Answer:
0.0084
Explanation:
The mole fraction of BaCl₂ (X) is calculated as follows:
X = moles BaCl₂/total moles of solution
Given:
moles of BaCl₂ = 0.400 moles
mass of water = 850.0 g
We have to convert the mass of water to moles, by using the molecular weight of water (Mw):
Mw of water (H₂O) = (2 x 1 g/mol)+ 16 g/mol = 18 g/mol
moles of water = mass of water/Mw of water = 850.0 g/(18 g/mol) = 47.2 mol
The total moles of the solution is given by the addition of the moles of solute (BaCl₂) and the moles of solvent (water):
total moles of solution = moles of BaCl₂ + moles of water = 0.400 + 47.2 mol = 47.6 mol
Finally, we calculate the mole fraction:
X = 0.400 mol/47.6 mol = 0.0084
A 0.380 g sample of an unknown monoprotic acid is titrated with 0.300 M KOH to the equivalence point. It requires 20.1 mL of KOH to reach this point. Elemental analysis is also performed, showing that the acid contains 1.6% H, 22.2% N, and 76.2% O. Use this information to determine the molecular formula and the molar mass of the unknown acid.
Answer:
Explanation:
20.1 mL of .3 M KOH reacts with .38 g of sample monoprotic acid
20.1 mL of .3 M KOH = .021 x .3 mole of KOH
= .0063 mole of KOH
.0063 mole of KOH will react with .0063 mole of monoprotic acid
.0063 mole of monoprotic acid = .38 g
1 mole of monoprotic acid = 60.3 or 60 g
molecular weight of monoprotic acid = 60
Acid contains 1.6 % H , 22.2 % N , 76.2 % O
Ratio of weight of H , N , O in sample
= 1.6 : 22.2 : 76.2
Ratio of moles of H , N , O
1.6 / 1 : 22.2 / 14 : 76.2 / 16
1.6 : 1.585 : 4.76
= 1.6 / 1.585 : 1 : 4.76 / 1.585
= 1 : 1 : 3
Empirical formula
= HNO₃
Mol formula = [tex](HNO_3)_n[/tex] ( let )
Mol weight = n ( 1 + 14 + 3 x 16 )
= 63n .
Mol weight calculated above = 60
63n = 60
n = 1 ( approx )
Mol formula = HNO₃
Mol mass = 63 .
Select all the correct statements, there is more than one.
a. Experiments to determine mechanisms involve looking at indirect evidence to help support or disprove a proposed mechanism.
b. Most intermediates are not typically isolated to determine reaction mechanisms.
c. Transition states can be isolated and characterized to determine reaction mechanisms.
d. Carbocations are very reactive and are typically not isolated for analysis.
e. Carbocations can be routinely isolated (separated from a reaction mixture) and analyzed.
f. Scientists can prove that a specific mechanism exists.
g. Evidence of intermediates sometimes can be seen using techniques such as nuclear magnetic resonance spectroscopy.
Answer:
Experiments to determine mechanisms involve looking at indirect evidence to help support or disprove a proposed mechanism.
Most intermediates are not typically isolated to determine reaction mechanisms.
Carbocations are very reactive and are typically not isolated for analysis.
Scientists can prove that a specific mechanism exists.
Evidence of intermediates sometimes can be seen using techniques such as nuclear magnetic resonance spectroscopy
Explanation:
The study of reaction mechanism and chemical kinetics often form the main thrust of study in organic, inorganic and physical chemistry.
We often want to know the actual processes involved in the conversion of one specie to another. Unfortunately, this information may have to be obtained indirectly by certain chemical reactions or by the use of new instrumental methods such as nuclear magnetic resonance spectroscopy.
Many organic reactions have carbocation intermediates. These carbocations are relatively short-lived and are transient intermediates which are rarely isolated unless they are isolated in a molecular cage using a macromolecule or in superacids.
By intensive study, scientists can proof or disprove the authenticity of any proposed mechanism.
We must know that a transition state has partial bonds. It is often an extremely short-lived specie which cannot be isolated.
What volume of nitrogen gas at STP would react with 37.2 g of magnesium to produce magnesium nitride
Answer:
11.58 L of N₂
Explanation:
We'll begin by calculating the number of mole in 37.2 g of magnesium. This can be obtained as follow:
Mass of Mg = 37.2 g
Molar mass of Mg = 24 g/mol
Mole of Mg =?
Mole = mass /Molar mass
Mole of Mg = 37.2 / 24
Mole of Mg = 1.55 moles
Next, we shall write the balanced equation for the reaction. This is illustrated below:
3Mg + N₂ —> Mg₃N₂
From the balanced equation above,
3 moles of Mg reacted with 1 mole of N₂.
Therefore, 1.55 moles of Mg will react with = (1.55 × 1)/3 = 0.517 mole of N₂
Thus, 0.517 mole of N₂ is need for the reaction.
Finally, we shall determine the volume of N₂ needed for the reaction as follow:
Recall:
1 mole of a gas occupies 22.4 L at STP.
1 mole of N₂ occupied 22.4 L at STP.
Therefore, 0.517 mole of N₂ will occupy = 0.517 × 22.4 = 11.58 L at STP
Thus, 11.58 L of N₂ is needed for the reaction.
The volume of nitrogen gas is 11.58 L of N₂
Calculation of volume:Mole = mass /Molar mass
= 37.2 / 24
= 1.55 moles
Now
1.55 moles of Mg will react with
= (1.55 × 1)/3
= 0.517 mole of N₂
Thus, 0.517 moles of N₂ is needed for the reaction.
Now
1 mole of a gas occupies 22.4 L at STP.
So,
Nitrogen gas is
= 0.517 × 22.4
= 11.58 L at STP
Learn more about the gas here: https://brainly.com/question/3134912
importance of solution in industry?
Answer:
Important industrial processes often utilize solution chemistry. The substance present in the major proportion is called the solvent, whereas the substance present in the minor proportion is called the solute.
Explanation:
Which number should go in the blank?
- H₂ + O2 -> 2H₂O
O
2
3
1
The products of photosynthesis are: Oxygen and carbon dioxide Carbon dioxide and glucose Оооо Carbon dioxide and water Oxygen and glucose
Answer:
oxygen and glucose
Explanation:
Photosynthesis produces oxygen and glucose. Glucose is a sugar which serves as "food" for the plant, and oxygen is just a by-product of the reaction.
How many grams of ^16N will be left from a 16.0 g sample after 21.6 s?
Answer:
2 g
Explanation:
From the question given above, the following data were obtained:
Original amount (N₀) = 16 g
Time (t) = 21.6 s
Amount remaining (N) =?
Next, we shall determine the number of half-lives that has elapse. This can be obtained as follow:
Time (t) = 21.6 s
Half-life (t½) of ¹⁶N = 7.13 s
Number of half-lives (n) =?
n = t / t½
n = 21.6 / 7.13
n = 3
Finally, we shall determine the amount of ¹⁶N remaining. This can be obtained as follow:
Original amount (N₀) = 16 g
Number of half-lives (n) = 3
Amount remaining (N) =?
N = 1/2ⁿ × N₀
N = 1/2³ × 16
N = 1/8 × 16
N = 2 g
Thus, the amount of ¹⁶N remaining is 2 g
What are the names of the stable forms of oxygen?
What volume of 0.450 M barium nitrate solution is needed to prepare 261.0 mL of a solution that is 0.272 M in nitrate
Answer:
78.8 mL .
Explanation:
Ba( NO₃ )₂ ⇄ Ba⁺² + 2 NO₃⁻
1 mole 2 mole
261 mL of .272 M in nitrate contains .261 x .272 gram -ions ( moles ) of NO₃⁻
= .071 gram-ions .
Let the volume of Ba(NO₃)₂ required be v litre .
moles of Ba( NO₃ )₂ in v volume = v x .45 moles
v x .45 moles of Ba( NO₃ )₂ will give 2 x v x .45 moles of NO₃⁻
According to question
2 x v x .45 = .071
v = .07888 litre
= 78.8 mL .
Harry vs Draco who has a better personality
Answer:
I-
Explanation:
Draco was better. Harry didn’t act too much like a main character and was kinda boring.. while Draco’s personality fit the role he played as the bully/mean kid and he still kept me interested.
How many moles of hydrogen atoms are present in 2.41 x 10^24 molecules of CH3OH?
Answer:
16.0 mol H.
Explanation:
Hello!
In this case, since the Avogadro's number help us to compute the moles of methanol in the given molecules:
[tex]n_{CH_3OH}=2.41x10^{24}molecCH_3OH*\frac{1molCH_3OH}{6.022x10^{23}molecCH_3OH}=4.00molCH_3OH[/tex]
Thus, since 1 mole of methanol contains 4 moles of hydrogen atoms, we obtain:
[tex]n_H=4.00molCH_3OH*\frac{4molH}{1molCH_3OH}\\\\n_H=16.0molH[/tex]
Best regards!
Which of the following would result if the gases that are responsible for the greenhouse effect were removed from our atmosphere?
Answer:
Nighttime temperatures would be greatly reduced.
Explanation:
What are the products of the acid-base reaction of sodium carbonate with acetic acid?
Answer:
The mixture quickly foams up with carbon dioxide gas. If enough vinegar is used, all of the baking soda can be made to react and disappear into the vinegar solution. The reaction is: Sodium bicarbonate and acetic acid reacts to carbon dioxide, water and sodium acetate.
Explanation:
hope this helps
Since water can be made of two other substances, it is not an element. Water is a ____________.
Answer:
water is a liquid
Explanation:
WATERRRDR ISSS A LIQUIIIDD
Water is a compound. A compound is made of two or more different elements chemically bonded together. Water is made up of two hydrogen molecules and one oxygen molecule.
