Answer:
1.88 A
Explanation:
Let's consider the reduction of copper in an electrolytic cell.
Cu²⁺ + 2 e⁻ ⇒ Cu
We can calculate the charge used to deposit 12.3 g of Cu using the following relations.
The molar mass of Cu is 63.55 g/mol.1 mole of Cu is deposited when 2 moles of electrons circulate.1 mole of electrons has a charge of 96486 C (Faraday's constant).The charge used is:
[tex]12.3 g \times \frac{1 molCu}{63.55gCu} \times \frac{2molElectron}{1molCu} \times \frac{96486C}{1molElectron} = 3.73 \times 10^{4} C[/tex]
We can convert 5.50 h to seconds using the conversion factor 1 h = 3600 s.
5.50 h × 3600 s/1 h = 1.98 × 10⁴ s
The current used is:
I = q/t = 3.73 × 10⁴ C/1.98 × 10⁴ s = 1.88 A
4. What is the percent yield of a reaction that produces 12.5 g CF2Cl2 from 32.9 g of CCl4 and excess HF
Answer:
Percent yield = 48.3%
Explanation:
The reaction is:
CCl₄ + 2HF → CF₂Cl₂ + 2HCl
1 mol of CCl₄ reacts with 2 moles of hydrofluoric acid in order to produce 1 mol of CF₂Cl₂ and 2 moles of hydrogen chloride.
HF is in excess, so the limiting reagent is the CCl₄.
We convert mass to moles:
32.9 g . 1mol / 153.8g = 0.214 moles
Ratio is 1:1. In conclussion: 0.0813 moles of CCl₄ can produce 0.0813 moles of CF₂Cl₂. We convert moles to mass, to determine the theoretical yield:
0.214 mol . 120.91g /mol = 25.8 g
Percent yield = (Yield produced /Theoretical yield) . 100
Percent yield = (12.5 g/ 25.8g) . 100 = 48.3%
Question 4 of 30
Scientific research shows that Earth's climate is changing due to human
activities. How can scientific research on climate change help society?
A. It can help us stop storms before they occur.
B. It can help us find a new way to make more water.
C. It can help us track how quickly elements of the climate are
changing
D. It can help us reverse the effects of climate change.
th
C. It can help us track how quickly element of the climate are changing
Suppose, in an experiment to determine the amount of sodium hypochlorite in bleach, you titrated a 23.92 mL sample of 0.0100 M K I O 3 with a solution of N a 2 S 2 O 3 of unknown concentration. The endpoint was observed to occur at 13.80 mL . How many moles of K I O 3 were titrated
Answer:
2.39x10⁻⁴ moles
Explanation:
As the problem asks us the number of moles of KIO₃ that were titrated, all that is required of us is to calculate how many moles of KIO₃ are there in 23.92 mL of a 0.0100 M solution (All moles in the samples are titrated).
We can do so by using the definition of molarity:
Molarity = moles / litersconverting 23.92 mL ⇒ 23.92 / 1000 = 0.02392 L
moles = 0.0100 M * 0.02392 Lmoles = 2.39x10⁻⁴ molesc) Solar energy is the source of all forms of energy.give reasons
Answer:
All energy is made by the sun because without the sun there would be no humans to produce other energy
Explanation:
We use many different forms of energy here on earth, but here’s the thing: almost all of them originate with the sun, not just light and heat (thermal) energy! The law of conservation of energy says that energy can’t be created or destroyed, but can change its form. And that’s what happens with energy from the sun—it changes into lots of different forms:
Plants convert light energy from the sun into chemical energy (food) by the process of photosynthesis. Animals eat plants and use that same chemical energy for all their activities.
Heat energy from the sun causes changing weather patterns that produce wind. Wind turbines then convert wind power into electrical energy.
Hydroelectricity is electrical energy produced from moving water, and water flows because heat energy from the sun causes evaporation that keeps water moving through the water cycle.
Right now, much human activity uses energy from fossil fuels such as coal, oil, and natural gas. These energy sources are created over very long periods of time from decayed and fossilized living matter (animals and plants), and the energy in that living matter originally came from the sun through photosynthesis.
solar panel shows what is the ultimate source of energy
The addition of chromic acid or chromate is a qualitative test for alcohols as the reaction causes a color change. However, not all alcohols react with chromic acid or chromate. Determine whether the named alcohol will react with chromic acid or chromate to cause a color change.
a. 3-hexanol
b. 1 -butanol
c. 2-pentanol
d. 3-ethyl-3-pentanol
Answer:
3-hexanol
1 -butanol
2-pentanol
Explanation:
Let us recall that chromic acid or chromate are strong oxidizing agents. When they are oxidized, their colour changes from orange to green.
This shows a reduction in chromic acid or chromate. The reaction of chromic acid or chromate with a primary alcohol yields a carboxylic acid while reaction with a secondary substrate yields an alkanal.
Note that Tertiary alkyl halides are not be oxidized hence reactions involving a point where invitation carried along occur.
3-ethyl-3-pentanol is a tertiary alkyl halide hence it can not be oxidized.
A chemist measures the energy change
ΔH during the following reaction:
2NH3(g)→N2(g)+3H2(g)
ΔH=160kJUse the information to answer the following questions.This reaction is:__________.
a. endothermic
b. exothermic
Suppose 70.9 g of NH3 react. Will any heat be released or absorbed?
a. Yes, absorbed
b. Yes, released
c. No.
If you said heat will be released or absorbed in the second part of this question, calculate how much heat will be released or absorbed. Round your answer to 3 significant digits.
Answer:
For (1): The correct option is (a)
For (2): The correct option is (a) and 333.6 kJ of heat will be absorbed when 70.9 g of ammonia reacts.
Explanation:
There are 2 types of reactions that are classified based on enthalpy change:
Endothermic reactions: These are the reactions where heat is absorbed by the reaction. The change in enthalpy of the reaction, [tex]\Delta H_{rxn}[/tex] is positive for these reactions.
Exothermic reactions: These are the reactions where heat is released by the reaction. The change in enthalpy of the reaction, [tex]\Delta H_{rxn}[/tex] is negative for these reactions.
For (1):For the given chemical reaction:
[tex]2NH_3(g)\rightarrow N_2(g)+3H_2(g);Delta H=160kJ[/tex]
As the change in enthalpy or heat of the reaction is positive. Thus, the reaction is an endothermic reaction because heat is absorbed by the reaction.
For (2):When ammonia reacts, some amount of heat will be absorbed by the reaction. Thus, we can say the heat will be absorbed.
The number of moles is calculated by using the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)
Given mass of ammonia = 70.9 g
Molar mass of ammonia = 17 g/mol
Using equation 1:
[tex]\text{Moles of ammonia}=\frac{70.9g}{17g/mol}=4.17mol[/tex]
By stoichiometry of the reaction:
If 2 mole of ammonia reacts, the heat absorbed is 160 kJ
So, if 4.17 moles of ammonia reacts, the heat absorbed will be = [tex]\frac{160kJ}{2mol}\times 4.17mol=333.6kJ[/tex]
Hence, 333.6 kJ of heat will be absorbed when 70.9 g of ammonia reacts
In a sample of oxygen gas at room temperature, the average kinetic energy of all the balls stays constant. Which postulate of kinetic molecular theory best explains how this is possible?
A. Attractive forces between gas particles are negligible because the particles of an ideal gas are moving so quickly.
B. Collisions between gas particles are elastic; there is no net gain or loss of kinetic energy.
C. Gases consist of a large number of small particles, with a lot of space between the particles.
D. Gas particles are in constant, random motion, and higher kinetic energy means faster movement.
Answer:
Collisions between gas particles are elastic; there is no net gain or loss of kinetic energy.
Explanation:
When a gas is paced in a container, the molecules of the gas have little or no intermolecular interaction between them. There is a lot of space between the molecules of the gas.
The gas molecules move at very high speed and collide with each other and with the walls of container.
The collision of these particles with each other is perfectly elastic hence the kinetic energy of the colliding gas particles do not change.
Indicate how the concentration of each species in the chemical equation will change to reestablish equilibrium after reactant or product is added.
2CO(g) + O2(g) ⇌ 2CO2
Answer:
Indicate how the concentration of each species in the chemical equation will change to reestablish equilibrium after reactant or product is added.
[tex]2CO(g) + O2(g) <=> 2CO2[/tex]
Explanation:
When the reactants concentration increases, then the equilibrium will shift towards products and when the concentration of products increases, then equilibrium will shift towards reactants.
So, increases in concentration of carbon monoxide (CO) shifts the equilibrium to favor the formation of carbondioxide.
Similarly increase in concentration of oxygen also favor the formation of product carbon dioxide.
Increase in concentration of CO2 favors the formation of CO and O2.
Decrease in product concentration also favors the formation of product.
Decrease in reactant concentration favors the formation of reactants only.
Ice and water constitute a system:
A Chemically heterogeneous and physically heterogeneous
B Chemically homogeneous and physically heterogeneous
C Chemically homogeneous and physically homogeneous
D Chemically heterogeneous and physically homogeneous
E None of the above
Answer:
B
Explanation:
It's the same substance but in different states.
HETEROGENEOUS mixtures contain substances that are
not uniform in composition. The parts in the mixture can be separated by physical means.
When sugar is added to a sugar solution, the sugar dissolves. Which term describes the original sugar solution?
Answer:
the answer is D .................
Plz help me ASAP in my final project I am ready to pay 20$
Answer:
what do you need help with
Which is NOT an indicator of a chemical change?
Answer:
The choice that is not an indicator of a chemical change is "State of matter changes". More common than not, chemical reactions produce energy in the form of light or heat. Along with energy, they also produce a new substance called the product that could be in any state of matter (solid, gas, or liquid).
Explanation:
Predict the product when 2-methylbutanol is oxidised with pyridium chlorochromate in dichloromethane (PCC/CH2C12) a. CH3CH2CH(CH3)COOH b. CH3CH2CH2CH(CH3)CHO C. CH3CH2CH(CH3)CHO d. CH3CH2CH(CH3)OH 8:40 PM Type a message
Answer:
c. CH3CH2CH(CH3)CHO
Explanation:
Hello there!
In this case, according to the process for the one-step oxidation of a primary alcohol with a moderately strong oxidizing agent like pyridinium chlorochromate (PCC), whereby an aldehyde is produced, we infer that the corresponding product will be 2-methylbutanal, which matches with the choice c. CH3CH2CH(CH3)CHO according to the following reaction:
[tex]CH_3CH_2CH(CH_3)CH_2OH\rightarrow CH_3CH_2CH(CH_3)COH[/tex]
Regards!
"All plants perform photosynthesis. The cactus on my windowsill is a plant, therefore it must be performing photosynthesis." This statement is an example of:
Group of answer choices
Deductive Reasoning
Logical Fallacy
Inductive Reasoning
Bias
Answer:
Deductive reasoning
Draw structures corresponding to the following IUPAC names:(a) (Z)-2-Ethyl-2-buten-1-ol (b) 3-Cyclohexen-1-ol(c) trans-3-Chlorocycloheptanol (d) 1,4-Pentanediol(e) 2,6-Dimethylphenol (f ) o-(2-Hydroxyethyl)phenol
Answer:
Draw structures corresponding to the following IUPAC names:(a) (Z)-2-Ethyl-2-buten-1-ol (b) 3-Cyclohexen-1-ol(c) trans-3-Chlorocycloheptanol (d) 1,4-Pentanediol(e) 2,6-Dimethylphenol (f ) o-(2-Hydroxyethyl)phenol
Explanation:
According to IUPAC rules, the name of a compound is:
Prefix+root word+suffix
1) Select the longest carbon chain and it gives the root word.
2) The substituents give the prefix.
3) The functional group gives the secondary suffix and the type of carbon chain gives the primary suffix.
The structure of the given compounds are shown below:
why might the melting point of the crystals obtained in this experiment be close to but below one of the reference melting points and melt slowly over several degrees
Answer: hello the experiment related to your question is missing but I will provide a more general answer within the scope of your question
answer :
presence of Impurities
Explanation:
The melting point of the crystals as obtained in the experiment will be close to but below reference melting points and will also melt slower because of the presence of impurities in the compound
Impurities alter the melting and freezing points from ideal freezing and melting points of compounds
PLEASE HELP!!
Solutions Pre-Lab Questions:
In this lab, you will make fruit drinks with powdered drink mix. Complete the pre-lab questions to get the values you need for your drink solutions.
1. Calculate the molar mass of powered fruit drink mix, made from sucrose (C12H22O11).
2. Using stoichiometry, determine the mass of powdered drink mix needed to make a 1.0 M solution of 100 mL.
(Hint: Use molarity = to find the moles of drink mix, then convert moles to grams using a mole conversion.)
3. What mass of powdered drink mix is needed to make a 0.5 M solution of 100 mL?
Answer:
Explanation:
C₁₂H₂₂O₁₁
1 )
Molar mass = 12 x 12 + 22 x 1 + 11 x 16
= 144 + 22 + 176
= 342 g
2 )
100 mL of 1.0 M will contain 1.0 x0.100 = .1 mole of sucrose
0.1 mole of sucrose = 0.1 x 342 g = 34.2 g of sucrose.
So , mass of sucrose required is 34.2 g .
3 )
100 mL of .5 M sucrose = .100 x .5 mole of sucrose
= .05 mole of sucrose
.05 mole of sucrose = .05 x 342 g = 17.1 g of sucrose .
So , mass of sucrose required is 17.1 g .
Draw bond-line formulas of all monochloro derivatives that might be formed when 1,1-dimethylcyclobutane is allowed to react with Cl2 under UV irradiation. For each structure, indicate, with an asterisk, any stereocenters that might be present.
Answer:
Attached below
Explanation:
Diagram of Bond-line formulas of all monochloro derivatives formed when 1,1-dimethylcyclobutane is allowed to react with c12 under UV
attached below
PLEASE HELP FAST!!!
Which of the following is an acid? (3 points)
Be(OH)2
HCl
LiBr
NH3
Answer:
HCl
Explanation:
I took the test :)
Out of the following compounds , HCl is an acid as it has hydrogen as the proton donor.
Acids are defined as substances which on dissociation yield H+ ions , and these substances are sour in taste.
According to the number of H+ ions which are generated on dissociation acids are classified as mono-protic , di-protic ,tri-protic and polyprotic acids depending on the number of protons which are liberated on dissociation.
Acids are widely used in industries for production of fertilizers, detergents batteries and dyes.They are used in chemical industries for production of chemical compounds like salts which are produced by neutralization reactions.
Learn more about acids,here:
https://brainly.com/question/29796621
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define a molecular mass and mole
Answer:
A molecular mass is mass on the substance and mole is a unit of substance such as atoms and electrons.
Explanation:
A molecular mass is the mass of a molecule of the substance and is called as molecular weight. Molar mass is measured in moles. Mass of one mole is 6.022x10²³ particles and is expressed in grams. The molar mass is said to be the mass of the given substance that is divided by the amount of the substance and s expressed in g/ml.Molecular mass: A molecule's molecular mass is equal to the sum of all of the atoms' individual atomic masses. It establishes the molecular mass of a single unit.
Example:
Molecular mass of O2 = 32 atomic mass units
Mole: A mole is [tex]6.02214076 x 10^2^3[/tex]of any chemical unit, including atoms, molecules, ions, and others. Due to the large number of atoms, molecules, or other components that make up any material, the mole is a useful measure to utilize. The initial definition of the mole was the number of atoms in 12 grams of carbon-12.
Learn more about mole here:https://brainly.com/question/22540912
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]
Using any data you can find in the ALEKS Data resource, calculate the equilibrium constant k at 25.0 celsius for the following reaction.
6Cl2(g)+2Fe2O3(s)----->4FeCl3(s)+3O2
Round answer to 2 significant digits.
Answer:
Explanation:
From the given reaction:
[tex]6Cl_{2(g)}+2Fe_2O_{3(s)} \to 4FeCl_{3(s)}+3O_2[/tex]
From the Gibbs Free Energy table at standard conditions, the value of each compound is as follows:
[tex]G_f^0 \ of \ Cl_2 = 0 \ KJ/mol[/tex] [tex]G_f^0 \ of \ Fe_2O_3 = -742.24 \ KJ/mol[/tex]
[tex]G_f^0 \ of \ Fe_2Cl_3 = -334.05 \ KJ/mol[/tex] [tex]G_f^0 \ of \ O_2 = 0 \ KJ/mol[/tex]
Now, the standard Gibb's Free energy for the given reaction can be estimated as follows:
[tex]\mathtt{\Delta G^0 = (4 *G_f^0(FeCl_3) +3*G_f^0(O_2)) - (6*G_f^0 (Cl_2) +2*G_f^0(Fe_2O_3))}[/tex]
[tex]\mathtt{\Delta G^0 = (4 *(-334.05) +3*(0)) - (6(0) +2(-742.24))}[/tex]
[tex]\mathtt{\Delta G^0 = 148.28 \ kJ/mol}[/tex]
using the following formula:
[tex]\mathtt{\Delta G^0 =-RTIn K_{eq}}[/tex]
the equilibrium constant can be determined as:
[tex]\mathtt{ In K_{eq} =\dfrac{\Delta G^0 }{-RT}}[/tex]
[tex]\mathtt{ In K_{eq} =\dfrac{148.28*10^3 J/mol }{-(8.314 \ J/k mol )*298 \ K}}[/tex]
[tex]\mathtt{ In K_{eq} =-59.85}[/tex]
[tex]\mathtt{ K_{eq} =e^{-59.85}}[/tex]
[tex]\mathtt{ K_{eq} =1.0*10^{-26}}[/tex] to 2 significant figures.
define saturated and unsaturated fats
Saturated fatty acids lack double bonds between the individual carbon atoms, while in unsaturated fatty acids there is at least one double bond in the fatty acid chain. Saturated fats tend to be solid at room temperature and from animal sources, while unsaturated fats are usually liquid and from plant sources.
Answer:
hope it is helpful to you
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Question 2: Functional Groups (6 points)
A. Methanoic acid is the simplest carboxylic acid molecule. It has one carbon atom. Draw the structural model for methanoic acid (using C and H). (3 points)
B. Methanal is the simplest aldehyde, with one carbon atom. Draw the structural model for methanal (using C and H). (3 points)
write Balance chemical reaction for preparation of chlorine with or without application heat
Answer:
2KMnO4(aq) + 16HCl(aq) ------> 2MnCl2(aq) + 2KCl(aq) + 8H2O(l) + 5Cl2(g)
Explanation:
Chlorine is a diatomic halogen gas known for its greenish-yellow colour. It has a pungent smell and is only moderately soluble in water.
It is a very reactive gas and is never found in free state in nature.
Chlorine can be prepared in the laboratory by oxidation of hydrochloric acid using KMnO4 as follows;
2KMnO4(aq) + 16HCl(aq) ------> 2MnCl2(aq) + 2KCl(aq) + 8H2O(l) + 5Cl2(g)
The set up does not need to be heated.
Suppose you ran this reaction without triethylamine and simply used an excess of reactant 1. At the end of the reaction, your methylene chloride solution would contain mostly reactant 1 and the product. What would you do to remove reactant 1 from the solution
ummm is that chemistry?
Answer:
is this chem
Explanation:
Define mass number of an atom.
Which one of the following compounds does NOT obey the "octet rule"?
LiF
BF3
H20
CBr4
Answer:
BF3
Explanation:
The octet rule describes atoms' preference and affinity for having eight (8) electrons in their valence shell. Whenever an atom is encircled by eight(8) electrons, it forms a stable configuration. This octet can be composed of its' own electrons as well as some shared electrons. In the periodic table, only the s-block and p-block electrons are considered for the octet rule.
However, out of the given option, only BF3 does not comply with the octet rule: This is because the Bromine contains 2 lone pairs of electrons and 3 other shared bonded pairs of electrons with Flourine making a total of 10 electrons in the valence shell and which does not conform with the octet rule.
Aqueous hydrobromic acid (HBr) will react with solid sodium hydroxide (NaOH) to produce aqueous sodium bromide (NaBr) and liquid water (H2O). Suppose 5.7 g of hydrobromic acid is mixed with 0.980 g of sodium hydroxide. Calculate the maximum mass of water that could be produced by the chemical reaction. Round your answer to significant digits.
Answer:
The maximum mass of water that could be produced by the chemical reaction=0.441g
Explanation:
We are given that
Given mass of HBr=5.7 g
Given mass of sodium hydroxide=0.980 g
Molar mass of HBr=80.9 g/ Mole
Molar mass of NaOH=40 g/mole
Molar mass of H2O=18 g/mole
Reaction
[tex]HBr+NaOH\rightarrow H_2O+NaBr[/tex]
Number of moles=[tex]\frac{given\;mass}{molar\;mass}[/tex]
Using the formula
Number of moles of HBr=[tex]\frac{5.7}{80.9}=0.0705 moles[/tex]
Number of moles of NaOH=[tex]\frac{0.980}{40}=0.0245moles[/tex]
Hydrogen bromide is in a great excess and the amount of water produced.
Therefore,
Number of moles of water, n(H2O)=Number of moles of NaOH=0.0245moles
Now,
Mass of water=[tex]n(H_2O)\times Molar\;mass\;of\;water[/tex]
Mass of water=[tex]0.0245moles\times 18=0.441g[/tex]
Hence, the maximum mass of water that could be produced by the chemical reaction=0.441g
An acid is a substance that produces hydrogen ions in a water solution true or false
Answer:
True I think
hope this helps
Answer:
true
Explanation:
because it reacts with the water molecules by giving a proton to them