Answer: a) 0.070 moles of oxygen were produced.
b) New pressure due to the oxygen gas is 2.4 atm
Explanation:
According to ideal gas equation:

P = pressure of gas = 2.7 atm
V = Volume of gas = 700 ml = 0.7 L
n = number of moles = ?
R = gas constant =
T =temperature = 329 K


Thus 0.070 moles of oxygen were produced.
When the 700 mL flask cools to a temperature of 293K.




The new pressure due to the oxygen gas is 2.4 atm
Answer: -
The chemical formula of Antimony(III) sulfide = Sb₂S₃
Mass of Sb produced = 175.6 g
Molar mass of Sb = 121.76 g /mol
Number of moles of Sb = 175.6g / (121.76 g/mol)
= 1.44 mol
The balanced chemical equation for this reaction is
Sb₂S₃ + 3 Fe → 2 Sb + 3 FeS
From the chemical equation we see
2 mol of Sb is produced from 1 mol of Sb₂S₃
1.44 mol of Sb is produced from 
= 0.72 mol of Sb₂S₃
Molar mass of Sb₂S₃ = 2 x 121.76 + 32.06 x 3
= 339.7 g / mol
Mass of Sb₂S₃ = 0.72 mol x 339.7 g/ mol
= 244.58 g
= 244.6 g rounded off to 4 significant figures.
The statement that is true about magnets is ''Similar poles of a magnet repel each other.''
<h3>What are the characteristics of magnet?</h3>
All magnets have both north and south poles. Opposite poles attract each other, whereas the similar poles repel each other. When you rub a piece of iron along a magnet, this force creates a magnetic field.
So we can conclude that The statement that is true about magnets is ''Similar poles of a magnet repel each other.''
Learn more about magnet here: brainly.com/question/14997726
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So potassium is more reactive than lithium because the outer electron of a potassium atom is further from its nucleus than the outer electron of a lithium atom. Hope this answers the question. Have a nice day. Feel free to ask more questions.