Exercice 1 Une mole de gaz parfait à une température initiale de 298K se détend d’une pression
de 5 atmosphères à une pression de 1 atmosphère. Dans chacun des cas suivants :
On donne :
v
p
C
C
= 1,4
Cp-Cv = nR
1.) détente isotherme et réversible
Calculer :
a) Le volume V1 et V2
b) la température finale du gaz (T2)
c) la variation de l’énergie interne du gaz
d) le travail effectué par le gaz
e) la quantité de chaleur mise en jeu
f) la variation d’enthalpie du gaz

Activity two: just lemons, inc. production here's a one-batch sample of just lemons lemonade production. determine the percent yield and amount of leftover ingredients for lemonade production and place your answers in the data chart. hint: complete stoichiometry calculations for each ingredient to determine the theoretical yield. complete a limiting reactant-to-excess reactant calculation for both excess ingredients. water sugar lemon juice lemonade percent yield leftover ingredients 946.36 g 196.86 g 193.37 g 2050.25 g 89% just lemons lemonade recipe equation: 2 water + sugar + lemon juice = 4 lemonade mole conversion factors: 1 mole of water = 1 cup = 236.59 g 1 mole of sugar = 1 cup = 225 g 1 mole of lemon juice = 1 cup = 257.83 g 1 mole of lemonade = 1 cup = 719.42 g show your calculations below. analysis questions 1. based on taste observations only, which ingredients were in excess in the lemonade samples in activity one? in activity one the excess substances for each sample were the water and sugar. 2. based on the data in activity two, which excess ingredients are affecting the taste of the lemonade in the sample batch? 3. what can just lemons, inc. do during production to reduce the amount of excess ingredients and improve the taste of their lemonade? 4. try to reduce the amount of leftover ingredients by changing the amount of one, two, or all three starting ingredients. show your stoichiometric calculations below. 5. during factory inspection, just lemons, inc. discovered that a water valve to the lemonade mixing station was not functioning. once they repair it, more water will enter the mixing station. from what you know about the limiting and excess ingredients for current lemonade production, what advice would you give engineers about the upcoming increase in water?

Which statements are true concerning mineral formation? check all that apply. the slower the cooling, the larger the crystals. the faster the cooling, the smaller the crystals. crystals formed from magma are smaller than crystals formed from lava. minerals can only form in solutions when the solution is heated deep underground. when a solution cools, elements and compounds leave the solution and crystallize as minerals. minerals formed from hot water solutions can form narrow channels in the surrounding rock.

What is the pressure of 0.500 moles of carbon dioxide gas in a 2.5 l tank and at a temperature of 301 k? (r=0.0821 l·atm/mol·k) 3.08 atm 1.2 atm 0.23 atm 4.01 atm 4.94 atm