Answer:
b. pH=12
Explanation:
Step 1: Given data
Concentration of NaOH: 0.01 mol/dm³ = 0.01 mol/L = 0.01 M
Step 2: Write the reaction for the dissociation of NaOH
NaOH is a strong base that dissociates according to the following equation.
NaOH(aq) ⇒ Na⁺(aq) + OH⁻(aq)
The molar ratio of NaOH to OH⁻ is 1:1. Then, the concentration of OH⁻ is 0.01 M.
Step 3: Calculate the pOH
pOH = -log [OH⁻] = -log 0.01 = 2
Step 4: Calculate the pH
We will use the following expression.
pH + pOH = 14
pH = 14 - pOH = 14 -2 = 12
How many moles of UF6 would have to be decomposed to provide enough fluorine to prepare 8.99 mol of CF4? (Assume sufficient carbon is available).
Answer:
5.99 moles of [tex]UF_6[/tex]
Explanation:
In this case, we can start with the decomposition of [tex]UF_6[/tex], so:
[tex]UF_6~->~U~+~3F_2[/tex] (Reaction 1)
The [tex]F_2[/tex] can react with carbon to produce [tex]CF_4[/tex]:
[tex]CF_4~+~2F_2~->~CF_4[/tex] (Reaction 2)
If we 8.99 mol of [tex]CF_4[/tex], we can calculate the moles of [tex]F_2[/tex] that we need. In reaction 2 we have a molar ratio of 1:2 (2 moles of [tex]F_2[/tex] will produce 1 mol of [tex]CF_4[/tex]):
[tex]8.99~mol~CF_4\frac{2~mol~F_2}{1~mol~CF_4}~=~17.98~mol~F_2[/tex]
With this value and using the molar ratio in reaction 1 (3 moles of [tex]F_2[/tex] are producing by each mol of [tex]UF_6[/tex]), so:
[tex]17.98~mol~F_2\frac{1~mol~UF_6}{3~mol~F_2}~=~5.99~mol~UF_6[/tex]
So, we will need 5.99 moles of [tex]UF_6[/tex] to produce 8.99 mol of [tex]CF_4[/tex].
I hope it helps!
. What is the difference between the geometries of the bonding of the two oxygen atoms in acetic acid
Answer:
One oxygen atom is tetrahedral while the other is trigonal planar
Explanation:
Acetic acid contains two oxygen atoms. The two oxygen atoms are different and have different geometries.
The first oxygen atom which is part of the carbonyl moiety in the molecule is in a trigonal planar geometry since it is sp2 hybridized.
The second oxygen atom is in sp3 hybridized state hence it is tetrahedral.
Thus one oxygen atom is tetrahedral and the other is trigonal planar in acetic acid.
For each name, draw the structure.
a) (E)-5-Methyl-2-hexene
b) (S)-1,1,2-Trichloro-2-fluoroethane
c) 2,5-Diethyl-1-methylcyclohexanol
Answer:
See figure 1
Explanation:
For this question, we can analyze each molecule:
-) (E)-5-Methyl-2-hexene
In this case, we have a carbon chain of 6 carbons. We have a double bond between carbons 3 and 2. Also, we have a methyl group is placed on carbon 5. Finally, the "E" configuration makes reference to the double bond, the groups on each side of the double bond must have an opposite configuration.
-) 2,5-Diethyl-1-methylcyclohexanol
In this molecule, we have a carbon chain of 2 carbons. In carbon 2 we have two chlorine atoms. In carbon 1 we have a fluorine atom and a chlorine atom. The "S" configuration makes reference to carbon 1 (the chiral carbon), so we have to assign the priorities for each group bonded to carbon 1:
1 = Chlorine
2 = Fluorine
3 = Carbon 2
4 = Hydrogen
If we need an "S" configuration the priorities must be placed in such a way that we have a counterclockwise orientation.
-) 2,5-Diethyl-1-methylcyclohexanol
In this molecule, we have a cyclic carbon chain of 6 carbons. In carbon 1 we have an "OH" group and a methyl group. In carbon s 2 and 5, we have ethyl groups.
See figure 1
I hope it helps!
Calculate the freezing point of a solution of 500.0 g of ethylene glycol dissovled in 500g water. Kf = 1.86 degrees C/m and Kb (which my instructor said was just extraneous info that is not used here) is 0.512 degrees C/m.
Answer: [tex]T_{f}[/tex] = -29.96 °C
Explanation: A solution has a lower freezing point compared to the pure solvent, due to the solute lowering the vapor pressure of the solvent.
The "new" freezing point is calculated as:
[tex]\Delta T_{f} = K_{f}.m[/tex]
[tex]K_{f}[/tex] is the molal freezing-point depression constant
m is molality concentration, i.e., moles of solute per kilogram of solvent
Before calculating freezing point, let's find moles of ethylene glycol ([tex]C_{2}H_{6}O_{2}[/tex]) in the solution:
Molar mass [tex]C_{2}H_{6}O_{2}[/tex] = 62.08 g/mol
For 500 g:
[tex]n = \frac{500}{62.08}[/tex]
n = 8.05 moles
The molality concentration for 0.5kg of water:
m = [tex]\frac{8.05}{0.5}[/tex]
m = 16.11
The freezing point will be:
[tex]\Delta T_{f} = K_{f}.m[/tex]
[tex]\Delta T_{f} = -1.86*16.11[/tex]
[tex]\Delta T_{f} = -29.96[/tex]
Freezing point of a solution of Ethylene Glycol and Water is -29.96°C
According to the following reaction, how many moles of dichloromethane (CH2Cl2) will be formed upon the complete reaction of 0.766 moles methane (CH4) with excess carbon tetrachloride?
methane (CH4) (g) + carbon tetrachloride (g) → dichloromethane (CH2Cl2) (g)
Answer:
[tex]1.53~moles~CH_2Cl_2[/tex].
Explanation:
We can start with the reaction, if we know the formula for each compound:
-) Methane: [tex]CH_4[/tex]
-) Carbon tetrachloride: [tex]CCl_4[/tex]
-) Dichloromethane: [tex]CH_2Cl_2[/tex]
With this in mind, we can write the reaction:
[tex]CH_4~+~CCl_4~->~CH_2Cl_2[/tex]
Now, we can balance the reaction:
[tex]CH_4~+~CCl_4~->~2CH_2Cl_2[/tex]
After this, we have 2 carbon atoms on each side, 4 hydrogen atom on each side, and 4 chlorine atoms on each side.
If we want to know how many moles of [tex]CH_2Cl_2[/tex] would be produced with .766 moles of [tex]CH_4[/tex], we have to check the balanced reaction and use the molar ratio. In this case, the molar ratio is 1 mol [tex]CH_4[/tex] will produce 2 moles of [tex]CH_2Cl_2[/tex] (1:2). So:
[tex]0.766~moles~CH_4\frac{2~moles~CH_2Cl_2}{1~mol~CH_4}=1.53~moles~CH_2Cl_2[/tex]
We wil have [tex]1.53~moles~CH_2Cl_2[/tex].
I hope it helps!
What is the chemical potential of an element in its standard state? Select the correct answer below: −1.00kJ/mol 0kJ/mol 1.00kJ/mol 9.384kJ/mol
Answer:
0 kJ/mol.
Explanation:
Hello,
In this case, since the chemical potential can be represented in terms of the Gibbs free energy of formation:
[tex]\mu = \frac{\Delta _fG}{n}[/tex]
Thus, since the Gibbs free energy of formation of an element is zero, the chemical potential is also zero, or just 0 kJ/mol.
Best regards.
What is the mass in grams of 366mL of ethylene glycol
Answer:
[tex]m=406.26g[/tex]
Explanation:
Hello,
In this case, since the density is defined as the degree of compactness of a substance and it mathematically defined as the ratio of the mass and volume:
[tex]\rho = \frac{m}{V}[/tex]
By knowing that its density is 1.11 g/mL, the mass in 366 mL is:
[tex]m=\rho V=366mL*1.11\frac{g}{mL}\\ \\m=406.26g[/tex]
Regards.
A 0.0447−mol sample of a nutrient substance, with a formula weight of 114 g/mol, is burned in a bomb calorimeter containing 6.19 × 102 g H2O. Given that the fuel value is 6.13 × 10−1 in nutritional Cal when the temperature of the water is increased by 5.05°C, what is the fuel value in kJ in scientific notation?
Answer:
The value is [tex]x = 2.565 *10^{3} \ kJ/kg[/tex]
Explanation:
From the question we are told that
The no of moles of the sample is n = 0.0447 mole
The formula weight is [tex]M = 114 \ g/mol[/tex]
The mass of water is [tex]m = 6.19 *10^{2}\ g[/tex]
The amount of the fuel is [tex]f= 6.13*10^{-1} \ nutritional \ Cal[/tex]
The temperature rise is [tex]\Delta T = 5.05^o[/tex]
Generally
[tex]1 \ nutritional \ Cal => 4.184*10^{3} \ kJ/kg[/tex]
=> [tex]f= 6.13*10^{-1} \ nutritional \ Cal \to x[/tex]
=> [tex]x = \frac{6.13 *10^{-1} * 4.184 *10^{3}}{1}[/tex]
=> [tex]x = 2.565 *10^{3} \ kJ/kg[/tex]
When 1.095 grams of NaOH was dissolved in a coffee cup calorimeter containing 150.00 grams of water, the temperature of the solution changed from 23.50 degree C to 25.32 degree C.
a) Calculate the heat of solution, Delta H_soln.
b) Calculate the Delta H_soln/mole of NaOH. The molar mass of NaOH is 40.00 grams/mole.
c) Is the heat of solution exothermic or endothermic?
Answer:
1. HEAT OF SOLUTION IS 1149.47 J
2. HEAT OF SOLUTION PER MOLE OF NaOH IS 41989.77 J/MOL OR 41.989 KJ/MOL
3. THE REACTION IS EXOTHERMIC
Explanation:
Mass of water = 150 g
Mass of NaOH = 1.095 g
Change in temperature = 25.32 - 23.50 = 1.82 C
Total mass of the mixture = 150 + 1.095 = 151.095 g
Specific heat capacity of water = 4.18 J/ g C
So to calculate the heat of solution, we have:
1. Heat of solution = mass * specific heat * change in temperature
Heat of solution = 151.095 * 4.18 * 1.82
Heat of solution = 1149.47 J
The heat of solution is therefore 1149.47 J or 1.15 kJ
2. Heat of solution per mole
1.095 g of NaOH produces 1149.47 J of heat
1 mole of NaOH contains 40 g
In other words:
1.095 g = 1149.47 J
40 g = x J
xJ = 40 * 1149.47 / 1.095
xJ = -41989.77 J
The heat of solution per mole of NaOH is -41.989 kJ / mol
3. The reaction is exothermic that is heat is evolved from the reaction. This is indicated by the negative sign.
An aerosol is a colloidal _____ suspended in a _____. A.liquid B.solid C.gas
Answer:
An aerosol is a colloidal A. liquid suspended in a C. gas.
Explanation:
Hence an aerosol is a colloidal solid or liquid suspended in a gas Smoke or fog, for example.
define aerosol?Aerosol is a system of equally dispersed, finely divided liquid or solid particles passing through a gas, often air. Dust and other aerosol particles, which serve as the nuclei for condensation and freezing, are crucial to the precipitation process.
Which two forms of aerosols exist?Secondary aerosols develop when gas is converted into a particle, whereas primary aerosols are made up of particles that are added directly to the gas. Key aerosol categories include sulfates, organic carbon, black carbon, nitrates, mineral dust, and sea salt. These substances typically clump together to create complicated mixtures.
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8. An unknown mixture that is uniform, does show the Tyndall Effect, and does
not have any particles settling out is a... *
solution
colloid
suspension
pure substance
Answer:
B. Colloid
Explanation:
Colloid is a mixture that is made up of very small homogeneous particles, thus can not be separated into fractions. Its particles do not settle as other solution, but are evenly dispersed in the medium. Some examples are: liquid milk, jelly, rubber etc
Since colloid is a solution, thus it is made up of two parts; its particles and dispersing medium.
Which of the following substances has the strongest intermolecular forces?
a. HCl
b. C8H18
c. CH3OH
d. CH4
e. CO2
Answer:
HCl.
Explanation:
Of all the type of bond, Ionic bonds are the strongest. Among all the compounds in the options only HCl has ionic bond, rest have covalent bonds. So, the strongest intermolecular forces is in HCl. Ionic bond are formed with the transfer of electrons, one atom is donor and the other is acceptor.
pleaaaaaaaaaaaaaaaase answerrrrrrr quickkkkkkkkkkk am scared can somebody write me a small kinda article about fractional distillation that could consist of points and paragraph both
Answer:
Hey!I think I can help....
Simple Distillation cannot be used to separate a mixture of two or more miscible liquids Fractional Distillation is used to separate such a mixture into its component parts or fractions. The fractions distil over in ascending order of their boiling points,starting with the fraction with the lowest boiling points. For efficient fractional distillation,the difference in the boiling points between successive fractions must be more than 10°C.In the laboratory,the apparatus for fractional distillation is same as the apparatus for simple distillation, except that a fractioning column is introduced between the distillation flask and the condenser.The fractionating column is packed with glass beads,and does the actual separation. The upper part of the column is at a lower temperature than the lower part .Only the vapour with the same temperature as the upper part of the fractionating column passes on the condenser.(This is the fraction with the lowest boiling point)Vapours with higher boiling points condense as they enter the upper part of the fractionating column and the flow back into the distillation flask.This process is repeated until the fraction with the lowest boiling point is distilled over completely. Then,the temperature in the upper part of yhe column rises until the boiling point of the next fraction is reached. This fraction then starts distilling over.The fractional distillation process continues until Al the component fractions in the mixture distil over.Crude oil or petroleum contains many important natural products such as petrol,kerosene,diesel, heavey oil,natural gases and bitumen.Each of these products can be recovered in its pure form by fractional distillation. The fractional distillation plant is made up of two maim parts----boiler,where the crude oil is kept boiling, and the fractionating tower,where yhe actual separation takes place.The fractions with the lower boiling points will emerge near the top part of the tower while those with higher boiling points will come out near the lower part of the tower..... Thank you for the question, I hope it helps you...Thank you.
A pool is 34.0 m long and 31.0 m wide. How many mL of water are needed to fill the pool to an average depth of 4.98 ft? Enter your answer in scientific notation.
____x10___mL
Answer:
Amount of water in mL = 1.75⁹ × 10 ml (Approx)
Explanation:
Given:
Length of pool = 34 m
Width of pool = 31 m
Height of pool = 4.98 ft
Find:
Amount of water in mL
Computation:
1 ft = 0.3048 m
Height of pool = 4.98 (0.3048)
Height of pool = 1.5179 m
Volume of pool = (34)(31)(1.5179)
Volume of pool = 1,754.70 m³
1 m³ = 10⁶ ml
Amount of water in mL = 1,754.70 × 10⁶ ml
Amount of water in mL = 1.75⁹ × 10 ml (Approx)
Which of the following substituents is a moderate activator and an o/p director in electrophilic aromatic substitution reactions?
A) -Br
B) -SO3H
C) -CO2H
D) -NHCOR
E) -CHO
Answer:
NHCOR
Explanation:
In electrophilic aromatic substitution, certain substituents on the aromatic ring such as
-NHCOR are known to enhance ortho-para substitution. These ortho-para activating groups stabilizes the intermediate cation.
These ortho-para activating groups usually consists of species that donate electron density towards the reaction centre thereby stabilizing the carbocation and making the reaction faster.
What kind of intermolecular forces act between a chloramine NH2Cl molecule and a water molecule?
Note: If there is more than one type of intermolecular force that acts, be sure to list them all, with a comma between the name of each force.
Answer:
Dispersion forcesHydrogen bondingDipole-dipole forceExplanation:
Dispersion force is caused by weak Van der Waals attraction between molecules.
Because chloroamine and water are both polar solvents, dipole-dipole force of attraction exists between them. There is also hydrogen bonding present from the water molecules.
Answer: The forces present include;
1. Hydrogen bonding
2. Dispersion bonding
3. Dipole to Dipole bonding.
Explanation:
1. Hydrogen bonding is an electrostatic force that occur between atoms of hydrogen which is covalently bonded to electronegative atoms.
2. Dispersion force is type of force that occur between molecules which is caused by weak Van der Waals attraction between molecules.
3. Dipole -Dipole force occur when atoms with partial charges within a molecule attract themselves with another opposite opposite partial charge that is around the molecule.
Therefore,
Because chloroamine and water are both polar solvents, hydrogen bond, dispersion force and dipole-dipole force of attration occur between them. The hydrogen bonding occur between the water molecules.
taxes you pay to the federal government are: A.federal taxes B.import taxes C.state taxes D.export taxes
Answer:
A federal taxes
Explanation:
because these are taxes paid to the federal government of a state
Answer:
Hey there!
As the name suggests, you pay Federal Taxes to the government.
Let me know if this helps :)
Vegetable oil has a specific heat of 1.67/* Calculate the heat required (in kilojoules) to raise the temperature of 500 g of
vegetable oil from room temp (20.0°C) to 150.0°C
Answer:
[tex]Q=108.55kJ[/tex]
Explanation:
Hello,
In this case, we can compute the required heat by using the following equation:
[tex]Q=mCp(T_2-T_1)[/tex]
Thus, by considering the given mass, specific heat and both initial and final temperature, we obtain:
[tex]Q=500g*1.67\frac{J}{g\°C} *(150.0\°C-20.0\°C)*\frac{1kJ}{1000J} \\\\Q=108.55kJ[/tex]
Regards.
Nurse Antonio measured out 7 grams of sodium chloride (NaCI). Using dimensional analysis, calculate how many moles of NaCI he weighed out.
Answer:
0.119 moles
Explanation:
Given that,
Mass measured by Nurse Antonio is 7 grams of NaCl
To find,
The no of moles of NaCl
Solution,
The number of moles is given by
[tex]n=\dfrac{m}{M}[/tex]
m is given mass
M is molar mass
For NaCl, molar mass is 23+35.5 = 58.5 grams
So,
[tex]n=\dfrac{7}{58.5}\\\\n=0.119\ \text{moles}[/tex]
Therefore, there are 0.119 moles of NaCl.
When you're deciding what to eat, you may want to consider the environmental impact of your meal. Rank these four foods according to the amount of resources (land or grain) required to produce 1kg of each.
1. Egg
2. Chicken
3. Pork
4. Beef
A. Least resources required
B. Most resources required
Answer:
From the most resources to the least, it is 3, 4, 2, 1.
Explanation:
Pork is a large animal but not as much as a cow but it also does not produce as much meat as a cow. In terms of land required and total meat produced, pork is the highest on this list so it is option B.
The most amount of land and resources are taken up by cows, but they also produce a lot more meat than porks so they are in the second place on this list.
Chickens require a small amount of space but produce little meat.
If we guess that each egg weighs 60 grams, 1 kg of eggs equals to almost 17 eggs which a single chicken can produce easily. So the eggs require the least resources which means that they are option A.
I hope this answer helps.
Write a chemical equation for the reaction that occurs in the following cell: Cu|Cu2+(aq)||Ag+(aq)|Ag. Of the two metals, copper and silver, which is the anode and which is the cathode?
Answer:
Explanation:
We are to write a chemical equation for the reaction that occurs in the following cell: Cu|Cu2+(aq)||Ag+(aq)|Ag.
And to determine which one of the two metals, (copper and silver) is the anode and which is the cathode?
The chemical equation for the reaction is as follows:
[tex]\mathbf{Cu + 2Ag^+ \to Cu^{2+}+2Ag}[/tex]
The atoms of the Copper electrodes undergo oxidation and loses two electrons each to form copper II ions [tex](Cu^{2+})[/tex] which go into the solution. The copper then becomes negatively charged and functions as the negative electrode i.e the anode
The oxidation half reaction is:
[tex]\mathsf{Cu \to Cu^{2+} + 2e^-}[/tex]
The silver ions [tex]Ag^+[/tex] becomes reduced by gaining two electrons each from the metallic copper which was deposited into the silver electrode. The silver electrode thus becomes positively charged and functions as the positive electrode. i.e the cathode.
The reduction half reaction is:
[tex]\mathtt{Ag^+ + 1 e^- \to Ag}[/tex]
A liquid boils when its:_________
a. Temperature is equal to 273 K (standard temperature).
b. Vapor pressure is equal to, or greater than, the external pressure pushing on it.
c. Temperature is greater than room temperature.
d. Vapor pressure is exactly 1 atmosphere.
Answer:
option a. Temperature is equal to 273 k. Is the correct one
A boils when its vapour pressure is equal to, or greater than, the external pressure pushing on it. Therefore, option (b) is correct.
What is the boiling point?A boiling point of a liquid can be defined as the temperature at which the vapour pressure becomes equal to the atmospheric pressure of the liquid. The liquid is converted into a vapour at this temperature.
With the addition of heat that the liquid changes into vapour without any increase in temperature. The vapour pressure increases until it is equal to the pressure of the gas surrounding it as a liquid is heated. Bubbles of vaporized liquid are formed within the liquid and rise to the surface.
At the boiling temperature, the vapour inside the bubble will exert enough pressure to prevent the bubble from collapsing. The molecules of a liquid will able to overcome the forces of attraction between molecules to create vapour.
Therefore, at boiling point, the vapour pressure is equal to, or greater than, the external pressure pushing on it.
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how many significants are in 54.0047
Answer:
There are 6
Explanation:
The significant figures in that number are 5 4 0 0 4 7
Hope this helps:)
This graduated cylinder is being used to measure an amount of a liquid. The numbers represent milliliters. What is the most precise measurement of the volume of this liquid? 37.0 ml 37.1 ml 37.2 ml 37.3 ml
Answer:
37.1 mL
Explanation:
To accurately read the measurement using a cylinder, we read the measurement at the meniscus i.e measurement under the curve as shown in the diagram above.
The meniscus i.e the measurement under the curve as shown above is 37.1 mL.
Therefore, the volume of the liquid as obtained from the cylinder is 37.1 mL
Answer:
37.1 ml
Explanation:
a graduated cylinder's measurement is taken at the bottom of the meniscus
What happens to the flame of a Bunsen burner when there is an adequate supply of oxygen available to react with the fuel
Answer:
The answer to your question is given below.
Explanation:
When there is an adequate supply of oxygen available to react with the fuel of a bunsen burner, the flame produce is a non luminous bunsen flame.
This flame i.e non luminous flame produced is much hotter than the luminous and three zones can be seen in the flame. This zones are
1. The zone of unburnt gas.
2. The luminous zone.
3. The outermost non luminous zone.
When an adequate supply of oxygen is available to react with the fuel of a Bunsen burner, there is complete combustion of the fuel and a non-luminous flame is produced.
Complete combustion occurs where there is plentiful supply of oxygen. During the reaction, more heat energy is produced as the flame is non-luminous and less soot is produced.
A non-luminous flame is a flame which produces less light but more heat energy. It is usually blue in color and consists of three zones. These zones are:
1. The zone of unburnt gas.
2. The luminous zone.
3. The outermost non luminous zone.
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A chemistry student answered 81 questions correctly on a 90-question test. What
percent of the questions did they get CORRECT?
HURRY PLEASE
Answer:
90%
Explanation:
it will be 81/90 ×100/1
81 over 90 × 100 over 1
What electron configuration repreents the first excited state of phosphorus?
A. 1s2 2s2 2p6 3s2 3p2 4s1
B. 1s2 2s2 2p6 3s2 3p4
C. 1s2 2s2 2p6 3s1 3p4
D. 1s2 2s2 2p6 3s2 3p3 4s1
E. 1s2 2s2 2p6 3s2 3p3
Answer:
Option C:
1s2 2s2 2p6 3s1 3p4
Explanation:
At a ground level, Phosphorous has an electronic configuration of 1s2 2s2 2p6 3s2 3p3 (using the spdf notation).
Once the atom becomes excited, an electron from the 3s sub-level will gain energy and jump over to the 3p sub-level, making the configuration 1s2 2s2 2p6 3s1 3p4.
The number of electrons at the 3p sub-level will now become 4 because of the addition of the new electron while the number of atoms at the 3S sub-level will reduce to 1 because an electron left this sub-level.
To cool 250 mL of coffee at 90.0°C, you put a 80 g metal spoon cooled to 0.0°C in the coffee. After thermal equilibrium has been reached, what is the final temperature of your coffee? Assume energy is exchanged only between the spoon and the coffee. The specific heat capacity of the metal spoon is 0.80 J/(g°C). Assume the specific heat and density of coffee are the same as those of water, 4.18 J/(g · °C) and 1.00 g/mL. Keep one decimal in your answer.
Answer:
The correct answer is 84.81 °C.
Explanation:
Based on the given information, the volume or mass of coffee is 250 ml, and the mass of metal spoon is 80 grams. The specific heat capacity of metal spoon is 0.80 J/g °C, and the specific heat capacity of coffee is 4.18 J/g °C. In the given case, heat is lost from the coffee and is gained by the spoon.
For finding the final temperature of the coffee, the formula to be used is Q = msΔT, here m is the mass, s is the specific heat, and ΔT is the change in temperature.
Heat lost from the coffee = Heat gained by the spoon
250 × 4.18 (90 - T2) = 80 × 0.8 (T2 - 0)
1045 (90 - T2) = 64 (T2 -0)
94050 - 1045 T2 = 64 T2
94050 = 1045 T2 + 64 T2
94050 = 1109 T2
T2 = 84.84 °C
Consider the following reaction at 298K.
2 H+(aq) + 2 Cr2+(aq) =H2(g) + 2 Cr3+(aq)
Which of the following statements are correct?
a) K > 1
b) ΔGo < 0
c) Eocell < 0
d) n = 2 mol electrons
The question is incomplete, the complete question is;
Consider the following reaction at 298K.
2 H+(aq) + 2 Cr2+(aq) =H2(g) + 2 Cr3+(aq)
Which of the following statements are correct?
Choose all that apply.
K > 1
ΔGo < 0
Eocell < 0
n = 2 mol electrons
The reaction is reactant-favored.
Answer:
K > 1
ΔGo < 0
n = 2 mol electrons
Explanation:
If we look at the reaction; 2 H+(aq) + 2 Cr2+(aq) -----> H2(g) + 2 Cr3+(aq), we will notice that the reaction is a spontaneous reaction because E°cell= 0-(-0.41) = 0.41 V
If the reaction is a spontaneous electrochemical process, we expect it to be product favoured with K>1. Also, a spontaneous reaction must have ∆G<0.
Lastly, we can see that two electrons were transferred according to the balanced equation for the electrochemical reaction.
A student determines the mass of a metal rod to be 39.35 g. it is places in 10.00 mL of water, and the water level rises to 15.00 mL. What is the density of the rod?
Answer:[tex]\rho=7.87g/mL[/tex]
Explanation:
Hello,
In this case, we are analyzing a problem in which the Archimedes principle is considered, thus, as the volume of the metal rod is determined by the difference between the mass of the water and the mass of the water and the rod:
[tex]V_{rod}=15.00mL-10.00mL=5.00mL[/tex]
In such a way, the density turns out:
[tex]\rho =\frac{m_{rod}}{V_{rod}}=\frac{39.35g}{5.00mL} \\ \\\rho=7.87g/mL[/tex]
Regards.