{V}}=\dfrac{{{\text{nRT}}}}{{\text{P}}}[/tex] ...... (2)
When the pressure (P) and temperature (T) of gas are constant and gas constant is also a consant. So the equation (2) can be modified so that all the constant can be replaced by K.
Substitute K for [tex]\dfrac{{{\text{RT}}}}{{\text{P}}}[/tex] in equation (2) and we get,
[tex]{\text{V}}={\text{nK}}[/tex] ...... (3)
As K is constant in equation (3) it can also be written as:
[tex]{\text{V}}\propto{\text{n}}[/tex] ...... (4)
According to equation (4), volume of gas is directly proportional to number of moles of gas at constant temperature and pressure.
Avogadro’s law:
Avogadro’s law is an experimental gas law that relates the volume of gas and number of moles of gas. It states that volume of an ideal gas is directly proportional to number of moles of an ideal gas at constant temperature and pressure.
The given plot also shows that volume of gas and number of moles at constant temperature and pressure is straight line. Therefore volume of gas increases with increase in number of moles of gas.
Hence, the correct statement is the volume of gas is directly proportional to amount (moles) of gas.
Learn more:
1. How many moles of nitrogen are present: https://brainly.com/question/2385746.
2.Calculate number of moles of Cl atom: https://brainly.com/question/1537871.
Answer details:
Grade: Senior School
Subject: Chemistry
Chapter: Ideal gas equation
Keywords: ideal gas, pressure, volume, absolute temperature, equation of state, hypothetical, universal gas constant, moles of gas, initial, final, P, R, T, V, n.
Which of the following is an example of a concentric contraction
A: dance move
B: bicep curl
C: slowly putting a heavy object down
D: injuring a non-dominant muscle
Answer:
B: bicep curl
Explanation:
In a bicep curl the muscle in the biceps contracts or shortens creating a tension on the muscle. During concentric contraction a lot of force is generated that allows the movement of an object such as a dumbbell. As the dumbbell is moved to the shoulder the bicep bulges or contracts. Concentric contraction is used for muscular hypertrophy.
What is the percent composition of calcium acetate (Ca(C2H3O2)2) Please show work!
The percent composition of calcium acetate (Ca(C2H3O2)2) is 25%, 7%, 0.6% and 10.12%.
How to determine the percent compositionTo determine the percent composition of calcium acetate, we would have to calculate the content of the compound. This would mean determining the percent presence of calcium, carbon, hydrogen nd oxygen. This can be done as follows:
First, determine molar mass
% = molar mass of elements / total molecular molar mass) x100
M (Ca(C2H3O2)2) = 2*(12*2 +3*1+16*2) + 40=158
Now determine percent composition
%Ca= 40/158x 100
= 0.25x 100
= 25%
%C = 12/158 x 100
= 0.07x 100=7%
%H= 1/158x 100=
0.006x 100
=0.6%
%O=16/158x 100
= 0.101x 100= 10.12%
Learn more about percent composition here:
https://brainly.com/question/17021926
#SPJ6
How many total electrons can be contained in the 5f sublevel?
fourteeeeeeeeeeeeeen
Answer: Total number of electrons that can be occupied in 5f-sub-level are 14.
Explanation: f-sub-level has in total 7 orbitals.
Each orbital can hold 2 electrons, both in opposite directions.
As, f-sub-level has in total of 7 orbitals, so the total number of electrons that can be held in 5f-sub-level is ( 7 × 2) = 14 electrons.
When a drawing made with a black marker gets wet, the marker bleeds and more separates into several colors. What method of separation does this describe?
When heated, mercury oxide produces oxygen plus mercury. What would be the combined mass of oxygen and mercury if 20g of mercury oxide were heated?
The combined mass of oxygen and mercury obtained from the thermal decomposition of 20g of mercury(II) oxide would also be 20g. The exact division between oxygen and mercury would depend on the stoichiometry of the reaction.
Explanation:The subject here is the thermal decomposition of mercury(II) oxide (HgO). When this compound is heated, it decomposes into mercury and oxygen. The mass principle in chemistry, also known as the Conservation of Mass, states that the combined mass of the products (oxygen and mercury in this case) should be equal to the mass of the reactant (mercury oxide). Therefore, if you heat 20g of mercury(II) oxide, you would obtain a combined mass of 20g of oxygen and mercury. The exact mass of oxygen and mercury would depend on the atomic mass and stoichiometry of the decomposition reaction. For example, if the reaction were 2HgO --> 2Hg + O2, you would get twice as much mercury mass as oxygen, due to the nature of the balanced equation.
Learn more about Thermal Decomposition here:https://brainly.com/question/14949019
#SPJ3
Which of the molecules below must be shown with resonance structures?
I. C2H2
II. CO
III. CO2 ...?
What type of chemical reaction is this? Cl2(g) + 2KBr(aq) - 2KCl(aq) + Br2(l)
A. Combination
B. Combustion
C. Single-replacement
D. Double-replacement