Acylinder with a movable piston records a volume of 12.6l when 3.0 mol of oxygen is added. the gas in the cylinder has a pressure of 5.83 atm. the cylinder develops a leak and the volume of gas is now recorded to be 12.1 l at the same pressure. how many moles of oxygen are lost?

Answer : The moles of oxygen gas lost are 2.88 mole

Explanation :

According to the Avogadro's Law, the volume is directly proportional to the number of moles of the gas at constant pressure and temperature.

  (At constant temperature and pressure)

or,

where,

= initial volume of oxygen gas = 12.6 L

= final volume of oxygen gas = 12.1 L

= initial moles of oxygen gas = 3.0 mole

= final moles of oxygen gas = ?

Now put all the given values in the above formula, we get the final moles of oxygen gas.

Therefore, the moles of oxygen gas lost are 2.88 mole

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e

the transfer of heat by electromagnetic radiation is called thermal radiation . it is usually carried out by electromagnetic waves in an energy range just below the visible spectrum, which is the infrared range.

so the answer would be radiation.

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