0.103 g of Zn (s) is combined with 50.0 mL HCl in a reaction vessel, the temperature changes from 22.5oC to 23.7oC. What is the ΔHof for the Zn2 + (aq). Use q = CmΔT, the C for liquid water (4.18 J/g oC), and the density of 1.0 g/mL to calculate the mass of HCl.

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Chemistry

Salma Church

11 September, 18:48

0.103 g of Zn (s) is combined with 50.0 mL HCl in a reaction vessel, the temperature changes from 22.5oC to 23.7oC. What is the ΔHof for the Zn2 + (aq). Use q = CmΔT, the C for liquid water (4.18 J/g oC), and the density of 1.0 g/mL to calculate the mass of HCl.

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Omari Mahoney · Answer 1

Given:

0.103 grams of Zinc (solid)

50 ml of HCl

Density of HCl = 1.0 g/mL

Initial Temperature (Ti) = 22.5 C

Final Temperature (Tf) = 23.7 C

Solve for the mass of HCl:

50 mL * 1.0 g/mL = 50 g

Assume that the Cp for HCl is similar to the Cp of water:

q = mCpdT

= mCp (Tf - Ti)

= 50 g * 4.18 J/gC * (23.7 - 22.5)

q = 250.8 J = H