Answer:
91.4%
Explanation:
Potassium hydrogen tartrate, KHT, reacts with KOH as follows.
KHT + KOH → H₂O + K₂T
where 1 mole of acid (KHT) reacts per mole o base (KOH), -That is acid/base ratio 1:1
The endpoint of a titration is the point in which moles of KOH = moles of KHT, you can see this endpoint with an indicator or doing a potentiometric titration.
As the endpoint requires 21.58mL = 0.02158L of a 0.1125M KOH, moles of KOH = moles of KHT are:
0.02158L × (0.1125mol / L) = 2.428x10⁻³ moles of KOH = moles of KHT
To convert these moles to grams you use molar mass of KHT (188.177g/mol):
2.428x10⁻³ moles of KHT × (188.177g / mol) = 0.457g of KHT are in the sample.
As you add 0.500g of sample, percentage of KHT in the sample is:
(0.457g / 0.500g) × 100 =
91.4%-That is the purity of the sample-
g When a 2.75g sample of liquid octane (C8H18) is burned in a bomb calorimeter, the temperature of the calorimeter rises from 22.0 °C to 41.5 °C. The heat capacity of the calorimeter, measured in a separate experiment, is 6.18 kJ/°C. Determine the ΔE for octane combustion in units of kJ/mol octane.
Answer:
The correct answer is 5021.25 kJ/mol octane
Explanation:
The heat absorbed by the calorimeter is given by:
heat absorbed = Ccal x ΔT
Given:
Ccal = 6.18 kJ/ºC (heat capacity of calorimeter)
ΔT= Final temperature - initial temperature = 41.5ºC-22.0ºC = 19.5ºC
We first calculate the heat absorbed:
heat absorbed = 6.18 kJ/ºC x 19.5ºC = 120.51 kJ
The change in internal energy (ΔE) is equal to the heat absorbed by the calorimeter. In order to determine ΔE in kJ/mol we have to divide the heat into the number of moles of octane (C₈H₁₈) burned in the calorimeter.
Molecular weight (C₈H₁₈) = (12 g/mol x 8) + (1 g/mol x 18) = 114 g/mol
Moles of C₈H₁₈= mass/molecular weight= (2.75 g)/(114 g/mol)= 0.024 moles
Finally, we calculate ΔE:
ΔE = heat absorbed/moles of octane = (120.51 kJ)/(0.024 mol octane) = 5021.25 kJ/mol octane
What happens to water 100°C as pressure is increased from 0.7 atm to 1.4 atm
Answer:
Explanation:
The graph shows the phase diagram of water . From it , it is clear that at 100°C water remains in equilibrium with water vapour and at this temperature , the vapour pressure is equal to one atm . So this must be boiling point of water.
At 0.7 atm pressure , boiling point must have been reduced . So when water is at 100°C , it must have been completely in vapour phase .
Now the pressure is increased to 1.4 atm . In this process of increase of pressure , the water in vapour state must have turned into liquid state as soon as the pressure increases beyond 1 atm . Beyond it its boiling point would have increased above 100°C so it can not remain in gaseous phase . At 1.4 atm , its boiling point would have increased to 110°C or so . Hence it must be in liquid phase because its temperature is below its boiling point at that pressure .
Hence water changes from gaseous phase to liquid phase when pressure changes from 0.7atm to 1.4 atm .
show bond formation in magnesium chloride
mg has a 2 in its valence shell
it will become mgcl2
. . . .
: Cl -------- Mg ------ Cl :
. . . .
Seawater is highly saline, which means it contains large amounts of dissolved salt. When seawater freezes and icebergs form, the water in the iceberg doesn’t take the salt with it. What effect will this phenomenon have on the concentration of salt in the water around the iceberg?
Answer:
Because the amount of liquid water decreases and the amount of dissolved salt remains constant, the concentration of salt in the liquid water around the iceberg will increase.
Explanation:
Answer:
Because the amount of liquid water decreases and the amount of dissolved salt remains constant, the concentration of salt in the liquid water around the iceberg will increase.
Explanation:
PLATO exact answer
What letter represents the enthalpy of reaction?
Answer:
Option D. T
Explanation:
Enthalpy change (ΔH) is simply the difference between the heat content of the product (Hp) and the heat content of the reactant (Hr). Mathematically, it is expressed as:
Enthalpy change (ΔH) = Heat of product (Hp) – heat of reactant (Hr)
ΔH = Hp – Hr
From the diagram given above, the difference between the heat content of product and the heat content of reactant is T.
Therefore, the enthalpy change of the reaction is T.
For which of the following reactions will a decrease in pressure shift the equilibrium to the left?
A). 2A2 (g) + B2 (g) --> 2A2B (g)
B). 2AB (g) --> A2 (g)+ B2 (g)
C). 2A2F3 (g) --> 4A (g) + 3F2 (g)
D). 2B (s) + 2HA (aq) --> 2BA (aq) + H2 (g)
Answer: I just took the test, the answer is A.
Explanation:
You are given a mixture of sand, sugar and sulphur. Give the method you will use to separate the three constituents. ___________
Answer:
1:put these in sneaker and add water since sulphur is insoluble and the sugar will dissolve and the sand will settle obtain the sulphur
2:filter the mixture of sand and sugar solution to obtain the sand as residue and solution as filtrate
3:using an evaporating dish evaporate sugar solution to saturation not dryness to get crystals.
MARKING BRAINLIEST!! - Chlorine reacts with methane to form gaseous hydrogen chloride and chloromethane according to the following equation: Cl2 (g) + CH4 (g) → HCl (g) + CH3Cl (g) If 100 mL of chlorine reacted with excess methane at constant pressure and temperature, what volume of chloromethane would be formed? Question 7 options: 50, cannot tell from the information provided, 200, 100
Answer:
100mL of chloromethane
Explanation:
Based on the equation:
Cl₂(g) + CH₄(g) → HCl(g) + CH₃Cl(g)
1 mole of chlorine reacts per mole of methane to produce 1 mole of HCl and 1 mole of chloromethane
Avogadro's law says that equal volumes of all gases, at the same temperature and pressure, have the same number of molecules. Using Avogadro's law we can say of the equation that:
1 mL of chlorine reacts per mL of methane to produce 1 mL of HCl and 1 mL of chloromethane
Because the system stays under constant pressure and temperature.
As 100mL of Cl₂ reacts with excess of CH₄ and 1mL of Cl₂ produce 1mL of CH₃Cl there are produced:
100mL of chloromethaneThe freezing point of pure chloroform is -63.5°C, and its freezing point depression constant is 4.07°C•kg/mol. If the freezing point of a solution of benzoic acid in chloroform is -70.55°C, what is the molality of this solution? 0.58 m 1.7 m 16 m 17 m
Answer: The molality of this solution is 1.7 m
Explanation:
Depression in freezing point:
[tex]T_f^0-T^f=i\times k_f\times m[/tex]
where,
[tex]T_f[/tex] = freezing point of solution = [tex]-70.55^0C[/tex]
[tex]T_f^0[/tex] = freezing point of pure chloroform = [tex]-63.5^0C[/tex]
[tex]k_f[/tex] = freezing point constant of benzene = [tex]4.07^0Ckg/mol[/tex]
m = molality
i = Van't Hoff factor = 1 (for non-electrolyte)
[tex]-63.5-(-70.55)^0C=1\times 4.07^0Ckg/mol\times m[/tex]
[tex]7.05=1\times 4.07^0Ckg/mol\times m[/tex]
[tex]m=1.7[/tex]
Thus the molality of this solution is 1.7 m
Which metal will react spontaneously with Cu2+ (aq) at 25°C?
Hg
Mg
Ag
Au
Answer:
Mg
Explanation:
The standard reduction potentials are
E°/V
Au³⁺(aq ) + 3e⁻ ⟶ Au(s); 1.42
Hg²⁺(aq) + 2e⁻ ⟶ Hg(l); 0.85
Ag⁺(aq) + e⁻ ⟶ Ag(s); 0.80
Cu²⁺(aq) + 2e⁻ ⟶ Cu(s); 0.34
Mg2+(aq) + 2e- ⟶ Mg(s); -2.38
The more negative the standard reduction potential, the stronger the metal is as a reducing agent.
Mg is the only metal with a standard reduction potential lower than that of Cu, so
Only Mg will react spontaneously with Cu²⁺.
Answer:
B. Mg
Explanation:
Select the correct answer.
What is the reason for heat transfer from one substance to another
Answer:
Difference in temperature.
Explanation:
Conduction is the movement of heat energy through a substance or from one substance to another by direct contact of atoms and molecules. Heat moves directly from one molecule to another. The heat energy speeds up the movement of the atoms and they collide with other molecules setting them into faster motion.
How many moles of ZnCl2 will be produced from 61.0 g of Zn, assuming HCl is excess?
Answer: 0.938 moles of [tex]ZnCl_2[/tex] will be produced.
Explanation:
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}[/tex]
moles of zinc:
[tex]\text{Number of moles}=\frac{61.0g}{65g/mol}=0.938moles[/tex]
[tex]Zn+2HCl\rightarrow ZnCl_2+H_2[/tex]
As HCl is in excess , zinc is the limiting reagent and it limits the formation of product.
According to stoichiometry :
1 mole of Zn produce = 1 mole of [tex]ZnCl_2[/tex]
Thus moles of Zn produce = [tex]\frac{1}{1}\times 0.938=0.938[/tex] moles of [tex]ZnCl_2[/tex]
Thus 0.938 moles of [tex]ZnCl_2[/tex] will be produced.
Name the hydro carbon.... I really need your help guyz
Answer:
The given hydrocarbon is Butanol
Easyyyyy plz ...................
Permanent hardness of water is caused by dissolved :-
A) CaCl
B) Ca(HCO3)2
C) Mg(HCO3)2
D) NaOH
Answer:
The answer is B
Explanation:
Answer:
Hello!
Your answer is B) Ca(HCO3)2!!
Explanation:
Hope this helps you!!
itsMATT04
:>
Ascorbic Acid is a organic compound with formula C6H8O6, originally called Hexuronic Acid. It's a white solid, but impure samples can be yellowish. It dissolves well in water to give mildly acidic solutions. It is a mild reducing agent.
What is the other name of Ascorbic Acid?
Explanation:
ascorbic acid is lemon
lemon contain ascorbic acid....
it is organic acid.....
A 35 gram of saturated solution is distilled out completely. If the solubility of the solute is 110, find the amount of residue solute snd distilled water
Answer:
3850g
Explanation:
Solubility is the amount of solute dissolved in a solvent.
Solubility is mass of solute÷mass of solvent
The solvent is 35grams
Solute?
Solubility of solute is 110
110=x/35
= 110 × 35
The amount of residue solute is 3850g
Which type of river is similar to a mature river, but flows more slowly so has less power to change the landscape? Select one: a. Youthful River b. Mature River c. Old Age River
Answer:
The correct option is;
C. Old Age River
Explanation:
Among the three stages of the development of a river, which are the youthful, mature, and old age stages, the old age river is least dynamic
The water is very slow moving with a low gradient and lesser erosive power to alter the landscape which results in the appearance of flood planes
Examples of old age rivers include, lower Ganges, lower Nile, Indus, and Yellow rivers
Old age rivers are characterized by a broad shape, with a wide flood plane, a very gentle gradient and the water current is low.
Answer:c
Explanation:
old age river
Which of the following choices would have a negative entropy change? A. CaCO3(s)−>CaO(s)+CO2(g)
Answer: N2(g) + 3H2(g)- >2NH3(g) denotes a negative entropy change.
Explanation:
Entropy is defined as the extent of disorder in a system. The degree of entropy is more in a gas and less in a solid.
Here, 1st reaction produces ammonia from nitrogen and hydrogen. We can see that four moles of gases produces 2 moles of gaseous product. So the degree of disorder in the system is decreasing. So the entropy is also decreasing.
Label the following as either an Element, Compound, or Mixture.
Answer:
27. Element (Because it contains all same atoms)
28. Compound (It contains atoms held together through chemical bonds)
29. Element (it contains all same atoms)
33. Mixture (It contains different atoms but they are not held together through chemical means)
34. Compound (Different atoms held together through chemical means)
35. Mixture (Mixture of elements and compounds)
30. Element (it contains all same atoms)
31. Mixture (Mixture of elements and compounds)
32. Element (Contain all same atoms although held together through chemical means they are not compounds)
What is the unit charge on each subatomic particles
Answer:
Protons, Electrons, Neutrons
Explanation:
Neutron: 0 or Neutral
Electron: -1 or Negative
Proton: +1 or Positive
For proton and neutron look at neutr for neutral and p for positive
Answer:
❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️
The answer is Protons, Electrons, Neutrons
There is three of them.....
Hope this will help you
❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️
Explanation:
Two oxides of lead were separately reduced to metallic lead by heating in a current of
i) Mass of yellow oxide taken=3.45g
ii) Mass of brown oxide taken=1.227g
Loss in mass during reduction=16g
Show that the above data illustrate the law of multiple proportions.
Answer:
HeyA ❤
Let us consider the mass of oxygen as 1 g.
Mass of lead obtained from yellow oxide = 3.45 g – 0.24 g = 3.21 g
Mass of oxygen = 0.24 g
The mass of lead that combines with 0.24 g of oxygen = 3.21 g
Therefore, mass of lead that combines with 1 g of oxygen = 3.21/ 0.24 = 13.4 g
Mass of lead obtained from brown oxide = 1.227 g – 0.16 g = 1.067
Mass of oxygen = 0.16g
The mass of lead that combines with 0.16 g of oxygen = 1.067 g
Therefore, mass of lead that combines with 1 g of oxygen = 1.067/ 0.16 = 6.66 g
Now, ratio of masses of lead which combines with a fixed mass of oxygen = 13.4 : 6.66
= 2 :1
Thus, masses of lead which combine with the fixed mass of oxygen are in the ratio of (2:1) i.e. small whole numbers.
Hence, the law of multiple proportions is illustrated.
Follow meehhhh Piper ❤
Which of the following may suggest a catalyst has been used in a reaction, given the energy diagram for the same reaction without a catalyst?
Which statement accurately describes a light-year
Answer:
B. distance light travels in a year
got it on edge :)
The statement which accurately and best describes a light-year is the total distance which light travels in a complete year
What is velocity of light?Velocity of light can simply be defined as that fundamental constant that represents the speed of electromagnetic radiation in a vacuum.
The velocity of light = 2.9979 × 10^10cm/s
So therefore, the statement which accurately and best describes a light-year is the distance which light travels in a complete year
Learn more about light-year:
https://brainly.com/question/1224192
#SPJ2
If the external vapor pressure is 2.0 atm , what is the vapor pressure of the water at its boiling point?
Answer:
22
Explanation:
22
The temperature of a sample of liquid water changes from 50°C to 30°C. Which statement best explains the change
that must happen at the molecular level?
ОООО
The molecules move more quickly and their average kinetic energy increases.
The molecules move more slowly and their average kinetic energy decreases.
The molecules move more quickly and their average kinetic energy decreases.
The molecules move more slowly and their average kinetic energy increases.
Answer:
The molecules move more slowly and their average kinetic energy decreases
Explanation:
The increased temperature meant that the atoms in liquid had a greater average energy of motion so as the temperature decreases the reaction would be inverse.
The branch of science which deals with the chemicals bond is called chemistry.
The correct option is B.
The energy which is produced by the motion of the particles is called kinetic energy. Temperature increases the motion of the particles. So, the kinetic energy increases when the temperature rises.
According to the question, the temperature of the water decreases therefore the kinetic energy decreases.
Hence, the correct option is B that is the molecules move more slowly and their average kinetic energy decreases.
For more information, refer to the link:-
https://brainly.com/question/25026730
How would you measure the mass and weight of an object?
Answer:
Weight = mass × earth's gravitational acceleration
Explanation:
Follow the following steps to measure the mass and weight of an object:
Measure the mass of the object using an accurate measuring scale.Multiply the mass of that object with earth's gravitational acceleration which is approximately 9.8 N/kgWhen the name of ions end with ide, is it true that they are all negative ions
For the α anomer of a D-sugar, the anomeric hydroxyl in a Haworth projection Group of answer choices has an upward projection (on the same side as the terminal CH2OH group). has a downward projection (on the opposite side from the terminal CH2OH group).
Answer:
The answer is "choice 2".
Explanation:
Its glycosidic fruit juice facility would be a chromosomal hydrogen bond and an aldehyde (or acetone) team generated from the intramolecular creation of the acetals (or ketal).
Its two heterocycles created at the anomeric core from of the 2 potential stereochemical are named anomers, that's why choice "has a downward projection (from terminal CH2OH party on the opposite side)" is correct.
Which of the following would NOT be a conversion factor for mole to mole calculations for the following reaction: 2Al + 3Cl2 --> 2AlCl3
A: 3 mol Cl2 3 mol Al
B: 2 mol Al 3 mol Cl2
C: 2 mol AlCl3 2 mol Al
D: 3 mole Cl2 2 mol AlCl3
Answer: A. 3 mol [tex]Cl_2[/tex] 3 mol Al:
Explanation:
Te given balanced chemical equation is :
[tex]2Al+3Cl_2\rightarrow 2AlCl_3[/tex]
According to the stochiometry :
A: 3 mol [tex]Cl_2[/tex] 3 mol Al:
3 moles of chlorine reacts with 2 moles of aluminium
B. 2 mol [tex]Al[/tex] 3 mol [tex]Cl_2[/tex]:
2 moles of aluminium reacts with 3 moles of chlorine
C. 2 mol [tex]AlCl_3[/tex] 2 mol Al
2 mol of aluminium produces 2 mol of [tex]AlCl_3[/tex]
D. 3 mol [tex]Cl_2[/tex] 2 mol [tex]AlCl_3[/tex]
3 moles of chlorine produces with 2 moles of [tex]AlCl_3[/tex]
Thus the conversion factor not used for mole to mole calculations is 3 mol [tex]Cl_2[/tex] 3 mol Al:
Below are 5 sets of potential solutes for you to compare. Both members of each pair are very soluble in water. If you had equal molar concentrations of each solution, which member of each pair would theoretically be the better conductor of electricity?
A. CsCl, CaCl2.
B. CaS, Li2S.
C. KBr, AlCl3.
D. AlCl3, MgC2.
E. KI, K2S.
Answer:
Option D. AlCl₃, MgC₂
Explanation:
We need to dissociate all the salts, to determine the i. (Van't Hoff factor).
The salt who has the highest value, will be the better conductor of electricity
CsCl → Cs⁺ + Cl⁻ i = 2
CaCl → Ca²⁺ + Cl⁻ i = 2
CaS → Ca²⁺ + S⁻² i = 2
Li₂S → 2Li⁺ + S⁻² i = 3
KBr → K⁺ + Br⁻ i = 2
AlCl₃ → Al³⁺ + 3Cl⁻ i = 4
MgC₂ → Mg²⁺ + 2C⁻ i = 3
KI → K⁺ + I⁻ i = 2
K₂S → 2K⁺ + S⁻² i = 3
The biggest i, is in pair D.
Answer:
Look at the Screenshot!!!
Explanation:
Got it right on Odessyware ;) Have a nice day!!!!!