<span>1. The evolution of energy
2. the production of a gas
3. the formation of a precipitate
4. color change
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11.....6 for Na, 1 for S and 4 for O
Answer:
The parts of an atom cannot be directly observed.
Explanation:
An atom is the smallest indivisible particle of a substance that can take part in a chemical reaction.
Atoms are not observed with naked eyes because they are found in the realm of very small particles. It is impossible to observe the parts of an atom directly.
As a result of this, models suffice in explaining the parts of an atom. Hence the answer.
Answer:
n= 2.55 moles
Explanation:
Using the formula of ideal gas law:
PV = nRT
nRT=PV
n= PV/RT
n= number of moles
R= Avogadro constant = 0.0821
T= Temperature in K => ºC + 273.15 K
V= volume in L
P= pressure in atm
n= (1 atm)(57.20 L) / (0.0821)(237.15 K)
n= 2.50 moles
Answer: E
How much NH₃ can be produced from the reaction below:
N₂ + 3H₂ - 2NH₃
The stoichiometric ratio of the reactants = 1:3
Given
74.2g of N₂, and Molar mass = 14g/mole
Mole of N₂ = 74.2/14=5.3mols of N₂,
and 14mols of H₂
From this given values and comparing with the stoichiometric ratio, H₂ will be the limiting reagent while N₂ is the excess reactant.
i.e, for every 14mols of H₂, we need 4.67mols of N₂ to react with it to produce 9.33mols of NH₃ as shown (vice versa)
From this we have 9.33mols of NH₃ produced
Avogadro constant, we have n = no of particles = 6.022x10²³ molecules contained in every mole of an element.
For a 9.33mols of NH3, we have 9.33x6.022x10²³molecules in NH3
5.62x10²⁴molecules of NH₃