The moles of I₂ will form from the decomposition of 3.58g of NI₃ is 0.0136 moles.
<h3>How we calculate moles?</h3>
Moles of any substance will be calculated as:
n = W/M, where
W = required mass
M = molar mass
Given chemical reaction is:
2NI₃ → N₂ + 3I₂
Moles of 3.58g of NI₃ will be calculated as:
n = 3.58g / 394. 71 g/mol = 0.009 moles
From the stoichiometry of the solution, it is clear that:
2 moles of NI₃ = produce 3 moles of I₂
0.009 moles of NI₃ = produce 3/2×0.009=0.0136 moles of I₂
Hence, option (3) is correct i.e. 0.0136 moles.
To know more about moles, visit the below link:
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Answer:
number of moles = 6.393 moles
Explanation:
One mole of any substance contains Avogadro's number (6.022 * 10^23) of atoms.
Therefore, to know the number of moles that contain 3.85 * 10^24 atoms, all we have to do is cross multiplication as follows:
1 mole ......................> 6.022 * 10^23
?? moles ..................> 3.85 * 10^24
number of moles = (3.85 * 10^24 *1) / (6.022 * 10^23)
number of moles = 6.393 moles
Hope this helps :)
Answer:
pH =3.8
Explanation:
Lets call the monoprotic weak acid HA, the dissociation equilibria in water will be:
HA + H₂O ⇄ H₃O⁺ + A⁻ with Ka = [ H₃O⁺] x [A⁻]/ [HA]
The pH is the negative log of the H₃O⁺ concentration, we know the equilibrium constant, Ka and the original acid concentration. So we will need to find the [H₃O⁺] to solve this question.
In order to do that lets set up the ICE table helper which accounts for the species at equilibrium:
HA H₃O⁺ A⁻
Initial, M 0.40 0 0
Change , M -x +x +x
Equilibrium, M 0.40 - x x x
Lets express these concentrations in terms of the equilibrium constant:
Ka = x² / (0.40 - x )
Now the equilibrium constant is so small ( very little dissociation of HA ) that is safe to approximate 0.40 - x to 0.40,
7.3 x 10⁻⁶ = x² / 0.40 ⇒ x = √( 7.3 x 10⁻⁶ x 0.40 ) = 1.71 x 10⁻³
[H₃O⁺] = 1.71 x 10⁻³
Indeed 1.71 x 10⁻³ is small compared to 0.40 (0.4 %). To be a good approximation our value should be less or equal to 5 %.
pH = - log ( 1.71 x 10⁻³ ) = 3.8
Note: when the aprroximation is greater than 5 % we will need to solve the resulting quadratic equation.
1- metal and non metal
2- true
3- chlorine
