Question

Nume. _ 1. At the top of Mount Everest, water boils at 70 °C. Explain why this is lower than its usual boiling point of 100°C. 2. a) How much heat is needed to heat 33.9 g of acetone (C.H.O) from 25.0°C to its boiling point of 56.05°C? (Specific heat of acetone is 2.15 J/g.c) b) How much heat is required to vaporize 33.9 g of acetone at its boiling point? (AHvap for acetone is 29.1 kJ/mole) 3. How much heat does your body lose when 5.86 g of sweat evaporates from your skin (Assume that the sweat is only water.) AHvap for water is 44.0 kJ/mole. 4. Write the type of solid (Molecular, ionic, metallic, or covalent network solid) next to each solid and then arrange the solids from lowest to highest melting point. a) C(s, diamond) b) Kr(s) c) NaCl(s) d) H2O(s)

Answer 1

Boiling point depends on external pressur Boiling point the temp at which arapour pressure of that digued becomes equal to external pressure - Bp X Pexe 100 °C is boiling point at Pext at I atm but when At the top of mount Everest Pent is less than I aton .so Bp will also be 70°C I q = mSoT = 33,9 x 2,15 x ( 329,05-298) = 2263,1 ] = 2.26 kJ I Shrap a Shrap - 29.1 kJ / mot q = nahrap = 33,9 x 29.1 = 17 KI

q =n Alrap 78 X 44 = 14.32 KJ a ccs, diamond) coralent network b kols) a molecular as atomic c Nach(s) Ionic d hous molemlar melting point cis, dia ) kr(s) <4015) <NaCl (s) < b < d <c<a