Question

please help me with #9 and 10 before 9:30

9. If the specific heat of methanol is 2.51 J/K-g, how many joules are necessary to raise the temperature of 50 g of methanol from 20 °C to 60 °C? 10. When a 3.25 g sample of solid sodium hydroxide was dissolved in a calorimeter in 100.0 g of water, the temperature rose from 23.9 °C to 32.0 °C. Calculate AH (in kJ/mol NaOH) for the following solution process: NaOH(s) — Na (aq) + OH(aq) Assume that it's a perfect calorimeter and that the specific heat of the solution is the same as that of pure water.

Answer 1

Answer 9:

. We know that, Q = mcpAT Given, Cpa = 2:51J/kg m = 50g AT = (60-20) = 40°C : Q = 50x 2:51J/kg x 40 Q = 5020