How many moles and grams of NaOH are needed to dissolve in water to make 4 liters of a 2.0M solution?
Solution 1
Solution:
Since we are given the concentration of the solution expressed in molarity and the volume of solution, we can use the equation for molarity defined as the number of moles of solute divided by the volume of the solution in liters:
molarity = moles of solute / volume of solution in liters
We rearrange the expression to solve for the number of moles of the solute:
moles of solute = molarity * volume of solution in liters
Substituting the given values, we have
moles of NaOH = (2.0 mol / 1L) * 4L = 8.0 mol
To calculate for the mass of NaOH solute, we will use the molar mass of NaOH that is equal to 40.0 g/mol:
mass of NaOH = 8.0 mol * (40.0g / 1mol) = 320 grams
📚 Related Questions
Balanced chemical reaction: Mg + 2HNO₃ → Mg(NO₃)₂ + H₂.
m(Mg) = 40.0g.
n(Mg) = m(Mg) ÷ M(Mg).
n(Mg) = 40 g ÷ 24.3 g/mol.
n(Mg) = 1.65 mol.
From chemical reaction: n(Mg) : n(H₂) = 1 : 1.
n(H₂) = n(Mg) = 1.65 mol.
m(H₂) = 1.65 mol · 2 g/mol.
m(H₂) = 3.3 g.
yield = 1.70 g ÷ 3.3 g · 100% = 51.5%.
n - amount of substance.
M - molar mass.
The percentage yield of Hydrogen is 51.1%
We'll begin by calculating the mass of Mg that reacted and the mass of H₂ produced from the balanced equation.
Mg + 2HNO₃ → Mg(NO₃)₂ + H₂
Molar mass of Mg = 24 g/mol
Mass of Mg from the balanced equation = 1 × 24 = 24 g
Molar mass of H₂ = 2 × 1 = 2 g/mol
Mass of H₂ from the balanced equation = 1 × 2 = 2 g
From the balanced equation above,
24 g of Mg reacted to produce 2 g of H₂.
Next, we shall determine the theoretical yield of H₂.
From the balanced equation above,
24 g of Mg reacted to produce 2 g of H₂.
Therefore,
40 g of Mg will react to produce = (40 × 2) / 24 = 3.33 g of H₂.
Thus the theoretical yield of H₂ is 3.33 g
Finally, we shall determine the percentage yield of H₂.
- Actual yield = 1.70 g
- Theoretical yield = 3.33 g
- Percentage yield =?
Percentage yield = (Actual / Theoretical) × 100
Percentage yield = (1.70 / 3.33) × 100
Percentage yield of H₂ = 51.1%
Learn more about percentage yield:
Solution:
Assuming ideal behavior of the helium gas, we can use the universal gas law equation
P1V1/T1 = P2V2/T2
The terms with subscripts of one represent the given initial values while for terms with subscripts of two represent the final conditions.
We rearrange the gas law equation to calculate for the new volume V2:
V2 = P1V1T2 / P2T1
We can now substitute the values to the expression. Therefore,
V2 = (925torr * 392cm3 * 258.15K) / (305.15K * 775torr)
V2 = 396 cm³ or 396 553 mL
Buring a match, you would see the ashes, and that it cannot be it's original substance again.
In rusting of an iron nail, the nail cannot be unrusted easily, which indicates that it has been through a chemical reaction.
4Fe + 3Sn(NO3)4 = 4Fe(NO3)3 + 3Sn is as below
Iron + Tin (iv) nitrate = iron(iii) nitrate + Tin
iron displaces tin from it compound ( Tin (iv) nitrate to form iron (iii) nitrate and tin.
from the equation above 4 moles of Fe displaces 3 moles of Sn(NO3)4 to form 4 moles of Fe(NO3)3 and 3 moles of SN
ppm = (Weight of Solute / Weight of Solution) × 10⁶
Data Given;
Weight of Solute (Hg) = 2.2 mg = 0.0022 g
Weight of Solution (Tap Water) = 750 g
Putting Values,
ppm = (0.0022 g / 750 g) × 10⁶
ppm = 2.93 × 10⁻⁶ × 10⁶
ppm = 2.93
Result:
It means if given tap water is containing 1 million particles then 2.93 particles in that are of Hg.
Answer: When an electron jumps from one state to another, the electron must gain or lose just the right amount of energy to actually travel the distance between the orbits.
Explanation:
Bohr in his structure of atom explained that protons which are positively charged particles and neutrons which are neutral particles, are contained in the center of an atom called as nucleus.
The electrons which are negatively charged particles revolve around the nucleus in fixed orbit or shell or energy levels which are termed as quantized. These energy levels are stable and are stationary along with different energy value. The electron remains in the state until energy is absorbed or released.
The electrons absorb energy when it moves from lower energy state to higher energy state. The electrons lose energy when it moves from higher energy state to lower energy state and thus emit radiations corresponding to the energy gap.
Thus the statement when an electron jumps from one state to another, the electron must gain or lose just the right amount of energy to actually travel the distance between the orbits is incorrect because energy is absorbed when electron jumps from one state to another.
The energy is lost when electron falls from one state to another.
Answer: An electron in a stationary state does not emit radiation
Explanation:
I put that on usa test prep and it says correct. the other person who answered this is wrong
Electrons are scattered in an atom which was given by J.J Thomson in his plum pudding model. J. J. Thomson, Ernest Rutherford and James Chadwick all supported the Dalton's model.
What are Postulates of Dalton's atomic theory?
Dalton's atomic theory was regarding atoms. Following are the postulates of Dalton's atomic theory
a) Atom are indivisible and are the smallest unit of any matter.
b) Atoms of same element have same mass.
c) Atoms of different elements differ in mass.
d) Elements combines with each other in whole number to form compounds.
Thomson matched the atomic structure to the water melon. The red part is positively charged and black seeds are the electrons embedder in that. Rutherford told that atom consist of nucleus and electrons revolves around the nucleus. Chadwick discovered the neutron that is present in the ucleus.
Therefore, J. J. Thomson, Ernest Rutherford and James Chadwick all supported the Dalton's model.
To know more about Dalton's atomic theory, here:
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Reason/Explanation:
Notice what options A, C, and D have on common. Ice, salt and sugar. Those are all dissolvable. Insoluble means un-able to dissolve. It can't dissolve. Wood shavings can't dissolve in water. They will just float. Sugar, salt and ice will all dissolve. Wood shavings won't.
-DustinBR
This question is about physical science/or chemistry.
Incorrect answer is A/C/and D.
Correct answer is B.
Wood shavings is a substances it insoluble and it floats to the water, ocean, and lake.
Hope it helped you.
-Charlie