Answer:
The correct answer is -1946.89 j/K.
Explanation:
The reaction is:
2H2O (l) ⇔ 2H2 (g) + O2(g)
First there is a need to find dHfrxn = dHf(Products) - dHf(reactants)
With the help of standard thermodynamic table, the values of dHf can be obtained,
dHf(H2O) = -285.8 kJ/mol
dHf(H2) = 0 kJ/mol
dHf(O2) = 0 kJ/mol
dHrxn = 2 × dHf (H2) + dHf(O2) - 2 × dHf(H2O)
= 2 × 0 + 0-2 × (-285.8) kJ = +571.6 kJ
This value is for 2 moles of H2O, for 2.03 moles of H2O, the value will be,
dHrxn = +571.6 kJ/2 mol × 2.03 mol
= 580.174 kJ
The given temperature is 298 K.
So, the value of dSsurr = -dHrxn/T
= -580.174kJ/298 K
= -580174 j/298K
= -1946.89 j/K
what are the answers easily!!!!
Answer:
True
True
Temperature
Explanation:
If bovine haemoglobin has an extinction coefficient of 30910 L mol-1 cm-1 at 570 nm in PBS, what is the concentration of a solution reading an absorbance of 0.7?
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Explanation:
The concentration of Bovine Hb with absorbance 0.7 at 570 nm has been 2.264 [tex]\mu[/tex]M.
According to Beer's law, the absorbance of the sample can be given by:
Absorbance = Extinction coefficient [tex]\rm \times[/tex] concentration [tex]\times[/tex] path length
The Bovine Hb has the extinction coefficient = 30910 L/mol/cm
The absorbance = 0.7
The path length has been 1 cm.
The concentration of the Bovine Hb can be given as:
0.7 = 30910 [tex]\times[/tex] concentration [tex]\times[/tex] 1
The concentration of Bovine Hb = 2.264 [tex]\rm \times\;10^-^6[/tex] moles/L
The concentration of Bovine Hb = 2.264 [tex]\rm \mu[/tex]moles/L
The concentration of Bovine Hb = 2.264 [tex]\mu[/tex]M.
For more information about the concentration on the basis of absorbance, refer to the link:
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why is the cell wall so important to the plant cell???
Explanation:
Cellulose fibers, structural proteins, and other polysaccharides help to maintain the shape and form of the cell. Additional functions of the cell wall include: Support: The cell wall provides mechanical strength and support. It also controls the direction of cell growth.
When 35.0 mL of 0.400 M hydrochloric acid and 35.0 mL of 0.400 M sodium hypochlorite are combined, the pH of the resulting solution will be :
Answer:
pH = 7.49
Explanation:
This is a buffer solution. We can apply Henderson Hasselbach equation:
pH = pKa + log ((total mmoles - mmoles HCl) / mmoles HCl)
We have the same amount of mmoles.
35 mL . 0.400 M = 14 mmoles HCl
35 mL . 0.400 M = 14 mmoles NaClO
Total moles are 28 mmoles.
We replace data:
pH = pKa + log ((28 mmoles -14 mmoles) / 14 mmoles)
Notice that the relation in log = 1. So pH = pKa
pKa for HClO is 7.49
When pH = pKa we have the same amount of base and acid. Notice, that we have the same mmoles of HCl and NaClO.
Remember that a buffer can be prepared with:
a) A weak acid and its conjugate base (acetic /acetate)
A weak base and its conjugate acid (ammonia/ammonium)
b) A weak acid with a strong base, where the acid can be in excess.
c) A conjugate base (salt from weak acid) with a strong acid, where the base can be in excess. (This case but, the base is not in excess, that's why ph = pKa)
An unknown metal with a mass of 8.5 g was heated in boiling water to a temperature of 100°C. The metal was immediately transferred to an insulated cup containing 50.0 g of water at 22°C. At equilibrium (when the temperature became constant) the temperature of the system was 23.2°C. Calculate the specific heat of the metal and determine its identity. Explain how you arrived at your conclusion. You must show your work to receive credit for your answer.
The specific heat of the metal : 0.384 J/g° C,
and a metal with a specific heat of 0.384 is copper
Further explanationThe law of conservation of energy can be applied to heat changes, i.e. the heat received / absorbed is the same as the heat released
Q in = Q out
Q lost(metal) = Q gained(water)
Heat can be calculated using the formula:
Q = mc∆T
Q = heat, J
m = mass, g
c = specific heat, joules / g ° C
∆T = temperature difference, ° C / K
[tex]\tt Q~metal=Q~water\\\\8.5\times c\times (100-23.2)=50\times 4.18\times(23.2-22)\\\\652.8\times c=250.8\Rightarrow c=\dfrac{250.8}{652.8}=0.384~J/g^oC[/tex]
Calculate the molar mass of a 2.89 g gas at 346 ml, a temperature of 28.3 degrees Celsius, and a pressure of 760 mmHg.
The molar mass of gas = 206.36 g/mol
Further explanationIn general, the gas equation can be written
[tex]\large{\boxed{\bold{PV=nRT}}}[/tex]
where
P = pressure, atm
V = volume, liter
n = number of moles
R = gas constant = 0.082 l.atm / mol K
T = temperature, Kelvin
mass (m)= 2.89 g
volume(V) = 346 ml = 0.346 L
T = 28.3 C + 273 = 301.3 K
P = 760 mmHg=1 atm
The molar mass (M) :
[tex]\tt PV=\dfrac{m}{M}RT\\\\M=\dfrac{mRT}{PV}\\\\M=\dfrac{2.89\times 0.082\times 301.3}{1\times 0.346}\\\\M=206.36~g/mol[/tex]
Using Gay-Lussac's Law, calculate what the new pressure in the following situation.
A tank of acetylene sits on the back of a truck. During the afternoon, the temperature
of a gas has reached 38°C (311 K) with a pressure of 508 kPa. That night, the
temperature drops to 29°C (302 K). Since the gas was in a metal tank, the volume
remained constant. What is the new pressure?
Answer: 311kpa
Explanation:
When discussing distances between the solar system, which term do we use
A. Actual distance
B. Relative Brightness
D. Realtive distance
If its right you get brainless
I'm in 5th grade
How many molecules are in 6.00 mol He?
HELP!!!!!
1. Define the units for molarity. Page |152 Exp. 14 pH and Solutions Pre Lab Questions (1 of 1) 2. A solution contains 5.25 grams of sodium chloride in 750.0 mL of solution. Determine the molarity of the solution. Na
Answer:
1. mol/L
2. 0.120 M
Explanation:
1. Molarity is equal to the moles of solute divided by the liters of solution. The units of molarity are mol/L.
2.
Step 1: Given data
Mass of sodium chloride (solute): 5.25 gVolume of solution (V): 750.0 mL = 0.7500 LStep 2: Calculate the moles of solute (n)
The molar mass of NaCl is 58.44 g/mol.
n = 5.25 g × 1 mol/58.44 g = 0.0898 mol
Step 3: Determine the molarity of the solution
We will use the definition of molarity
M = n/V
M = 0.0898 mol / 0.7500 L = 0.120 M
What is the molecular formula of a component whose molar mass is 88.0 and whose percent composted is 9.1
The molecular formula : C₄H₈O₂
Further explanationMaybe a compound is 54.5% carbon, 9.1% hydrogen and 36.4% oxygen,so :
mol C :
[tex]\tt \dfrac{54.5}{12}=4.54[/tex]
mol H :
[tex]\tt \dfrac{9.1}{1}=9.1[/tex]
mol O :
[tex]\tt \dfrac{36.4}{16}=2.28[/tex]
Divide by 2.28(the smallest ratio) :
C H : O =
[tex]\tt \dfrac{4.54}{2.28}\div \dfrac{9.1}{2.28}\div \dfrac{2.28}{2.28}=2\div 4\div 1[/tex]
The empirical formula : C₂H₄O
(The empirical formula)n=molecular formula
(2.12+4.1+16)n=88
(44)n=88⇒n=2
PLEASE HELP
predict the product of the following reactants and the balance.
1. _______CuSO4+ _____NH4OH->
Answer:
CuSO4 + 2NH4OH -----> Cu(OH)2 + (NH4)2SO4
Explanation:
helppppppppppppppppppppppppppppppppppppppppppppppppppp
Answer:
C hydrogen and orange boxes element
Explanation:
What does the theory of continental drift state?
A
All the continents were once one continent that broke up and drifted apart over hundreds of millions of years.
B
The continents have always been separate but may one day drift together to form a single continent.
C
The layout of the continents is the same today as it has always been.
D
New continents are continually being created and destroyed.
How many protons, neutrons, and electrons does the following atom have?
Answer:
Option C 28 Proton 31 neutron 26 elecrtons
Explanation:
Gaseous methane CH4 will react with gaseous oxygen O2 to produce gaseous carbon dioxide CO2 and gaseous water H2O. Suppose 0.80 g of methane is mixed with 1.92 g of oxygen. Calculate the maximum mass of water that could be produced by the chemical reaction. Round your answer to 3 significant digits.
Answer:
1.08 g of water
Explanation:
The balanced chemical equation for the reaction of combustion of methane (CH₄) is the following:
CH₄(g) + 2 O₂(g) → CO₂(g) + 2 H₂O(g)
According to the equation, 1 mol of CH₄ reacts with 2 moles of O₂. We convert from mol to grams by using the molar masses:
1 mol CH₄ = (1 x 12 g/mol) + (4 x 1 g/mol) = 16 g
2 mol O₂ = 2 x (2 x 16 g/mol) = 64 g
2 mol H₂O = 2 x ((2 x 1 g/mol) + 16 g/mol)= 36 g
From the masses of reactants (CH₄ and O₂), we can see that the stoichiometric ratio is 64 g O₂/16 g CH₄ = 4.
First, we have to identify which reactant is the limiting reactant. We can compare the stoichiometric ratio with the actual reactants ratio (the masses of reactants we have):
1.92 g O₂/0.80 g CH₄ = 2.4
As 4>2.4, we can conclude that O₂ is the limiting reactant.
Now, we consider the stoichiometric ratio between the limiting reactant (64 g O₂) and the product we have to calculate (36 g H₂O), and we multiply the ratio by the actual mass of O₂:
1.92 g O₂ x 36 g H₂O/64 g O₂ = 1.08 g
Therefore, 1.08 g of H₂O will be produced by the chemical reaction of 0.80 g of methane with 1.92 g of oxygen.
Calcium carbonate is a white mineral. A chemist heats calcium carbonate, CaCO3, to produce carbon dioxide, CO2, and a white powder, CaO. The following chemical equation shows the reaction.CaCO3 → CO2 + CaO Explain why the products have different properties than the reactants
Answer:
A chemical change has occurred
Explanation:
Given reaction expression:
CaCO₃ → CaO + CO₂
The reaction is a decomposition reaction in which a compound is dissociated into simple products.
The reason why the products have different properties than the reactants is because a chemical change has occurred.
A chemical change is accompanied by the formation of a new productSuch new products have different properties compared to the compound that forms them. Therefore, the products and reactants are different chemically due to chemical change that has occurred.The products of the decomposition of calcium carbonate have different properties because a chemical change has occured in the reaction to form new substances.
CHEMICAL CHANGE:A chemical change is a type of change in which new products are formed. The bonds of the reactants are broken and rearranged to form entirely new substances. According to this question, calcium carbonate is a white mineral, which when heated produces carbon dioxide, CO2, and a white powder, CaO as follows: CaCO3 → CO2 + CaOThe products in this reaction are different in their properties from the reactants because a chemical change has caused new substances to be formed.Learn more about chemical change at: https://brainly.com/question/1161517?referrer=searchResults
rap music to hype up on bus to game
Answer:
Ram Ranch
Explanation:
Answer: FLEXUP by lil yacthy and future and playboi carti one of the best songs right now
Explanation:
which elements are solid at room temperature
Answer:bromine , neon , helium , argon , lithium , beryllium
Explanation:
Elements can be divided into three state that are solid, liquid and gas depending the intermolecular forces of attraction, distance between the particles etc. Lithium, beryllium, boron, carbon, sodium, magnesium, iron, copper, etc. are solid at room temperature.
What is element?Element generally consist of atoms or we can atoms combine to form element. Atoms of an element is always same, means all the properties of all atoms of one type of element is same.
Two or more than two atoms with different physical or chemical properties can not combine together to form an element. Elements can be solid liquid or gas at room temperature.
Therefore, Lithium, beryllium, boron, carbon, sodium, magnesium, iron, copper, etc. are solid at room temperature.
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uhh ill give brainliest??
Explanation:
Given parameters:
Density of the ethanol = 0.789g/mL
Volume of the ethanol in the cylinder = 900mL
Unknown:
Mass of the ethanol = ?
Solution:
Since density is the mass per unit volume of a substance;
mass = density x volume
Now insert the parameters and solve;
mass = 0.789g/mL x 900mL
mass = 710g
In scientific notation we have 7.10 x 10²g
Answer rrrrrrrrr....
Answer:
The answer is "Option b".
Explanation:
[tex]\to \text{number of moles} = \frac{\text{number of atoms}}{\text{avogadro number}}[/tex]
[tex]= \frac{7.0 \times 10^{19}}{6.0221 \times 10^{23}}\\\\= 1.16 \times 10^{-4} \ moles\\\\ =1.2 \times 10^{-4} \ moles[/tex]
[tex]\to \text{sample mass}= \text{number of moles} \times \text{molar mass}[/tex]
[tex]=1.16 \times 10^{-4}\times 58.9\\\\=0.00685 \\\\ = 6.85\ g[/tex]
The mitochondrial form of the PEPCK enzyme, with oxaloacetate as substrate, is a(n)__________enzyme for the Citric Acid Cycle
(a) inhibitory
(b) activatory
(c) anapleurotic
(d) catapleurotic
Answer:
(d) catapleurotic
Explanation:
Phosphoenolpyruvate carbokinase (PEPCK) is usually used in the conversion of oxaloacetate to phosphoenolpyruvate (an important intermediate in glycolysis and gluconeogenesis, C₃H₅O₆P). The main function of this catapleurotic enzymes is in the catalysis of the forward conversion of oxaloacetate to phosphoenolpyruvate.
A gaseous fossil fuel produced from organic matter that is used to heat homes and cook
Answer:
Natural gas
Explanation:
Natural gas is a gaseous fossil fuel produced from organic matter that is used to heat homes and cook food.
Natural gas is one of the most volatile part of hydrocarbons that exist together with fossil fuel.
In a reservoir, natural gas is usually on top of the fossil fuel reserve. It can also be distilled from crude oil as they rises up on top of the column first due to their low boiling pointThe gas mixture is made up light hydrocarbons from methane to hexane.What is the standard cell potential for a voltaic cell using the Pb2 /Pb and Mg2 /Mg half-reactions and which metal is the cathode
Answer:The standard cell potential, E˚cell =2.234 V, Pb metal is the cathode.
Explanation:
The Half cell reactions are
Pb2+(aq) + 2e– > Pb(s) ------E˚ = –0.136 V
Mg2+(aq) + 2e–>Mg(s)------- E˚ = –2.37 V
In a voltaic cell, reduction occurs at the cathode and oxidation occurs at the anode
Mg(s)---->Mg2+(aq) + 2e– ( anodic oxidation)
Pb2+(aq) + 2e----> Pb(s) ( Cathodic reduction)
We can see that Mg has a more negative reduction potential value leading to having a low reduction potential and therefore will occur at the anode since it will be oxidized. On the other hand Pb2+ has a less negative reduction potential and therefore will have a high reduction making it to occur at the cathode and be reduced
Using The standard cell potential, E˚cell = E˚cathode – E˚anode
E˚cell = –0.136 - (–2.37)
E˚cell=2.234 V
Which of these best explains why Earth's tectonic plates move?
b
Convection currents in the asthenosphere make fluid particles move.
Cooling causes contraction and shifting of the fluid particles in the lithosphere.
Cooling causes expansion and shifting of the fluid particles in the asthenosphere
d
Convection currents in the lithosphere make fluids move in a circular motion
Answer:
Cooling causes contraction and shifting of the fluid particles in the lithosphere.
Answer:
The 2 answer
Explanation:
If a truck's tires are filled to a pressure of 2.38 atm when they are 25.0
degrees Celsius, what would their pressure be, if the temperature of the
tire goes up to 52.78 degrees Celsius after driving on the highway.
Answer:
P₂ = 2.60 atm
Explanation:
Given data:
Initial pressure = 2.38 atm
Initial temperature = 25.0 °C
Final pressure = ?
Final temperature = 52.78°C
Solution:
Initial temperature = 25.0 °C (25.0+273 = 298 K)
Final temperature = 52.78°C (52.78+273 = 325.78 K)
According to Gay-Lussac Law,
The pressure of given amount of a gas is directly proportional to its temperature at constant volume and number of moles.
Mathematical relationship:
P₁/T₁ = P₂/T₂
Now we will put the values in formula:
2.38 atm / 298 K = P₂/325.78 K
P₂ = 2.38 atm × 325.78 K / 298 K
P₂ = 775.35 atm. K /293 K
P₂ = 2.60 atm
barium chloride + sodium phosphate
Answer with double replacement
Answer:
Barium chloride + Sodium phosphate → barium phosphate + sodium chloride
Explanation:
Double replacement:
It is the reaction in which two compound exchange their ions and form new compounds.
AB + CD → AC +BD
Chemical equation:
BaCl₂ + Na₃PO₄ → Ba₃(PO₄)₂ + NaCl
Balanced chemical equation:
3BaCl₂ + 2Na₃PO₄ → Ba₃(PO₄)₂ + 6NaCl
The cation and anion of both reactants are exchanged with each other.
Ba²⁺ react with PO₄³⁻ and form Ba₃(PO₄)₂ while Cl⁻ react with Na⁺ and form sodium chloride.
Molecular equation:
Barium chloride + Sodium phosphate → barium phosphate + sodium chloride
Name the group of elements that will not participate in ionic bonding.
Alkali Metals
Alkaline Earth Metals
Transition Metals
Halogens
Noble Gases
Answer:
Noble Gases
Explanation:
Noble gases are very unreactive because they already have a full valence shell and therefore, do not need to bond.
Answer:
Noble gases
Explanation:
In the reaction __S+3O2->2SO3 what coefficient should be placed in front of the S
to balance the reaction?
1
2
3
Answer:
i think 3
Explanation:
Answer:
Your answer Should be 2
Explanation:
because i need to flex my brain cells
Ionic compounds can conduct electricity when dissolved in water due to the presence of free floating ions.
True or False
Answer:
True
Explanation: