Answer:
128g of Li, will react in this reaction
Explanation:
Before to start working, we need the reaction:
N₂ and Li react, in order to produce Li₃N (lithium nitride)
N₂ + 6Li → 2Li₃N
1 mol of nitrogen reacts with 6 moles of lithium
We convert the mass of N₂ to moles → 86.1 g . 1 mol/ 28g = 3.075 moles
1 mol of N₂ reacts with 6 mol of Li
Therefore, 3.075 moles of N₂ will react with 18.4 moles of Li
We conver the moles to mass → 18.4 mol . 6.94g / 1mol = 128 g
Answer: The oxidation state of selenium in SeO3 is +6
Explanation:
SeO3 is the chemical formula for selenium trioxide.
- The oxidation state of SeO3 = 0 (since it is stable and with no charge)
- the oxidation number of oxygen (O) IN SeO3 is -2
- the oxidation state of selenium in SeO3 = Z (let unknown value be Z)
Hence, SeO3 = 0
Z + (-2 x 3) = 0
Z + (-6) = 0
Z - 6 = 0
Z = 0 + 6
Z = +6
Thus, the oxidation state of selenium in SeO3 is +6
Answer : The temperature of the gas is, 245.9 K
Explanation :
To calculate the temperature of gas we are using ideal gas equation:
where,
P = pressure of gas = 2770.96 torr = 3.646 atm
Conversion used : (1 atm = 760 torr)
V = volume of gas = 88.84 L
T = temperature of gas = ?
R = gas constant = 0.0821 L.atm/mole.K
w = mass of gas = 609.64 g
M = molar mass of 
gas = 38 g/mole
Now put all the given values in the ideal gas equation, we get:
Therefore, the temperature of the gas is, 245.9 K
Answer:
The mass is recorded as 32.075 g
Explanation:
"The first digit of uncertainty is taken as the last significant digit", this is the rule for significant figures in the analysis. The balance measures the mass up to three decimal places, so it makes the most sense to note the whole figure.
Answer: 
Explanation:
The balanced chemical equation :
To calculate the moles, we use the equation:
According to stoichiometry:
4 moles of 
produces = 902.0 kJ of energy
415.1 moles of produces =
of energy
Thus the change in enthalpy is
