Answer:
The molal concentration of the solution is approximately 0.124 molal
Explanation:
The given parameters are;
The reduced freezing point of the water = -0.23°C
For freezing point depression of a solution, we have;
[tex]\Delta T_f[/tex] = [tex]K_f[/tex]· b·i
Where;
[tex]\Delta T_f[/tex] = The freezing point depression
[tex]K_f[/tex] = Cyroscopic constant (The freezing-point depression constant) = 1.86° Cm⁻¹ for water
b = The molality of the solution
i = van't Hoff factor = 1
Therefore;
[tex]\Delta T_f[/tex] = [tex]T^{\circ}_f - T_f[/tex]
Where;
[tex]T^{\circ}_f[/tex] = The freezing point of pure water = 0°C
[tex]T_f[/tex] = The freezing point of the solution = -0.23°C
∴ [tex]\Delta T_f[/tex] = [tex]T^{\circ}_f - T_f[/tex] = 0°C - (-0.23°C) = 0.23 °C
From, [tex]\Delta T_f[/tex] = [tex]K_f[/tex]· b·i, we have;
0.23°C = 1.86°C/m × b × 1
∴ b = (0.23°C/1.86°C/m) ≈ 0.124 molal
Therefore, the molal concentration of the solution, b ≈ 0.124 molal.
1. When _____
are added or removed from an atom, _____
is formed
Answer:
1.) protons or electrons 2.) ion
Explanation:
Which is an example of a chemical change?
A. heating a block of ice to form liquid water
B. heating a tungsten wire until it glows brightly
C. adding sugar crystals to water to form a clear, colorless liquid
D. passing an electric current through water to form hydrogen and oxygen
Answer:
D. passing an electric current through water to form hydrogen and oxygen
Explanation:
only one that's not just a physical change.
19) Which one of the following statements describes a chemical property of hydrogen gas?
A) Hydrogen gas has a density of 0.00009 g/cm’ at STP.
B) Hydrogen gas burns in air.
C) Hydrogen gas has a boiling point of 20. K at standard pressure.
D) Hydrogen gas is colorless.
Oleic acid's melting point is 14°C and it's boiling point is 360°С. What phase is this substance
at room temperature 25°C?*
A. Solid
B. Liquid
C. Gas
D. Impossible to tell
What is the percent composition (by mass) of MgBr2?
Answer:
13.2% Mg, 86.8% Br
Explanation:
Mg has a molar mass of 24.31g/mol.
Bromine has a molar mass of 79.90 g/mol.
There is one mole of Mg and two moles of Br in the compound:
79.90x2 + 24.31 = 184.11
So the total molar mass of MgBr2 is 184.11.
A percent tells us a part of a whole, so we will divide each part of the mass into the whole mass.
24.31g Mg / 184.11g MgBr2 = .132
159.8g Br / 184.11g MgBr2 = .868
Multiply these decimals by 100 to make them into a percent.
.132 x 100 = 13.2% Mg
.868 x 100 = 86.8% Br
Gold can be pounded out to make a foil only a few atoms thick because of
A. Metallic Bonds
B. Ionic Bonds
C. Valence Bonds
D. Covalent Bonds
Answer:
A. Metallic Bonds
Explanation:
Metallic bonding is a type of chemical bonding that arises from the electrostatic attractive force between conduction electrons and positively charged metal ions.
Colin decided to investigate soil erosion by water. He measured rates of erosion on
model hills made of soil, rock, and sand. Which of the following was the test
(independent) variable?
Answer:
i just had a test on this with 2 attempts and got it wrong on both but i do know that the answer is not...
the steepness of the models hillside
or
the rate of erosion on the hills
so the answer is either...
the amount of water sprayed on the hills
or
the type of material used to construct the model hills
but i think its the amount of water sprayed on the hills...i hope i helped a lil ;)
Explanation:
HELP!! 30 POINTS!!!! What does the energy graph look like for this reaction??
C3H8+5O2 -> 3CO2+4H2O
I have the data, I just need to know how to make the graph, please!!
total enthalpy of reactants= -103.85
total enthalpy of products= =-2147.81
=-2043.96 kJ/mol exothermic reaction
Answer:
Bottle Nose Dolphin ummmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm
Explanation:
Which of these do NOT show malleability a) Iron
b) Sulfur
c) Copper
d) Aluminum
Answer:Sulfur
Hope this helps!
Explanation:
object with a mass of 30 kg is observed to accelerate at the rate of 4 m/s2. Calculate the force required
Can someone please help me with the right answer? I only have one more attempt :(
is copper an elementary substance or a compound?
Two tons of water is pumped into a tank 15 ft. High in 5 minutes. Determine the power output of the pump. (Note: One ton is equal to 2,000 lb. And remember to convert the minutes to seconds.)
Answer:
200 lb•ft/s
Explanation:
From the question given above, the following data were obtained:
Force (F) = 2 tons
Time (t) = 5 mins
Height (h) = 15 ft
Power (P) =?
Next, we shall convert 2 tons to pound. This can be obtained as follow:
1 ton = 2000 lb
Therefore,
2 tons = 2 × 2000
2 tons = 4000 lb
Next, we shall convert 5 mins to seconds. This can be obtained as follow:
1 min = 60 s
Therefore,
5 mins = 5 × 60
5 mins = 300 s
Finally, we shall determine the power of the pump. This can be obtained as follow:
Force (F) = 4000 lb
Time (t) = 300 s
Height (h) = 15 ft
Power (P) =?
P = F × h / t
P = 4000 × 15 / 300
P = 60000 / 300
P = 200 lb•ft/s
Thus, the power of the pump is 200 lb•ft/s
Answer:
It's 200 ft-lb/sec
Explanation:
I did it before!
helllllppppppp pleaseeeeeee
The large number before a molecule in a chemical formula is called a _______________.
O subscript
O coefficient
O equation
Answer:
Subscript
Explanation:
The little number you see to the right of the symbol for an element is called a subscript. That number indicates the number of atoms of that element present in the compound. When balancing an equation, you can change the coefficients but not the subscripts.
hope this helps! if not, it's got to be coefficient or equation
El etanol combustiona con el oxigeno produciendo dióxido de carbono gaseoso y agua: En un proceso se hacen reaccionar 450.2 g de dioxígeno con 998. 2 g de etanol . a) ¿Cuál de los reactivos es el limitante? b) Calcule la masa de dióxido de carbono que se formará c) ¿ Cuanto del reactivo en exceso quedará sin reaccionar?
Answer:
uh oh stinky uh oh stinky
Determine the representative particles of
0.075 mol Ti
2.10 mol CO2
Answer:
0.o75 mol Ti = 4.5x10∧22
2.10 mol CO2 = 1.26x10∧24 molecules
hope this helped
Determine from the balanced chemical reaction if
the derived mole ratio is correct or incorrect.
2FeBr3 + 3Na2S → Fe2S3 + 6NaBr
2 moles FeBra
3 moles Na2S
Answer:
Correct
Explanation:
According to the balanced chemical reaction, 2 mol FeBr3 are consumed for every 3 mol Na2S consumed.
A balanced equation obey the law of conservation of mass. The coefficients are the numbers which are added to balance the chemical equation. Here the given mole ratio is correct.
What is a balanced equation?An equation in which the number of atoms of reactants and products on both sides of the equation are balanced is defined as the balanced chemical equation. The coefficients which are added in front of the formula of each component represents the number of the species.
A molar ratio denotes the ratio between the amounts in moles of any two compounds involved in a balanced chemical reaction. By comparing the coefficient of each component, the mole ratio can be determined.
Here for the given reaction, for every 3 moles of Na₂S consumption 2 moles of FeBr₃ is also consumed. So the molar ratio of Na₂S to FeBr₃ is 2/3. Molar ratios are used as the conversion factors between products and reactants in many chemistry problems.
To know more about mole ratio, visit;
https://brainly.com/question/29095152
#SPJ7
what is the pH when h+=0.045 M?
Answer:
pH≈1.35
Explanation:
-log(0.045)≈1.35
A student asks why the ashes from a fire have much lower mass than the wood that was burned. Which of the following is the correct answer to the student's question?
Answer:
It have lower mass because much of the ashes came from the burned wood. (ashes were like little parts of the wood). plus most of the fuel was turned in to fire (light and heat energy) so yeah ash is just the left over.
Explanation:
What number is pointing to the area where magma is less dense due to
heat?
Answer:
I think it's 2
Explanation:
The magma gets so hot, it floats up before cooling and sinking again
help please see attached file
Answer:
balanced equation of glucose
6CO2 + 6H2O----------C6H12O6 + 6O2
in the presence of sun light.
Sulfuric acid reacts with aluminum hydroxide by double replacement producing aluminum sulfate and water Write chemical reaction. If 30 g of sulfuric acid reacts with 25 g of aluminum hydroxide, identify the limiting reactant?
Answer: [tex]H_2SO_4[/tex] is the limiting reagent.
Explanation:
A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.
The balanced chemical equation is:
[tex]3H_2SO_4(aq)+2Al(OH)_3(aq)\rightarrow Al_2(SO_4)_3(aq)+6H_2O(l)[/tex]
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]
[tex]\text{Moles of} H_2SO_4 =\frac{30g}{98g/mol}=0.31moles[/tex]
[tex]\text{Moles of} Al(OH)_3=\frac{25g}{78g/mol}=0.32moles[/tex]
According to stoichiometry :
3 moles of [tex]H_2SO_4[/tex] require = 2 moles of [tex]Al(OH)_3[/tex]
Thus 0.31 moles of [tex]H_2SO_4[/tex] will require=[tex]\frac{2}{3}\times 0.31=0.21moles[/tex] of [tex]Al(OH)_3[/tex]
Thus [tex]H_2SO_4[/tex] is the limiting reagent as it limits the formation of product and [tex]Al(OH)_3[/tex] is the excess reagent.
Ohio Achievement Test Coach Science, Grade 5
10. Bob first blows whistle hard. Then he blows the same whistle gently. What
changed when Bob blew the whistle the second time?
POSTTEST
A pitch
B. volume
C. pitch and volume
D. frequency
This is agree or disagree I need help ASAP!!
Answer:
disagree
sometimes they attract
Explanation:
Answer:
Explanation:
2. Agree
3. Agree
4. Agree
5. agree
6. disagree
If im wrong its because im tired lol
Covert 50oC to k
(I’ll mark you as brainlister)
Answer:
323 K
Explanation:
To convert Celcius to kelvin first you need to remember this equation:
C + 273 = K (K = kelvin and C = celsius)
Next, you substitute with what you have given:
50 + 273 = K
Solve the equation by adding 50 and 273
k = 323
If you had 14.5 moles of gold, how many atoms would you expect to have?
Answer:
(14.5 mol) x (6.022 x 10^23 atoms/mol) = 8.73 × 10^24 atoms
Explanation:
pls mark brainliest
How is a calorimeter used in this experiment different from the ones used to find the energy content of a snack
Answer:
Kindly check the explanation section.
Explanation:
PS: Note that enough information are not being provided and we do not know the experiment this question is all about. However, some information are provided below which is going to aid in solving when you get access to the main question.
The determination of the heat transferred from one substance to another is one of the important aspect in science. The method in which this heat is being measured is known as calorimetry and the instrument used in this technique is known as the calorimeter.
When the energy content of a snack is needed to be calculated, there is the need use a type of instrument known as bomb calorimeter.
Most of the calorimeters used by students are not so expensive like the used in the industries. Most of these calorimeters operates at a constant pressure while the Bomb Calorimeter operates at constant volume.
When one element replaces another element the reaction is known as a _ replacement reaction
Answer:
Single replacement reaction
Explanation:
A single replacement reaction, sometimes called a single displacement reaction, is a reaction in which one element is substituted for another element in a compound.
You are melting a chocolate and accidentally have the stove up to high. the chocolate starts to burn on the bottom of your pot. Physical or Chemical Change?
Answer:
it is a chemical change because it can't be change back to it normal position when it gets burnt