Flame tests are used to identify the presence of a relatively small number of metal ions in a compound. Not all metal ions give flame colors. For Group 1 compounds, flame tests are usually by far the easiest way of identifying which metal you have got.
Answer:
Following are the answer to this question:
Explanation:
In the given question an attachment file is missing, that is attached. please find the attached file, and the following are the description of the given points:
a. At 100 degrees in 100 mL 5 g is dissolved.
For, it required:
b. At 0 degrees 100 mL dissolve in 0.3 g.
So, the dissolve:
After refrigeration 0.12 g will still be dissolved.
c. After dissolving and freezing, precipitation can occur which would still be impure if the cooling is instantaneous. The added solvent was also too hard to recrystallize. The solvent was placed below its place of reservation.
d. Recovery percentage:
The melting point of acetanilide:
Found=109(medium)
Melting point error percentages:
а о
Explanation:
The given cation:
(Rf₂Al₂F₃)³⁺
The oxidation number gives the extent to which a specie is oxidized in a reaction.
This number is assigned based on some rules:
- Elements in combined state whose atoms combines with themselves have an oxidation number of zero.
- The charge carried on simple ions gives their oxidation number.
- Algebraic sum of all the oxidation numbers of atoms in neutral compound is zero. In an ion with more than one kind of atom, the charge on it is the oxidation number.
for the specie given;
Known:
oxidation number of Al = +3
F = -1
charge = +3
let the oxidation number of Rf = k
2k + 2(3) + 3(-1) = +3
2k + 6 - 3 = 3
2k = 0
k = 0
The oxidation state of rutherfodium is 0
learn more:
Oxidation state brainly.com/question/10017129
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Question:
Zinc metal is added to hydrochloric acid to generate hydrogen gas and is collected over a liquid whose vapor pressure is the same as pure water at 20.0 degrees C (18 torr). The volume of the mixture is 1.7 L and its total pressure is 0.987 atm. Determine the number of moles of hydrogen gas present in the sample.
A. 0.272 mol
B. 0.04 mol
C. 0.997 mol
D. 0.139 mol
E. 0.0681 mol
Answer:
The correct option is;
E. 0.0681 mol
Explanation:
The equation for the reaction is
Zn + HCl = H₂ + ZnCl₂
Vapor pressure of the liquid = 18 torr = 2399.803 Pa
Total pressure of gas mixture H₂ + liquid vapor = 0.987 atm
= 100007.775 Pa
Therefore, by Avogadro's law, pressure of the hydrogen gas is given by the following equation
Pressure of H₂ = 100007.775 Pa - 2399.803 Pa = 97607.972 Pa
Volume of H₂ = 1.7 L = 0.0017 m³
Temperature = 20 °C = 293.15 K
Therefore,
Therefore, the number of moles of hydrogen gas present in the sample is n ≈ 0.0681 moles.
Refer to the diagram shown below.
The piston supports the same load W at both temperatures.
The ideal gas law is
where
p = pressure
V = volume
n = moles
T = temperature
R = gas constant
State 1:
T₁ = 20 C = 20+273 = 293 K
d₁ = 25 cm piston diameter
State 2:
T₂ = 150 C = 423 K
d₂ = piston diameter
Because V, n, and R remain the same between the two temperatures, therefore
If the supported load is W kg, then
Similarly,
Because p₁/p₂ = T₁/T₂, therefore
The minimum piston diameter at 150 C is 20.8 cm.
Answer: 20.8 cm diameter