Answer:
Theory
Explanation:
We are given the statement;
"A helium filled balloon floats."
Now, this statement is an attempt to explain to us why balloons float. And the reason is because they are filled with helium. This is no prediction or law or observation because to find out if the balloons contain helium, there must have been experiments to confirm that.
Thus, the statement in the question is a theory.
When taking a measurement with a pH meter, keep the instrument in the _______storage solution or water until it is needed. Rinse the pH meter with
_______deionized water or acetone and gently pat dry. Place the meter in the sample solution, and record the measurement when the pH _______stabilizes or reaches the maximum value
Answer:
storage solution , deionized water, stabilizes
Explanation:
A pH meter is a scientific device or instrument that is used to measure the pH of a given aqueous solution thereby determining the nature of the solution whether it is acidic or basic or neutral.
While using the pH meter or taking the measurement using the pH meter --
it should be kept in a storage solution for effective working.Before using the device, it is rinsed with a deionized water and pat dry.Record the measurements when the pH meter stabilizes.Design an experiment to demonstrate phototropism.
Answer:
Object: To demonstrate phototropism
equipments: A black box, window with light source, a well watered potted plant.
Experiment: A wellwatered potted plant is placed inside a darkened black box that is having a small window on one side. This is called as phototropic chamber. Window is remain closed for a day the plant shows normal growth.
Whereas if window is opened atwo days it will be found that shoot tip bends and grows towards light proving that it is positively phototropic.
A compound, C7H13Cl, is reacted with sodium ethoxide and gives a single elimination product, C7H12. Treatment with ozone followed by zinc and water gives the compound below. Identify the original compound.
A. 2-chloro-1,1-dimethylcyclopentane.
B. 1-chloro-1,2-dimethylcyclopentane.
C. 4-chloro-1,2-dimethylcyclopentane.
D. 2-chloro-1,3-dimethylcyclopentane.
Answer:2-chloro-1,3-dimethylcyclopentane
Explanation
A frozen TV dinner contains 21 g of protein, 59 g of carbohydrate, and 18 g of fat. What is the total number of kilojoules (kJ) of potential energy within this TV
dinner? The accepted values for potential energy are 17 kJ per gram of protein, 17 kJ per gramof carbohydrate, and 38 kJ per gram of fat.
Round your answer to the nearest tens place and with the appropriate units.
Answer:
2040 kJ
Explanation:
Step 1: Calculate the energy provided by 21 g of protein
17 kJ are provided per gram of protein.
21 g × 17 kJ/g = 357 kJ
Step 2: Calculate the energy provided by 59 g of carbohydrate
17 kJ are provided per gram of carbohydrate.
59 g × 17 kJ/g = 1003 kJ
Step 3: Calculate the energy provided by 18 g of fat
38 kJ are provided per gram of fat.
18 g × 38 kJ/g = 684 kJ
Step 4: Calculate the total energy provided by the dinner
357 kJ + 1003 kJ + 684 kJ = 2044 kJ ≈ 2040 kJ
Identify a process that is NOT reversible. Identify a process that is NOT reversible. melting of snow baking of bread deposition of carbon dioxide freezing water melting of aluminum
Answer:
Identify a process that is NOT reversible.
Melting of snow
baking of bread
deposition of carbon dioxide
freezing water
melting of aluminum
Explanation:
A physical change is the one in which there is a change only in its physical state, color, the appearance of the substance. But the chemical composition of the substance remains unchanged.
It is a temporary change and can be reversed easily.
For example:
melting, freezing, deposition etc.
Baking is a permanent change and the chemical composition of the substance changes.
Hence, among the given options, baking of bread is not a reversible change.
Out of the following all are physical changes except baking of bread and physical changes are reversible so the process which is not reversible is baking of bread.
What are physical changes?Physical changes are defined as changes which affect only the form of a substance but not it's chemical composition. They are used to separate mixtures in to chemical components but cannot be used to separate compounds to simpler compounds.
Physical changes are always reversible using physical means and involve a change in the physical properties.Examples of physical changes include melting,boiling , change in texture, size,color,volume and density.Magnetism, crystallization, formation of alloys are all reversible and hence physical changes.
They involve only rearrangement of atoms and are often characterized to be changes which are reversible.
Learn more about physical changes,here:
https://brainly.com/question/17931044
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Ammonia and oxygen react to form nitrogen monoxide and water. Construct your own balanced equation to determine the amount of NO and H2O that would form when 2.78 mol NH3 and 5.19 mol O2 react.
Answer:
The amount of NO formed s 2.78 moles or 83.4 grams
The amount of H2O formed is 4.17 moles or 75.1 grams
Explanation:
Step 1: Data given
Ammonia = NH3
Oxygen = O2
nitrogen monoxide = NO
water = H2O
Number of moles NH3 = 2.78 moles
Number of O2 = 5.19 moles
Step 2: The balanced reaction
4NH3 + 5O2 → 4NO + 6H2O
Step 3: Calculate moles of products
For 4 moles NH3 we need 5 moles O2 to produce 4 moles NO and 6 moles H2O
NH3 is the limiting reactant
All the NH3 will react. There will be 0 moles of NH3 left
For 4 moles NH3 we need 5 moles O2
For 2.78 moles NH3 we need 5/4 * 2.78 = 3.475 moles
There will be left 5.19 - 3.475 = 1.715 moles O2
For 4 moles NH3 we need 5 moles O2 to produce 4 moles NO and 6 moles H2O
For 2.78 moles NH3 we'll have 2.78 moles NO and 6/4 * 2.78 = 4.17 moles H2O
Step 4: Calculate mass of NO and H2O
Mass = moles * molar mass
Mass NO = 2.78 moles * 30.01 g/mol
Mass NO = 83.43 grams
Mass H2O = 4.17 moles * 18.02 g/mol
Mass H2O = 75.14 grams
The amount of NO formed s 2.78 moles or 83.4 grams
The amount of H2O formed is 4.17 moles or 75.1 grams
Identify the change in state that does NOT have an increase in entropy. Identify the change in state that does NOT have an increase in entropy. water evaporating dry ice subliming steam condensing water boiling popsicle melting
Answer:
condensing water
Explanation:
Entropy refers to the level of disorderliness in a system. The entropy of liquids is greater than that of solids. The entropy of gases is greater than that of liquids.
A process of physical change involving a change of state from solid to liquid or liquid to gas is accompanied by increase in entropy.
However, a change of state involving a change from liquid to solid or gas to liquid is accompanied by decrease in entropy.
Hence, steam condensing to water leads to decrease and not increase in entropy of the system.
liquid junction potential arise due to?
Answer:
liquid junction potentials
when a cell contains a boundary between two electrolytic solutions of different composition or concentration, a liquid junction potential is developed due to the "diffusion of the various components at characteristic rates in the boundary zone."
#carryonlearning
The balanced equation for the reaction between aqueous ammonium sulfate and aqueous barium acetate is:________.
A. (NH4)2SO4 (aq) + Ba(C2H302)2 (aq) - Baso, (aq) + 2 NH.C2H2O2 (s).
B. (NH4)2SO3 (aq) + Ba(C2H302)2 (aq) - BaSO3(aq) + NH.C2H3O2 (aq).
C. (NH4)2SO4 (aq) + Ba(C2H302)2 (aq) - BaSO4(s) + 2 NH C2H2O2 (aq).
D. (NH4)2SO4 (aq) + Ba(C2H202)2 (aq) - BaSO4(s) + NHC2H2O2 (aq).
E. NH,SO4 (aq) + BaC2H302 (aq) -- BaSO4(s) + NH4C2H2O2 (aq).
Answer:
(NH4)2SO4 (aq) + Ba(C2H302)2 (aq) - BaSO4(s) + 2 NH4C2H3O2 (aq).
Explanation:
In balancing redox reaction equations, the rule of thumb is that the number of atoms on the left hand side of the reaction equation must be equal to the number of atoms of the same element on the left hand side of the reaction equation.
To ensure this, the correct coefficients are written in front of each of the reactants/products and the number of atoms of each element is counted to ensure that the equation is balanced.
If all these procedures are meticulously carried out, the balanced equation for the reaction between aqueous ammonium sulfate and aqueous barium acetate is:
(NH4)2SO4 (aq) + Ba(C2H302)2 (aq) - BaSO4(s) + 2 NH4C2H3O2 (aq).
How many g of Al are required to produce 2.8 mol of Al2O3
Answer:
290 g Al₂O₃
General Formulas and Concepts:
Atomic Structure
Reading a Periodic TableMolesStoichiometry
Using Dimensional AnalysisExplanation:
Step 1: Define
[Given] 2.8 mol Al₂O₃
[Solve] g Al₂O₃
Step 2: Identify Conversions
[PT] Molar Mass of Al: 26.98 g/mol
[PT] Molar Mass of O: 16.00 g/mol
Molar Mass of Al₂O₃: 2(26.98) + 3(16.00) = 101.96 g/mol
Step 3: Convert
[DA] Set up: [tex]\displaystyle 2.8 \ mol \ Al_2O_3(\frac{101.96 \ g \ Al_2O_3}{1 \ mol \ Al_2O_3})[/tex][DA] Multiply [Cancel out units]: [tex]\displaystyle 285.488 \ g \ Al_2O_3[/tex]Step 4: Check
Follow sig fig rules and round. We are given 2 sig figs.
285.488 g Al₂O₃ ≈ 290 g Al₂O₃
Topic: AP Chemistry
Unit: Atomic Structure
I have an unknown volume of gas at a pressure of 0.50 atm and a temperature of 325 K. If I raise the pressure to 1.2 atm, decrease the temperature to 320 K, and measure the final volume to be 48 liters, what was the initial volume of the gas?
SHOW YOUR WORK
Answer:
the answer is 2.1 atm
Explanation:
the way people normally do it is by simply deciding the 325k with the 1.2
What is unit? Write down the units of mass, temperature and power
Explanation:
a single thing, person, or group forming part of a whole There are 36 units in my apartment building. the least whole number : one. a fixed quantity (as of length, time, or value) used as a standard of measurement An inch is a unit of length.mass=kilogram (kg)
temperature=kelvin
power=watt
hope it helps
stay safe healthy and happy..Plz!!!!Plz!!!!!help help
Answer:
false
Explanation:
category 1 is the worst
4019K Express your answer as a nuclear equation.
Answer:
[tex]_{19} ^{40} K[/tex] → [tex]_{20} ^{40} Ca[/tex] + [tex]_{-1} ^{0} e[/tex] + ¯v
Explanation:
[tex]_{19} ^{40} K[/tex] is an unstable potassium isotope which has the capacity to undergo beta decay. During the decay process, it transforms to calcium atom with a release of beta particle and an antineutrino.
The required nuclear equation is:
[tex]_{19} ^{40} K[/tex] → [tex]_{20} ^{40} Ca[/tex] + [tex]_{-1} ^{0} e[/tex] + ¯v
The calcium formed due to this process is a stable atom.
Each of the following reactions were in equilibrium when the pressure of their containers was doubled. Chose which way the reaction shifted after the pressure change:
2NH3 (g)㈠No(g) +3H2(g) [Select ]
2Na3 PO4 (aq) + 3CaCl2 (aq) ㈠ Ca3 (PO4 )2 (s) + 6NaCl(aq) [Select ]
2C0(g)+O2 (g)->2CO2 (g) [Select ]
2H1(g) ㈠ H2(g) + 12(g) Neither
Answer:
Each of the following reactions was in equilibrium when the pressure of their containers was doubled. Chose which way the reaction shifted after the pressure change:
2NH3 (g)->N2(g) +3H2(g)
2Na3 PO4 (aq) + 3CaCl2 (aq) -> Ca3 (PO4 )2 (s) + 6NaCl(aq)
2CO(g)+O2 (g)->2CO2 (g)
2HI(g) -> H2(g) + I2(g)
Explanation:
Effect of pressure on equilibrium:
When pressure is increased on an equilibrium system,then equilibrium will shift in such a direction towards less number of moles of substrates.
For the first system,
2NH3 (g)->N2(g) +3H2(g)
increase in pressure,shifts the equilibrium towards the left side that is the formation of ammonia is favored.
For the second reaction:
2Na3 PO4 (aq) + 3CaCl2 (aq) -> Ca3 (PO4 )2 (s) + 6NaCl(aq)
The quilibrium will shift towards right.
Becuase right side less number of moles of substrates are there.
2CO(g)+O2 (g)->2CO2 (g)
For this system,the equilibrium will shift towards right side that is formation of CO2 gas is favored.
For the last system,
2HI(g) -> H2(g) + I2(g)
there is no effect of pressure.
Becuase the number of moles of substrates are same on both sides.
A student dropped a piece of silver metal into a solution of HCl(aq). He observed the formation of gas bubbles and collected the gas into another test tube. The student performed a splint test and observed that the splint produced a popping sound when he placed the splint into the test tube of the gas. What can be said about the results of this students experiment?
a. The student performed the splint test incorrectly. He should of observed the splint flare up when the splint was placed in the test tube.
b. The student completed the experiment correctly and there were no errors in the experiment.
c. The experiment was performed incorrectly. Silver doesn't react with HCl. Therefore, the student picked up the wrong metal when conducting the experiment.
d. The student performed the splint test incorrectly. He should of observed the flame being extinguished when the splint was placed in the test tube.
Answer:
The student completed the experiment correctly and there were no errors in the experiment.
Explanation:
When a pea size amount of Ag is dropped into a solution of HCl, the following reaction occurs;
Ag(s) + 2HCl(aq) ----> AgCl(aq) + H2(g)
The gas H2 burns with a pop sound. The gas obtained does not react to litmus. The products of the reaction are expected.
Hence, the experiment was properly conducted and the student completed the experiment correctly and there were no errors in the experiment.
The radius of a platinum atom is 139 pm. How many platinum atoms would have to be laid side by side to span a distance of 1.39 mm?
Answer:
5x10⁶ atoms of platium have to be laid side by side
Explanation:
1 atom of platium has a radius of 139pm = 139x10⁻¹²m. The distance that occupies 1 atom of platinum is 2 times its ratio:
139x10⁻¹²m*2 = 2.78x10⁻¹⁰m
Assuming there is no distance between to atoms of platinum, just its ratio. The amount of atoms necessary to occupy 1.39mm = 1.39x10⁻³m is:
1.39x10⁻³m / 2.78x10⁻¹⁰m =
5x10⁶ atoms of platium have to be laid side by sideSuppose 20.8 g of sodium iodide is dissolved in 250. mL of a 0.70 M aqueous solution of silver nitrate. Calculate the final molarity of ALL IONS in the solution. You can assume the volume of the solution doesn't change when the sodium iodide is dissolved in it. Round your answer to 3 significant digits.
Answer:
[Ag+] = [NO3-] = 0.700M
0.555M = [Na+] = [I-]
Explanation:
To solve this question we need to find the moles of sodium iodide, NaI, using its molar mass -. With the moles and the volume we can find the molarity of Na+ and I-. The molarity of the ions of silver nitrate, AgNO3 doesn't change because we are assuming the volume doesn't change:
Molarity Ag⁺ = Molarity NO₃⁻ = 0.700M
Moles NaI -Molar mass: 149.89g/mol-
20.8g NaI * (1mol/149.89g) = 0.0139 moles NaI
Molarity:
0.0139 moles NaI / 0.250L = 0.555M = [Na+] = [I-]
which of the following is not an instance of benefit in from gases ?
1) filling thermometers
2) inflating tyres
3) in LP gas cylinders
4) in pressure cookers
Answer:
1) filling thermometers
Explanation:
thermometers are filled with liquid mercury
Suppose of sodium iodide is dissolved in of a aqueous solution of potassium carbonate. Calculate the final molarity of sodium cation in the solution. You can assume the volume of the solution doesn't change when the sodium iodide is dissolved in it. Round your answer to significant digits.
Answer:
0.2762M Na+ in the solution
Explanation:
2.07g of sodium iodide Is Dissolved In 50.ML Of A 0.30M...
To solve this question we need to find the moles of sodium iodide, NaI, that are the same than the moles of sodium cation, Na+. The volume in liters of the solution is 0.050L. The molarity is:
Moles NaI = Moles Na+ -Molar mass NaI: 149.89g/mol-
2.07g NaI * (1mol / 149.89g) = 0.01381 moles NaI = Moles Na+
Molarity:
0.01381 moles Na+ / 0.0500L =
0.2762M Na+ in the solution
Which equation expresses the solubility product of Zn3(PO4)2?
a. Ksp = [Zn2+][PO43]
b. Ksp = [Zn2+]3 [PO43]2
c. Ksp = 6[Zn2+][PO43]2
d. Ksp = 108[Zn2+][PO43]2
⇒b. Ksp = [Zn2+]3 [PO43]2
Hope It Helps You ✌️
if salt and sand is mixed with distilled water, what will be the residue? and, what will be the filtrate?
Answer:
Filtration is a technique used as a remedy to separate mixes
Explanation:
If you have a sodium, then you will explore that salt dissolves but the sand is still the same.
If the salt in the resin water solution scanners, the sand remains the residue and passes through the filter paper.
All you have to do now is pleasant the salty water so that the water can evaporate, leaving the salt behind.
In an exothermic chemical reaction:____.
A. The mass of the products is greater than the mass of the reactants.
B. The mass of the products is less then the mass of the reactants.
C. Heat is released as the reaction proceeds.
D. Heat is absorbed as the reaction proceeds.
Answer:
C
Explanation:
Think of 'exo' as exit and 'thermic' as relating to thermal energy/ heat. Thus, an exothermic release thermal energy as the reaction proceeds.
In an exothermic reaction, the total energy of the products is lesser than that of the reactants and ΔH (change in energy) is less than zero.
When heat is absorbed as the reaction proceeds, the chemical reaction is an endothermic reaction.
An unidentified gas is determined to be 24.0% carbon and 76% fluorine by mass. What is the empirical formula of this gas
Answer:
CF₂
Explanation:
Let's assume we have 100 g of the gas. If that were the case we'd have
24 g of C76 g of FNow we convert both masses into moles, using their respective molar mass:
24 g C ÷ 12 g/mol = 2 mol C76 g F ÷ 19 g/mol = 4 mol FWe can express those results as C₂F₄.
To determine the empirical formula we reduce those coefficients to the lowest possible integers, leaving us with CF₂.
A chemist fills a reaction vessel with 9.47 atm nitrogen monoxide (NO) gas, 2.61 atm chlorine (C12) gas, and 8.64 atm nitrosyl chloride (NOCI) gas at a temperature of 25.0°C. Under these conditions, calculate the reaction free energy AG for the following chemical reaction:
2NO(g) + Cl2(g) = 2NOCI (g)
Use the thermodynamic information in the ALEKS Data tab. Round your answer to the nearest kilojoule.
Answer: The Gibbs free energy change of the reaction is 2.832 kJ.
Explanation:
The relationship between Gibbs free energy change and reaction quotient of the reaction is:
[tex]\Delta G^o=-RT\ln Q_p[/tex]
where,
[tex]\Delta G^o[/tex] = Gibbs free energy change
R = Gas constant = 8.314 J/mol.K
T = temperature = [tex]25^oC=298K[/tex]
[tex]Q_p[/tex] = reaction quotient = [tex]\frac{p_{NOCl}^2}{(p_{NO}^2)\times (p_{Cl_2})}[/tex]
We are given:
[tex]p_{NOCl}=8.64atm\\p_{NO}=9.47atm\\p_{Cl_2}=2.61atm[/tex]
Putting values in above equation, we get:
[tex]\Delta G^o=-(8.314)\times 298K\times \ln (\frac{(8.64)^2}{(9.47)^2\times (2.61)})\\\\\Delta G^o=-8.314\times 298\times (-1.143)[/tex]
[tex]\Delta G^o=2831.86J=2.832kJ[/tex] (Conversion factor: 1 kJ = 1000 J)
Hence, the Gibbs free energy change of the reaction is 2.832 kJ.
from the following equation in which decomposition of CaCO3 takes place, give your justification. CaCO3 gives Ca +CO2
Answer:
CaCO₃(s) => CaO(s) + CO₂(g) ... GpIIA Decomp
Explanation:
Metallic Carbonates decompose into a metallic oxide and carbon dioxide.
Examples:
Na₂CO₃(s) => Na₂O(s) + CO₂(g) ... GpIA Decomp
MgCO₃(s) => MgO(s) + CO₂(g) ... GpIIA Decomp
aromatic compounds aliphatic compounds
Answer:
I hoped it helps you fod blessed:)
Which of the following was NOT explained by Dalton's atomic theory?
ANSWER:
A. the Law of Multiple Proportions
B. the difference between elements and compounds
C.?the difference between isotopes of an element
D. the Law of Conservation of Mass
Answer:
i think 1. law of muliple proportion
Explanation:
please like
What volume is occupied by 0.104 mol of helium gas at a pressure of 0.91 atm and a temperature of 314 K ?
Answer:
The volume will be "2.95 L".
Explanation:
Given:
n = 0.104
p = 0.91 atm
T = 314 K
Now,
The Volume (V) will be:
= [tex]\frac{nRT}{P}[/tex]
By putting the values, we get
= [tex]\frac{0.104\times 0.0821\times 314}{0.91}[/tex]
= [tex]\frac{2.6810}{0.91}[/tex]
= [tex]2.95 \ L[/tex]
when (S)-3-bromo-2,3-dimethylpentane is treated with sodium chloride with water as the solvent, the products formed are ___________. *Select all that apply
Answer:
(S)-3-chloro-2,3-dimethylpentane
Explanation:
When sodium chloride is treated with bromo dimethylpentane in presence of water, then chloro dimethylpentane is formed. This chemical reaction is stable reaction in water because of its solvency.
