Three student chemists measured 50.0 mL of 1.00 M NaOH in separate Styrofoam cof

Question

Three student chemists measured 50.0 mL of 1.00 M NaOH in separate Styrofoam coffee cup calorimeters. Brett added 50.0 mL of 1.10 M HCl to his solution of NaOH; Dale added 45.5 mL of 1.10 M HCl (equal moles) to his NaOH solution. Lyndsay added 50.0 mL of 1.00 M HCl to her NaOH solution. Each student recorded the temperature change and calculated the enthalpy of neutralization. Identify the student who observes a temperature change that will be different from that observed by the other two chemists. Explain why and how (higher or lower) the temperature will be different.

Explanation / Answer

Initial mole of HCl = 50.0 * 1.00 /1000 = 0.0500 mol

Brett added, 50.0*1.10 / 1000 = 0.0550 mol of HCl

Dale added, 45.5 * 1.10 / 1000 = 0.05005 mol of HCl

Lyndsay added 50.0 * 1.00 / 1000 = 0.0500 mol of HCl

SInce Dale and Lyndsay added almost same quantiites, so they will get same temperatures. But Brett get a different temperature value.

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.