Answer:
pH = 9.48
Explanation:
We have first to realize that NH₃ is a weak base:
NH₃ + H₂O ⇔ NH₄⁺ + OH⁻ Kb = 1.8 x 10⁻⁵
and we are adding this weak base to a solution of NH₄NO₃ which being a salt dissociates 100 % in water.
Effectively what we have here is a buffer of a weak base and its conjugate acid. Therefore, we need the Henderson-Hasselbach formula for weak bases given by:
pOH = pKb + log ( [ conjugate acid ] / [ weak base ]
mol NH₃ = 0.139 L x 0.39 M = 0.054 mol
mol NH₄⁺ = 0.169 L x 0.19 M = 0.032 mol
Now we have all the information required to calculate the pOH ( Note that we dont have to calculate the concentrations since in the formula they are a ratio and the volume will cancel out)
pOH = -log(1.8 x 10⁻⁵) + log ( 0.032/0.054) = 4.52
pOH + pH = 14 ⇒ pH = 14 - 4.52 = 9.48
The solution is basic which agrees with NH₃ being a weak base.
Answer:
Covalent compounds are held by intermolecular forces while network solids are held by strong bonds in unit cells which are closely packed together.
Explanation:
Covalent compound molecules are held by vanderwaals forces which are relatively weak but strong enough to hold some covalent molecules together in the solid state. However, network solids contain atom to atom covalent bonds arranged in an orderly manner and regular repeating unit cells to form a rigid three dimensional network solid.
<span>Although two centuries old, Dalton's atomic theory remains valid in modern chemical thought. 1) All matter is made of atoms. Atoms are indivisible and indestructible. 3) Compounds are formed by a combination of two or more different kinds of atoms.</span>
To do this problem, we must first look at the balanced chemical equation for the decomposition of potassium chlorate:
<span>2KClO3 --> 2KCl + 3O2 </span>
<span>We can take the given amount of grams, and use the molar mass of KClO3 to convert to moles. Then, we can use the stoichiometric ratios to relate moles of KClO3 to moles of O2. </span>
<span>(39.09)+(35.45)+(3*15.99)= 122.51 g/ mol = molar mass of KClO3 </span>
<span>45.8 g KClO3/ 122.51 g/ mol KClO3 = .374 moles KClO3 </span>
<span>.374 mol KClO3 *(3 moles O2/2 mol KClO3)= .560 moles O2 </span>
<span>Once we have moles of O2, we can convert to grams of O2. </span>
<span>(2*15.99)= 31.98 g/mol = molar mass of O2 </span>
<span>(.560 moles O2) (31.98 g/mol)= 17.91 g O2 </span>
<span>Hope this helps :)</span>
