The two reason behind the invalidity of flame test are false positive and false negative.
while performing the flame test you must have to be accurate otherwise you will get false results may be positive for some element or may be negative in case the element is present. The main reason to get the false positive and false negative is the presence and contamination of sodium.
Explanation:
Use the density formula to determine the volume of the piece of metal.
density
=
mass
volume
Rearrange the equation to isolate volume.
volume
=
mass
density
volume
=
147
g
7.00
g
mL
=
21.0 mL
The final volume in the cylinder after adding the piece of metal is
20.0 mL
+
21.0 mL
=
41.0 mL
In ions atoms lose and gain electrons
Answer:
The specific heat of iron is 0.45 J/g.°C
Explanation:
The amount of heat absorbed by the metal is given by:
heat = m x Sh x ΔT
From the data, we have:
heat = 180.8 J
mass = m = 22.44 g
ΔT = Final temperature - Initial temperature = 39.0°C - 21.1 °C = 17.9°C
Thus, we calculate the specific heat of iron (Sh) as follows:
Sh = heat/(m x ΔT) = (180.8 J)/(22.44 g x 17.9°C) = 0.45 J/g.°C
Answer: 318 K
Explanation:
Combined gas law is the combination of Boyle's law, Charles's law and Gay-Lussac's law.
The combined gas equation is,
where,
= initial pressure of gas = 231 kPa
= final pressure of gas = 168 kPa
= initial volume of gas = 3.25 L
= final volume of gas = 4.35 L
= initial temperature of gas = 
= final temperature of gas = ?
Now put all the given values in the above equation, we get:
At 318 K of temperature will the same gas take up 4.35 liters of space and have a pressure of 168 kPa
