Answer:
Hess’s Law describes how the __Heat__ energy of a reaction consists of the _Enthalpy__ of the energy changes of the individual step reactions
Explanation:
Hess law is a legendary law which is given by
[tex]\\ \rm\Rrightarrow ∆H_{net}=\sum \delta H_r[/tex]
S + 6 HNO3 → H2SO4 + 6 NO2 + 2 H2O
In the above equation, how many grams of water can be made when 19.5 moles of HNO3 are consumed?
Answer:
117 grams H₂O
Explanation:
To find the amount, you need to (1) convert from moles HNO₃ to moles H₂O (via mole-to-mole ratio from equation) and then (2) convert from moles H₂O to grams (via molar mass from periodic table). The final answer should have 3 sig figs according the the given value (19.5).
S + 6 HNO₃ --> H₂SO₄ + 6 NO₂ + 2 H₂O
Molar Mass (H₂O): 15.999 g/mol + 2(1.008 g/mol)
Molar Mass (H₂O): 18.015 g/mol
19.5 moles HNO₃ 2 moles H₂O 18.015 grams
-------------------------- x ---------------------- x ---------------------- = 117 grams H₂O
6 moles HNO₃ 1 mole H₂O
Which products are formed when propane (C3Hg) undergoes combustion?
O A. Water and carbon
OB. Water and carbon dioxide
OC. Hydrogen and carbon dioxide
OD. Water, carbon dioxide, and oxygen
Answer:
Water and carbon dioxide
Explanation:
The product of combustion for all hydrocarbons are carbon dioxide and water
What substances had lower thermal conductivity, metal,
wood, or plastic
Answer: plastic
Explanation:
The thermal conductivity of a material is highly depending on composition and structure. Generally speaking dense material such as medals and stone are good conductors of heat while load density substances such as gas and porous installations are poor conductors of heat
Answer:
Or plastic
Explanation:
May be useful................
What is the ph of a 0.00043 molar solution of lithium hydroxide (lioh)?
Answer:
pH = 10.63.
Explanation:
Recall that lithium hydroxide (LiOH) is a strong base and hence dissociates completely into Li⁺ and OH⁻ ions.
Therefore, the concentration of OH⁻ ions is equivalent to the concentration of the base.
Find pOH:
[tex]\displaystyle \begin{aligned} \text{pOH} & = -\log[\text{OH}^-] \\ \\ & = -\log(0.00043) \\ \\ & = 3.37 \end{aligned}[/tex]
Using the relationships between pH and pOH, hence determine pH:
[tex]\displaystyle \begin{aligned}\text{pH} + \text{pOH} & = \text{p}K_w = 14.00 \\ \\ \text{pH} & = 14.00 - 3.37 \\ \\ & = 10.63\end{aligned}[/tex]
In conclusion, the pH of the solution is about 10.63.
A student mixed two chemicals to allow them to
react. The temperature before the reaction was 25
°C. The temperature after the reaction was 50° C.
Which of the following is true?
A. there was no change in heat energy
B. it is an exothermic reaction
help plsssss
Answer:
B .it is an exothermic reaction
Explanation:
i need brainleyest
Mix two liquids together and shake them up. You see that you have microscopic droplets of one liquid suspended in the other. You would call this:
Answer:
The awnser is cloudy suspension.
As the microscopic droplets of one liquid are suspended in the other, it is a heterogeneous mixtures.
What are heterogeneous mixtures?
Heterogenous mixtures is defined as a type of mixture where in the composition is not uniform throughout the mixture.It consists as two or more phases. The phases are chemically distinct from each other.
As there are two or more phases present in heterogenous mixtures they can be separated by solvent extraction where in one phase is miscible with the solvent and the other phase is immiscible.
Components of a heterogenous mixtures are distinctly visible . There are two types of heterogenous mixtures, the colloids and the suspensions.These two vary with each other with respect to particle size.These are the mixture which are easy to separate out.
Learn more about heterogenous mixtures,here:
https://brainly.com/question/29207752
#SPJ2
Which of the following reactions shows a chemical change producing a solid?
2CH₂OH()+30₂(g) → 200₂(g) + 4H₂O(1) 2AgNO3(aq) + CaBr₂(aq) → 2AgBr(s) + Ca(NO3)2(aq) H₂(g) + O₂(g) → H₂O(l) NaCl(s) → NaCl(aq)
The chemical change producing a solid would be [tex]2AgNO_3(aq) + CaBr_2(aq) --- > 2AgBr(s) + Ca(NO_3)_2(aq)[/tex]
What are precipitation reactions?They are reactions involving two soluble salts with one of the products being an insoluble salt.
In the reaction below: [tex]2AgNO_3(aq) + CaBr_2(aq) --- > 2AgBr(s) + Ca(NO_3)_2(aq)[/tex]
[tex]AgNO_3[/tex] and [tex]CaBr_2[/tex] are soluble salts while [tex]AgBr[/tex] produced is an insoluble salt. The insoluble salt is a solid.
More on precipitation reactions can be found here: https://brainly.com/question/24158764
#SPJ1
Answer: 2AgNO3(aq)+CaBr2(aq)—>2AgBr(s)+Ca(NO3)2(aq)
Explanation:
just did on apex; 2AgNO3(aq)+CaBr2(aq)>2AgBr(s)+Ca(NO3)2(aq)
What makes this lever effective?
A: The man had more mass than the rock
B: The man is closer to the fulcrum than the rock is
C: The man is farther from the fulcrum than the rock is
D: The rock has more mass than the man
An atom was observed with +3 charge, n = 38, and e = 28. What is the mass number of the atom?
A. 66
B. 69
C. 72
D. 63
Answer: 66
Explanation: To find the mass number you would have to add the number of protons and the number of neutrons.
Identify the balanced chemical equation that represents a decomposition reaction.
2Fe(OH) 3 ⟶ 2FeO 3 + H 2O
CuSO 4 ⟶ CuO + 2SO 3
2Fe(OH) 3 ⟶ Fe 2O 3 + 3H 2O
P 4 + 3O 2 ⟶ P 2O 3
Identify the balanced chemical equation that represents a decomposition reaction.
2Fe(OH) 3 ⟶ 2FeO 3 + H 2O
CuSO 4 ⟶ CuO + 2SO 3
2Fe(OH) 3 ⟶ Fe 2O 3 + 3H 2OP 4 + 3O 2 ⟶ P 2O 3
Explanation:
Answer:
Option C
Explanation:
A decomposition reaction is a type of reaction in which one reactant breaks down in to two or more products.
Here in option C
On both reactant and products side
Fe=2O=6H=6Hence balanced
Chemistry
Bellringer: Find the mass of 5.78 moles of carbon
dioxide.
Answer:
254.32
Explanation:
The formula to calculate mass is:
no. of moles ×molar mass. and the molar mass of carbon dioxide is 44
Given a balance chemical equation, 2 H2(g) O2(g) 2 H2O(g) If a reaction mixture contains 3 moles of O2(g) with 4 moles of H2(g), which reactant is the limiting reactant and what is the mass remaining of the reactant in excess
We have the equation [tex]2\text{H}_{2}+\text{O}_{2} \longrightarrow 2\text{H}_{2}\text{O}[/tex].
This means that for every mole of oxygen consumed, 2 moles of hydrogen are consumed.
Considering the oxygen, the reaction can occur 3 times.Considering the hydrogen, the reaction can occur 4/2=2 times.Therefore, hydrogen is the limiting reactant.
If all 4 moles of the hydrogen are consumed, then 2 moles of the oxygen will be consumed. This means 1 mole of oxygen, which has a mass of 15.9994 grams, will remain.
If a gas has a volume of 350 mL at 780 mm Hg, what pressure will be needed to cause its volume
to be 500 mL?
Could you state the law used?
The required pressure of the gas is 546 mmHg.
What is the relation between volume and pressure?Relation between the volume and pressure of gas is explained through the ideal gas equation PV = nRT, and for the question required equation is:
P₁V₁ = P₂V₂, where
P₁ & V₁ are the initial pressure and volume.
P₂ & V₂ are the final pressure and volume.
On putting values from the question to the equation, we get
P₂ = (780)(350) / (500) =
P₂ = 546 mmHg
Hence required pressure is 546 mmHg.
To know more about ideal gas equation, visit the below link:
https://brainly.com/question/24236411
#SPJ1
WILL MARK BRAINLIST!! A chemist weighs a steel cylinder of compressed oxygen, O2, and finds that it has a mass of 1027.8 g. After some of the oxygen is used in an experiment, the cylinder has a mass of 1023.2 g. How many moles of oxygen gas are used in the experiment?
When answering this question include the following:
Explain how you found the mass of oxygen gas.
Explain how to find the molar mass of the compound.
Explain how many significant figures your answer needs to have.
The numerical answer
Answer:
0.14376 moles O₂
Explanation:
To find the amount of moles lost, (1) convert the grams O₂ before to moles (via molar mass from periodic table), then (2) convert the grams O₂ after to moles, then (3) subtract the moles O₂ after from the moles O₂ before.
Molar Mass (O₂) = 2(15.999) g/mol
Molar Mass (O₂) = 31.998 g/mol
Before Experiment:
1,027.8 grams O₂ 1 mole O₂
-------------------------- x ---------------------- = 32.121 moles O₂
31.998 grams
After Experiment:
1,023.2 grams O₂ 1 mole O₂
-------------------------- x ---------------------- = 31.977 moles O₂
31.998 grams
Moles Before - Moles After = Moles Lost
32.121 moles - 31.977 moles = 0.14376 moles O₂
The number of significant figures is determined by the significant figures of the values given. Both of the given values (1,027.8 and 1,023.2) have 5 sig figs. Therefore, the answer should also have 5 sig figs.
PLEASE HURRY AND CHECK IMMAGE. Predict the shape of the molecule.
0
H
H
A. bent
B. linear
C. trigonal planar
D. tetrahedral
Answer:
A. bent
Explanation:
7. Which metal is more easily oxidated, copper or aluminum?
Answer:
alumimum
Explanation:
Aluminum oxidation happens faster than that of steel, because aluminum has a really strong affinity for oxygen. Rather than flaking though, aluminum oxide just forms a hard, whitish-colored surface skin. When all the aluminum atoms have bonded with oxygen the oxidation process stops.
hope this answers your question.
102. What is the Pauli exclusion principle? What is Hund's rule?
Pauli Exclusion Principle is about quantum numbers of an atom. Hund rule is about how electrons are filled to the orbitals of an atom.
What is the "modern" definition of atomic theory?
Answer: The modern atomic theory states that atoms of one element are the same, while atoms of different elements are different. Each element has its own characteristic atomic number. Atoms of the same element can have different numbers of neutrons, however.
Explanation: N/A
A lunar eclipse occurs when the Moon casts a shadow on the Earth.
Answer:
No....see below
Explanation:
Well not quite.... that would be a solar eclipse....when the Earth shadows the moon from the Sun is a lunar eclipse
Devices that use a liquid spray to remove pollutants from the air are called __________. A) alloys B) particulates C) scrubbers D) minerals E) chlorofluorocarbons (CFCs)
Devices that use a liquid spray to remove pollutants from the air are called scrubbers. The correct option is C.
What is a wet scrubber?Wet scrubber is a pollution removing technique from the air. It is a sprayer which trap the harmful gas molecules from the air.
It is used in factories and industrial exhaust steams.
Thus, the correct option is C. scrubbers.
Learn more about wet scrubber
https://brainly.com/question/27071223
#SPJ1
What is the half-life of an isotope if after 14 days you have 31.25 g remaining from a
250.0 g sample?
Answer:
4 2/3 days
Explanation:
31.25 = 250 ( 1/2)^n solve for n
31.25/250 = 1/2 ^n log both sides to find n = 3 half lives
14 days = 3 half lives
14/3 = 4 2/3 day half life
What is the purpose of cross breeding or selective breeding
why would solution iv be considered the most concentrated base out of the four substances?
Acids and bases are the property of the solution based on the concentration of the ions. Solution IV is the most concentrated base as it has the highest concentration of hydroxide ions.
What are bases?Bases are substances or solution that has the potential of hydrogen above 7 on the pH meter scale. It has more hydroxide ions than hydronium or hydrogen ions.
The higher the hydroxide concentration lower will be the pOH and the more alkaline will be the solution. The hydroxide ions have more electrons and can donate some to other species.
Therefore, solution IV is a concentrated base because of high hydroxide ion concentrations.
Learn more about bases here:
https://brainly.com/question/8990802
#SPJ1
A student has a sample of 1.33 moles of fluorine gas that is contained in a 23.3 L container at 314 K. What is the pressure of the sample? The ideal gas constant is 0.0821 L*atm/mol*K. Round your answer to the nearest 0.01 and include units.
1.4715 atm is the pressure of the sample 1.33 moles of fluorine gas that is contained in a 23.3 L container at 314 K.
What is an ideal equation?
The ideal gas equation, pV = nRT, is an equation used to calculate either the pressure, volume, temperature or number of moles of a gas. The terms are: p = pressure, in pascals (Pa).
Given data:
Volume (V) = 23.3 L
Number of mole (n) = 1.33 moles
Temperature (T) = 314 K
Gas constant (R) = 0.821 atm.L/Kmol
Pressure (P) =?
The pressure inside the container can be obtained by using the ideal gas equation as illustrated below:
PV = nRT
P × 23.3 L = 1.33 moles × 0.0821 ×314 K
P = 1.4715 atm
Therefore, the pressure of the sample is 1.4715 atm.
Learn more about the ideal gas equation:
https://brainly.com/question/23826793
SPJ1
Two objects are filled with air, and have the exact same mass. There air in the first object is heated and it now has a higher temperature than the second object. The air in which object has more thermal energy?
Water cools from 2oc to -2oc. during this time, what happens to the motion of the molecules?
Answer:
The motion of the molecules remains the same.
balanced symbol equation for the following:
magnesium hydroxide + nitric acid → magnesium nitrate + water
[tex]\text{Mg(OH)}_2 + 2\text{HNO}_3 \rightarrow \text{Mg(NO}_3)_2+ 2\text{H}_2 \text{O}[/tex]
What is the name of the functional group that is attached to this hydrocarbon? a carbon atom is single bonded to o h to the right, and h below, left, and above. alkyl halide alcohol carbonyl ketone
The name of the functional group of the hydrocarbon that has a chemical formula of CH3OH is alcohol (OH). Details about alcohol can be found below.
What is a functional group?In chemistry, a functional group is a specific class of a group of compounds that determines the chemical properties of the group.
The hydrocarbon given in this question has the chemical formula of CH3OH is methanol. Methanol as the name implies has a functional group called alcohol.
Therefore, the name of the functional group of the hydrocarbon that has a chemical formula of CH3OH is alcohol (OH).
Learn more about alcohol at: https://brainly.com/question/14618322
#SPJ4
Fill in the blank with the correct response.
————— surveys are measurement tools that use a series of questions to obtain data from respondents.
Surveys are the data collection tool and research methods. The questionnaire survey tool is used to collect the data based on questions.
What are questionnaires?Questionnaires are the tool used for the research and the data collection for the analysis, investigation, and conclusion. It is one of the data collection tools that comprises questions and prompts.
Questionnaires are the part of surveys that gathers information on the topic of the research and is easy to analyze and cost-effective. It is a valuable tool that collects data from a large number of participants.
Therefore, the correct blank is the questionnaire.
Learn more about the questionnaire here:
https://brainly.com/question/20335282
#SPJ1
In an experiment, the same mass of magnesium metal reacted with the same amount of two different acids. the acid used in reaction 1 was ethanoic acid and in reaction 2 it was hydrochloric acid. which reaction produced the most gas?
The mole ratio of the reaction shows that equal volumes of hydrogen gas will be produced by the two reactions.
What is the mole ratio of a reaction?The mole ratio of a reaction is the ratio in which the reactants and products of a given reaction occur for the reaction to proceed to completion.
The mole ratio of a reaction is also known as the stoichiometry of the reaction.
The equation of the two reactions are given below:
[tex]Mg + 2HCl \rightarrow MgCl_2 + H_2[/tex]
[tex]Mg + 2CH_3COOH \rightarrow (CH_3COO)_2Mg + H_2 \\ [/tex]
From the equation of the reaction reaction, an equal volume of hydrogen gas will be produced by the two reactions.
Therefore, the mole ratio of the reaction shows that equal volumes of hydrogen gas will be produced by the two reactions.
Learn more about mole ratio at: https://brainly.com/question/19099163
#SPJ1