A student carries out an experiment to identify an unknown metal Use the experim

Question

A student carries out an experiment to identify an unknown metal Use the experimental results and observations from the notebook (below) to identify the metal Data: Mass of metal 0.1230 g Volume of 16 M HCI 40 mL Water temperature 25.0 C Volume of gas produced = 47.68 mL Barometric pressure 767.61 mm Hg Observation: The metal is a silvery color The HCI is a clear, colorless liquid After the tube is flipped, bubbles form After 5 minutes the silvery colored solid is gone and no more bubbles are formed a. Calculate the moles of hydrogen gas based on the data. See Figure on page 1 of the exam. b. If the metal has a charge of + 1, write a balanced chemical equation. Use M as the symbol for the metal - and determine the atomic mass of the metal. c. If the metal has a charge of +2. write a balanced chemical equation - Use M as the symbol for the metal - and determine the atomic mass of the metal. d. Based on your results, identify the unknown metal and support your claim. Be sun include observations that show the reaction went to completion and explain why you did select other possible answers.

Explanation / Answer

a)

moles of H:

PV = nRT

Pgas = Ptotal - Pvap = 767.61-23.8 = 743.81 mm Hg

V = 47.68 mL = 47.68*10^-3 L

T = 298K

so

n = PV/(RT)

n = (743.81)(47.68*10^-3)/(62.3*298) = 0.0019102 mol of H2

b)

charge = +1

for the metal:

2M(s) + 2HCl --> 2M+ + 2Cl- + H2(g)

c)

charge = +2

for the metal:

M(s) + 2HCl --> M+2 + 2Cl- + H2(g)

d)

identify metal claim:

if +1 charged

Molar Mass = mass/mol = (0.1230)/(0.0019102) = 64.391 g/mol

if this is +2 charged

Molar = 1/2 * mass/mol = 1/2* (0.1230)/(0.0019102) = 32.195g/mol

metals with MW = 32.2 g/mo

this is most likelu Cu+

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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