100 g of ice is mixed with 100 g of ${\text{H}}_{\text{2}}\text{O}$ at$\text{100°C}$ . The final temperature of the mixture is

We know

${\text{Q}}_{\text{Lost}}={\text{Q}}_{\text{gain}}$

${\text{m}}_{\text{w}}{\text{s}}_{\text{w}}\left(100-\text{T}\right)={\text{m}}_{\text{ice}}\text{L}+{\text{m}}_{\text{ice}}{\text{s}}_{\text{w}}\Delta \text{t}$

$\Rightarrow \text{100×1}\left(100-\text{T}\right)\text{=100}\left[80+\text{T}\right]$

$\Rightarrow 100-\text{T}=\text{80}+\text{T}$

$\therefore \text{T}=10°\text{C}$