Answer:
c. 29 J
Explanation:
Step 1: Given data
Specific heat capacity of Pb (c): 0.13 J/g.K (= 0.13 J/g.°C)Mass of Pb (m): 15 gInitial temperature: 22 °CFinal temperature: 37 °CStep 2: Calculate the temperature change
ΔT = 37 °C - 22 °C = 15 °C
Step 3: Calculate the heat (Q) required to raise the temperature of the lead piece
We will use the following expression.
Q = c × m × ΔT
Q = 0.13 J/g.°C × 15 g × 15 °C = 29 J
What do we need to know to understand the formation of a chemical bond?
Answer:
A chemical bond is a lasting attraction between atoms, ions or molecules that enables the formation of chemical compounds. The bond may result from the electrostatic force of attraction between oppositely charged ions as in ionic bonds or through the sharing of electrons as in covalent bonds.
Explanation:
You have to put energy into a molecule to break its chemical bonds. The amount needed is called the bond energy. After all, molecules don't spontaneously break
According to an informal 1992 survey, the drinking water in about one-third of the homes in Chicago had lead levels of about 10 ppb. Dr. Koether lived in Chicago from 1996 to 1998. Assuming she drank 1.4 L of water a day, calculate the total amount of lead in mg (using one decimal place) that she was exposed to over the two years if she lived in a home that had such high levels of lead.
Answer:
10.2 mg
Explanation:
Step 1: Calculate the total amount of water she drank
1 year has 365 days and she lived in Chicago for 2 years = 2 × 365 days = 730 days.
If she drank 1.4 L of water per day, the total amount of water she drank is:
730 day × 1.4 L/day = 1022 L
Step 2: Calculate the amount of Pb in 1022 L of water
The concentration of Pb is 10 ppb (10 μg/L).
1022 L × 10 μg/L = 10220 μg
Step 3: Convert 10220 μg to milligrams
We will use the conversion factor 1 mg = 1000 μg.
10220 μg × 1 mg/1000 μg = 10.2 mg
Using the following equation for the combustion of octane calculate the heat associated with the formation of 100.0 g of carbon dioxide. The molar mass of octane is 114.33 g/mole.
2C8H18 + 25O2 → 16 CO2 + 18 H2O
ΔH°rxn = -11018 kJ
Answer:
The right solution is "-602.69 KJ heat".
Explanation:
According to the question,
The 100.0 g of carbon dioxide:
= [tex]\frac{100.0 \ g}{114.33\ g/mole}[/tex]
= [tex]0.8747 \ moles[/tex]
We know that 16 moles of [tex]CO_2[/tex] formation associates with -11018 kJ of heat, then
0.8747 moles [tex]CO_2[/tex] formation associates with,
= [tex]-\frac{0.8747}{16}\times 11018 \ KJ \ of \ heat[/tex]
= [tex]-0.0547\times 11018[/tex]
= [tex]-602.69 \ KJ \ heat[/tex]
Which gas has the highest diffusing rate between nitrogen , oxygen , hydrogen and chlorine
Answer:
hydrogen
Explanation:
The gas with the least molecular weight effuses the fastest (Graham's Law). Hence, H gas has a higher rate of diffusion compared to N, O, and Cl.
So, Cl is the slowest when it comes to the rate of diffusion, because it has the highest molecular weight.
If 1 mol of ferric oxide reacts with 3 moles of carbon monoxide to yield 2 mols of iron and 3 mols of carbon dioxide, how much CO will be needed to completely react with 50.26 g of ferric oxide?
Answer:
26.4g
Explanation:
The balanced chemical equation as stated in this question is given as follows:
Fe2O3 + 3CO → 2Fe + 3CO2
According to this balanced equation, 3 moles of carbon monoxide (CO) will react with 1 mole of Ferric oxide (Fe2O3).
We need to change 50.26 g of ferric oxide to moles by using the formula;
mole = mass/molar mass
Molar mass of Fe2O3 = 56(2) + 16(3)
= 112 + 48
= 160g/mol
mole = 50.26/160
mole = 0.314mol of Fe2O3
If 3 moles of carbon monoxide (CO) will react with 1 mole of Ferric oxide (Fe2O3).
Hence, 0.314 mol of Fe2O3 will completely react with (0.314 × 3) mol of CO
0.314 × 3 = 0.94 mol of CO
molar mass of CO = 12 + 16 = 28g/mol
mole = mass/molar mass
mass = mole × M.M
mass = 0.94 × 28
mass = 26.4g of CO
3. (07.05 LC)
When zinc reacts with hydrochloric acid, it produces hydrogen gas. As the reaction proceeds, why does the rate of production of hydrogen gas decrease? (3 points)
the rate would decrease because the reactants are being depleted.
An aqueous solution contains 0.374 M ammonia (NH3). How many mL of 0.276 M nitric acid would have to be added to 125 mL of this solution in order to prepare a buffer with a pH of 8.970.
Answer:
111.95mL of HNO3 are needed to prepare the buffer
Explanation:
We can solve this equation using H-H equation for bases:
pOH = pKb + log [HA+] / [A]
Where pOH is the pOH of the solution
pOH = 14 - pH = 14 - 8.970 = 5.03
pKb is the pKb of NH3 = 4.74
[HA+] could be taken as moles of NH4+
[A] as moles of NH3
The NH3 reacts with nitric acid, HNO3, as follows:
NH3 + HNO3 → NH4+ + NO3-
That means the moles of HNO3 added = X = Moles of NH4+ produced
And moles of NH3 are initial moles NH3 - X
Initial moles of NH3 are:
0.125L * (0.374mol/L) = 0.04675 moles NH3
Replacing in H-H equation:
pOH = pKb + log [HA+] / [A]
5.03 = 4.74 + log [X] / [0.04675-X]
0.29 = log [X] / [0.04675-X]
1.95 = [X] / [0.04675-X]
0.0912 - 1.95X = X
0.0912 = 2.95X
X = 0.0309 moles
We need to add 0.0309 moles of HNO3. From a solution that is 0.276M:
0.0309 moles of HNO3 * (1L / 0.276moles) = 0.11195L of HNO3 are needed
In mL:
111.95mL of HNO3 are needed to prepare the buffer
What is the energy of a photon emitted with a wavelength of 654 nm?
O A. 3.04 x 10^-19 J
O B. 1.01 * 10^-27 J
O C. 1.30 x 10^-22 J
O D. 4.33 * 10^-22 J
Answer:
A. 3.04×10^-19J
Explanation:
Hope this will help you.
Each 5-ml teaspoon of Extra Strength Maalox Plus contains 450 mg of magnesium hydroxide and 500 mg of aluminum hydroxide. How many moles of hydronium ions H3O are neutralized by 1 teaspoon of antacid product?
Answer:
0.0347 moles of hydronium ions
Explanation:
The equation of the neutralization reaction between hydroxide and hydronium ions is given below:
H₃O+ (aq) + OH- (aq) ----> 2 H₂O (l)
From the equation above, 1 mole of hydroxide ions will neutralize one mole hydronium ions.
The moles of hydroxide ions present in 1 teaspoon or 5 mL of antacid product is calculated as follows:
Number of moles = mass / molar mass
Molar mass of Magnesium hydroxide, Mg(OH)₂ = 58 g/mol
Molar mass of aluminium hydroxide, Al(OH)₃ = 78 g/mol
Mass of magnesium hydroxide = 450 g = 0.45 g
Mass of aluminium hydroxide = 500 mg = 0.5 g
Moles of magnesium hydroxide = (0.45/58) moles
Moles of aluminium hydroxide = (0.5/78) moles
Equation of the ionization of magnesium hydroxide and aluminium hydroxide is given below:
Mg(OH)₂ (aq) ----> Mg²+ (aq) + 2 OH- (aq)
Al(OH)₃ (aq) ---> Al³+ (aq) + 3 OH- (aq)
Number of moles of hydroxide ions present in (0.45/58) moles of magnesium hydroxide = 2 × (0.45/58) moles = 0.0155 moles
Number of moles of hydroxide ions present in (0.5/78) moles of aluminium hydroxide = 3 × (0.5/78) moles = 0.0192 moles
Total moles of hydroxide ions = 0.0155 + 0.0192 = 0.0347 moles hydroxide ions
Therefore, 0.0347 moles of hydroxide ions will neutralize 0.0347 moles of hydronium ions.
What is the mass of carbon in 69.00 mg of co2
Answer:
18.82 mg
Explanation:
From the given information:
The molar mass of CO2 is calculated as follow
= (12 + (16 ×2))
= 44
The mass of carbon is determined by dividing the mass no of carbon from co2 by the molar mass of CO2, followed by multiplying it by 69.00 mg
= [tex](\dfrac{12}{44}\times 69 )[/tex]
=(0.2727 × 69 )
= 18.82 mg
Based on the following observations decide the order of reactivity for hydrogen, magnesium, and copper. Hydrochloric acid reacts with magnesium but did not react with copper. magnesium reacted with copper sulfate. Write your answers in the blanks. For magnesium write magnesium for hydrochloric acid write hydrogen and for copper sulfate write copper.
Answer:
Mg> H> Cu
Explanation:
We can see from the question that hydrochloric acid reacted with magnesium as follows;
Mg(s) + 2HCl(aq) ----> MgCl2(aq) + H2(g)
Copper does not react with HCl which means that copper is less reactive than hydrogen hence it can not displace hydrogen from a dilute acid solution.
The order of reactivity of the elements then is ; Mg> H> Cu
the ability for carbon to form long chain or rings is
which primitive organic molecule was essential to form lipid bilayer?
a)protenoid
b)phospholipid
c)autocatalytic RNA
d)aminoacids
Answer:
c) autocatalytic RNA is the primitive organic molecules was essential to form lipid bilayer.
) The C O bond dissociation energy in CO2 is 799 kJ/mol. The maximum wavelength of electromagnetic radiation required to rupture this bond is ________.
Answer:
λ = 150 nm
Explanation:
For C-O bond rupture:
The required energy to rupture C-O bond = bond energy of C-O bond
= 799 kJ/mol
[tex]\mathsf{= 799 \ kJ/mol \times ( \dfrac{1 \ mol }{6.023 \times 10^{23} \ C-O \ bonds })}[/tex]
[tex]\mathsf{= 1.3265 \times 10^{-21} \ kJ/ C-O \ bond}[/tex]
[tex]\mathsf{= 1.33 \times 10^{-18} \ J/C-O \ bond}[/tex]
Recall that the wavelength associated with energy and frequency is expressed as:
[tex]E = \dfrac{hc}{\lambda}[/tex]
[tex]\lambda = \dfrac{hc}{E}[/tex]
[tex]\lambda = \dfrac{(6.626 \times 10^{-34} \ J.s^{-1}) \times (3.0 \times 10^8 \ ms^{-1})}{ 1.33 \times 10^{-18} \ J/C-O \ bond}}[/tex]
[tex]\mathsf{\lambda = 1.50 \times 10^{-7} \ m}[/tex]
λ = 150 nm
Phosphagens are a group of molecules that includes creatine phosphate (in vertebrates), and arginine phosphate, lombricine, and phosphoopheline (in invertebrates). These molecules have similar functions in different organisms.
a. True
b. False
Answer: True
Explanation:
Phosphagens are high energy storage compounds that are usually found in the tissue of animals.
Based on the question, the molecules have similar functions in different organisms such as the fact that they can accept phosphoryl groups from ATP in a situation where the ATP is in excess. Also, they donate phosphoryl groups to ADP in order for the regeneration of ATP.
Tech A says that the PCM monitors the pre-cat and post-cat oxygen sensors to determine catalytic converter efficiency. Tech B says that a catalytic converter can be tested by graphing the oxygen sensor readings on a scan tool or lab scope and comparing them. Who is correct
Answer:
Both Tech A and Tech B.
Explanation:
Catalyst is an element used to start chemical reaction but is not used in the reaction. Catalysts material used in catalytic converter include Rhodium, Palladium and platinum. The pre cat and post cat oxygen sensors helps determine converter efficiency.
Answer:
Explanation:
B
A student has accidentally spilled 100.0 mL of 3.0 mol/L nitric acid onto the lab bench. What mass of sodium bicarbonate would the teacher need to sprinkle on this spill to neutralize and clean it up?
Answer:
25 g
Explanation:
Step 1: Write the balanced equation
HNO₃ + NaHCO₃ ⇒ NaNO₃ + H₂O + CO₂
Step 2: Calculate the reacting moles of HNO₃
100.0 mL of 3.0 mol/L HNO₃ reacted.
0.1000 L × 3.0 mol/L = 0.30 mol
Step 3: Calculate the reacting moles of NaHCO₃
The molar ratio of HNO₃ to NaHCO₃ is 1:1. The reacting moles of NaHCO₃ are 1/1 × 0.30 mol = 0.30 mol.
Step 4: Calculate the mass corresponding to 0.30 moles of NaHCO₃
The molar mass of NaHCO₃ is 84.01 g/mol.
0.30 mol × 84.01 g/mol = 25 g
balance equation of aluminium chloride+ hydrogen
[tex]\boxed{\sf {AlCl_3\atop Aluminium\:Chloride}+{H_2\atop Hydrogen}\longrightarrow {Al\atop Aluminium}+{HCl\atop Hydrochloric\:acid}}[/tex]
Balanced Equation:-
[tex]\boxed{\sf {2AlCl_3\atop Aluminium\:Chloride}+{3H_2\atop Hydrogen}\longrightarrow {2Al\atop Aluminium}+{6HCl\atop Hydrochloric\:acid}}[/tex]
The density of an aqueous solution containing 25.0 percent of ethanol (C2H5OH) by mass is 0.950 g/mL. (a) Calculate the molality of this solution. m (b) Calculate its molarity. M (c) What volume of the solution would contain 0.275 mole of ethanol
Answer:
a. 7.24m
b. 5.15M
c. 53.4mL of the solution would contain this amount of ethanol.
Explanation:
Molality, m, is defined as the moles of solute (ethanol, in this case) per kg of solvent.
Molarity, M, are the moles of solute per kg of solvent
To solve this question we need to find the moles of solute in 100g of solution and the volume using its density as follows:
a. Moles ethanol -Molar mass: 46.07g/mol-:
25g ethanol * (1mol/46.07g) = 0.54265 moles ethanol
kg solvent:
100g solution - 25g solute = 75g solvent * (1kg / 1000g) = 0.075kg
Molality:
0.54265 moles ethanol / 0.075kg = 7.24m
b. Liters solution:
100g solution * (1mL / 0.950g) = 105.3mL * (1L / 1000mL) = 0.1053L
Molarity:
0.54265 moles ethanol / 0.1053L = 5.15M
c. 0.275 moles ethanol * (1L / 5.15moles Ethanol) = 0.0534L =
53.4mL of the solution would contain this amount of ethanol
14. What is the oxidation number of oxygen in HSO4 -
Answer:
2
Explanation:
i did this
The reaction for photosynthesis producing glucose sugar and oxygen gas is:
__CO2(g) + __H2O(l) UV/chlorophyl−→−−−−−−−−−−−−−− __C6H12O6(s) + __O2(g)
What is the volume of oxygen gas at STP produced from 2.20 g of CO2 (44.01 g/mol)?
a. 1.12 L
b. .187 L
c. 4.32 L
d. 6.72 L
e. 1.60 L
Answer:
a. 1.12 L
Explanation:
Step 1: Write the balanced equation for the photosynthesis
6 CO₂(g) + 6 H₂O(l) ⇒ C₆H₁₂O₆(s) + 6 O₂(g)
Step 2: Calculate the moles corresponding to 2.20 g of CO₂
The molar mass of CO₂ is 44.01 g/mol.
2.20 g × 1 mol/44.01 g = 0.0500 mol
Step 3: Calculate the moles of O₂ produced
The molar ratio of CO₂ to O₂ is 6:6. The moles of O₂ produced are 6/6 × 0.0500 mol = 0.0500 mol
Step 4: Calculate the volume occupied by 0.0500 moles of O₂ at STP
At STP, 1 mole of O₂ occupies 22.4 L.
0.0500 mol × 22.4 L/1 mol = 1.12 L
Kevin's supervisor, Jill, has asked for an update on today's sales. Jill is pretty busy moving back and forth between different store locations. How can Kevin most effectively deliver an update to her? a) Send a detailed email Send a detailed text message Oc) Book a one-hour meeting for tomorrow morning O d) Call with a quick update
Kevin can effectively deliver an update by sending a detailed EMAIL to Jill
Email, which means electronic mail is a technological advanced way of passing information from persons to persons without physical contact. Sending emails are also official ways of passing vital information regarding business, work to and fro. According to this question, Jill is a very busy supervisor who hardly. The best way for Kevin to deliver any update concerning the store he is managing is to send Jill an updated email that can even be assessed outside work hours. Learn more: https://brainly.com/question/7098974Congratulations! You are now the head biologist at the local "Cells and Bells" research lab! It has come to other cell biologists' attention recently that some cells are too small to contain all of the organelles inside of them. They decide that it's best to get rid of an organelle, but they're not sure which one. In the first process of this decision, they need to know "which organelle is the most important?"
Your job, as the head cell biologist, is to decide which organelle the cell cannot live without.
Write a research paper (intro, body, and conclusion) on which organelle is the most important and why.
When naming organic compounds, there are strict rules regarding punctuation.
1. A comma is used to separate two numbers.
2. A hyphen is used to separate a number from a letter.
Rewrite the name of this compound using hyphens and commas as appropriate.
The question is incomplete, the complete question is shown in the image attached to this answer
Answer:
2,3,3-trimethylhexane
Explanation:
IUPAC nomenclature provides a universally acceptable method of naming organic compounds from its structure.
According to this system of nomenclature;
A comma is used to separate two numbers.
A hyphen is used to separate a number from a letter.
Applying these rules, the name of the compound shown in the question should be written as 2,3,3-trimethylhexane.
What is represented by a straight line on a graph?
o the sum of the independent and dependent variables
O only the independent variable
O only the dependent variable
o the relationship between independent and dependent variable
1 2
3
4
5
Answer:
the relationship between independent and dependent variable
Explanation:
A straight line or linear graph is one of the ways to represent a given data. It shows the relationship between two given set of data; one called the independent variable is plotted on the x-axis (horizontal) while the other called the dependent variable is plotted on the y-axis (vertical).
The straighter the line is, the stronger the relationship between the two variables and vice versa. Hence, the straight line in the graph represents the relationship between independent and dependent variable.
Oxygen is composed of three isotopes: oxygen-16, oxygen-17 and oxygen-18 and has an average atomic mass of 15.9982 amu. Oxygen-17 has a mass of 16.988 amu and makes up 0.032% of oxygen. Oxygen-16 has a mass of 15.972 amu and oxygen-18 has a mass of 17.970 amu. What is the percent abundance of oxygen-18?
Answer:
The percent abundance of oxygen-18 is 1.9066%.
Explanation:
The average atomic mass of oxygen is given by:
[tex] m_{O} = m_{^{16}O}*\%_{16} + m_{^{17}O}*\%_{17} + m_{^{18}O}*\%_{18} [/tex]
Where:
m: is the atomic mass
%: is the percent abundance
Since the sum of the percent abundance of oxygen isotopes must be equal to 1, we have:
[tex] 1 = \%_{16} + \%_{17} + \%_{18} [/tex]
[tex] 1 = x + 3.2 \cdot 10^{-4} + \%_{18} [/tex]
[tex] \%_{18} = 1 - x - 3.2 \cdot 10^{-4} [/tex]
Hence, the percent abundance of O-18 is:
[tex] m_{O} = m_{^{16}O}*\%_{16} + m_{^{17}O}*\%_{17} + m_{^{18}O}*\%_{18} [/tex]
[tex]15.9982 = 15.972*x + 16.988*3.2 \cdot 10^{-4} + 17.970*(1 - 3.2 \cdot 10^{-4} - x)[/tex]
[tex] x = 0.980614 \times 100 = 98.0614 \% [/tex]
Hence, the percent abundance of oxygen-18 is:
[tex]\%_{18} = (1 - 3.2 \cdot 10^{-4} - 0.980614) \times 100 = 1.9066 \%[/tex]
Therefore, the percent abundance of oxygen-18 is 1.9066%.
I hope it helps you!
A nuclease enzyme breaks the covalent bond originally connecting the phosphate to the 5' carbon in a nucleic acid. After allowing this enzyme to completely digest the nucleic acid down to monomers, you perform tests to determine where the phosphate is attached to each monomer. Where do you expect to find this phosphate
Answer:
The phosphate will remain attached to the 5' carbon of the deoxy or the ribose sugar in the nucleic acid monomers.
Explanation:
The structure of nucleic acid polymers is built up from monomers of nucleotides.
A nucleotide consists of a sugar backbone which is either a ribose or deoxyribose sugar, a nitogenous base which is either a purine or pyrimidine, and a phosphate group. The nitrogenous base is attached to the carbon number 1 or C-1 of the sugar backbone by a covalent bond. The phosphate group on the other hand is covalently attached to the carbon number 5 or 5' carbon of the sugar backbone.
When polymers of nucleic acids are formed, the phosphate at the 5' carbon of the sugar backbone is covalently linked in a phosphodiester bond to the 3' carbon of the sugar backbone in another nucleotide molecule, thus extending the strands of the nucleic acid molecule.
Nucleases are enzymes that break down the phosphodiseter bonds in nucleic acids resulting in nucleotide monomers. After complete digestion ofmthe nucleic acid polymer by nucleases, the phosphate will remain attached to the 5' carbon of the deoxy or the ribose sugar in the nucleic acid monomers.
NCEPT The mass of NaClcontaining the Avogadro Number of particles is.
Answer:
one mole of water (6.022 x 10 23 molecules) has a mass of 18.02 g. One mol of NaCl (6.02 x1023 formulas) has a mass of 58.44 g.
Explanation:
• The mole (or mol) represents a certain number of objects.
• SI def.: the amount of a substance that contains the same
number of entities as there are atoms in 12 g of carbon-12.
• Exactly 12 g of carbon-12 contains 6.022 x 10 23 atoms.
• One mole of H 2O molecules
contains 6.022 x 10 23 molecules.
• 1 mole contains 6.022 x 10 23 entities (Avogadro’s number)
• One mole of NaCl contains 6.022 x 10 23 NaCl formula units.
• Use the mole quantity to count formulas by weighing them.
• Mass of a mole of particles = mass of 1 particle x 6.022 x 1023
Mass of 1 H atom: 1.008 amu x 1.661 x10-24 g/amu = 1.674 x10-24 g
Mass of 1 mole of H atoms:
1.674 x10-24g/H atom x 6.022 x1023H atoms = 1.008 g
• The mass of an atom in amu is numerically the same
as the mass of one mole of atoms of the element in grams.
• One atom of sulfur has a mass of 32.07 amu;
one mole of S atoms has a mass of 32.07 g
PLEASE HELP ASAP
Use the equation below to answer the following questions.
2Al(s) + 3Cu(NO3)2(aq) 3Cu(s) + 2Al(NO3)3(aq)
Determine the oxidation state of the atoms in the equation's reactants and products: (6 points)
Oxidation state of Al in reactant:
in product:
Oxidation state of Cu in reactant:
in product:
Oxidation state of N in reactant:
in product:
Oxidation state of O in reactant:
in product:
Explain why this is a redox reaction.
Thank you!
Answer:
hlo.......................,
How can beta particles be dangerous to living cells?
A. They move fast and penetrate the skin.
B. They are very high in energy and can travel through most
materials.
C. They move slowly but are very large.
D. They are very low in energy but remain in the body for a long time.
