Question

plz can someone help me?

Answer 1

I would use the unit-factor method to solve this question, but formulas are easier to write about. The relevant formula to use is:

Q = (CP)(delta-T)(n) where Q is the heat energy transferred into or out of a material, CP is the heat capacity of the material, delta-T is the temperature change, and n is the number of moles. If the heat capacity were given on a mass-basis (as a specific heat capacity of a specific heat) then the mass m would be used instead of the number of moles n.

In this case, we're told that the temperature of sodium can't increase by more than 10.0 °C. A change of 10.0 °C is the same as a change of 10 K. We need to convert megajoules to Joules. Solving for n yields:

n = Q/((CP)(delta-T)) = (8.30X106 J)/((30.8 J/(K·mol))(10.0 K)) = 2.69X104 moles of Na .

Convert to grams of Na for your final answer.
http://www.wyzant.com/resources/answers/17701/liquid_sodium_is_being_considered_as_an_engine_coolant_how_many_grams_of_liquid_sodium_minimum_are_n

Answer 2

Also a previous asked question
http://openstudy.com/study#/updates/50132cd7e4b0fa24672fff79

Answer 3

thank you so much for the link @sarah786. it was very helpful :)

Answer 4

yw :)