I believe the correct answers from the choices listed above are the second and the last option. At constant pressure, the systems 2A(g) + B(g) ---> 4C(g) and 2C(g) A(s) + B(s) ---> C(g) produces work to the surroundings. <span>When a gas is evolved during a chemical reaction, the gas can be imagined as displacing the atmosphere - pushing it back against the atmospheric pressure. The work done is therefore V*P where V is the volume of gas evolved, and P is the atmospheric pressure. </span>
Answer:
Molarity = 0.809 M
mole fraction = 0.047
Explanation:
The complete question is
Calculate the molarity and mole fraction of acetone in a 1.09-molal solution of acetone (CH3COCH3) in ethanol (C2H5OH). (Density of acetone = 0.788 g/cm3; density of ethanol = 0.789 g/cm3.) Assume that the volumes of acetone and ethanol add.
Solution -
Solution for molarity:
1.09-molal means 1.09 moles of acetone in 1.00 kilogram of ethanol.
1)
Mass of 1.09 mole of acetone
= 1.09 mol x 58.0794 g/mol = 63.306 g
Density of acetone = 0.788 g/cm3
Thus, volume of 1.09 moles of acetone = 63.306 g/0.788 g/cm3 = 80.34 cm3
For ethanol
1000 g divided by 0.789 g/cm3 = 1267.427 cm3
Total volume of the solution = Volume of acetone + Volume of ethanol = 80.34 cm3 + 1267.427 cm3 = 1347.765 cm3 = 1.347 L
a) Molarity:
1.09 mol / 1.347 L = 0.809 M
Mole Fraction
a) moles of ethanol:
1000 g / 46.0684 g/mol = 21.71 mol
b) moles of acetone:
1.09 / (1.09 + 21.71) = 0.047
The phases of the moon occur because the moon orbits earth which causes the portion illuminated to change. The earth casts changing angles on the moon causing portions to be illuminated or dark.
Chemical reaction is any process that involves rearangent of the molecular or ionic structure of substances. each chemical reaction is characterised by an activation energy required for the reaction to occur ,for the change or rearrangement to take place
now fro combustion of fuel:we provide this energy by spark (heat pulse).now what about electrolysis?just the mode and manner of providing energy is different:instead of talking of activation energy,we talk of activation overpotential,both bring conceptually the same thing.heat energy is replaced by potential difference in rough terms.
so in short ,electrolysis is a chemical change ,just the mode of activation is different that thermally initiated chemical reactions
