<span>Mass Number = (Atomic Number) + (Number of Neutrons) so you solve for the Number of Neutrons and you get:
Number of Neutrons = (Mass number) - (Atomic Number)
Mass Number equals protons plus neutrons, round atomic weight to nearest whole number
Atomic Number equals number of Protons</span>
answer: 3.40625 moles
Explanation: see the attached pics
1. Salt is KNO₃<span>
<span>This is a </span>strong acid - strong base<span> <span>reaction. </span></span>HNO</span>₃ is the strong acid<span> <span>and </span></span>KOH is the strong
base<span>. </span><span>
H</span>⁺<span> in the HNO₃<span>
and </span></span>OH⁻<span> <span>of the KOH pair up and make </span></span>H₂O(l)<span>. </span><span>
NO</span>₃⁻<span> <span>and </span></span>K⁺<span> <span>pair up to make </span></span>KNO₃ salt<span>. </span><span>
<span>When writing chemical formulas </span>positive ion comes first<span> <span>and second
is negative ion. The charges should be switched. Since </span></span>positive ion has +1 and negative
ion has -1<span> <span>after
the switching off charges </span>the </span>product should be KNO</span>₃.<span>
Balance
equation is </span><span>
HNO</span>₃<span>(aq) + KOH(aq) → H</span>₂O(l) + KNO<span>₃(aq)</span><span>
<span>
2. Salt is Ca(NO</span></span>₃)₂<span>
</span>This is a strong acid - strong
base<span> reaction. </span>HNO₃ is the strong acid<span> and </span>Ca(OH)₂ is the strong base<span>. </span><span>
<span>
H</span></span>⁺<span> in the HNO₃ and </span>OH⁻<span> of the Ca(OH)₂
pair up and make </span>H₂O(l)<span>. </span><span>
Ca²⁺
and </span>NO₃⁻<span> pair up to make </span>Ca(NO₃)₂ salt<span>. </span><span>
<span>
</span><span>Positive ion is </span>Ca²⁺<span>
which has </span></span>+2 charge<span> and negative ion is</span> NO₃⁻<span> <span>which has </span></span>-1 charge<span>. From switching the charges </span>Ca²⁺ gets 1<span> <span>while </span></span>NO₃⁻ gets 2.<span> Hence, the salt should be </span>Ca(NO₃)₂.<span>
Balanced equation
is
</span>2HNO₃<span>(aq) + Ca(OH)</span>₂<span>(aq) → 2H</span>₂O(l) + Ca(NO<span>₃)₂(aq)</span><span>
<span>
3. Salt is CaCl</span></span>₂<span>
This is a strong acid - strong base<span> reaction. </span>HCl is the
strong acid<span> and </span>Ca(OH)</span>₂ is the strong base<span>. </span><span>
<span>
H</span></span>⁺<span> in the HCl and </span>OH⁻<span> of the Ca(OH)₂
pair up and make </span>H₂O(l)<span>. </span><span>
Ca²⁺
and </span>Cl⁻<span> pair up to make </span>CaCl₂ salt<span>. </span><span>
<span>
</span><span>Positive ion is </span>Ca²⁺
which has </span>+2
charge<span> and negative ion is</span> Cl⁻<span> which has </span>-1
charge<span>. By switching the charges </span>Ca²⁺ gets 1<span> while </span>NO₃⁻ gets 2.<span> Hence, the salt should be </span>CaCl₂.<span>
Balance
equation is
</span><span>2HCl(aq) + Ca(OH)</span>₂<span>(aq) → 2H</span>₂O(l) + CaCl₂<span>(aq)
4. Salt is KCl<span>
</span>This is a strong acid - strong base<span> reaction. </span>HCl is the
strong acid<span> and </span>KOH is
the strong base<span>. </span>
<span>
H</span></span>⁺<span> in the HCl and </span>OH⁻<span> of the KOH pair up and make </span>H₂O(l)<span>. </span><span>
K</span><span>⁺ and </span>Cl⁻<span> pair up to make </span>KCl salt<span>. </span><span>
<span>
</span><span>Positive ion is K</span></span><span>⁺ which has </span>+1
charge<span> and negative ion is</span> Cl⁻<span> which has </span>-1
charge<span>. By switching the charges </span>K⁺ gets 1<span> and </span>Cl⁻ also gets 1.<span> Hence, the salt should be </span>KCl.<span>
Balance
equation is
</span><span>HCl(aq) + KOH(aq) → H</span>₂<span>O(l) + KCl(aq)</span>
