Before you begin titration, drops of indicator are added to the Erlenmeyer flask. This happens when preparing to measure pH change.
This question is quite vague, as the initial concentration of ethanol is not provided. However, from experience I can tell you that most laboratory work is done with 98% ethanol, and not absolute ethanol (100%). So in order to calculate the final concentration, we need to take the given values, which includes the initial concentration (98%), the initial volume (50.0mL) and the final volume (100.0mL). We apply the following equation to calculate the final concentration:
C1V1 = C2V2
C1 = Initial concentration
C2 = Final concentration
V1 = Initial volume
V2 = Final volume
(98%)(50.0mL) = (C2)(100.0mL)
Therefore, the final concentration (C2) = 49%
Answer:Ethyne
Explanation:
Ethyne is more commonly known under the trivial name acetylene. It is the simplest of the alkynes, consisting of two carbon atoms connected by a triple bond, leaving each carbon able to bond to one hydrogen atom. Since both carbon atoms are linear in shape, all four atoms lie in a straight line.
Answer:
Partial pressure O₂ = 1.78 atm
Explanation:
We can apply the mole fraction to solve the question:
Moles of gas / Total moles = Partial pressure of gas / Total pressure
Total moles = 1 H₂ + 2.5 He + 2O₂ = 4.5 moles
2 mol O₂ / 4.5 mol = Partial pressure O₂ / 4 atm
(2 mol O₂ / 4.5 mol ) . 4 atm = Partial pressure O₂ → 1.78 atm
The atomic mass of an element is a result of the weighted average of the masses of its corresponding isotopes.
<span>We are given: </span>
<span>Sb-121: mass of 120.9038 amu, x abundance </span>
<span>Sb-123: mass of 122.9042 amu, 1-x abundance </span>
<span>To be able to calculate the atomic mass of antimony, we multiply the percent abundances of the isotopes by their respective atomic masses. Then, we add,</span>
<span>Atomic mass = (Atomic Mass of Sb-121) (% Abundance) + (Atomic Mass of Sb-123) (% Abundance )</span>
121.760 amu = (120.9038 amu)(x) + (122.9042 amu)(1 -x)
<span>Solving for x,</span>
<span>120.9038x + 122.9042 -122.9042x = 121.760</span>
<span>x = 0.57096 or 57.096% </span>
1-x = 1-0.57096 = 0.42904 or 42.90%
