Question

slader An experiment is carried out where 13.9 g of solid NaOH is dissolved in 250.0 g of water in a coffee-cup calorimeter. Dissolution is not a chemical reaction, but is a chemical process: NaOH(s) → Na+(aq) + OH-(aq) The mixture can be assumed to have the same specific heat capacity as liquid water (4.18 J g-1 ºC-1). What is the mass of the surroundings where the temperature is being measured in the experiment?

Answer 1

Answer:

The mass of the surrounding is $M_t = 263.9 \ g$

Explanation:

From the question we are told that

      The mass of  $NaOH$ is  $m = 13.9 \ g$

      The mass of water is $m_w = 250.0g$

      The chemical equation for the dissociation process is

       $NaOH _{(s) } ---> Na^{+}_{(aq)} + OH^{-} _{(aq)}$

       The specific heat capacity of the mixture is $c_p = 4.18 J g^{-1} C^{-1}$

       

The combined mass of the solution is

         $M_t = 13 + 250$

         $M_t = 263.9 \ g$

The mass of the surround here is the mass of the coffee-cup calorimeter and this contain the mixture ( water and the NaOH ) so the mass of the surrounding is  

  $M_t = 263.9 \ g$