Answer:
0.07789 M is the sodium hydroxide concentration.
Explanation:
Mass of potassium hydrogen phthalate = 0.6986 g
Molar mass of potassium hydrogen phthalate = 204.22 g/mol
Moles of potassium hydrogen phthalate = 

According to reaction , 1 mole og KHp reactswith 1 mole of NaOH , then 0.003421 moles of KHp will react with :

Moles of NaOH = 0.003421 mole
Volume of NaOH solution = 43.92 ml = 0.04392 L ( 1 mL = 0.001L)

Concentration of NaOH :

0.07789 M is the sodium hydroxide concentration.
In this question, you are given the NaOH volume but asked for concentration.
Don't forget that for every 1 mol of NaOH there will be 1 mol OH- ion, but for every 1 mol of H2SO4 there will be 2 mol of H- ion.
To neutralize you need the same amount of OH- and H+, so the equation should be:
OH-= H+
<span>35.50cm3 * x*1= 25cm3* 0.2mol/dm3 *2
</span>x= 10/35.5 mol/dm3= 0.2816/dm3
<u>Given:</u>
Mass of Ag = 1.67 g
Mass of Cl = 2.21 g
Heat evolved = 1.96 kJ
<u>To determine:</u>
The enthalpy of formation of AgCl(s)
<u>Explanation:</u>
The reaction is:
2Ag(s) + Cl2(g) → 2AgCl(s)
Calculate the moles of Ag and Cl from the given masses
Atomic mass of Ag = 108 g/mol
# moles of Ag = 1.67/108 = 0.0155 moles
Atomic mass of Cl = 35 g/mol
# moles of Cl = 2.21/35 = 0.0631 moles
Since moles of Ag << moles of Cl, silver is the limiting reagent.
Based on reaction stoichiometry: # moles of AgCl formed = 0.0155 moles
Enthalpy of formation of AgCl = 1.96 kJ/0.0155 moles = 126.5 kJ/mol
Ans: Formation enthalpy = 126.5 kJ/mol
Answer:
https://download.cnet.com/1-Click-Answers/3000-2378_4-10060189.html
Explanation: