Answer:
145 grams of a 0.480 % KCN solution contains 697 mg of KCN.
Explanation:
w/w % : The percentage mass or fraction is mass of the of solute present in 100 grams of the solution.

given = w/w% = 0.480 %
Mass of solute that KCN = 697 mg = 0.697 g
(1 mg = 0.001 g)
Mass of the solution = ? = x


x = 145.21 g ≈ 145 g
145 grams of a 0.480 % KCN solution contains 697 mg of KCN.
Answer:
Substitution and Na(No3) + Fe
Explanation:
<span>the answer is 1 the 4s1 electron........................
</span><span>
</span>
1°/ . 2 Al + 6 HCl → 2 AlCl3 + 3 H2
<span>k1 = n(Al) / 2 = 4,5 / 2 = 2,25 </span>
<span>k2 = n(HCl) / 6 = 11,5 / 6= 1,92 </span>
<span>k2 < k1 ==> HCl is the limiting reactant </span>
<span>6 mol of HCl ---> 2 mol of H2 </span>
<span>11,5 mol of HCl ---> 3,83 mol of H2 </span>
Molar mass Na = 23.0 g/mol
1 mol ---- 23.0 g
n mol ---- 69 g
n = 69 / 23.0
n = 3.0 moles
1 mole -------- 6.02x10²³ molecules
3.0 moles ---- ?
3.0 * 6.02x10²³ / 1
= 1.806x10²⁴ molecules
hope this helps!