Cooling and heating system involves the collection and dissipation of heat appropriately. Heat gradient is important for heat transfer between systems because heat travels from the warmer system to the cooler system. The right medium for heat transfer is also important for this exchange – A good conductor of heat is required.
Answer: C. Electrochemical cells involve oxidation-reduction reactions.
Explanation: Oxidation occurs at the anode, and reduction occurs at the cathode.
To find the atomic mass of chlorine, the atomic mass of each isotope is multiplied by the relative abundance (the percent abundance in decimal form) and then the individual masses are added together. The atomic mass of chlorine is 35.45 amu.
Answer:
X(EtOH) = 0.0891
X(H₂O) = 0.9109
Explanation:
Given 20% aqueous solution ethanol.
Ethanol => C₂H₅OH (or, EtOH) => molecular weight = 46 g//mole
20% solution by weight = 20 grams EtOH / 100 grams of solution
20 grams EtOH / 100 grams of solution = 20 grams EtOH + 80 grams H₂O
moles EtOH = (20g/46g/mol) = 0.4348 mole
moles H₂O = (80g/18g/mol) = 4.4444 mole
moles EtOH + moles H₂O = 0.4348 + 4.4444 = 4.8792
X(EtOH) = 0.4348/4.8792 = 0.0891
X(H₂O) = 4.4444/4.8792 = 0.9109
∑mole fractions must equal 1.000 => 0.0891 + 0.9109 = 1.000 (check!)
