Answer to Question #107372 in Molecular Physics | Thermodynamics for Nyx

Question

One liter of water at 43◦C is used to make iced
tea.
How much ice at 0 ◦C must be added to
lower the temperature of the tea to 14 ◦C?
The specific heat of water is 1 cal/g · ◦ C and
latent heat of ice is 79.7 cal/g.
Answer in units of g.

Answer 1

$$Q_{in}=Q_{out}\to m _w c Δ T _w = m _{ ice} L_ f + m_{ ice} c Δ T _{ ice}$$

$$m_{ice}(79.7+1(14-0))=1(1000)(43-14)$$

$$m_{ice}=309.5\ g$$