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.
Answer:
121 K
Explanation:
Step 1: Given data
- Initial volume (V₁): 79.5 mL
- Initial temperature (T₁): -1.4°C
- Final volume (V₂): 35.3 mL
Step 2: Convert "-1.4°C" to Kelvin
We will use the following expression.
K = °C + 273.15 = -1.4°C + 273.15 = 271.8 K
Step 3: Calculate the final temperature of the gas (T₂)
Assuming ideal behavior and constant pressure, we can calculate the final temperature of the gas using Charles' law.
V₁/T₁ = V₂/T₂
T₂ = V₂ × T₁/V₁
T₂ = 35.3 mL × 271.8 K/79.5 mL = 121 K
Salt=compound, soda=liquid solution, aluminum foil=element, milk=colloid,
steel=solid solution
Molar mass of CuSO4 * 5 H2O
= 63.546 + 32 + 16*4 + 5*18
= 249.546 g/mol
Mass of water in that formula: 5 * 18 = 90 g/mol
Percent by mass of water = 90 / 249.546 = 36%
<span>So, 36% of your 8.22 g is water. 0.36 * 8.22= 2.95 g of water
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