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:
21 g of N₂ are produced by the decomposition
Explanation:
The reaction is: 2 NaN3 → 2 Na + 3 N2
2 moles of sodium nitride decompose in order to produce 2 moles of Na and 3 moles of nitrogen gas.
According to stoichiometry, ratio is 2:3. Therefore we say,
2 moles of nitride can produce 3 moles of N₂
Then, 0.5 moles of NaN₃ will produce (0.5 . 3) / 2 = 0.75 moles of N₂
We convert the moles to mass, to find the answer
0.75 mol . 28 g / 1 mol = 21 g
The answer is D, because gems are usually not mettallic
Three uses of coal:
1. Electricity generation
2. Steel production
3. Cement manufacturing and as a liquid fuel
Hope it helps!
Answer:
The concentration of the solution is 1.364 molar.
Explanation:
Volume of perchloric acid = 29.1 mL
Mass of the solution = m
Density of the solution = 1.67 g/mL
Percentage of perchloric acid in 48.597 solution :70.5 %
Mass of perchloric acid in 48.597 solution :
= 
Moles of perchloric acid = 
In 29.1 mL of solution water is added and volume was changed to 250 mL.
So, volume of the final solution = 250 mL = 0.250 L (1 mL = 0.001 L)
The concentration of the solution is 1.364 molar.
