Answer:
The nichrome wire is dirty.
The solution is contaminated.
Explanation:
If the nichrome wire is dirty, it may contain sodium contaminants which may be responsible for the yellow flame. The nichrome wire is first inserted into the flame without the sample to check for impurities.
The test solution may also have been contaminated. This leads to the appearance of a colour different from the expected colour of the test cation in the solution.
Answer:
0.26×10²³ molecules
Explanation:
Given data:
Volume of gas = 1.264 L
Temperature = 168°C
Pressure = 946.6 torr
Number of molecules of gas = ?
Solution:
Temperature = 168°C (168+273= 441 K)
Pressure = 946.6 torr (946.6/760 = 1.25 atm)
Now we will determine the number of moles.
PV = nRT
P= Pressure
V = volume
n = number of moles
R = general gas constant = 0.0821 atm.L/ mol.K
T = temperature in kelvin
n = PV/RT
n = 1.25 atm ×1.264 L / 0.0821 atm.L/ mol.K ×441 K
n = 1.58 /36.21 /mol
n = 0.044 mol
Now we will calculate the number of molecules by using Avogadro number.
1 mol = 6.022×10²³ molecules
0.044 mol × 6.022×10²³ molecules/ 1mol
0.26×10²³ molecules
Explanation:
A mixture is made of two or more substances that are not chemically combined whereas a compound is made of 2 or more elements that are chemically combined. The elements that make up the compound are combined in fixed ratios.
Answer:
The enthalpy of atomization is the enthalpy change that accompanies the total separation of all atoms in a chemical substance. This is often represented by the symbol ΔₐₜH or ΔHₐₜ. All bonds in the compound are broken in atomization and none are formed, so enthalpies of atomization are always positive.
Explanation:
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Fats , oils , waxes and sterols are collectively known as lipidsand the true fats contain only carbon , hydrogen and oxygen
